Spontaneous use of tools as straws in great apes
Manrique HM & Call J 4.12.10 Anim Cogn - Epub ahead of print

Gr.apes can use multiple tools to extract food embedded in substrates, and
can invent new ways to exploit those resources.
We tested 5 Pp, 5 Pt & 6 Po : they had to use & modify a tool as a straw to
drink the juice located inside a container.

Exper.1
4 Po & 1 Pt invented the use of a piece of electric cable to get the juice.

Exper.2
Can subjects transform a non-functional hose into a functional one, by
removing blockages that impeded the free flow of juice?
Po outperformed Pt & Pp, by differentially removing those blockages that
prevented the flow of juice, often doing so before attempting to extract the
juice.

Exper.3
We presented Pt & Po with 4 three-tool sets (each tool set contained a
single straw-like tool) and allowed them to select one tool.
Unlike Pt, Po succeeded in selecting the straw-like tool above chance
levels, without having to physically manipulate it.
We suggest : Po's superior performance is related to their greater reliance
on mouth actions during foraging.

Exper.4
Are Po also capable of selecting the suitable tool, not by its appearance,
but by the effects that it produced?
After witnessing the experimenter blow bubbles or absorb liquid with a
functional tool, but fail to accomplish the same thing with the
non-functional tool, Po failed to select the functional tool above chance
levels.

______

www.metafro.be/primates/panpaniscustype

----- Original Message -----
From: dons3148
To: AAT@yahoogroups.com
Sent: Wednesday, December 29, 2010 12:59 AM
Subject: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
Hypotheses)

Hello Bill........
>
> > > > Yes, but would a gorilla-size mouth/jaw have been
> > > > an impediment that was so severe that it led to a
> > > > reproductive disadvantage?
> > >
> > > Their rivals would have had the smaller jaws; and
> > > smaller jaws probably came with a smaller mouth
> > > opening, perhaps the advantage when it came to
> > > extracting the contents of oysters. So perhaps the
> > > reproductive advantage lay with those with the gene
> > > mutation?
> > >
> > I think that 'perhaps' is about right......when extracting
> > the edibles from oysters (etc.,) the shells are opened and
> > the meat is detached from the shell before it's simply
> > tipped into the mouth. This opening and detaching is
> > best done with a tool of some sort, but if it came to
> > using the teeth, then wouldn't those without the mutation
> > have an advantage?
>
> Probably in the end neither had the advantage... or
> any choice; it was perhaps more a matter of either
> adapting to the gene mutation or going extinct (!)
>
D'you mean genetic drift?
>
> > Wouldn't the deliberately deceptive behaviour that has
> > been observed in other great apes be evidence of
> > imagination (at the very least 'theory of mind')?
> >
> > An interesting read....
> >
> > Neocortex size predicts deception rate in primates
> > By Richard W. Byrne and Nadia Corp
> >
> > http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1691785/pdf/15306289.pdf
> > ______________
>
> Thanks for the link...
>
> As to your point, I am not so certain that deceptive
> behavior is anything other than behavior as numerous
> species can use and do use deceptive behavior from
> birds, to animals, to fish to insects that use mimicry
> and deceptive behavior pretty effectively.
>
> As apparently can plants and even a robot, as
> robots can now be programed to use `deceptive
> behavior' to evade detection (!)
>
Do you mean predatory plants like the pitcher-plant?
I would classify this as 'ambush predation'.
>
> Humans can tell a straight faced lie for individual gain,
> insects can use mimicry deceptive behavior to evade
> predation or to gain reproductive advantage; both I
> would say are using deceptive behavior for gain.
>
> Perhaps it is anticipation that is involved when someone
> lies, a primate deceives, but I cannot see any role for
> imagination.
>
Yes.....I think of animal deception as camouflage of one
sort or another. But what we're dealing with in humans and
apparently other great apes, is deliberate deception and
at the very least this entails the recognition of the existence
another subjective point of view that can be deceived.....
that can construct a reality that fails to accurately inform
about the actual world

Given that 'a subjective point of view' is by definition
not something that can be objectively confirmed, then
it seems to me that the recognition of a subjective point
of view other than your own has to be an act of the
imagination.

As for robots....if one can deceive me on the basis of
what it knows about the way I think, my predispositions
and my fears and desires.....on its recognition of me as
a person, then I'll return the compliment and accept that
robot as a person with a prosthetic body.   :-)
>
> (imagination is the plaything of the mind)
>
:-)

>
> > The one thing that comes to mind that would over-ride
> > such (xenophobic) impulses is a catastrophic collapse
> > in the population...such as you'd get with a malarial
> > epidemic? Although this still wouldn't explain a
> > reproductive advantage for the survivors with weaker-
> > jaws .
>
> It would as possibly in such a situation random
> chance (genetic drift) would more likely determine
> the outcome than the long drawn out processes of
> natural selection an environmental adaptation.
>
> Essentially the survivors would have had one choice...
> adapt to having a weaker jaw or die(go extinct).
>
Could be, but I have a very negative intuitive reaction
to anything that says 'you may reason to this point, but
no further'. (I have the same reaction to the Big Bang
Theory and reject it for the same reason......the Pope
knew what he was doing when he gave a medal to
Stephen Hawking for the way his work could be seen
to reconcile science and religion.)

I'm happier with the thought that as yet I haven't been
able to think of a way to cogently place these two
mutations within the context of natural selection.....at
least this leaves possibilities to explore - if I see either
of the mutations as the result of arbitrary drift, then
that's an end to it as there's nowhere left to go.

>
> > > Agree, H.erectus was in the wrong places to be a
> > > littoral dweller. H.erectus at least outside of north
> > > Africa was a scavenger/hunter and perhaps the
> > > prey of predators.
> > >
> > My position here is that I can't on the one hand use a
> > DHA-rich littoral diet to explain the encephalisation
> > that we see in H.e/e and at the same time argue that
> > they stopped encephalising while still exploiting a
> > littoral diet. The most parsimonious solution to the
> > conundrum of the H.e/e stasis in brain enlargement
> > is to assume that they inherited their large brains
> > from predecessors who did exploit the littoral, then
> > they maintained this enlarged size through an inland
> > diet that included meat (brains, bone-marrow etc.,)
> > But of course those who doubt that our ancestors grew
> > their big brains at the littoral are stuck with the same
> > conundrum.....they have to argue that an inland diet
> > was sufficient for the initial encephalisation and that a
> > continuation of this same diet was then insufficient for
> > encephalisation.
>
> Agree it is more the parsimonious explanation, as it
> is highly unlikely that the H.erectus (or its immediate
> predecessor, if there was one) inherited a larger brain
> from a littoral predecessor, than for H.erectus to have
> exploited a littoral niche.
>
> Though it should be said that there are two other
> factors that impose a physical limits on further
> encephalisation in our species, namely our bipedal
> gait and the ability to give birth relatively safely,
> however I do not think either of these would have
> applied to the much smaller brained H.erectus.
>
It does though, raise an issue that must be dealt with
if the 'encephalisation/DHA/littoral' connection is to
hold together......after a million years or so H.e/e
brains did enlarge to a degree that was at least equal
to the encephalisation that produced H.e/e brains in
the first place. What happened to cause this change
after a stasis of more than a million years?

>
> > As for H.e/e I think only the survivors of hyena attacks
> > could have had a reproductive impact sufficient to make
> > thicker skulls a species characteristic and I have to
> > doubt that there would have been enough of these to
> > make such a difference......particularly if the usual victims
> > were the young, the old and the infirm.
>
> Good points, in fact very good points, so perhaps
> the description in Noel T. Boaz and Russell L. Ciochon
> book "Dragon Bone Hill" (2004) of the H.erectus is the
> one closest to the truth:
>
> [quote]
> "Armed with a shaky hold on fire and some sharp
> rocks, Homo erectus incredibly survived for over
> 1.5 million years, much longer than our own species
> Homo sapiens has been on Earth. Tell-tale marks on
> fossil bones show that the lives of these early
> humans were brutal, ruled by hunger and who could
> strike the hardest blow, yet there are fleeting
> glimpses of human compassion as well. The small
> brain of Homo erectus and its strangely unchanging
> culture indicate that the species could not talk.
> Part of that primitive culture included ritualized
> aggression, to which the extremely thick skulls
> of Homo erectus bear mute witness."
> ______________________
>
> So maybe the unfortunate H.erectus did finally share
> something with its hyena predator - a hard, brutal
> life scavenging on the kills of predators as they
> followed the seasonal movements of herd animals
> across wilds of Asia.
>
Why d'you suppose that modern humans have a
vomit reflex to the smell of rancid meat? Some four
years ago I had a long and interesting conversation
with Pauline about this and I've found nothing since
then to cause me to change my opinion......

(Pauline....
>
> Unless some strong evidence nails H. e/e as a hunter, the
> conservative position is that he got his meat from (some
> sort of) scavenging.
>
Rob.....
Here I do disagree. The vomit-reflex is evidence not
that H.e/e was a hunter, but that scavenging resulted
in a selection process which left us with exactly the
opposite reaction to rancid meat that is the hallmark
of all scavengers. Whether H.e/e hunted meat or not
is a different issue - I think that because they could,
then they probably did, but we got that reflex from
somewhere and given the deadly nature of rancid
meat, it seems to me to be one of the most straight-
forward examples of adaptation through natural
selection that I've come across. It's the total absence
of any reference to it in the literature that puzzles me.

http://tech.dir.groups.yahoo.com/group/AAT/message/36495?o=0&var=1
_________)

What's your view of this?

As for the suggestion that life was short, hard and
brutal for H.e/e.........I don't doubt it at all.

  >
> It's almost certainly the case that endogenous Neu5Gc
> had allowed repeated infections of P.reich from before
> the H/P LCA until the CMAH mutation. In modern
> humans exogenous Neu5Gc is used by other pathogens,
> but AFAIK the P.reich parasite is the only one we can
> be reasonably certain about prior to c. 2.5 Mya.
>
> One way of looking at it Rob, would be to say if it was
> not for the P.reich parasite an the loss of Neu5Gc...
> we might have been just another extinct ape species in
> the forest.
>
Or turned to rock alongside H.georg.

>
> However as the year 2010 ends our 'friend' the
> ubiquitous mosquito is still adapting, still intent on
> conquering new territory...
>
> A Malaria Mosquito Is Becoming Two Species in a Hurry
>
>
http://www.livescience.com/animals/malaria-mosquitos-species-splitting-101021.ht\
ml
>
> [quote]
> A strain of African mosquito that carries the
> deadly malaria parasite is splitting into two
> species faster than expected, according to a
> new study. The finding helps explain why the
> insect can survive in environments spanning
> from humid rainforests to arid savannas.
>
> The mosquito, Anopheles gambiae, is one of the
> top carriers of malaria parasites, which infect
> 250 million people a year, according to the
> World Health Organization.
>
> -------------------------
>
We've got floods here in Queensland and I suspect
that the mozzies are going to love it!
>
> With best wishes for 2011
>
And to you.

Rob.


--- In AAT@yahoogroups.com, "Rob Dudman" <ausell@...> wrote:
>
>
> ----- Original Message -----
> From: dons3148
> To: AAT@yahoogroups.com
> Sent: Wednesday, December 22, 2010 7:50 AM
> Subject: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> Hypotheses)
>

Hello Rob...

> Hello Bill........
> >
> > > > Then essentially a `tool using' habilis was no different
> > > > from a `tool using' gorilla using a stick to test the depth
> > > > of the water it was walking through or an otter using a
> > > > stone to crack open a shell...
> > >
> > > IMO, absolutely no difference at all.
> >
> > Yes, they are essentially using 'tools' for the same job -
> > namely to get at food.
> >
> That's an interesting distinction.....it had occurred to me that
> what is different about our use of tools is that we use them
> for purposes other than obtaining food, but then I had to
> pause with your example of the gorilla probing for depth
> before venturing further into water. No doubt the ultimate
> objective is to get at food, but the immediate objective is
> (I presume) to avoid getting dunked. There's also the
> example of chimps using branches to intimidate...although
> AFAIK, these branches aren't modified to make them
> more effective as weapons.

Birds dropping shells on rocks, otters, chimpanzees
shaping sticks to get at honey and a gorilla using a
stick as it walks through waist deep water to reach
a tasty morsel all appear to be in pursuit of same
objective, food ,which is probably the origins too
`tool usage' among humans. It may offer too an
explanation as to why the H.erectus repeatedly made
the same `stone tools' for hundreds thousands of
years (roughly 1.4 million years) with little
or no change.

Human tools;, tools that were used for purposes other
than getting at the food probably made an appearance
about a quarter a million years ago as flint
tools, probably the first genuine multi-purpose
tool a stone tool with a razor sharp edge(!)

> > > ............................What else can they imagine
> > > as they sit for hours chewing their stalks? Probably not
> > > much, but I can't think of a way that this could be shown
> > > scientifically.
> >
> > Perhaps only when `scientist' can devise a scanning
> > method that literally `reads' thoughts, will that
> > question ever come close to being answered.
> >
> I've got the rather unhappy idea that if this sort of scanning
> is ever invented (which I doubt will happen), it'll be so far
> into the future that we'll be the only extant primate (having
> caused the extinction of all the others by then).

:-)

Hopefully it will be very far into the future ...
or when I am old enough not too care one way or
the other.

Then again it might be just around the corner (!)

As some neuroimaging experts believe they will soon
be able to tell what a person is thinking by the
areas of the brain activated when a person
looks at something...

> > Gorillas are not using `imagination' in the human sense
> > but probably something that is on the face of it similar
> > but is entirely different, namely `anticipation' though
> > the ability `to anticipate' is also believed by some to
> > be uniquely human as it is said to involve the frontal
> > lobes of the brain.
> >
> > However, it seems to me that by using a stick to test
> > the depth of the water its walking through the gorilla
> > can be said to be anticipating what would happen if
> > it got out of its depth in water...
> >
> > I would add - that imagination - the ability to form
> > images, concepts and sensations in the mind is beyond
> > doubt uniquely human. (probably the point at which
> > mankind's early ancestors could imagine - was when
> > they became human!)
> >
> Wouldn't the deliberately deceptive behaviour that has
> been observed in other great apes be evidence of
> imagination (at the very least 'theory of mind')?
>
> An interesting read....
>
> Neocortex size predicts deception rate in primates
> By Richard W. Byrne and Nadia Corp
>
> http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1691785/pdf/15306289.pdf
> ______________

Thanks for the link...

As to your point, I am not so certain that deceptive
behavior is anything other than behavior as numerous
species can use and do use deceptive behavior from
birds, to animals, to fish to insects that use
mimicry and deceptive behavior pretty
effectively...

As apparently can plants and even a robot, as
robots can now be programed to use `deceptive
behavior' to evade detection (!)

Humans can tell a straight faced lie for
individual gain, insects can use mimicry
deceptive behavior to evade predation or to
the gain reproductive advantage; both I would
say are using deceptive behavior for gain.

Perhaps it is anticipation that is involved when
someone lies, a primate deceives, but I cannot
see any role for imagination.

(imagination is the plaything
of the mind)

> > > Yes, but would a gorilla-size mouth/jaw have been
> > > an impediment that was so severe that it led to a
> > > reproductive disadvantage?
> >
> > Their rivals would have had the smaller jaws; and
> > smaller jaws probably came with a smaller mouth
> > opening, perhaps the advantage when it came to
> > extracting the contents of oysters. So perhaps the
> > reproductive advantage lay with those with the gene
> > mutation?
> >
> I think that 'perhaps' is about right......when extracting
> the edibles from oysters (etc.,) the shells are opened and
> the meat is detached from the shell before it's simply
> tipped into the mouth. This opening and detaching is
> best done with a tool of some sort, but if it came to
> using the teeth, then wouldn't those without the mutation
> have an advantage?

Probably in the end neither had the advantage... or
any choice; it was perhaps more a matter of either
adapting to the gene mutation or going extinct (!)

> > Arguably though natural selection and reproductive
> > strategies are themselves weak explanations as neither
> > can explain satisfactorily explain why humans ended
> > up with small jaws. They also fail as explanations, to
> > explain how those that looked physically different
> > as a result of a gene mutation, were accepted? (even
> > birds are known to attack a member of their own kind
> > if they look different, or are weak)
> >
> You make a good point.....humans are well-known to
> attack their own kind because of such differences
> and indeed this xenophobia is probably a characteristic
> shared by most (if not all) gregarious species.

At species level, I have often wondered if this is
some kind of weird instinctive behavior aimed at
preserving and reinforcing the identity of a species...
but that seems to create problems for speciation as
such (as most `new' species would have to remain
isolated until the old and new species could
no longer breed).

Humans unfortunately through the use of language and
the exchange of ideas seem to have taken xenophobia
to a `new' extreme level, to the point where they no
longer see other humans as just being different but
not even human(!)

> (We may well have an explanation here for the way people
> in these discussion groups attack each other because
> of differing ideas......it may also explain why they
> can't stop.)

Think you are right... I tend to regard anyone who
resorts to personal attacks or insults as simply
having nothing to add to the discussion...

> The one thing that comes to mind that would over-ride
> such impulses is a catastrophic collapse in the population...
> such as you'd get with a malarial epidemic? Although this
> still wouldn't explain a reproductive advantage for the
> survivors with weaker-jaws .

It would as possibly in such a situation random
chance (genetic drift) would more likely determine
the outcome than the long drawn out processes of
natural selection an environmental adaptation.

Essentially the survivors would have had one
choice... adapt to having a weaker jaw or
die(go extinct).

> > > I would expect that erectus and ergaster would share
> > > the characteristics that they inherited from their littoral
> > > predecessors and differences in attritbutes would reflect
> > > the different post-littoral environments that each had to
> > > deal with.
> > >
> > > This suggests to me that H.e/e left the littoral with
> > > the thinner skulls of ergaster, while the Asian erectines
> > > developed the heavier bones for reasons that are far
> > > from obvious.
> > >
> > > > I may be wrong but I think Marc attributes a thick
> > > > skull in H.e to a diving adaptation (but modern
> > > > humans today seem to dive pretty successful with
> > > > their thin boned domed skulls).
> > >
> > > H.erectus was not exploiting a littoral diet.
> >
> > Agree, H.erectus was in the wrong places to be a
> > littoral dweller. H.erectus at least outside of north
> > Africa was a scavenger/hunter and perhaps the
> > prey of predators.
> >
> My position here is that I can't on the one hand use a
> DHA-rich littoral diet to explain the encephalisation
> that we see in H.e/e and at the same time argue that
> they stopped encephalising while still exploiting a
> littoral diet. The most parsimonious solution to the
> conundrum of the H.e/e stasis in brain enlargement
> is to assume that they inherited their their large brains
> from predecessors who did exploit the littoral, then
> they maintained this enlarged size through an inland
> diet that included meat (brains, bone-marrow etc.,)
> But of course those who doubt that our ancestors grew
> their big brains at the littoral are stuck with the same
> conundrum.....they have to argue that an inland diet
> was sufficient for the initial encephalisation and that a
> continuation of this same diet was then insufficient for
> encephalisation.

Agree it is more the parsimonious explanation, as it
is highly unlikely that the H.erectus (or its immediate
predecessor, if there was one) inherited a larger brain
from a littoral predecessor, than for H.erectus to have
exploited a littoral niche.

Though it should be said that there are two other
factors that impose a physical limits on further
encephalisation in our species, namely our bipedal
gait and the ability to give birth relatively
safely, however I do not think either of these
would have applied to the much smaller
brained H.erectus.

> > > > One answer could be if H.e were prey to predators as
> > > > some have claimed then a thick skull may have increased
> > > > their chances of surviving an attack (hyenas of old in
> > > > China - are said to have specialised in cracking open
> > > > the skulls of their H.e prey).
> > > >
> > > > The Skull-Crushing Hyenas of Dragon Bone Hill
> > > >
> > > >
http://www.wired.com/wiredscience/2010/06/repost-the-skull-crushing-hyenas-of-dr\
agon-bone-hill/
> > > > ____________________________________
> > >
> > > Predation stresses would be a clear selection mechanism,
> > > but I don't think that skulls in a hyena den is the evidence
> > > in this case.....cracking open skulls to get at brains would
> > > have been done port-mortem and unlikely to have a great
> > > deal of reproductive impact. For this we'd have to assume
> > > that the survival rate from these hyena predations would
> > > be greater among those with the thicker bones.....but here
> > > we're talking about an extremely large and powerful
> > > hyena and I doubt that even the thickest of post-cranial
> > > erectine bones would have been much of a defence. In
> > > fact I'd have thought that survival rates would be highest
> > > among those with lighter bones as the only way to
> > > survive such an encounter would be not get caught.
> >
> > Or perhaps if initially a thicker skull conferred
> > some survival advantage for the H.erectus...
> >
> > They then lost out when the endless `arms race'
> > between predator and prey have moved up a notch,
> > with the hyenas not only adapting their predation skills
> > but adapting to crack open the tougher skulls of their
> > prey to get at the H.erectus brain (a source of fat?).
> >
> Pachycrocuta brevirostris......they were active in Asia
> as far back as c. 3 Mya and for a lot of this time they
> would not have coincided with H.e/e....would the arrival
> of a new and fairly sparsely distributed potential prey
> have had an impact on their morphology? H.e/e was
> larger than their usual prey, but as hyenas we can
> reasonably assume that they were pack predators who
> overwhelmed their prey and a thicker skull would have
> made little difference at the kill.
>
> As for H.e/e I think only the survivors of hyena attacks
> could have had a reproductive impact sufficient to make
> thicker skulls a species characteristic and I have to
> doubt that there would have been enough of these to
> make such a difference......particularly if the usual victims
> were the young, the old and the infirm.

Good points, in fact very good points, so perhaps
the description in Noel T. Boaz and Russell L. Ciochon
book "Dragon Bone Hill" (2004) of the H.erectus is the
one closest to the truth:

[quote]
"Armed with a shaky hold on fire and some sharp
rocks, Homo erectus incredibly survived for over
1.5 million years, much longer than our own species
Homo sapiens has been on Earth. Tell-tale marks on
fossil bones show that the lives of these early
humans were brutal, ruled by hunger and who could
strike the hardest blow, yet there are fleeting
glimpses of human compassion as well. The small
brain of Homo erectus and its strangely unchanging
culture indicate that the species could not talk.
Part of that primitive culture included ritualized
aggression, to which the extremely thick skulls
of Homo erectus bear mute witness."
______________________

So maybe the unfortunate H.erectus did finally share
something with its hyena predator - a hard, brutal
life scavenging on the kills of predators as they
followed the seasonal movements of herd animals
across wilds of Asia.

> > > > There may be an entirely different reason for the
> > > > both the inactivation of MYH16 and that of Neu5Gc
> > > > in the human lineage that we may have missed...both
> > > > may have result from genetic-drift, not natural selection
> > > > (positive or otherwise).
> > >
> > > Could be I suppose. I'd given it some thought, but decided
> > > it's the explanation of last resort and that's where I left it..
> >
> > Not so certain, as genetic drift - does have the
> > advantage over `natural selection' in removing from
> > the equation convoluted and non-parsimonious
> > explanations... as it leaves a species faced with
> > a gene mutation the sole option of either adapting
> > to the change or going extinct...
> >
> > If we were take Neu5Gc as an example - the gene
> > mutation could have arose from repeated pathogen
> > infections over several generations some two to
> > three million years ago, then after another serious
> > endemic that reduced their number once more the only
> > ones that reproduced passed on the mutated gene
> > (thus eradicating in a single generation the `normal'
> > copy of the gene) leaving their successors to either
> > adapt to life without Neu5Gc or go extinct.
> >
> > Perhaps other species have been faced with this
> > choice in the past, but have failed to adapt to the
> > loss of Neu5Gc. Humans may have survived simply
> > because the mutation in the human lineage coincided
> > with an increase in the size of the brain, with an enlarged
> > brain and competitive edge perhaps compensating for
> > a compromised immune and cardiovascular system.
> >
> It's almost certainly the case that endogenous Neu5Gc
> had allowed repeated infections of P.reich from before
> the H/P LCA until the CMAH mutation. In modern
> humans exogenous Neu5Gc is used by other pathogens,
> but AFAIK the P.reich parasite is the only one we can
> be reasonably certain about prior to c. 2.5 Mya.
> >
> > Happy Christmas
> >
> Onya, mate!
>
> :-)
>
> Rob.

:-)

One way of looking at it Rob, would be to say
if it was not for the P.reich parasite an the
loss of Neu5Gc... we might have been just
another extinct ape species in the forest.

However as the year 2010 ends our 'friend' the
ubiquitous mosquito is still adapting, still
intent on conquering new territory...

A Malaria Mosquito Is Becoming Two Species
in a Hurry

http://www.livescience.com/animals/malaria-mosquitos-species-splitting-101021.ht\
ml

[quote]
A strain of African mosquito that carries the
deadly malaria parasite is splitting into two
species faster than expected, according to a
new study. The finding helps explain why the
insect can survive in environments spanning
from humid rainforests to arid savannas.

The mosquito, Anopheles gambiae, is one of the
top carriers of malaria parasites, which infect
250 million people a year, according to the
World Health Organization.

-------------------------

With best wishes for 2011

--Bill

__________________________________________

> --- In AAT@yahoogroups.com, "Rob Dudman" <ausell@> wrote:
> >
> >
> > ----- Original Message -----
> > From: dons3148
> > To: AAT@yahoogroups.com
> > Sent: Friday, December 17, 2010 12:41 AM
> > Subject: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> > Hypotheses)
> >
>
> Hello Rob...
>
> > Hello Bill........
> > >
> > > > > Can an ancient hominid 3.4 Mya picking up a sharp
> > > > > edged stone to scrape and cut the last scraps of
> > > > > meat of the bones of a predators kill, be classed
> > > > > as a stone tool user?
> > > > >
> > > > > IMO, yes.
> > > > >
> > > > > Or would this kind of behaviour be no different from
> > > > > that of any number of other species - from otters to
> > > > > chimpanzees - who use whatever is available - a twig
> > > > > a stone - to get at something edible or tasty).
> > > >
> > > > Essentially no difference at all (IMO). Even modifying
> > > > stones into sharp-edged tools is essentially no different
> > > > to when a chimp strips leaves from a twig so that it
> > > > will fit into a termite hole. Knapping is certainly more
> > > > complicated in that it uses a tool (a hammer stone)
> > > > to make a tool, but there's no type difference in the
> > > > behaviour.
> > >
> > > Then essentially a `tool using' habilis was no different
> > > from a `tool using' gorilla using a stick to test the depth
> > > of the water it was walking through or an otter using a
> > > stone to crack open a shell...
> > >
> > IMO, absolutely no difference at all.
>
> Yes, they are essentially using 'tools' for the
> same job - namely to get at food.
>
> > > Then I would say tool use in Man as such cannot be
> > > used to define anything other the start of when the
> > > human imagination (the ability of forming mental images,
> > > sensations and concepts) kicked in (bringing an end to
> > > replicating the same stone tools over and over again).
> > >
> > I'm very wary of using subjective concepts like 'imagination',
> > 'mental images', 'sensations' etc., when discussing a scientific
> > topic......I intuitively agree that our human capacity to
> > imagine is far greater than that of other primates, but
> > science needs measurement and I'm not too sure how
> > one would measure a gorilla's imagination to find out what
> > this difference actually is.
> >
> > They certainly have something going on when they test
> > the depth of water with a stick....if the water is too deep,
> > then they don't go there - why not? We might say it's
> > because they 'know' that stepping into deep water will
> > have unpleasant consequences because it's happened
> > previously, but then they have to be able to imagine
> > that it will happen again in the future and act accordingly
> > using an appropriate tool. What else can they imagine
> > as they sit for hours chewing their stalks? Probably not
> > much, but I can't think of a way that this could be shown
> > scientifically.
> >
>
> Perhaps only when `scientist' can devise a scanning
> method that literally `reads' thoughts, will that
> question ever come close to being answered.
>
> Gorillas are not using `imagination' in the human sense
> but probably something that is on the face of it similar
> but is entirely different, namely `anticipation' though
> the ability `to anticipate' is also believed by some to
> be uniquely human as it is said to involve the frontal
> lobes of the brain.
>
> However, it seems to me that by using a stick to test
> the depth of the water its walking through the gorilla
> can be said to be anticipating what would happen if
> it got out of its depth in water...
>
> I would add - that imagination - the ability to form
> images, concepts and sensations in the mind is beyond
> doubt uniquely human. (probably the point at which
> mankind's early ancestors could imagine - was when
> they became human!)
>
> > The use of one specific tool - the control of fire - may
> > well be the exception that can tell us a great deal about
> > the quintessentially human.....indeed, show me a controlled
> > fire and I'll show you a human being.
>
> Agree - the control of fire - tells us more than
> `stone tool use- ever could. It also represents
> another significant change in the human diet, as
> `cooking' changes the nature of what is being
> cooked...
>
> [quote]
> Cooking may have had the largest impact on human
> evolution because cooked meat requires significantly
> less energy to digest it than raw meat, thus freeing
> up even more energy in the diet that could be routed
> for brain development (Nixon. 2008). Cooked food does
> not need to be heated to body temperature, is easier
> to chew and digest, and less prone to carry harmful
> bacteria. While archaeologists generally agree that
> cooking was one of our ancestors' early uses of
> fire, there is disagreement as to when this began.
>
> The Great Leaps Forward
> Anthony Stigliani
> http://fubini.swarthmore.edu/~ENVS2/astigli1/greatleapsforward.html
> ________________________________________
>
> Note also Rob, the chart (fig.2) indicating the
> spurt in human brain size between 800,000 years
> ago and 200,000 years ago.
>
> > > > > .........a smaller mouth opening may have been more
> > > > > advantageous than massive ape mouth of old when
> > > > > it came dealing with some shellfish (like the slimy
> > > > > slippery contents of oysters).
> > > >
> > > > How 'massive' d'you think this must have been to
> > > > prevent them from tipping oysters (or whatever)
> > > > into their mouths? Even if those with 'massive' jaw
> > > > muscles found themselves at some disadvantage,
> > > > this still wouldn't explain the edge gained by those
> > > > with the smallest jaw muscles. Inbetween 'massive'
> > > > and 'smallest' would have been simply 'big' and
> > > > these too would have lost out to the weakest-
> > > > jawed.
> > >
> > > The difference in terms of comparison may have
> > > been between say the jaws, mouth size and oral
> > > cavity of a gorilla and that of an AMH (modern
> > > human) today... the former today is probably better
> > > adapted to masticating large amounts of vegetable
> > > matter than that of the average human.
> > >
> > Yes, but would a gorilla-size mouth/jaw have been
> > an impediment that was so severe that it led to a
> > reproductive disadvantage?
>
> Their rivals would have had the smaller jaws; and
> smaller jaws probably came with a smaller mouth
> opening, perhaps the advantage when it came to
> extracting the contents of oysters. So perhaps the
> reproductive advantage lay with those with the
> gene mutation?
>
> Arguably though natural selection and reproductive
> strategies are themselves weak explanations as neither
> can explain satisfactorily explain why humans ended up
> with small jaws. They also fail as explanations, to
> explain how those that looked physically different
> as a result of a gene mutation, were accepted? (even
> birds are known to attack a member of their own kind
> if they look different, or are weak)
>
> > > However, I would say that the outcome on the shore
> > > a couple of million years and more ago, may have
> > > depended more on how the facial bones would have
> > > developed in life with smaller muscles - since
> > > the mutation in question would only have
> > > affected the jaw muscles.
> > >
> > I may not be getting your meaning here, but it seems
> > to me that if all we have is the ongoing experience of a
> > soft-food diet, then this seems very much like a Lamarkian
> > explanation for a genetic change.
>
> Basically this particular mastication muscle gene
> mutation (MYH16) makes no sense, unless there was
> for example a corresponding change in the size of
> the jaw bone (as changing the size of mastication
> muscles, but leaving their owner with large jaws
> does not seem a recipe for
> reproductive success)
>
> > > > I've also got an uncomfortable feeling that there's a
> > > > contradiction here somewhere that's being overlooked.....
> > > > what advantage would be gained for a DHA-driven
> > > > brain enlargement by losing the sagittal crest as the
> > > > result of a MHY16 mutation, if the skull then thickened?
> > >
> > > On the face of it, it does seem somewhat contradictory;
> > > then again there was something of a stasis in the
> > > enlargement in the size of the H.e ...
> > >
> > > (the H.ergaster on the other hand is said to have had
> > > a thinner skull, a skull more like that of a
> > > modern human).
> > >
> >
> > I would expect that erectus and ergaster would share
> > the characteristics that they inherited from their littoral
> > predecessors and differences in attritbutes would reflect
> > the different post-littoral environments that each had to
> > deal with.
> >
> > This suggests to me that H.e/e left the littoral with
> > the thinner skulls of ergaster, while the Asian erectines
> > developed the heavier bones for reasons that are far
> > from obvious.
> > >
> > > I may be wrong but I think Marc attributes a thick
> > > skull in H.e to a diving adaptation (but modern
> > > humans today seem to dive pretty successful with
> > > their thin boned domed skulls).
> > >
> > H.erectus was not exploiting a littoral diet.
>
> Agree, H.erectus was in the wrong places to be
> a littoral dweller. H.erectus at least outside
> of north Africa was a scavenger/hunter and
> perhaps the prey of predators.
>
> > > One answer could be if H.e were prey to predators as
> > > some have claimed then a thick skull may have increased
> > > their chances of surviving an attack (hyenas of old in
> > > China - are said to have specialised in cracking open
> > > the skulls of their H.e prey).
> > >
> > > The Skull-Crushing Hyenas of Dragon Bone Hill
> > >
> > >
http://www.wired.com/wiredscience/2010/06/repost-the-skull-crushing-hyenas-of-dr\
agon-bone-hill/
> > >
> > ____________________________________
> >
> > Predation stresses would be a clear selection mechanism,
> > but I don't think that skulls in a hyena den is the evidence
> > in this case.....cracking open skulls to get at brains would
> > have been done port-mortem and unlikely to have a great
> > deal of reproductive impact. For this we'd have to assume
> > that the survival rate from these hyena predations would
> > be greater among those with the thicker bones.....but here
> > we're talking about an extremely large and powerful
> > hyena and I doubt that even the thickest of post-cranial
> > erectine bones would have been much of a defence. In
> > fact I'd have thought that survival rates would be highest
> > among those with lighter bones as the only way to
> > survive such an encounter would be not get caught.
>
> Or perhaps if initially a thicker skull conferred
> some survival advantage for the H.erectus...
>
> They then lost out when the endless `arms race'
> between predator and prey have moved up a notch, with
> the hyenas not only adapting their predation skills
> but adapting to crack open the tougher skulls of
> their prey to get at the H.erectus brain
> (a source of fat?).
>
> > > > > > Until further evidence turns up I think the most
> > > > > > plausible null-hypothesis is that the lack of Neu5Gc
> > > > > > freed up the Neu5Ac that otherwise would have been
> > > > > > used to make Neu5Gc. The additional Neu5Ac was
> > > > > > then used to create synaptic connections in the brains
> > > > > > being enlarged by the plentiful DHA.
> > > > >
> > > > > Was its loss simply accident of evolution, or was it a
> > > > > necessary step in the evolution of a relatively large
> > > > > brain in the human lineage - I would say it was the
> > > > > latter.
> > > >
> > > >
> > > > Both.
> > >
> > > There may be an entirely different reason for the
> > > both the inactivation of MYH16 and that of Neu5Gc
> > > in the human lineage that we may have missed...both
> > > may have result from genetic-drift, not natural selection
> > > (positive or otherwise).
> > >
> > Could be I suppose. I'd given it some thought, but decided
> > it's the explanation of last resort and that's where I left it..
> >
> > Rob.
>
> Not so certain, as genetic drift - does have the
> advantage over `natural selection' in removing from
> the equation convoluted and non-parsimonious
> explanations... as it leaves a species faced with
> a gene mutation the sole option of either adapting
> to the change or going extinct...
>
> If we were take Neu5Gc as an example - the gene
> mutation could have arose from repeated pathogen
> infections over several generations some two to
> three million years ago, then after another serious
> endemic that reduced their number once more the only
> ones that reproduced passed on the mutated gene
> (thus eradicating in a single generation the
> `normal' copy of the gene) leaving their successors
> to either adapt to life without Neu5Gc or go extinct.
>
> Perhaps other species have been faced with this
> choice in the past, but have failed to adapt to the
> loss of Neu5Gc. Humans may have survived simply because
> the mutation in the human lineage coincided with an
> increase in the size of the brain, with an enlarged
> brain and competitive edge perhaps compensating for
> a compromised immune and cardiovascular system.
>
> Happy Christmas
>
> --Bill
>
> This post may be slightly delayed as I am having
> new phone line installed hopefully in the next
> couple of days (my existing phone line gave
> up the ghost yesterday).
>
> --------------------------------
>
> > --- In AAT@yahoogroups.com, "Rob Dudman" <ausell@> wrote:
> > >
> > >
> > > ----- Original Message -----
> > > From: dons3148
> > > To: AAT@yahoogroups.com
> > > Sent: Sunday, December 12, 2010 11:24 PM
> > > Subject: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> > > Hypotheses)
> > >
> > > Hello Bill........
> > > >
> > > > > [No garhi fossils from before or after, yet here we
> > > > > have eight more or less in the same place and from
> > > > > the same time? Now that's odd. Maybe they died of
> > > > > P.reich malaria and those who survived the epidemic
> > > > > scarpered and eventually found themselves at the
> > > > > coast.......... :-)]
> > > >
> > > > :)
> > > >
> > > > Or perhaps they were a `hunting/scavenging' or scouting
> > > > party that fell foul of pack of predators.........
> > > >
> > > Wouldn't such an attack have left some evidence on
> > > the bones? To be sure, there need be no bone trauma
> > > for a predator to kill its prey, but eating the meat should
> > > have left some marks.
> >
> > Hello Rob...
> >
> > > > .......(like a'piths - australopithecines - they still had
> > > > the sagittal crest on the top of the skull, that functioned
> > > > as muscle anchor for the jaw muscles).
> > > >
> > > Well yes......Bouri is dated c. 2.5 - 2.6 Mya and the
> > > MHY16 mutation didn't happen until c. 2.4 Mya.
> > > The Bouri date is coincident with the CMAH mutation.
> >
> > Yes since they had the sagittal crest, it can be said
> > to be clear evidence that the date of the CMHA mutation
> > was around 2.4 Mya and rule out the argument that it
> > could have occurred at a much earlier date.
> >
> > > > > From what I can see, the main gripe about the
> > > > > Bouri evidence has been related to the notion that
> > > > > A'piths didn't/couldn't manufacture and use Mode 1
> > > > > stone tools, so these had to have been made by
> > > > > Homo and the only candidate has been habilis. IMO,
> > > > > this is imposing an a-priori rule to the physical evidence
> > > > > and thus a very poor approach to understanding that
> > > > > evidence.
> > > >
> > > > Can an ancient hominid 3.4 Mya picking up a sharp
> > > > edged stone to scrape and cut the last scraps of
> > > > meat of the bones of a predators kill, be classed
> > > > as a stone tool user?
> > > >
> > > IMO, yes.
> > > >
> > > > Or would this kind of behaviour be no different from
> > > > that of any number of other species - from otters to
> > > > chimpanzees - who use whatever is available - a twig
> > > > a stone - to get at something edible or tasty).
> > > >
> > > Essentially no difference at all (IMO). Even modifying
> > > stones into sharp-edged tools is essentially no different
> > > to when a chimp strips leaves from a twig so that it
> > > will fit into a termite hole. Knapping is certainly more
> > > complicated in that it uses a tool (a hammer stone)
> > > to make a tool, but there's no type difference in the
> > > behaviour.
> >
> > Then essentially a `tool using' habilis was no
> > different from a `tool using' gorilla using a
> > stick to test the depth of the water it was
> > walking through or an otter using a stone to
> > crack open a shell...
> >
> > Then I would say tool use in Man as such cannot
> > be used to define anything other the start of
> > when the human imagination (the ability of forming
> > mental images, sensations and concepts) kicked in
> > (bringing an end to replicating the same
> > stone tools over and over again).
> >
> > > > The habilis makes a pretty lousy candidate for
> > > > Bouri (wrong place, wrong time for the `habilis').
> > > > Bouri predates the earliest habilis `fossil' by
> > > > several hundred thousand years. The older garhi
> > > > (older by several hundred thousand years) is
> > > > the better candidate.
> > > >
> > > By far the better candidate IMO, particularly given
> > > that the garhi fossils were 'proximal' to the tools..
> > > >
> > > > Incidentally I think Bruce Bower for his article in
> > > > ScienceNews came up with the best headline for this
> > > > news story...
> > > >
> > > > "Ancient hominid butchers get trampled"
> > > >
> > > >
http://www.sciencenews.org/view/generic/id/65558/title/Ancient_hominid_butchers_\
get_trampled
> > > >
> > > :-)
> > >
> > > >
> > > > > > > > If that had been the case Rob, then the possible
> > > > > > > > consequences for those that had been free of the
> > > > > > > > parasite inland for generations moving into a
> > > > > > > > littoral habitat could have been disastrous, they
> > > > > > > > may even literally have faced extinction (perhaps
> > > > > > > > only the elimination of Neu5Gc in the human
> > > > > > > > lineage, dragging them back from the brink
> > > > > > > > of extinction?)
> > > > > > >
> > > > > > > Yes....that's my suggested alternative to the hair-loss
> > > > > > > explanation for an increase in vulnerability to P.reich
> > > > > > > that led to the Neu5Gc adaptation. Having had the
> > > > > > > hair-loss explanation so cruelly euthanased by
> > > > > > > yourself, the adaptation seemed rather pointless
> > > > > > > and in need of some provenance.
> > > > > >
> > > > > > :)
> > > > > >
> > > > > > Would not say your explanation was entirely
> > > > > > euthanized by a more recent date for hair loss
> > > > > > in the human lineage, as relative hair loss in
> > > > > > Man in the last million years could have mirrored
> > > > > > the last phase in the expansion of the human
> > > > > > brain to its current size, with AMH (modern Man)
> > > > > > inheriting the condition from their immediate
> > > > > > predecessors of 240,000 years ago (early H.s.s)
> > > > > >
> > > > > Yes, it's still a possibility I suppose, but its probability
> > > > > has taken a definite nose-dive!
> > > >
> > > > Maybe not... I downloaded a copy of Hermelita Winter's
> > > > paper that appeared in `Human Genetics' in 2000, out of
> > > > curiosity to see how they arrived at such a recent date
> > > > for the inactivation of the KRTHAP1 gene (hair gene)
> > > > in the human lineage...
> > > >
> > > > Now I have questions about the date they came up with
> > > > for the mutation of the hair gene.
> > > >
> > > > I am probably wrong - but their conclusion appears to
> > > > be somewhat contradictory - as the date they give for
> > > > the gene mutation predates the emergence of those
> > > > they claim first acquired the gene mutation.
> > > >
> > > > They claim that only AMH living in Africa acquired
> > > > the hair gene mutation. Yet the date they claim for
> > > > the gene mutation predates somewhat the first
> > > > appearance of AMH in Africa by at least 50,000
> > > > years to 90,000 years (apparently in the authors
> > > > view it would have been too complicated for earlier
> > > > groups of humans living outside of Africa to have
> > > > acquired the gene mutation!).
> > > >
> > > > [quote]
> > > > "Two controversial hypotheses are currently discussed
> > > > regarding the origin of modern humans. Both concepts
> > > > entail an expansion approximately 1.5 million years ago
> > > > of Homo erectus from Africa into the Old World (Tattersall
> > > > 1997; Disotell 1999). The "multiregional continuity"
> > > > hypothesis maintains that our lineage, from then on,
> > > > consisted of a continual stream of populations evolving
> > > > in all areas of the Old World, constantly linked by gene
> > > > flow that allowed evolutionary changes in one region to
> > > > spread into others (Tattersall 1997; Disotell 1999;
> > > > Wolpoff 1998). By contrast, the "single African origin"
> > > > hypothesis contends that all modern humans descended
> > > > from a single ancestral founder population, which
> > > > consisted of approximately 10,000 breeding adults, and
> > > > which emerged in Africa about 200,000 years ago, staying
> > > > relatively isolated for probably thousands of years before
> > > > expanding into the Old World and thereby gradually
> > > > replacing more primitive forebears from the first
> > > > migrational wave..."
> > > >
> > > > (the authors clearly favour the out-of-date "out
> > > > of Africa" hypotheses of the 1980's)
> > > >
> > > > (AMH - Modern humans emerged between 165,000 and
> > > > 190,000 years ago)
> > > >
> > > > The paper:
> > > >
> > > > Human type I hair keratin pseudo gene fhHaA has
> > > > functional orthologs in the chimpanzee and gorilla:
> > > > evidence for recent inactivation of the human gene
> > > > after the Pan-Homo divergence
> > > >
> > > > http://www.springerlink.com/content/kygkdy6cdhw1kjkw/
> > > > _______________________________
> > > >
> > > Unfortunately for my idea that hairlessness could have
> > > been a determining factor in the Neu5Gc mutation, the
> > > timing is still way out by a couple of million years.
> >
> > That does seem to be the case Rob; unless some new
> > research comes up with an earlier date for the
> > inactivation of the hair gene that resulted in a
> > relatively hairless species known as Man. (the
> > habilis and H.erectus could have been as hairy
> > as a gorilla or a chimpanzee today...)
> >
> > > > > For there to have been a genetic adaptation we certainly
> > > > > require something in addition to a diet that no longer
> > > > > needed strong jaws. It is the case that the weaker
> > > > > jawed mutation became the norm, but in a situation
> > > > > where all were experiencing the same diet, then the
> > > > > diet in itself can't explain the reproductive edge
> > > > > gained by those already with the CMAH mutation
> > > > > to then establish it as the norm.
> > > >
> > > > To become the norm, I would think - those with the
> > > > mutation would have had to over time outnumbered
> > > > those without the mutation, and selection in general
> > > > would have had to acted favour those with the mutation
> > > > so unless those born without the mutation were
> > > > bumped off - it is unlikely to have happen
> > > > overnight, in evolutionary terms.
> > > >
> > > > However, there must have been something that drove
> > > > the change, perhaps an edge in masticating some
> > > > seafoods better than their large jawed kin......
> > > >
> > > > .........a smaller mouth opening may have been more
> > > > advantageous than massive ape mouth of old when
> > > > it came dealing with some shellfish (like the slimy
> > > > slippery contents of oysters).
> > > >
> > > How 'massive' d'you think this must have been to
> > > prevent them from tipping oysters (or whatever)
> > > into their mouths? Even if those with 'massive' jaw
> > > muscles found themselves at some disadvantage,
> > > this still wouldn't explain the edge gained by those
> > > with the smallest jaw muscles. Inbetween 'massive'
> > > and 'smallest' would have been simply 'big' and
> > > these too would have lost out to the weakest-
> > > jawed.
> >
> > The difference in terms of comparison may have
> > been between say the jaws, mouth size and oral
> > cavity of a gorilla and that of an AMH (modern
> > human) today... the former today is probably better
> > adapted to masticating large amounts of vegetable
> > matter than that of the average human.
> >
> > However, I would say that the outcome on the shore
> > a couple o million years and more ago, may have
> > depended more on how the facial bones would have
> > developed in life with smaller muscles - since
> > the mutation in question would only have
> > affected the jaw muscles.
> >
> > > .....And this gives us a second candidate for this
> > > > > reproductive edge.....bigger heads. At least this
> > > > > doesn't suffer from the generalised rule of small
> > > > > and weak not being sexy, but it's still not apparent
> > > > > why larger heads per se would be sexy. But if
> > > > > larger heads meant larger brains and larger brains
> > > > > gave rise to more intelligent behaviour, then we
> > > > > have a third candidate that is intuitively cogent.
> > > > >
> > > > > What do I mean by 'more intelligent behaviour'?
> > > > > Well, it wasn't more success in provisioning as
> > > > > we're assuming an abundant littoral, so I'd guess
> > > > > that was in courting technique!
> > > >
> > > > :)
> > > >
> > > > Not all of the of H.e chose a bigger head, some seem
> > > > to have contradicted the trend towards expanding the
> > > > brain by favouring thick boned skulls - possibly having
> > > > a thick skull was a positive survival advantage for
> > > > those that hunted? (or maybe H.e courting technique
> > > > involved head-butting a potential mate...)
> > > >
> > > I don't think H.e/e mating choices had anything to with
> > > the MHY16 mutation......at c. 2.4 Mya we're dealing
> > > with the H.e/e precursor.
> > >
> > > (Head-butting a potential mate? Lor', I can't see them
> > > lasting as long as they did if that was the extent of their
> > > charm. Anyone who has grown up in a modern urban
> > > setting knows that (fore)head-butting is a commonplace
> > > [and very effective] occurrence between fighting males,
> > > but as an explanation for H.e/e thick skulls.......mmmm,
> > > I'll leave that one in the 'pending more evidence' box.)
> >
> > Head-butting today, is known in a city somewhat
> > further up the coast from here as giving someone
> > a Glasgow kiss...
> >
> > It is Glasgwegien slang for headbutt - a vicious
> > headbutt (is there another kind!)
> > >
> > > > I've also got an uncomfortable feeling that there's a
> > > > contradiction here somewhere that's being overlooked.....
> > > > what advantage would be gained for a DHA-driven
> > > > brain enlargement by losing the sagittal crest as the
> > > > result of a MHY16 mutation, if the skull then thickened?
> > >
> > > On the face of it, it does seem somewhat contradictory;
> > > then again there was something of a stasis in the
> > > enlargement in the size of the H.e ...
> > >
> > > (the H.ergaster on the other hand is said to have had
> > > a thinner skull, a skull more like that of a
> > > modern human).
> > >
> > > > > Until further evidence turns up I think the most
> > > > > plausible null-hypothesis is that the lack of Neu5Gc
> > > > > freed up the Neu5Ac that otherwise would have been
> > > > > used to make Neu5Gc. The additional Neu5Ac was
> > > > > then used to create synaptic connections in the brains
> > > > > being enlarged by the plentiful DHA.
> > > >
> > > > Was its loss simply accident of evolution, or was it a
> > > > necessary step in the evolution of a relatively large
> > > > brain in the human lineage - I would say it was the
> > > > latter.
> > > >
> > > Both.
> > >
> > > Rob.
> >
> > There may be an entirely different reason for the
> > both the inactivation of MYH16 and that of Neu5Gc
> > in the human lineage that we may have missed...
> > both may have result from genetic-drift, not
> > natural selection (positive or otherwise).
> >
> > What is Genetic Drift?
> > http://www.biology.arizona.edu/evolution/act/drift/about.html
> >
> > Genetic drift [Wikipedia]
> >
> > Genetic drift is an important evolutionary process
> > which leads to changes in allele frequencies over
> > time. It may cause gene variants to disappear
> > completely, and thereby reduce genetic variation.
> > In contrast to natural selection, which makes gene
> > variants more common or less common depending on
> > their reproductive success,] the changes due to
> > genetic drift are not driven by environmental or
> > adaptive pressures, and may be beneficial, neutral,
> > or detrimental to reproductive success. [quote]
> >
> > http://en.wikipedia.org/wiki/Genetic_drift
> >
> > _______________________________
> >
> > --Bill
> >
> > > --- In AAT@yahoogroups.com, "Rob Dudman" <ausell@> wrote:
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: dons3148
> > > > To: AAT@yahoogroups.com
> > > > Sent: Thursday, December 09, 2010 12:33 AM
> > > > Subject: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> > > > Hypotheses)
> > >
> > > Hello Rob...
> > >
> > > > Hello Bill........
> > > > >
> > > > > > > On the other hand if the garhi was using tools to
> > > > > > > butcher red-meat inland 2.5 Mya, then they would
> > > > > > > have had to have been moving into a littoral
> > > > > > > habitat, or in a littoral habitat at around the
> > > > > > > same time... is that likely?
> > > > > >
> > > > > > Well, garhi do seem to have vacated the African
> > > > > > scene after c. 2.5 Mya.
> > > > >
> > > > > The garhi have though have seemingly retained the
> > > > > `title' of earliest stone tool user, as a recent claim for
> > > > > even older `tool use' some 3 Mya based on bone
> > > > > cut marks appears to have been dismissed, with
> > > > > the alleged `cut marks' apparently now attributed
> > > > > to the bones simply being trampled on.
> > > > >
> > > > > You may recall there was a controversial claim
> > > > > back in August this year for evidence for stone
> > > > > tool use 3.4 Mya that was based on cut marks on
> > > > > some bones found in the Lower Awash.
> > > > > (The Dikika Cut Marks)
> > > > >
> > > > > Trampling Over The Dikika Cut Marks
> > > > >
http://anthropology.net/2010/11/19/trampling-over-the-dikika-cut-marks/
> > > > >
> > > > That's a reasonably convincing rebuttal of the claim
> > > > that the Dikika cut marks are evidence of tool use.
> > > > However, the Bouri evidence was published over a
> > > > decade ago and no-one (AFAIK) has yet claimed
> > > > that these are not cut-marked bones that are 'proximal'
> > > > to the remains of eight individual garhi.
> > > >
> > > > [No garhi fossils from before or after, yet here we
> > > > have eight more or less in the same place and from
> > > > the same time? Now that's odd. Maybe they died of
> > > > P.reich malaria and those who survived the epidemic
> > > > scarpered and eventually found themselves at the
> > > > coast.......... :-)]
> > >
> > > :)
> > >
> > > Or perhaps they were a `hunting/scavenging' or scouting
> > > party that fell foul of pack of predators. (like a'piths -
> > > australopithecines - they still had the sagittal crest
> > > on the top of the skull, that functioned as muscle
> > > anchor for the jaw muscles).
> > >
> > > > From what I can see, the main gripe about the
> > > > Bouri evidence has been related to the notion that
> > > > A'piths didn't/couldn't manufacture and use Mode 1
> > > > stone tools, so these had to have been made by
> > > > Homo and the only candidate has been habilis. IMO,
> > > > this is imposing an a-priori rule to the physical evidence
> > > > and thus a very poor approach to understanding that
> > > > evidence.
> > >
> > > Can an ancient hominid 3.4 Mya picking up a sharp
> > > edged stone to scrape and cut the last scraps of
> > > meat of the bones of a predators kill, be classed
> > > as a stone tool user?
> > >
> > > Or would this kind of behaviour be no different from
> > > that of any number of other species - from otters to
> > > chimpanzees - who use whatever is available - a twig
> > > a stone - to get at something edible or tasty).
> > >
> > > The habilis makes a pretty lousy candidate for
> > > Bouri (wrong place, wrong time for the `habilis').
> > > Bouri predates the earliest habilis `fossil' by
> > > several hundred thousand years. The older garhi
> > > (older by several hundred thousand years) is
> > > the better candidate.
> > >
> > > Incidentally I think Bruce Bower for his article in
> > > ScienceNews came up with the best headline for this
> > > news story...
> > >
> > > "Ancient hominid butchers get trampled"
> > >
> > >
http://www.sciencenews.org/view/generic/id/65558/title/Ancient_hominid_butchers_\
get_trampled
> > >
> > > ___________________________________
> > >
> > > The `habilis' wasn't much of a hunter either, as
> > > apparently there is evidence that it was more
> > > prey than hunter as it appears to have been among
> > > the favoured prey of ancient big cats like the
> > > Dinofelis (a sabre tooth big cat about the size
> > > of a lion). Ancient crocs too apparently liked
> > > to snack on the unfortunate `habilis'
> > >
> > > Ancient Horned Crocodile Found-Ate Early Humans?
> > >
> > > "Crocodile bite marks had previously been found on
> > > hominid bones from the gorge. Based on the latest
> > > find, scientists suspect that the crocodile not only
> > > ate our ancestors, but that it was their biggest
> > > predator at the time. "[quote]
> > >
> > >
http://news.nationalgeographic.com/news/2010/02/100225-new-horned-crocodile-earl\
y-humans/
> > >
> > > ___________________________________
> > >
> > > > > > I understand that temperature is the key factor and
> > > > > > of course increasing altitude mimics increasing
> > > > > > latitude.
> > > > >
> > > > > That appears to be the case as after a bit of a
> > > > > search this morning on the subject, it appears
> > > > > the mosquito larvae is killed if the temp drops
> > > > > below 15.C.
> > > > >
> > > > > Surprisingly though... mosquitoes themselves
> > > > > do somehow survive in temperate climes, by
> > > > > hibernating through the winter (among them
> > > > > a mosquito in Alaska called the snow-mosquito!).
> > > > >
> > > > Given the staggering numbers of those tundra mozzies
> > > > it's some consolation that they're not called anopheles!
> > > > I seem to recall reading that anopheles were found
> > > > in England during this past summer....d'you know
> > > > anything about that?
> > >
> > > No... but it would not be a surprise if they were
> > > overwintering in southern England, as apparently
> > > there are a number of mosquito species in Britain
> > > (there is even a mosquito recording scheme!)
> > >
> > > http://www.britishmosquitoes.org.uk/recordingscheme/index.html
> > >
> > > However, in these parts pesky midges are the
> > > problem, not mosquitoes.
> > >
> > > http://www.snh.org.uk/publications/on-line/advisorynotes/29/29.htm
> > >
> > > ______________________________________
> > >
> > > > > > > If that had been the case Rob, then the possible
> > > > > > > consequences for those that had been free of the
> > > > > > > parasite inland for generations moving into a
> > > > > > > littoral habitat could have been disastrous, they
> > > > > > > may even literally have faced extinction (perhaps
> > > > > > > only the elimination of Neu5Gc in the human
> > > > > > > lineage, dragging them back from the brink
> > > > > > > of extinction?)
> > > > > >
> > > > > > Yes....that's my suggested alternative to the hair-loss
> > > > > > explanation for an increase in vulnerability to P.reich
> > > > > > that led to the Neu5Gc adaptation. Having had the
> > > > > > hair-loss explanation so cruelly euthanased by
> > > > > > yourself, the adaptation seemed rather pointless
> > > > > > and in need of some provenance.
> > > > >
> > > > > :)
> > > > >
> > > > > Would not say your explanation was entirely
> > > > > euthanized by a more recent date for hair loss
> > > > > in the human lineage, as relative hair loss in
> > > > > Man in the last million years could have mirrored
> > > > > the last phase in the expansion of the human
> > > > > brain to its current size, with AMH (modern Man)
> > > > > inheriting the condition from their immediate
> > > > > predecessors of 240,000 years ago (early H.s.s)
> > > > >
> > > > Yes, it's still a possibility I suppose, but its probability
> > > > has taken a definite nose-dive!
> > >
> > > Maybe not... I downloaded a copy of Hermelita Winter's
> > > paper that appeared in `Human Genetics' in 2000, out of
> > > curiosity to see how they arrived at such a recent date
> > > for the inactivation of the KRTHAP1 gene (hair gene)
> > > in the human lineage...
> > >
> > > Now I have questions about the date they came up with
> > > for the mutation of the hair gene.
> > >
> > > I am probably wrong - but their conclusion appears to
> > > be somewhat contradictory - as the date they give for
> > > the gene mutation predates the emergence of those
> > > they claim first acquired the gene mutation.
> > >
> > > They claim that only AMH living in Africa acquired
> > > the hair gene mutation. Yet the date they claim for
> > > the gene mutation predates somewhat the first
> > > appearance of AMH in Africa by at least 50,000
> > > years to 90,000 years (apparently in the authors
> > > view it would have been too complicated for earlier
> > > groups of humans living outside of Africa to have
> > > acquired the gene mutation!).
> > >
> > > [quote]
> > > "Two controversial hypotheses are currently discussed
> > > regarding the origin of modern humans. Both concepts
> > > entail an expansion approximately 1.5 million years ago
> > > of Homo erectus from Africa into the Old World (Tattersall
> > > 1997; Disotell 1999). The "multiregional continuity"
> > > hypothesis maintains that our lineage, from then on,
> > > consisted of a continual stream of populations evolving
> > > in all areas of the Old World, constantly linked by gene
> > > flow that allowed evolutionary changes in one region to
> > > spread into others (Tattersall 1997; Disotell 1999;
> > > Wolpoff 1998). By contrast, the "single African origin"
> > > hypothesis contends that all modern humans descended
> > > from a single ancestral founder population, which
> > > consisted of approximately 10,000 breeding adults, and
> > > which emerged in Africa about 200,000 years ago, staying
> > > relatively isolated for probably thousands of years before
> > > expanding into the Old World and thereby gradually
> > > replacing more primitive forebears from the first
> > > migrational wave..."
> > >
> > > (the authors clearly favour the out-of-date "out
> > > of Africa" hypotheses of the 1980's)
> > >
> > > (AMH - Modern humans emerged between 165,000 and
> > > 190,000 years ago)
> > >
> > > The paper:
> > >
> > > Human type I hair keratin pseudo gene fhHaA has
> > > functional orthologs in the chimpanzee and gorilla:
> > > evidence for recent inactivation of the human gene
> > > after the Pan-Homo divergence
> > >
> > > http://www.springerlink.com/content/kygkdy6cdhw1kjkw/
> > >
> > > _______________________________
> > >
> > > > > > You suggest that those with little or no activated
> > > > > > MYH16 may have had a reproductive edge over
> > > > > > their contemporaries by being more attractive as
> > > > > > mating partners, but again I find this difficult to
> > > > > > sequence. This group would have been a small,
> > > > > > handicapped minority in a species that had required
> > > > > > strong jaws and they would have remained a small
> > > > > > minority during the change from an inland diet to
> > > > > > a littoral one.
> > > > >
> > > > > Circumstances seem to have favoured those with the
> > > > > gene mutation as the mutation became the norm in
> > > > > the human lineage, which may indicate there was
> > > > > positive selection in favor of gene mutation...
> > > > >
> > > > > The link to diet could be that it was specifically
> > > > > two masticatory (jaw) muscles that were affected
> > > > > by the gene mutation, in other words two jaw muscles
> > > > > directly involved in chewing. (So whatever they were
> > > > > doing on the shore it involved less chewing and less
> > > > > time spent chewing like a gorilla/chimpanzee)
> > > > >
> > > > > It is likely a reduction in the size of two jaw
> > > > > muscles would influence how the jaw bones developed
> > > > > in life, but perhaps it took a generation or two (or
> > > > > maybe more?) for a new smaller jaw as such to become
> > > > > the norm in the human lineage (possibly giving those
> > > > > involved, time to adjust to their `new facial
> > > > > configuration'?).
> > > > >
> > > > For there to have been a genetic adaptation we certainly
> > > > require something in addition to a diet that no longer
> > > > needed strong jaws. It is the case that the weaker
> > > > jawed mutation became the norm, but in a situation
> > > > where all were experiencing the same diet, then the
> > > > diet in itself can't explain the reproductive edge
> > > > gained by those already with the CMAH mutation
> > > > to then establish it as the norm.
> > >
> > > To become the norm, I would think - those with the
> > > mutation would have had to over time outnumbered
> > > those without the mutation, and selection in general
> > > would have had to acted favour those with the mutation
> > > - so unless those born without the mutation were
> > > bumped off - it is unlikely to have happen
> > > overnight, in evolutionary terms.
> > >
> > > However, there must have been something that drove
> > > the change, perhaps an edge in masticating some
> > > seafoods better than their large jawed kin.
> > >
> > > > > Incidentally... the upper masticatory muscle of the
> > > > > two mastication muscles affected by the mutation would
> > > > > have receded from being anchored to the top of the
> > > > > skull down to the sides of the skull.
> > > > >
> > > > > Perhaps this change alone removed a restraint on the
> > > > > expansion of the human brain as the skull would no
> > > > > longer be constrained by massive jaw muscles
> > > > > attached and anchored to the top of the skull.
> > > > >
> > > > And this gives us a second candidate for this
> > > > reproductive edge.....bigger heads. At least this
> > > > doesn't suffer from the generalised rule of small
> > > > and weak not being sexy, but it's still not apparent
> > > > why larger heads per se would be sexy. But if
> > > > larger heads meant larger brains and larger brains
> > > > gave rise to more intelligent behaviour, then we
> > > > have a third candidate that is intuitively cogent.
> > > >
> > > > What do I mean by 'more intelligent behaviour'?
> > > > Well, it wasn't more success in provisioning as
> > > > we're assuming an abundant littoral, so I'd guess
> > > > that was in courting technique!
> > >
> > > :)
> > >
> > > Not all of the of H.e chose a bigger head, some seem
> > > to have contradicted the trend towards expanding the
> > > brain by favouring thick boned skulls - possibly having
> > > a thick skull was a positive survival advantage for
> > > those that hunted? (or maybe H.e courting technique
> > > involved head-butting a potential mate...)
> > >
> > > > > One further complication arising from a reduction in
> > > > > the two jaw muscles and a related reduction in the
> > > > > jaw itself, are the teeth. Those initially born with
> > > > > mutation may have had a mouthful of ill-fitting
> > > > > teeth...
> > > > >
> > > > That's hardly going to enhance the sexual attraction
> > > > of the smaller, weaker jaw!
> > >
> > > :)
> > >
> > > > > > ........Even today the square jaw is considered an
> > > > > > attractive male feature....large jaws may be 'out'
> > > > > > but 'weak-chinned' or 'chinless' is still a euphemism
> > > > > > for 'unmasculine'.
> > > > > > For modern females OTOH, a small, more
> > > > > > pointed jaw-line is considered attractive and
> > > > > > here is a gender difference that strongly suggests
> > > > > > sexual selection. It seems that so far females have
> > > > > > not been finding weaker jaws more attractive in
> > > > > > potential mating partners.
> > > > >
> > > > > That may have been the case if the mutation had
> > > > > affected only one sex... but this mutation of the
> > > > > jaw mastication muscles would have affected both
> > > > > sexes equally.
> > > > >
> > > > > So perhaps from a male perspective a couple of
> > > > > million years ago, females with born smaller jaws
> > > > > were a lot more 'attractive' than those females
> > > > > born with 'masculine' large jaws. (thus male
> > > > > mating choice, perhaps ensured there was
> > > > > positive selection for the mutation)
> > > > >
> > > > Perhaps.
> > > > >
> > > > > > It had occurred to me that if the CMAH mutation
> > > > > > was the result of a bottleneck effect created by a
> > > > > > severe P.reich malarial epidemic and this had in some
> > > > > > way set up the conditions where the exceptionally
> > > > > > weak-jawed would mate more frequently, but so
> > > > > > far it hasn't occurred to me how this could have
> > > > > > been the case.
> > > > >
> > > > > Brain expansion remains an explanation for the gene
> > > > > mutation, as only after the reduction in the size of the
> > > > > jaw muscles in question could brain expansion have
> > > > > become a possibility...
> > > > >
> > > > Yes.....on arrival at the littoral that small percentage of
> > > > the population that were handicapped with weak jaws
> > > > because of a genetic disorder (the CMAH mutation),
> > > > would have been able to respond to a high DHA diet
> > > > in a way that their stronger jawed contemporaries could
> > > > not. I think they may have outwitted their rivals in the
> > > > mating game.
> > >
> > > That seems a distinct possibility, Rob.
> > >
> > > One other may have been a smaller mouth as a
> > > consequence of the changes resulting from the
> > > mutation, an a smaller mouth opening may have
> > > been more advantageous than massive ape mouth
> > > of old when it came dealing with some
> > > shellfish (like the slimy slippery
> > > contents of oysters).
> > >
> > > > > > Unless an objective difference can be identified to
> > > > > > distinguish the Neu5Gc of one species from another,
> > > > > > then I have to say that your conclusion seems very
> > > > > > much a guess. In my reading about Neu5Gc I've
> > > > > > come across nothing to even hint that there's a
> > > > > > difference in this regard between species and if
> > > > > > there is in fact no difference, then we do need an
> > > > > > explanation for the human immune system response.
> > > > >
> > > > > The way I look at this question is to do so from the
> > > > > perspective of the human immune system, in that they
> > > > > both represent a threat to the body.
> > > > >
> > > > > This after some 2.5 Mya (taking into account a few
> > > > > genus Homo ancestors and possibly a predecessor or
> > > > > two to genus Homo since the inactivation Neu5Gc in
> > > > > the human lineage) can be seen as a reasonable
> > > > > response on the part of the immune system, as
> > > > > humans as such have evolved happily for some
> > > > > two million of years and more without a
> > > > > functional need for endogenous Neu5Gc.
> > > > >
> > > > > Not so certain the comparison with Vit.C is a valid
> > > > > one, as Neu5Gc is basically antigenic in Man (it invokes
> > > > > an immune response), whereas Vit.C, exogenous Vit.C is
> > > > > something that is essential for collagen synthesis
> > > > > (without it we would get scurvy, a condition in
> > > > > which the body falls apart)
> > > > >
> > > > > All primates (apes and monkeys) have been dependent
> > > > > on an exogenous source of Vit.C for tens of millions of
> > > > > years.
> > > > >
> > > > > Vit.C inactivation as such is said to have occurred
> > > > > in primates about 60 Mya - around the time the wet
> > > > > and dry noses split (primates) - so it can be said
> > > > > to be an oddity we share with our primate kin
> > > > > (apes and monkeys).
> > > > >
> > > > I'd read that it was about 40 Mya, but for the
> > > > purposes of our discussion the difference is of little
> > > > consequence. Here's an interesting take on why
> > > > primates ceased producing endogenous Vit. C......
> > > >
> > > > Vitamin C--the primate fertility factor?
> > > > Millar J.
> > > >
> > > > Abstract
> > > > The loss of the ability of primates and man to synthesise
> > > > ascorbic acid (vitamin C) is usually seen as an evolutionary
> > > > accident, with no benefit to the species. This paper argues
> > > > that the loss of this biosynthetic ability has allowed vitamin C
> > > > to act as a 'fertility factor' in primate societies. It is argued
> > > > that the requirement for vitamin C increases with age, and
> > > > so in times of food shortages the older members of society
> > > > suffer higher mortality than the younger. This reduces the
> > > > median age of the population towards the younger and
> > > > most fertile members, and so enables the population to
> > > > regrow rapidly when food resources are restored.
> > > >
> > > > http://www.ncbi.nlm.nih.gov/pubmed/1491626
> > > > ________________
> > >
> > > Interesting theory, but the gene mutation as such
> > > apparently occurred tens of millions of years ago,
> > > just after the split from the `wet noses' that can
> > > make their own Vit.C and before the tarsier - who
> > > cannot make Vit.C - branched off (about 58/57 Mya).
> > > So primates themselves, early primate society
> > > 60 Mya was probably very different from how
> > > primates organised themselves today. (the gene
> > > mutation in question occurred long before the
> > > emergence of the apes some 23/24 Mya).
> > >
> > > Losing the ability to turn glucose into Vit.C would
> > > seem on the face of it is a pretty negative adaptation
> > > (as it amount to losing something essential) for any
> > > species, have read somewhere that the loss of the
> > > ability to make Vit.C paralleled the loss of the
> > > ability to break down uric acid in primates (how
> > > those two link together is anybody's guess!).
> > >
> > > [quote]
> > > "Among the animals that have lost the ability to
> > > synthesise vitamin C are simians (specifically the
> > > suborder haplorrhini, which includes humans), guinea
> > > pigs, a number of species of passerine birds (but
> > > not all of them-there is some suggestion that the
> > > ability was lost separately a number of times in
> > > birds), and many (probably all) major families of
> > > bats, including major insect and fruit-eating bat
> > > families. These animals all lack the
> > > L-gulonolactone oxidase (GULO) enzyme, which
> > > is required in the last step of vitamin
> > > C synthesis, because they have a defective
> > > form of the gene for the enzyme
> > > (Pseudogene ΨGULO)."
> > >
> > > http://www.news-medical.net/health/What-is-Vitamin-C.aspx
> > >
> > > ____________________________________
> > >
> > > > > Arguably humans are only unique in one sense we
> > > > > have a relatively large brain, so perhaps the absence
> > > > > of endogenous Neu5Gc is somehow favourable to
> > > > > the brain.
> > > > >
> > > > Until further evidence turns up I think the most
> > > > plausible null-hypothesis is that the lack of Neu5Gc
> > > > freed up the Neu5Ac that otherwise would have been
> > > > used to make Neu5Gc. The additional Neu5Ac was
> > > > then used to create synaptic connections in the brains
> > > > being enlarged by the plentiful DHA.
> > > >
> > > > Rob.
> > >
> > > Was its loss simply accident of evolution, or
> > > was it a necessary step in the evolution of a
> > > relatively large brain in the human lineage -
> > > I would say it was the latter.
> > >
> > > --Bill
> > >
> >
>

Hello Heather......

Here's an article from March 2009 that may be of interest
to you.........

Live Fast, Die Young? Maybe Not

http://www.sciencedaily.com/releases/2009/03/090309162121.htm
__________

Rob



----- Original Message -----
From: "Heather Twist" <HeatherTwist@...>
To: <AAT@yahoogroups.com>
Sent: Wednesday, December 15, 2010 4:40 PM
Subject: Re: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
Hypotheses)


On Tue, Dec 14, 2010 at 7:38 PM, Rob Dudman <ausell@...> wrote:

>
>
>
> ----- Original Message -----
> From: "Heather Twist" <HeatherTwist@... <HeatherTwist%40gmail.com>>
> To: <AAT@yahoogroups.com <AAT%40yahoogroups.com>>
> Sent: Tuesday, December 14, 2010 4:15 PM
> Subject: Re: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> Hypotheses)
>
> Hello Heather......thanks for an interesting contribution to the
> conversation.
>
Thanks for listening!

> Has anyone investigated the link between Neu5gc and longevity?
> > It seems an interesting coincidence, but mammals, which all produce
> > lots of GC, have rather short lifespans and do not age gracefully.
> Whereas
> > fish, who have little GC, don't seem to age much (they just get bigger)
> > and
> > birds, which have little GC, do age but not as obviously as mammals do.
> >
> AFAIK, no-one has yet published studies that specifically
> focus on Neu5Gc and longevity. Humans have an immune
> reaction to ingested Neu5Gc and there's evidence that
> chronic immune stressors negatively affect longevity. There's
> emerging evidence that Neu5Gc plays a major role in
> causing Hemolytic-uremic syndrome....a gastrointestinal
> disorder that occurs mostly in children and the elderly......
>
> 'A dietary non-human sialic acid may facilitate hemolytic-
> uremic syndrome'
> By Jonas C. Löfling et al.
>
> http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2752721/
> _________
>
> Endogenous Neu5Gc is known to cluster in human
> cancer tumours and its presence there is somewhat
> enigmatic.......the fact that other mammals seem to
> suffer less from cancer than we do suggests that in
> some way the presence of Neu5Gc inhibits tumour
> growth.
>
> However, there's accumulating evidence that the
> presence of anti-Neu5Gc antibodies is correlated
> with accelerated growth in tumours......
>
> 'Evidence for a human-specific mechanism for diet
> and antibody-mediated inflammation in carcinoma
> progression'
> By Maria Hedlund et al.
>
> http://tinyurl.com/23md5c2
> _________
>
The thing is, it's pretty clear that the gc can promote
inflammation in humans. I'm not sure that is the main point though:
it doesn't cause inflammation in the animals that produce it?
As far as I can tell, gc doesn't cause problems in birds that
eat it either, even though birds are low in gc.

But the gc is common in cells with high turnover ... like the
gut. And rare in cells with low turnover ... like the brain.

So an animal with high gc is, well, maybe somehow primed
for a "high turnover" kind of life. Live fast, die young. Unlike, say,
a sea turtle, which is very much the opposite, or a grey parrot.
GC is high in beef. Beef cattle get old rather quickly, considering
their size: 15 years old is considered very old for a cow.
Mice live all of one year maybe.  But a  parrot can live 90 years.

Also, the only fish that seemed high in gc was salmon. But
salmon are noted for dying after they spawn ... unlike other
fish that can live until someone eats them.



> Since mammals are more prone to overpopulation problems than fish
> > or birds seem to be, it makes sense that they would have shorter
> > lifespans......
> >
> While human mediated overpopulation problems among
> mammals are not uncommon, if we adjust for this surely
> there's no reason to think that the ecological population
> control mechanisms for mammals are any different than
> those for fish and birds? In times of plenty populations
> grow and in times of scarcity they shrink. Overpopulation
> problems occur when the times of plenty come to an
> end and the times of scarcity commence.
>
When you look at the flocks of flamingos or fish ... they
are really, really dense. The thing that fish and birds have
in common is the ability to go long distances, rather quickly.
They rarely die of starvation. Flamingos can fly 50 miles
a day just to eat. A rabbit can't do that, nor can a cow. Mice
tend to live within a few yards of where they were born. The
starvation cycles of mice and rabbits are pretty well documented.
There aren't such starvation cycles (at least that I've seen) for
say, seagulls. Seagulls just fly to where the fish are, and maybe
have fewer eggs if there is less food.

I think humans *are* different in this way. Early humans were
highly nomadic, making them more like birds or fish, and less
like cattle or mice. Plus the ocean is pretty much infinite as a
food source (until the invention of big ships, anyway).

So *IF* switching to an AG kind of metabolism makes one live
longer, then humans could start working off a longer-term lifecycle,
like parrots, turtles, and fish. That would mean: you could learn
more in one lifetime.

The tradeoff would be: you have to figure out how to have fewer
kids (menopause?) and how to find different sources of food
quickly.


> >
> > ....Although the mice that don't express GC weren't said to
> > live any longer than other mice, so likely it is more complex than just
> > that one molecule. One of the big differences between chimps and humans
> > though, is the way we age.
> >
> I agree that the issue of inceasing human longevity is
> likely to be more complex than the effects of any one
> molecule. If I try and suggest just one thing that has
> had the most profound effect on both the quality and
> the increasing length of human life it would be the
> control of bacterial infection.
>
That is a good point. Having raised many animals, the thing
that gets me is: the animals I raise, rarely die from infection.
I'm sure it does happen, but it doesn't seem to happen often.
Usually when they get older, they get slower, and a predator
eats them. Also they die if their "group" disowns them.

Human beings though, at least in our culture, DO die from infection,
quite a bit. That might be a result of how we live, our diet, the density of
how we live? I don't think in ancient times it was such an issue:
the fact Oetzi could survive multiple injuries (or the fact the
Egyptians could do trepanation) seems to indicate people weren't
so prone to infection, for whatever reason. People in the modern
age started living to an older age when we learned about hygiene,
and esp. about sewage systems (less cholera). But by that point we
were already living rather closely together. How about in hominid times?
When did women start living long enough to make menopause start
being worthwhile as an adaptation?

"Pachyostosis" in aquatic amniotes: a review
Alexandra HOUSSAYE 2009 DOI 10.1111/j.1749-4877.2009.00146.x
Integrative Zoology 4:325­340
<http://onlinelibrary.wiley.com/doi/10.1111/inz.2009.4.issue-4/issuetoc>

During the course of amniote evolution, numerous taxa secondarily adapted to
an aquatic life.  It appears that many of these taxa primitively display
"pachyostosis", an osseous specialization characterized by an increase in
bone compactness &/or volume.
The term "pachyostosis" is used in morphological & histological descriptions
to describe what in fact corresponds to different patterns.
The aim of this paper is to present the current state of knowledge relative
to this adaptation among aquatic amniotes.

All the taxa that have returned to an aquatic environment are listed.
Moreover,
- their degree of adaptation to the marine environment,
- their life environment &
- the nature of their "pachyostotic" pattern (when present)
are described.
This inventory
- enables the evaluation of the current quality of the data relative to this
specialization&
- provides an indication of the work that remains to be done.
The functional consequences of "pachyostosis" & notably its importance for
buoyancy control in the context of hydrostatic regulation of the body trim,
are discussed, and opposed to the requirement of improved swimming abilities
in the case of a hydrodynamic mode of trim regulation.
Questions are posed about the signification of the polymorphism displayed by
this specialization between different taxa, different specimens of the same
taxon & different bones of the same specimen & the problem of quantification
of pachyostosis is discussed.

_______


Evolution of Sirenian Pachyosteosclerosis, a Model-case for the Study of
Bone Structure in Aquatic Tetrapods
Vivian de Buffrénil, Aurore Canoville, Ruggero D¹Anastasio & Daryl P.
Domning 2010 Journal of Mammalian Evolution 17:101-120
DOI 10.1007/s10914-010-9130-1

Osteosclerosis (inner bone compaction) & pachyostosis (outer hyperplasy of
bone cortices, swollen bones) are typical features of tetrapods secondarily
adapted to life in water.
These peculiarities are spectacularly exemplified by the ribs of extant &
extinct Sirenia.  Sea cows are thus the best model for studying this kind of
bone structural specializations.
In order to document how these features differentiated during sirenian
evolution, the ribs of 15 spp (from the most basal form Pezosiren portelli
up to extant taxa) were studied & compared to those of other mammalian spp
from both & and histological points of view.
- Pachyostosis was the first of these 2 specializations to occur, by the
middle of the Eocene, and is a basal feature of the Sirenia.
However, it subsequently regressed in some taxa that do not exhibit
hyperplasic rib cortices.
- Osteosclerosis was only incipient in P.portelli. Its full development
occurred later, by the end of the Eocene.
These 2 structural specializations of bone are variably pronounced in
extinct & extant sirenians, and rel.independent from each other, although
frequently associated.
They are possibly due to similar heterochronic mechanisms bearing on the
timing of osteoblast activity. These results are discussed with respect to
the functional constraints of locomotion in water.

That's sort of my point. Mice grow up fast and die fast, so do cattle.
Birds don't have an "endpoint" to their lives though, nor do most
fish. Birds and fish don't produce neu5GC .... although it's found
in many animals, including bacteria and worms, and most of *them*
do have a set lifespan.

Bird metabolism is faster than a mouse, and they often live harder
lives (they don't usually live in holes most of the day). Yet a 90-year-
old albatross can still fly. It's like the difference between annuals
and perennials in plants: mice have a "stop" mechanism that will make
them die no matter what. Birds don't, nor do most fish.

I am thinking that neu5GC participates in this somehow: it's found
mainly in high-turnover cells. It can't be the only factor, because mice
without
neu5GC still age. But the only fish that appears to produce GC is salmon,
and salmon are one of the few fish that age? (I don't know what kind of
salmon they were testing). I think the GC-type metabolism might also
make the animals grow faster or bigger ... cows grow really fast, and
also human populations that eat dairy or cow meat tend to be taller
and also seemingly not as long lived. (i.e., the Japanese tend to be
short, even though they get plenty of protein, maybe, I'm thinking,
because it is fish and egg protein. They get taller and bigger on an
"American style" diet: Sumo wrestlers get more beef, pork, and wheat
noodles. Some populations though are short just because they
don't get enough protein, or because they are unhealthy).


On Sat, Jan 1, 2011 at 9:25 PM, Rob Dudman <ausell@...> wrote:

>
>
> Hello Heather......
>
> Here's an article from March 2009 that may be of interest
> to you.........
>
> Live Fast, Die Young? Maybe Not
>
> http://www.sciencedaily.com/releases/2009/03/090309162121.htm
> __________
>
> Rob
>
> ----- Original Message -----
> From: "Heather Twist" <HeatherTwist@... <HeatherTwist%40gmail.com>>
> To: <AAT@yahoogroups.com <AAT%40yahoogroups.com>>
> Sent: Wednesday, December 15, 2010 4:40 PM
> Subject: Re: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> Hypotheses)
>
> On Tue, Dec 14, 2010 at 7:38 PM, Rob Dudman
<ausell@...<ausell%40skymesh.com.au>>
> wrote:
>
> >
> >
> >
> > ----- Original Message -----
> > From: "Heather Twist" <HeatherTwist@...
<HeatherTwist%40gmail.com><HeatherTwist%
> 40gmail.com>>
> > To: <AAT@yahoogroups.com <AAT%40yahoogroups.com> <AAT%40yahoogroups.com
> >>
> > Sent: Tuesday, December 14, 2010 4:15 PM
> > Subject: Re: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> > Hypotheses)
> >
> > Hello Heather......thanks for an interesting contribution to the
> > conversation.
> >
> Thanks for listening!
>
> > Has anyone investigated the link between Neu5gc and longevity?
> > > It seems an interesting coincidence, but mammals, which all produce
> > > lots of GC, have rather short lifespans and do not age gracefully.
> > Whereas
> > > fish, who have little GC, don't seem to age much (they just get bigger)
> > > and
> > > birds, which have little GC, do age but not as obviously as mammals do.
> > >
> > AFAIK, no-one has yet published studies that specifically
> > focus on Neu5Gc and longevity. Humans have an immune
> > reaction to ingested Neu5Gc and there's evidence that
> > chronic immune stressors negatively affect longevity. There's
> > emerging evidence that Neu5Gc plays a major role in
> > causing Hemolytic-uremic syndrome....a gastrointestinal
> > disorder that occurs mostly in children and the elderly......
> >
> > 'A dietary non-human sialic acid may facilitate hemolytic-
> > uremic syndrome'
> > By Jonas C. Löfling et al.
> >
> > http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2752721/
> > _________
> >
> > Endogenous Neu5Gc is known to cluster in human
> > cancer tumours and its presence there is somewhat
> > enigmatic.......the fact that other mammals seem to
> > suffer less from cancer than we do suggests that in
> > some way the presence of Neu5Gc inhibits tumour
> > growth.
> >
> > However, there's accumulating evidence that the
> > presence of anti-Neu5Gc antibodies is correlated
> > with accelerated growth in tumours......
> >
> > 'Evidence for a human-specific mechanism for diet
> > and antibody-mediated inflammation in carcinoma
> > progression'
> > By Maria Hedlund et al.
> >
> > http://tinyurl.com/23md5c2
> > _________
> >
> The thing is, it's pretty clear that the gc can promote
> inflammation in humans. I'm not sure that is the main point though:
> it doesn't cause inflammation in the animals that produce it?
> As far as I can tell, gc doesn't cause problems in birds that
> eat it either, even though birds are low in gc.
>
> But the gc is common in cells with high turnover ... like the
> gut. And rare in cells with low turnover ... like the brain.
>
> So an animal with high gc is, well, maybe somehow primed
> for a "high turnover" kind of life. Live fast, die young. Unlike, say,
> a sea turtle, which is very much the opposite, or a grey parrot.
> GC is high in beef. Beef cattle get old rather quickly, considering
> their size: 15 years old is considered very old for a cow.
> Mice live all of one year maybe. But a parrot can live 90 years.
>
> Also, the only fish that seemed high in gc was salmon. But
> salmon are noted for dying after they spawn ... unlike other
> fish that can live until someone eats them.
>
> > Since mammals are more prone to overpopulation problems than fish
> > > or birds seem to be, it makes sense that they would have shorter
> > > lifespans......
> > >
> > While human mediated overpopulation problems among
> > mammals are not uncommon, if we adjust for this surely
> > there's no reason to think that the ecological population
> > control mechanisms for mammals are any different than
> > those for fish and birds? In times of plenty populations
> > grow and in times of scarcity they shrink. Overpopulation
> > problems occur when the times of plenty come to an
> > end and the times of scarcity commence.
> >
> When you look at the flocks of flamingos or fish ... they
> are really, really dense. The thing that fish and birds have
> in common is the ability to go long distances, rather quickly.
> They rarely die of starvation. Flamingos can fly 50 miles
> a day just to eat. A rabbit can't do that, nor can a cow. Mice
> tend to live within a few yards of where they were born. The
> starvation cycles of mice and rabbits are pretty well documented.
> There aren't such starvation cycles (at least that I've seen) for
> say, seagulls. Seagulls just fly to where the fish are, and maybe
> have fewer eggs if there is less food.
>
> I think humans *are* different in this way. Early humans were
> highly nomadic, making them more like birds or fish, and less
> like cattle or mice. Plus the ocean is pretty much infinite as a
> food source (until the invention of big ships, anyway).
>
> So *IF* switching to an AG kind of metabolism makes one live
> longer, then humans could start working off a longer-term lifecycle,
> like parrots, turtles, and fish. That would mean: you could learn
> more in one lifetime.
>
> The tradeoff would be: you have to figure out how to have fewer
> kids (menopause?) and how to find different sources of food
> quickly.
>
> > >
> > > ....Although the mice that don't express GC weren't said to
> > > live any longer than other mice, so likely it is more complex than just
> > > that one molecule. One of the big differences between chimps and humans
> > > though, is the way we age.
> > >
> > I agree that the issue of inceasing human longevity is
> > likely to be more complex than the effects of any one
> > molecule. If I try and suggest just one thing that has
> > had the most profound effect on both the quality and
> > the increasing length of human life it would be the
> > control of bacterial infection.
> >
> That is a good point. Having raised many animals, the thing
> that gets me is: the animals I raise, rarely die from infection.
> I'm sure it does happen, but it doesn't seem to happen often.
> Usually when they get older, they get slower, and a predator
> eats them. Also they die if their "group" disowns them.
>
> Human beings though, at least in our culture, DO die from infection,
> quite a bit. That might be a result of how we live, our diet, the density
> of
> how we live? I don't think in ancient times it was such an issue:
> the fact Oetzi could survive multiple injuries (or the fact the
> Egyptians could do trepanation) seems to indicate people weren't
> so prone to infection, for whatever reason. People in the modern
> age started living to an older age when we learned about hygiene,
> and esp. about sewage systems (less cholera). But by that point we
> were already living rather closely together. How about in hominid times?
> When did women start living long enough to make menopause start
> being worthwhile as an adaptation?
>
>
>



--
Heather Twist
http://eatingoffthefoodgrid.blogspot.com/


[Non-text portions of this message have been removed]

An Analysis of Vertebral "Pachyostosis" In Carentonosaurus Mineaui
(Mosasauroidea, Squamata) from the Cenomanian (Early Late Cretaceous) of
France, with Comments on its Phylogenetic and Functional Significance
Alexandra Houssaye, Vivian De Buffrenil, Jean-Claude Rage & Nathalie Bardet
2008   Journal of Vertebrate Paleontology 28:685-691
doi 10.1671/0272-4634(2008)28[685:AAOVPI]2.0.CO;2

The study of the so-called vertebral "pachyostosis" of Carentonosaurus
mineaui (plesiopedal mosasauroid sensu Bell & Polcyn, Cenomanian (Late
Cretaceous), Charente-Maritime, W-France) has revealed that it actually
corresponds to pachyosteosclerosis resulting from the combination of
cortical hyperplasy with bone compaction, due to an inhibition of
chondroclastic & osteoclastic activities.
This characteristic also occurs in other Cretaceous squamates, eg,
Pachyvaranus crassispondylus & Simoliophis rochebrunei, but it is absent in
extant squamates.
On the contrary, vertebrae of the latter display a very strong porosity due
to intense bone remodelling during growth.
The phylogenetic significance of pachyosteosclerosis in squamates is thus
discussed.
The peculiar structure of the vertebrae of Carentonosaurus may be regarded
as the result of a heterochronic process, more specifically neoteny.
Its association with an adaptation to shallow marine environment is
consistent with the inferred ecology of C.mineaui.
Moreover, the histological features of the periosteal bone of
Carentonosaurus vertebrae provide information about its growth pattern
(asymmetry, rate, cyclicity) which may be compared to the ones of
Pachyvaranus & Simoliophis.

________


"Pachyostosis" in aquatic amniotes: a review
Alexandra HOUSSAYE 2009 DOI 10.1111/j.1749-4877.2009.00146.x
Integrative Zoology 4:325­340
<http://onlinelibrary.wiley.com/doi/10.1111/inz.2009.4.issue-4/issuetoc>

During the course of amniote evolution, numerous taxa secondarily adapted to
an aquatic life.  It appears that many of these taxa primitively display
"pachyostosis", an osseous specialization characterized by an increase in
bone compactness &/or volume.
The term "pachyostosis" is used in morphological & histological descriptions
to describe what in fact corresponds to different patterns.
The aim of this paper is to present the current state of knowledge relative
to this adaptation among aquatic amniotes.

All the taxa that have returned to an aquatic environment are listed.
Moreover,
- their degree of adaptation to the marine environment,
- their life environment &
- the nature of their "pachyostotic" pattern (when present)
are described.
This inventory
- enables the evaluation of the current quality of the data relative to this
specialization&
- provides an indication of the work that remains to be done.
The functional consequences of "pachyostosis" & notably its importance for
buoyancy control in the context of hydrostatic regulation of the body trim,
are discussed, and opposed to the requirement of improved swimming abilities
in the case of a hydrodynamic mode of trim regulation.
Questions are posed about the signification of the polymorphism displayed by
this specialization between different taxa, different specimens of the same
taxon & different bones of the same specimen & the problem of quantification
of pachyostosis is discussed.

_______


Evolution of Sirenian Pachyosteosclerosis, a Model-case for the Study of
Bone Structure in Aquatic Tetrapods
Vivian de Buffrénil, Aurore Canoville, Ruggero D¹Anastasio & Daryl P.
Domning 2010 Journal of Mammalian Evolution 17:101-120
DOI 10.1007/s10914-010-9130-1

Osteosclerosis (inner bone compaction) & pachyostosis (outer hyperplasy of
bone cortices, swollen bones) are typical features of tetrapods secondarily
adapted to life in water.
These peculiarities are spectacularly exemplified by the ribs of extant &
extinct Sirenia.  Sea cows are thus the best model for studying this kind of
bone structural specializations.
In order to document how these features differentiated during sirenian
evolution, the ribs of 15 spp (from the most basal form Pezosiren portelli
up to extant taxa) were studied & compared to those of other mammalian spp
from both & and histological points of view.
- Pachyostosis was the first of these 2 specializations to occur, by the
middle of the Eocene, and is a basal feature of the Sirenia.
However, it subsequently regressed in some taxa that do not exhibit
hyperplasic rib cortices.
- Osteosclerosis was only incipient in P.portelli. Its full development
occurred later, by the end of the Eocene.
These 2 structural specializations of bone are variably pronounced in
extinct & extant sirenians, and rel.independent from each other, although
frequently associated.
They are possibly due to similar heterochronic mechanisms bearing on the
timing of osteoblast activity. These results are discussed with respect to
the functional constraints of locomotion in water.


------ Einde van doorgestuurd bericht

The Many Human Faces and Homo Erectus:
http://pfpuech.newsvine.com/_news/2010/12/31/5742126-the-many-human-face\
s
<http://pfpuech.newsvine.com/_news/2010/12/31/5742126-the-many-human-fac\
es>
Considering that the Denisovans point to consider the eventuality of a
new type of Human concerns the evidence needed to check for the presence
of significant data in the evolution of species of Homo.
That is why paleoanthropologists are always looking at odd fossils,
trying to figure how one can classify all the fossil specimens;
In an attempt to recognise and delimit species in the fossil record
-that is not done today for Denisovans- tooth morphology dated about 450
000 years was studied.
A research concerning Pithecanthropus has already heighten the challenge
of understanding modern human origin. The scanty robust remains from
Java and equally scanty ones from Europe may be interpreted as relics of
an early radiation of Pithecanthropus, or as a result of regional
migrations during the Mindel-Riss interglacial period, when weather was
humid and warm.
http://independent.academia.edu/pfpuech/
<http://independent.academia.edu/pfpuech/>

     * Public Discussion
<http://pfpuech.newsvine.com/_news/2010/12/31/5742126-the-many-human-fac\
es?threadId=3017930#comments>

Briwnys : « Recent advances in paleogenetics, such as the sequencing
of archaic genomes like the Neanderthals and the Denisovans, have raised
the startling possibility that all members of the genus Homo to which
humans belong, from Homo erectus to Homo sapiens sapiens, are, in
reality - Homo erectus. That includes anatomically modern humans. Us.

Until these recent advances in genetics, species were designated by
morphology, which means, by the form and structure of their physical
shape. Now, genomic analysis has discovered that the human gene pool and
genetic structure predates anatomically modern humans. This conclusion
supports human evolution models that incorporate interbreeding between
divergent branches of the genus Homo although the data cannot establish
when the interbreeding may have occurred. It may be that the modern
human physical type arose first and interbreeding was a consequence of
the rapid expansion of the population. This is most likely since the
relative isolation of African populations from Eurasian populations is
reflected in the lack of the archaic admixture of genes in most of the
population remaining in Africa that is otherwise present throughout the
rest of the world. Alternatively, the modern human physical appearance
may, itself, be the by-product of interbreeding. In either case, while
the majority of the anatomically modern human genome may descend from a
single population in Africa, the evolutionary lineage leading to modern
humans did not develop in reproductive isolation from other, more
archaic, human subpopulations and, thus, anatomically modern humans
cannot be considered a distinct biological species compared to those
so-called archaic species once thought to be extinct.

Between 1 and 4% of the genetic material of populations outside Africa
matches the Neanderthal genome. In today's population of five billion,
that is the equivalent of a genetic heritage from at least five million
individuals. Far from being extinct, Neanderthal lives on in modern
form. And that is not the only archaic source of our modern genetic
heritage. As much as 10% of our ancestral genes is not traceable to
anatomically modern humans from Africa. Other recent discoveries point
to at least two and possibly more archaic forms that arose in Eurasia,
not the least of which may be Homo erectus itself. The polymorphic
variations that were once thought to identify different species are now
known to be the result of interaction between genetically determined
characteristics and adaptations to specific environmental conditions. In
essence, what in the past appeared to be the different species
identified by conventional anthropology are actually only variations
that identify progressive stages of transformation and adaptation within
the evolutionary history of a single species. »





[Non-text portions of this message have been removed]

V de Buffrénil 2010 Journal of Mammalian Evolution 17:101-120
"Evolution of Sirenian Pachyosteosclerosis, a Model-case for the Study of
Bone Structure in Aquatic Tetrapods"
... All authors consider that osteosclerosis &/or pachyostosis have a
hydrostatic role, and contribute, as ballast, to regulating buoyancy & trim
in tetrapods incipiently adapting to life in water, or specialized in
feeding on fixed or slow-moving prey in shallow waters ...




[Non-text portions of this message have been removed]

Very interesting Marc. Before I don't think H erectus would be much aquatic (at
least compare to H sapiens), but seems you got some evidences.

- Evidence = POS, coastal/saline paleo-environemnt,... any more?

- What do other PAs says about their heavy bones? Any hypotheses from them?  Or
more importantly, do they even discribe H erectus as "pachyosteosclerotic"?

- Some marine mammals (e.g. cetaceans) have *secondarily* reduced bone density,
i.e. they had heavy bones before, but evolved lighter bones for faster movement
together with: (a) lung compression during deep dive, (b) bigger and fewer red
blood cells and (c) higher haemoglobin concentration to store more oxygen in
blood.

Now H erectus have heavier-than-normal bones, and H sapiens have
lighter-than-normal bones, can we say that we also have *secondarily* reduced
bone density like the cetaceans? Not to mention H sapiens also fulfill the above
(a), (b) and (c) when compared to chimps.

Happy New Year!

Chak



--- In AAT@yahoogroups.com, Marc Verhaegen <m_verhaegen@...> wrote:
>
> 1)    H.erectus is pachyosteosclerotic.
> 2)    All pachyosteosclerotic animals are aquatic.
> ergo: H.erectus is aquatic.
>
> _____
>
> Some commments:
>
> 1)
> Pachy-osteo-sclerosis (POS) means that the bones are
> - denser than expected (high calcium content = osteo-sclerosis),
> - thicker (compared to joint size = pachy-ostosis) &
> - with narrower bone marrow canal (medullary stenosis).
> These 3 features make the bone heavier.
> Heavier bones are not stronger, to the contrary, eg, seacows (heaviest bones
> known) have very brittle bones.
> For terrestrial mammals there's an optimum between calcium & collagen
> content & medulla size etc that makes the bones strong & supple enough & not
> too brittle.
> Some erectus bones have more POS than others.  The skull (esp.occiput =
> posterior part), femora, humeri, pelvis (except perhaps the pubic part =
> anterior part) etc are 2 or 3 times as heavy as is the case in comparable
> terrestrial animals, eg, in most erectus the skull is twice as thick, the
> diploe (medulla) is thinner, and the bone is denser.
> Of all primates, only H.erectus & relatives ("archaic" spp) are known to
> have POS.  Neandertals are intermediate in this respect between He & Hs.
> H.sapiens doesn't have POS, or only to a very small degree.
>
> 2)
> All tetrapods with POS are aquatic (google pachyosteosclerosis).
> The reverse is not true: many aquatic mammals (esp.Cetacea & fast swimmers)
> have lightly built skeletons, lighter than terrestrial mammals (support is
> less necessary in the water than outside).
> But slow aquatics in shallow waters, esp.sea water, that dive for sessile
> foods, typically have POS.  POS is most commonly seen in incipient aquatics,
> often semi-aquatic, but the fully aquatic seacows have extreme POS.  Which
> bones show most POS depends on the life-& swimming style, eg, bottom-walkers
> often have dense leg bones (legs down, sea-otter, hippo), pronograde divers
> often have dense ribs (seacow), dense skulls are seen in head-down divers
> (seacow, walrus).
> That the ventral skeleton (paranasal region, pubis) in erectus is less dense
> than the dorsal part might suggest they back-floated parttime.
> Committed aquatics lose POS.  AFAIK the only exception are seacows (very
> slow), presumably to compensate for their large lungs (shallow-diving
> mammals typically have very large lungs, but deep diving spp have rel.small
> lungs).
> POS not necessarily means fulltime aquaticness, but at least requires a
> strong dependence on aquatic life, typically slow diving in salt water for
> plants or slow prey that live on the bottom.
> POS exclude fast running, of course: typical cursorials have very lightly
> built skeletons (Arabic horse, greyhound, Kenyan long-distance runners):
> endurance running hypotheses on erectus are nonsense.
>
> AFAWK all erectus fossils have been found next to salt/brackish water (eg,
> google econiche homo, see table), at least from Mojokerto 1.8 Ma to Eritrea
> c 125 ka (eg, Joordens below), with the exception of KNM-OL-45500
> (discussion below).  They have been found on islands that only could be
> reached oversea.  All fossil evidence confirms that erectus is no exception
> among pachyostotic animals.
>
> In a Hs adult, the skeleton comprises c 14 % of the total body Wt (c 1/7).
> Presumably, erectus had thick SC fat layers (eg, 1/5 of body Wt instead of c
> 1/7, with specific gravity of fat tissue = c 0.92) & rel.large lungs (say c
> 3.5 instead of 2.5 litres in normally filled lungs).
>
> Some very rough estimations & calculations:
> Specific gravities (densities):
> - SC fat tissue   0.92  (fat alone c 0.9)
> - lung tissue     0.55  (air c 0.0015)
> - compact bone    1.85  (but denser in He)
> - cancellous bone 1.08
> dm3 in Hs of 70 kg:
> - fat tissue         10    (male vs female)
> - mean lung volume    2.5  (partly inflated)
> - compact bone        7    (most of the bone)
> - cancellous bone     3    (medulla)
> dm3 in He:
> - fat tissue         14   (cf aquatic)
> - mean lung volume    3.5 (shallow aquatic)
> - compact bone       10   (often twice as thick)
> - cancellous bone     2.5
> Difference in kg in He compared to Hs of 70 kg:
> - SC fat     - 0.40
> - lung       - 0.45
> - compact bone     + 4 (thicker & denser bone)
> - cancellous bone  - 0.05
> Sum 3.4 kg, ie, c 2.38 % heavier (vs Hs 70 kg)
> (large uncertainties = lung, bone & fat tissues).
>
> I don't know whether freshwater mammals are generally somewhat heavier or
> lighter (specific gravity) than terrestrial mammals, eg, hippos
> (bottom-walkers, AFAIK heavy skeletons)? tapirs?
> Sea water is c 2.4 % heavier than fresh water (but can be much denser in
> shallow tropical marine or saline "enclaves" (evaporation) where possibly
> some He might have lived preferably).
> The high bone density of He suggests a marine/saline milieu, but if their
> lungs or SC fat were much larger (well possible IMO), a brackish milieu or a
> combination of fresh & salt waters could also have been possible (see
> Joordens paper below).
>
> POS can evolve & disappear in rel.short time spans (a few 100s or 1000s of
> years? = secular trend):
> - The small skull OL-45500 (Olorgesailie, Kenya, c 1 Ma?, ass.x Acheulian
> handaxes) had He-like features (eg, well-developed post-toral sulcus +
> shelf-like morphology, wide convex inter-orbital region, short temporal
> squama + flat superior border, mid-line keeling of frontal bone), but thin
> cranial bones overall.  R.Potts cs.2004 Sci.305:75-78: "Fossils found by
> sieving of the sandy silt adhering to the frontal bone include amphibian
> bones and a single tooth of the rodent Otomys sp., which inhabits thick
> grasses in and around modern East African swamps, lakes and rivers..." =
> freshwater dweller?
> - OTOH some Hs fossils (Kow Swamp) had archaic features & heavy skeletons
> when they lived near lakes where they consumed mussels. When the shellfish
> there became extinct c 19 ka, the lake was abandoned.
>
> --marc
>
> _____
>
> Relevance of aquatic environments for hominins:
> A case study from Trinil (Java, Indonesia)
> JCA Joordens cs.2009 JHE 57:656-671 doi 10.1016/j.jhevol.2009.06.003
>     ... we provide ecological context for the current debate on modernity
> (or not) of aquatic resource exploitation by hominins. We use the H.erectus
> site of Trinil as a case study to investigate how research questions on
> possible dietary relevance of aquatic environments can be addressed. Faunal
> & geochemical analysis of aquatic fossils from Trinil Hauptknochenschicht
> (HK) fauna demonstrate that Trinil at 1.5 Ma contained near-coastal rivers,
> lakes, swamp forests, lagoons & marshes with minor marine influence,
> laterally grading into grasslands.  Trinil HK environments yielded at least
> 11 edible mollusc spp & 4 edible fish spp that could be procured with no or
> minimal technology.  We demonstrate that, from an ecological point of view,
> the default assumption should be that omnivorous hominins in coastal
> habitats with catchable aquatic fauna could have consumed aquatic resources.
> The hypothesis of aquatic exploitation can be tested with taphonomic
> analysis of aquatic fossils associated with hominin fossils.  We show that
> midden-like characteristics of large bivalve shell assemblages containing
> Pseudodon & Elongaria from Trinil HK indicate deliberate collection by a
> selective agent, possibly hominin.
>
> ______
>
> Skeleton weight allometry in aquatic and terrestrial vertebrates
> WW Reynolds 1977 Hydrobiologia 56:35-37 doi 10.1007/BF00023283
>     The relation of skeleton Wt to body Wt with increasing size is compared
> for aquatic & terrestrial vertebrates.  Due to the buoyancy of water, the
> skeleton weights of aquatic vertebrates (fishes & whales) vary in nearly
> direct proportion (exponent 1.0) to body Wt ; the skeletons of terrestrial
> vertebrates occupy an increasingly greater proportion of total body Wt as
> size increases (exponent >1) due to the necessity of supporting their Wt on
> land.
>
> _____
>
> Density of fresh and embalmed human compact and cancellous bone
> PL Blanton & NL Biggs 1968 AJPA 29:39?4 doi?0.1002/ajpa.1330290113
>     This investigation was undertaken to determine the densities of
> - fresh human compact & cancellous bone (marrow constituents intact),
> - compact & cancellous bone taken from embalmed cadavers.
> The density of 107 bone specimens was determined on the basis of the Wt &
> volume of each specimen. Mean density results were:
> - fresh compact bone     1.85,
> - fresh cancellous bone  1.08,
> - embalmed compact bone    1.85,
> - embalmed cancellous bone 1.09.
> Embalming did not appear to have altered the density of either compact or
> cancellous bone.
> It was observed also that the densities of several bone specimens taken from
> the same area of one bone varied greatly.
>

--- In AAT@yahoogroups.com, "Rob Dudman" <ausell@...> wrote:
>
>
> ----- Original Message -----
> From: dons3148
> To: AAT@yahoogroups.com
> Sent: Wednesday, December 29, 2010 12:59 AM
> Subject: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> Hypotheses)





Hello Rob...



> Hello Bill........
> >
> > > > > Yes, but would a gorilla-size mouth/jaw have been
> > > > > an impediment that was so severe that it led to a
> > > > > reproductive disadvantage?
> > > >
> > > > Their rivals would have had the smaller jaws; and
> > > > smaller jaws probably came with a smaller mouth
> > > > opening, perhaps the advantage when it came to
> > > > extracting the contents of oysters. So perhaps the
> > > > reproductive advantage lay with those with the gene
> > > > mutation?
> > > >
> > > I think that 'perhaps' is about right......when extracting
> > > the edibles from oysters (etc.,) the shells are opened and
> > > the meat is detached from the shell before it's simply
> > > tipped into the mouth. This opening and detaching is
> > > best done with a tool of some sort, but if it came to
> > > using the teeth, then wouldn't those without the mutation
> > > have an advantage?
> >
> > Probably in the end neither had the advantage... or
> > any choice; it was perhaps more a matter of either
> > adapting to the gene mutation or going extinct (!)
> >
> D'you mean genetic drift?



Yes, as genetic drift and natural selection are the two
forces that drive evolution, genetic drift being random
change in gene frequency resulting in mutations which,
regardless of their adaptive value, become fixed. (it
is said to be more effective in small populations – an
humans were few in number for millions of years). It
could be described as the- adapt or die option

It is not the only adapt or die option (!) as
environmental changes can also result in the adapt
or die option, for example for predators that for
generations have specialised in hunting particular
prey species, or species like pandas that eat a
limited choice of foods.

Trees, forests faced with a permanent decrease or
increase in temperature or reduced rainfall are also
faced with the adapt or die option(!)

Adapt or die(!) could have been the option facing the
LCA some five million years ago, as the Chad sea and
surrounding forests were decimated by the MSC. The
option that led to the ancestors of the chimpanzee
and Man going their separate ways...





> > > Wouldn't the deliberately deceptive behaviour that has
> > > been observed in other great apes be evidence of
> > > imagination (at the very least 'theory of mind')?
> > >
> > > An interesting read....
> > >
> > > Neocortex size predicts deception rate in primates
> > > By Richard W. Byrne and Nadia Corp
> > >
> > > http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1691785/pdf/15306289.pdf
> > > ______________
> >
> > Thanks for the link...
> >
> > As to your point, I am not so certain that deceptive
> > behavior is anything other than behavior as numerous
> > species can use and do use deceptive behavior from
> > birds, to animals, to fish to insects that use mimicry
> > and deceptive behavior pretty effectively.
> >
> > As apparently can plants and even a robot, as
> > robots can now be programed to use `deceptive
> > behavior' to evade detection (!)
> >
> Do you mean predatory plants like the pitcher-plant?
> I would classify this as 'ambush predation'.



Yes and no, while carnivore plants do use deception,
the plant I had in mind however was not a carnivore
one feeding on insects but a common orchid that tricks
wasps with a flower that deceives male wasps into
copulating with the flower as if it was a female
wasp as a way of further spreading its pollen
(guess male wasps are easily tricked (!).

However, some plant species have proved a little too
successful at the art of deception that rye and oats
once weeds in wheat and barley crops, got a little
too good at avoiding being weeded by deceiving early
crop growers into thinking they might be wheat that
they are now grown and harvested own right as a food
crop (having effectively cultivated themselves (!

Vavilovian mimicry in some plants though cannot
explain the weird deceptive behaviour of carrion
flowers, for example the one that grows in S.Africa
that is blood red and is foul smelling (said to
smell like rotting meat (!)






> > Humans can tell a straight faced lie for individual gain,
> > insects can use mimicry deceptive behavior to evade
> > predation or to gain reproductive advantage; both I
> > would say are using deceptive behavior for gain.
> >
> > Perhaps it is anticipation that is involved when someone
> > lies, a primate deceives, but I cannot see any role for
> > imagination.
> >
> Yes.....I think of animal deception as camouflage of one
> sort or another. But what we're dealing with in humans and
> apparently other great apes, is deliberate deception and
> at the very least this entails the recognition of the existence
> another subjective point of view that can be deceived.....
> that can construct a reality that fails to accurately inform
> about the actual world
>
> Given that 'a subjective point of view' is by definition
> not something that can be objectively confirmed, then
> it seems to me that the recognition of a subjective point
> of view other than your own has to be an act of the
> imagination.



Being able to anticipate the consequences of their
deceptive behaviour, does take the art of deception
to a higher level (for example lions anticipating
the reaction of their surprised prey). Guess for
apes and humans', deceptive behaviour was and is
a means for middle ranking members of a troupe
to get further up the food chain… get nearer
the `top table'.

Would you say deceptive and manipulative
behaviour are the same thing?




> As for robots....if one can deceive me on the basis of
> what it knows about the way I think, my predispositions
> and my fears and desires.....on its recognition of me as
> a person, then I'll return the compliment and accept that
> robot as a person with a prosthetic body.   :-)


:-)


Just think that robotic lawn mower happily mowing
your lawn might give a year or two of service before
suddenly cornering you and finding another use for
its razor sharp blades...

Researchers Give Robots the Capability for
Deceptive Behavior

http://www.sciencedaily.com/releases/2010/09/100909114113.htm





> > (imagination is the plaything of the mind)
> >
> :-)
>



> > > The one thing that comes to mind that would over-ride
> > > such (xenophobic) impulses is a catastrophic collapse
> > > in the population...such as you'd get with a malarial
> > > epidemic? Although this still wouldn't explain a
> > > reproductive advantage for the survivors with weaker-
> > > jaws .
> >
> > It would as possibly in such a situation random
> > chance (genetic drift) would more likely determine
> > the outcome than the long drawn out processes of
> > natural selection an environmental adaptation.
> >
> > Essentially the survivors would have had one choice...
> > adapt to having a weaker jaw or die(go extinct).
> >
> Could be, but I have a very negative intuitive reaction
> to anything that says 'you may reason to this point, but
> no further'. (I have the same reaction to the Big Bang
> Theory and reject it for the same reason......the Pope
> knew what he was doing when he gave a medal to
> Stephen Hawking for the way his work could be seen
> to reconcile science and religion.)



Science and Stephen Hawking have gone far beyond
the limitations of the old `Big Bang theory', he
himself has a new book out on sciences current
understanding of the Multiverse.(an amazing an
fascinating concept - worlds without end in an
infinity of universes (!)



> I'm happier with the thought that as yet I haven't been
> able to think of a way to cogently place these two
> mutations within the context of natural selection.....at
> least this leaves possibilities to explore - if I see either
> of the mutations as the result of arbitrary drift, then
> that's an end to it as there's nowhere left to go.



I take a slightly different approach and regard
`genetic drift'(random chance) as part and parcel
of evolution as is `natural selection', as it is
just as fascinating to see how life adapts
to both...

After all, life itself may owe its existence
to random chance (!)





> > > > Agree, H.erectus was in the wrong places to be a
> > > > littoral dweller. H.erectus at least outside of north
> > > > Africa was a scavenger/hunter and perhaps the
> > > > prey of predators.
> > > >
> > > My position here is that I can't on the one hand use a
> > > DHA-rich littoral diet to explain the encephalisation
> > > that we see in H.e/e and at the same time argue that
> > > they stopped encephalising while still exploiting a
> > > littoral diet. The most parsimonious solution to the
> > > conundrum of the H.e/e stasis in brain enlargement
> > > is to assume that they inherited their large brains
> > > from predecessors who did exploit the littoral, then
> > > they maintained this enlarged size through an inland
> > > diet that included meat (brains, bone-marrow etc.,)
> > > But of course those who doubt that our ancestors grew
> > > their big brains at the littoral are stuck with the same
> > > conundrum.....they have to argue that an inland diet
> > > was sufficient for the initial encephalisation and that a
> > > continuation of this same diet was then insufficient for
> > > encephalisation.
> >
> > Agree it is more the parsimonious explanation, as it
> > is highly unlikely that the H.erectus (or its immediate
> > predecessor, if there was one) inherited a larger brain
> > from a littoral predecessor, than for H.erectus to have
> > exploited a littoral niche.
> >
> > Though it should be said that there are two other
> > factors that impose a physical limits on further
> > encephalisation in our species, namely our bipedal
> > gait and the ability to give birth relatively safely,
> > however I do not think either of these would have
> > applied to the much smaller brained H.erectus.
> >
> It does though, raise an issue that must be dealt with
> if the 'encephalisation/DHA/littoral' connection is to
> hold together......after a million years or so H.e/e
> brains did enlarge to a degree that was at least equal
> to the encephalisation that produced H.e/e brains in
> the first place. What happened to cause this change
> after a stasis of more than a million years?



The key here is perhaps to isolate the stasis in
the size of the He brain as such, from the increase
in the human brain, that is to say while there was
little or no increase in the size of the He brain
there was an increase in the size of the human brain
(reaching its current size some 200,000 years ago)
that began some 800,000 years ago...

There also remains the possibility that H.erectus
was not a direct ancestor of Modern Man.


Human Evolution (chart)
http://www.handprint.com/LS/ANC/evol.html

__________________________________




New finds in the Middle East and of the possibility
there was a third human species, have also muddied
recent human origins somewhat.

December 2010
Fossilised tooth changes human history?
http://english.pravda.ru/science/tech/28-12-2010/116375-fossilised_tooth-0/


2010 Nature 468:1012 doi 10.1038/4681012a
Fossil genome reveals ancestral link
A distant cousin raises questions about human origins.
http://www.nature.com/news/author/Ewen+Callaway/index.html



_____________________________





> > > As for H.e/e I think only the survivors of hyena attacks
> > > could have had a reproductive impact sufficient to make
> > > thicker skulls a species characteristic and I have to
> > > doubt that there would have been enough of these to
> > > make such a difference......particularly if the usual victims
> > > were the young, the old and the infirm.
> >
> > Good points, in fact very good points, so perhaps
> > the description in Noel T. Boaz and Russell L. Ciochon
> > book "Dragon Bone Hill" (2004) of the H.erectus is the
> > one closest to the truth:
> >
> > [quote]
> > "Armed with a shaky hold on fire and some sharp
> > rocks, Homo erectus incredibly survived for over
> > 1.5 million years, much longer than our own species
> > Homo sapiens has been on Earth. Tell-tale marks on
> > fossil bones show that the lives of these early
> > humans were brutal, ruled by hunger and who could
> > strike the hardest blow, yet there are fleeting
> > glimpses of human compassion as well. The small
> > brain of Homo erectus and its strangely unchanging
> > culture indicate that the species could not talk.
> > Part of that primitive culture included ritualized
> > aggression, to which the extremely thick skulls
> > of Homo erectus bear mute witness."
> > ______________________
> >
> > So maybe the unfortunate H.erectus did finally share
> > something with its hyena predator - a hard, brutal
> > life scavenging on the kills of predators as they
> > followed the seasonal movements of herd animals
> > across wilds of Asia.
> >
> Why d'you suppose that modern humans have a
> vomit reflex to the smell of rancid meat? Some four
> years ago I had a long and interesting conversation
> with Pauline about this and I've found nothing since
> then to cause me to change my opinion......
>
> (Pauline....
> >
> > Unless some strong evidence nails H. e/e as a hunter, the
> > conservative position is that he got his meat from (some
> > sort of) scavenging.
> >
> Rob.....
> Here I do disagree. The vomit-reflex is evidence not
> that H.e/e was a hunter, but that scavenging resulted
> in a selection process which left us with exactly the
> opposite reaction to rancid meat that is the hallmark
> of all scavengers. Whether H.e/e hunted meat or not
> is a different issue - I think that because they could,
> then they probably did, but we got that reflex from
> somewhere and given the deadly nature of rancid
> meat, it seems to me to be one of the most straight-
> forward examples of adaptation through natural
> selection that I've come across. It's the total absence
> of any reference to it in the literature that puzzles me.
>
> http://tech.dir.groups.yahoo.com/group/AAT/message/36495?o=0&var=1
> _________)
>
> What's your view of this?



Intriguing question...

Perhaps it is the gut (the GI tract) that makes the
difference; the difference being between predators
and omnivores - not so much hunters and scavengers.

Meat fresh and rotten meat spends less time being
digested in the gut of predator and meat scavengers
(less time for bacteria to multiply in the tougher
gut of a predator?) than it would in the gut of an
omnivore like Man. So whilst early Man may once have
been able to digest raw fresh meant and relatively
fresh meat, the reflex may have acted as a warning
for meat that was a little too risky for our slower
digestive systems to handle.

Perhaps its 24 to 72 hrs for the human gut, and
say 6 to 8 hrs for a predator like a lion?
(meat digestion)

Chimpanzees kill, chimpanzees eat meat, so it
is highly likely away from the savanna and the
tropics early human ancestors also hunted and
ate raw meat on a regular basis.

One other factor for the vomit reflex, possibly
could be 'civilised' human reactions to what is
uncooked meat.



> As for the suggestion that life was short, hard and
> brutal for H.e/e.........I don't doubt it at all.
>
>  >
> > It's almost certainly the case that endogenous Neu5Gc
> > had allowed repeated infections of P.reich from before
> > the H/P LCA until the CMAH mutation. In modern
> > humans exogenous Neu5Gc is used by other pathogens,
> > but AFAIK the P.reich parasite is the only one we can
> > be reasonably certain about prior to c. 2.5 Mya.
> >
> > One way of looking at it Rob, would be to say if it was
> > not for the P.reich parasite an the loss of Neu5Gc...
> > we might have been just another extinct ape species in
> > the forest.
> >
> Or turned to rock alongside H.georg.

:-)



> > However as the year 2010 ends our 'friend' the
> > ubiquitous mosquito is still adapting, still intent on
> > conquering new territory...
> >
> > A Malaria Mosquito Is Becoming Two Species in a Hurry
> >
> >
http://www.livescience.com/animals/malaria-mosquitos-species-splitting-101021.ht\
ml
> >
> > [quote]
> > A strain of African mosquito that carries the
> > deadly malaria parasite is splitting into two
> > species faster than expected, according to a
> > new study. The finding helps explain why the
> > insect can survive in environments spanning
> > from humid rainforests to arid savannas.
> >
> > The mosquito, Anopheles gambiae, is one of the
> > top carriers of malaria parasites, which infect
> > 250 million people a year, according to the
> > World Health Organization.
> >
> > -------------------------
> >
> We've got floods here in Queensland and I suspect
> that the mozzies are going to love it!
> >
> > With best wishes for 2011
> >
> And to you.
>
> Rob.



The Queensland floods have been one of the lead news
item on the news channels for several days (certainly
is a massive amount of water). This morning they were
mentioning crocs and snakes may be an added risk to
house owners in the flooded areas...  Are you
outside the areas affected?


--Bill















> --- In AAT@yahoogroups.com, "Rob Dudman" <ausell@> wrote:
> >
> >
> > ----- Original Message -----
> > From: dons3148
> > To: AAT@yahoogroups.com
> > Sent: Wednesday, December 22, 2010 7:50 AM
> > Subject: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> > Hypotheses)
> >
>
> Hello Rob...
>
> > Hello Bill........
> > >
> > > > > Then essentially a `tool using' habilis was no different
> > > > > from a `tool using' gorilla using a stick to test the depth
> > > > > of the water it was walking through or an otter using a
> > > > > stone to crack open a shell...
> > > >
> > > > IMO, absolutely no difference at all.
> > >
> > > Yes, they are essentially using 'tools' for the same job -
> > > namely to get at food.
> > >
> > That's an interesting distinction.....it had occurred to me that
> > what is different about our use of tools is that we use them
> > for purposes other than obtaining food, but then I had to
> > pause with your example of the gorilla probing for depth
> > before venturing further into water. No doubt the ultimate
> > objective is to get at food, but the immediate objective is
> > (I presume) to avoid getting dunked. There's also the
> > example of chimps using branches to intimidate...although
> > AFAIK, these branches aren't modified to make them
> > more effective as weapons.
>
> Birds dropping shells on rocks, otters, chimpanzees
> shaping sticks to get at honey and a gorilla using a
> stick as it walks through waist deep water to reach
> a tasty morsel all appear to be in pursuit of same
> objective, food ,which is probably the origins too
> `tool usage' among humans. It may offer too an
> explanation as to why the H.erectus repeatedly made
> the same `stone tools' for hundreds thousands of
> years (roughly 1.4 million years) with little
> or no change.
>
> Human tools;, tools that were used for purposes other
> than getting at the food probably made an appearance
> about a quarter a million years ago as flint
> tools, probably the first genuine multi-purpose
> tool a stone tool with a razor sharp edge(!)
>
> > > > ............................What else can they imagine
> > > > as they sit for hours chewing their stalks? Probably not
> > > > much, but I can't think of a way that this could be shown
> > > > scientifically.
> > >
> > > Perhaps only when `scientist' can devise a scanning
> > > method that literally `reads' thoughts, will that
> > > question ever come close to being answered.
> > >
> > I've got the rather unhappy idea that if this sort of scanning
> > is ever invented (which I doubt will happen), it'll be so far
> > into the future that we'll be the only extant primate (having
> > caused the extinction of all the others by then).
>
> :-)
>
> Hopefully it will be very far into the future ...
> or when I am old enough not too care one way or
> the other.
>
> Then again it might be just around the corner (!)
>
> As some neuroimaging experts believe they will soon
> be able to tell what a person is thinking by the
> areas of the brain activated when a person
> looks at something...
>
> > > Gorillas are not using `imagination' in the human sense
> > > but probably something that is on the face of it similar
> > > but is entirely different, namely `anticipation' though
> > > the ability `to anticipate' is also believed by some to
> > > be uniquely human as it is said to involve the frontal
> > > lobes of the brain.
> > >
> > > However, it seems to me that by using a stick to test
> > > the depth of the water its walking through the gorilla
> > > can be said to be anticipating what would happen if
> > > it got out of its depth in water...
> > >
> > > I would add - that imagination - the ability to form
> > > images, concepts and sensations in the mind is beyond
> > > doubt uniquely human. (probably the point at which
> > > mankind's early ancestors could imagine - was when
> > > they became human!)
> > >
> > Wouldn't the deliberately deceptive behaviour that has
> > been observed in other great apes be evidence of
> > imagination (at the very least 'theory of mind')?
> >
> > An interesting read....
> >
> > Neocortex size predicts deception rate in primates
> > By Richard W. Byrne and Nadia Corp
> >
> > http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1691785/pdf/15306289.pdf
> > ______________
>
> Thanks for the link...
>
> As to your point, I am not so certain that deceptive
> behavior is anything other than behavior as numerous
> species can use and do use deceptive behavior from
> birds, to animals, to fish to insects that use
> mimicry and deceptive behavior pretty
> effectively...
>
> As apparently can plants and even a robot, as
> robots can now be programed to use `deceptive
> behavior' to evade detection (!)
>
> Humans can tell a straight faced lie for
> individual gain, insects can use mimicry
> deceptive behavior to evade predation or to
> the gain reproductive advantage; both I would
> say are using deceptive behavior for gain.
>
> Perhaps it is anticipation that is involved when
> someone lies, a primate deceives, but I cannot
> see any role for imagination.
>
> (imagination is the plaything
> of the mind)
>
> > > > Yes, but would a gorilla-size mouth/jaw have been
> > > > an impediment that was so severe that it led to a
> > > > reproductive disadvantage?
> > >
> > > Their rivals would have had the smaller jaws; and
> > > smaller jaws probably came with a smaller mouth
> > > opening, perhaps the advantage when it came to
> > > extracting the contents of oysters. So perhaps the
> > > reproductive advantage lay with those with the gene
> > > mutation?
> > >
> > I think that 'perhaps' is about right......when extracting
> > the edibles from oysters (etc.,) the shells are opened and
> > the meat is detached from the shell before it's simply
> > tipped into the mouth. This opening and detaching is
> > best done with a tool of some sort, but if it came to
> > using the teeth, then wouldn't those without the mutation
> > have an advantage?
>
> Probably in the end neither had the advantage... or
> any choice; it was perhaps more a matter of either
> adapting to the gene mutation or going extinct (!)
>
> > > Arguably though natural selection and reproductive
> > > strategies are themselves weak explanations as neither
> > > can explain satisfactorily explain why humans ended
> > > up with small jaws. They also fail as explanations, to
> > > explain how those that looked physically different
> > > as a result of a gene mutation, were accepted? (even
> > > birds are known to attack a member of their own kind
> > > if they look different, or are weak)
> > >
> > You make a good point.....humans are well-known to
> > attack their own kind because of such differences
> > and indeed this xenophobia is probably a characteristic
> > shared by most (if not all) gregarious species.
>
> At species level, I have often wondered if this is
> some kind of weird instinctive behavior aimed at
> preserving and reinforcing the identity of a species...
> but that seems to create problems for speciation as
> such (as most `new' species would have to remain
> isolated until the old and new species could
> no longer breed).
>
> Humans unfortunately through the use of language and
> the exchange of ideas seem to have taken xenophobia
> to a `new' extreme level, to the point where they no
> longer see other humans as just being different but
> not even human(!)
>
> > (We may well have an explanation here for the way people
> > in these discussion groups attack each other because
> > of differing ideas......it may also explain why they
> > can't stop.)
>
> Think you are right... I tend to regard anyone who
> resorts to personal attacks or insults as simply
> having nothing to add to the discussion...
>
> > The one thing that comes to mind that would over-ride
> > such impulses is a catastrophic collapse in the population...
> > such as you'd get with a malarial epidemic? Although this
> > still wouldn't explain a reproductive advantage for the
> > survivors with weaker-jaws .
>
> It would as possibly in such a situation random
> chance (genetic drift) would more likely determine
> the outcome than the long drawn out processes of
> natural selection an environmental adaptation.
>
> Essentially the survivors would have had one
> choice... adapt to having a weaker jaw or
> die(go extinct).
>
> > > > I would expect that erectus and ergaster would share
> > > > the characteristics that they inherited from their littoral
> > > > predecessors and differences in attritbutes would reflect
> > > > the different post-littoral environments that each had to
> > > > deal with.
> > > >
> > > > This suggests to me that H.e/e left the littoral with
> > > > the thinner skulls of ergaster, while the Asian erectines
> > > > developed the heavier bones for reasons that are far
> > > > from obvious.
> > > >
> > > > > I may be wrong but I think Marc attributes a thick
> > > > > skull in H.e to a diving adaptation (but modern
> > > > > humans today seem to dive pretty successful with
> > > > > their thin boned domed skulls).
> > > >
> > > > H.erectus was not exploiting a littoral diet.
> > >
> > > Agree, H.erectus was in the wrong places to be a
> > > littoral dweller. H.erectus at least outside of north
> > > Africa was a scavenger/hunter and perhaps the
> > > prey of predators.
> > >
> > My position here is that I can't on the one hand use a
> > DHA-rich littoral diet to explain the encephalisation
> > that we see in H.e/e and at the same time argue that
> > they stopped encephalising while still exploiting a
> > littoral diet. The most parsimonious solution to the
> > conundrum of the H.e/e stasis in brain enlargement
> > is to assume that they inherited their their large brains
> > from predecessors who did exploit the littoral, then
> > they maintained this enlarged size through an inland
> > diet that included meat (brains, bone-marrow etc.,)
> > But of course those who doubt that our ancestors grew
> > their big brains at the littoral are stuck with the same
> > conundrum.....they have to argue that an inland diet
> > was sufficient for the initial encephalisation and that a
> > continuation of this same diet was then insufficient for
> > encephalisation.
>
> Agree it is more the parsimonious explanation, as it
> is highly unlikely that the H.erectus (or its immediate
> predecessor, if there was one) inherited a larger brain
> from a littoral predecessor, than for H.erectus to have
> exploited a littoral niche.
>
> Though it should be said that there are two other
> factors that impose a physical limits on further
> encephalisation in our species, namely our bipedal
> gait and the ability to give birth relatively
> safely, however I do not think either of these
> would have applied to the much smaller
> brained H.erectus.
>
> > > > > One answer could be if H.e were prey to predators as
> > > > > some have claimed then a thick skull may have increased
> > > > > their chances of surviving an attack (hyenas of old in
> > > > > China - are said to have specialised in cracking open
> > > > > the skulls of their H.e prey).
> > > > >
> > > > > The Skull-Crushing Hyenas of Dragon Bone Hill
> > > > >
> > > > >
http://www.wired.com/wiredscience/2010/06/repost-the-skull-crushing-hyenas-of-dr\
agon-bone-hill/
> > > > > ____________________________________
> > > >
> > > > Predation stresses would be a clear selection mechanism,
> > > > but I don't think that skulls in a hyena den is the evidence
> > > > in this case.....cracking open skulls to get at brains would
> > > > have been done port-mortem and unlikely to have a great
> > > > deal of reproductive impact. For this we'd have to assume
> > > > that the survival rate from these hyena predations would
> > > > be greater among those with the thicker bones.....but here
> > > > we're talking about an extremely large and powerful
> > > > hyena and I doubt that even the thickest of post-cranial
> > > > erectine bones would have been much of a defence. In
> > > > fact I'd have thought that survival rates would be highest
> > > > among those with lighter bones as the only way to
> > > > survive such an encounter would be not get caught.
> > >
> > > Or perhaps if initially a thicker skull conferred
> > > some survival advantage for the H.erectus...
> > >
> > > They then lost out when the endless `arms race'
> > > between predator and prey have moved up a notch,
> > > with the hyenas not only adapting their predation skills
> > > but adapting to crack open the tougher skulls of their
> > > prey to get at the H.erectus brain (a source of fat?).
> > >
> > Pachycrocuta brevirostris......they were active in Asia
> > as far back as c. 3 Mya and for a lot of this time they
> > would not have coincided with H.e/e....would the arrival
> > of a new and fairly sparsely distributed potential prey
> > have had an impact on their morphology? H.e/e was
> > larger than their usual prey, but as hyenas we can
> > reasonably assume that they were pack predators who
> > overwhelmed their prey and a thicker skull would have
> > made little difference at the kill.
> >
> > As for H.e/e I think only the survivors of hyena attacks
> > could have had a reproductive impact sufficient to make
> > thicker skulls a species characteristic and I have to
> > doubt that there would have been enough of these to
> > make such a difference......particularly if the usual victims
> > were the young, the old and the infirm.
>
> Good points, in fact very good points, so perhaps
> the description in Noel T. Boaz and Russell L. Ciochon
> book "Dragon Bone Hill" (2004) of the H.erectus is the
> one closest to the truth:
>
> [quote]
> "Armed with a shaky hold on fire and some sharp
> rocks, Homo erectus incredibly survived for over
> 1.5 million years, much longer than our own species
> Homo sapiens has been on Earth. Tell-tale marks on
> fossil bones show that the lives of these early
> humans were brutal, ruled by hunger and who could
> strike the hardest blow, yet there are fleeting
> glimpses of human compassion as well. The small
> brain of Homo erectus and its strangely unchanging
> culture indicate that the species could not talk.
> Part of that primitive culture included ritualized
> aggression, to which the extremely thick skulls
> of Homo erectus bear mute witness."
> ______________________
>
> So maybe the unfortunate H.erectus did finally share
> something with its hyena predator - a hard, brutal
> life scavenging on the kills of predators as they
> followed the seasonal movements of herd animals
> across wilds of Asia.
>
> > > > > There may be an entirely different reason for the
> > > > > both the inactivation of MYH16 and that of Neu5Gc
> > > > > in the human lineage that we may have missed...both
> > > > > may have result from genetic-drift, not natural selection
> > > > > (positive or otherwise).
> > > >
> > > > Could be I suppose. I'd given it some thought, but decided
> > > > it's the explanation of last resort and that's where I left it..
> > >
> > > Not so certain, as genetic drift - does have the
> > > advantage over `natural selection' in removing from
> > > the equation convoluted and non-parsimonious
> > > explanations... as it leaves a species faced with
> > > a gene mutation the sole option of either adapting
> > > to the change or going extinct...
> > >
> > > If we were take Neu5Gc as an example - the gene
> > > mutation could have arose from repeated pathogen
> > > infections over several generations some two to
> > > three million years ago, then after another serious
> > > endemic that reduced their number once more the only
> > > ones that reproduced passed on the mutated gene
> > > (thus eradicating in a single generation the `normal'
> > > copy of the gene) leaving their successors to either
> > > adapt to life without Neu5Gc or go extinct.
> > >
> > > Perhaps other species have been faced with this
> > > choice in the past, but have failed to adapt to the
> > > loss of Neu5Gc. Humans may have survived simply
> > > because the mutation in the human lineage coincided
> > > with an increase in the size of the brain, with an enlarged
> > > brain and competitive edge perhaps compensating for
> > > a compromised immune and cardiovascular system.
> > >
> > It's almost certainly the case that endogenous Neu5Gc
> > had allowed repeated infections of P.reich from before
> > the H/P LCA until the CMAH mutation. In modern
> > humans exogenous Neu5Gc is used by other pathogens,
> > but AFAIK the P.reich parasite is the only one we can
> > be reasonably certain about prior to c. 2.5 Mya.
> > >
> > > Happy Christmas
> > >
> > Onya, mate!
> >
> > :-)
> >
> > Rob.
>
> :-)
>
> One way of looking at it Rob, would be to say
> if it was not for the P.reich parasite an the
> loss of Neu5Gc... we might have been just
> another extinct ape species in the forest.
>
> However as the year 2010 ends our 'friend' the
> ubiquitous mosquito is still adapting, still
> intent on conquering new territory...
>
> A Malaria Mosquito Is Becoming Two Species
> in a Hurry
>
>
http://www.livescience.com/animals/malaria-mosquitos-species-splitting-101021.ht\
ml
>
> [quote]
> A strain of African mosquito that carries the
> deadly malaria parasite is splitting into two
> species faster than expected, according to a
> new study. The finding helps explain why the
> insect can survive in environments spanning
> from humid rainforests to arid savannas.
>
> The mosquito, Anopheles gambiae, is one of the
> top carriers of malaria parasites, which infect
> 250 million people a year, according to the
> World Health Organization.
>
> -------------------------
>
> With best wishes for 2011
>
> --Bill
>
> __________________________________________
>
> > --- In AAT@yahoogroups.com, "Rob Dudman" <ausell@> wrote:
> > >
> > >
> > > ----- Original Message -----
> > > From: dons3148
> > > To: AAT@yahoogroups.com
> > > Sent: Friday, December 17, 2010 12:41 AM
> > > Subject: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> > > Hypotheses)
> > >
> >
> > Hello Rob...
> >
> > > Hello Bill........
> > > >
> > > > > > Can an ancient hominid 3.4 Mya picking up a sharp
> > > > > > edged stone to scrape and cut the last scraps of
> > > > > > meat of the bones of a predators kill, be classed
> > > > > > as a stone tool user?
> > > > > >
> > > > > > IMO, yes.
> > > > > >
> > > > > > Or would this kind of behaviour be no different from
> > > > > > that of any number of other species - from otters to
> > > > > > chimpanzees - who use whatever is available - a twig
> > > > > > a stone - to get at something edible or tasty).
> > > > >
> > > > > Essentially no difference at all (IMO). Even modifying
> > > > > stones into sharp-edged tools is essentially no different
> > > > > to when a chimp strips leaves from a twig so that it
> > > > > will fit into a termite hole. Knapping is certainly more
> > > > > complicated in that it uses a tool (a hammer stone)
> > > > > to make a tool, but there's no type difference in the
> > > > > behaviour.
> > > >
> > > > Then essentially a `tool using' habilis was no different
> > > > from a `tool using' gorilla using a stick to test the depth
> > > > of the water it was walking through or an otter using a
> > > > stone to crack open a shell...
> > > >
> > > IMO, absolutely no difference at all.
> >
> > Yes, they are essentially using 'tools' for the
> > same job - namely to get at food.
> >
> > > > Then I would say tool use in Man as such cannot be
> > > > used to define anything other the start of when the
> > > > human imagination (the ability of forming mental images,
> > > > sensations and concepts) kicked in (bringing an end to
> > > > replicating the same stone tools over and over again).
> > > >
> > > I'm very wary of using subjective concepts like 'imagination',
> > > 'mental images', 'sensations' etc., when discussing a scientific
> > > topic......I intuitively agree that our human capacity to
> > > imagine is far greater than that of other primates, but
> > > science needs measurement and I'm not too sure how
> > > one would measure a gorilla's imagination to find out what
> > > this difference actually is.
> > >
> > > They certainly have something going on when they test
> > > the depth of water with a stick....if the water is too deep,
> > > then they don't go there - why not? We might say it's
> > > because they 'know' that stepping into deep water will
> > > have unpleasant consequences because it's happened
> > > previously, but then they have to be able to imagine
> > > that it will happen again in the future and act accordingly
> > > using an appropriate tool. What else can they imagine
> > > as they sit for hours chewing their stalks? Probably not
> > > much, but I can't think of a way that this could be shown
> > > scientifically.
> > >
> >
> > Perhaps only when `scientist' can devise a scanning
> > method that literally `reads' thoughts, will that
> > question ever come close to being answered.
> >
> > Gorillas are not using `imagination' in the human sense
> > but probably something that is on the face of it similar
> > but is entirely different, namely `anticipation' though
> > the ability `to anticipate' is also believed by some to
> > be uniquely human as it is said to involve the frontal
> > lobes of the brain.
> >
> > However, it seems to me that by using a stick to test
> > the depth of the water its walking through the gorilla
> > can be said to be anticipating what would happen if
> > it got out of its depth in water...
> >
> > I would add - that imagination - the ability to form
> > images, concepts and sensations in the mind is beyond
> > doubt uniquely human. (probably the point at which
> > mankind's early ancestors could imagine - was when
> > they became human!)
> >
> > > The use of one specific tool - the control of fire - may
> > > well be the exception that can tell us a great deal about
> > > the quintessentially human.....indeed, show me a controlled
> > > fire and I'll show you a human being.
> >
> > Agree - the control of fire - tells us more than
> > `stone tool use- ever could. It also represents
> > another significant change in the human diet, as
> > `cooking' changes the nature of what is being
> > cooked...
> >
> > [quote]
> > Cooking may have had the largest impact on human
> > evolution because cooked meat requires significantly
> > less energy to digest it than raw meat, thus freeing
> > up even more energy in the diet that could be routed
> > for brain development (Nixon. 2008). Cooked food does
> > not need to be heated to body temperature, is easier
> > to chew and digest, and less prone to carry harmful
> > bacteria. While archaeologists generally agree that
> > cooking was one of our ancestors' early uses of
> > fire, there is disagreement as to when this began.
> >
> > The Great Leaps Forward
> > Anthony Stigliani
> > http://fubini.swarthmore.edu/~ENVS2/astigli1/greatleapsforward.html
> > ________________________________________
> >
> > Note also Rob, the chart (fig.2) indicating the
> > spurt in human brain size between 800,000 years
> > ago and 200,000 years ago.
> >
> > > > > > .........a smaller mouth opening may have been more
> > > > > > advantageous than massive ape mouth of old when
> > > > > > it came dealing with some shellfish (like the slimy
> > > > > > slippery contents of oysters).
> > > > >
> > > > > How 'massive' d'you think this must have been to
> > > > > prevent them from tipping oysters (or whatever)
> > > > > into their mouths? Even if those with 'massive' jaw
> > > > > muscles found themselves at some disadvantage,
> > > > > this still wouldn't explain the edge gained by those
> > > > > with the smallest jaw muscles. Inbetween 'massive'
> > > > > and 'smallest' would have been simply 'big' and
> > > > > these too would have lost out to the weakest-
> > > > > jawed.
> > > >
> > > > The difference in terms of comparison may have
> > > > been between say the jaws, mouth size and oral
> > > > cavity of a gorilla and that of an AMH (modern
> > > > human) today... the former today is probably better
> > > > adapted to masticating large amounts of vegetable
> > > > matter than that of the average human.
> > > >
> > > Yes, but would a gorilla-size mouth/jaw have been
> > > an impediment that was so severe that it led to a
> > > reproductive disadvantage?
> >
> > Their rivals would have had the smaller jaws; and
> > smaller jaws probably came with a smaller mouth
> > opening, perhaps the advantage when it came to
> > extracting the contents of oysters. So perhaps the
> > reproductive advantage lay with those with the
> > gene mutation?
> >
> > Arguably though natural selection and reproductive
> > strategies are themselves weak explanations as neither
> > can explain satisfactorily explain why humans ended up
> > with small jaws. They also fail as explanations, to
> > explain how those that looked physically different
> > as a result of a gene mutation, were accepted? (even
> > birds are known to attack a member of their own kind
> > if they look different, or are weak)
> >
> > > > However, I would say that the outcome on the shore
> > > > a couple of million years and more ago, may have
> > > > depended more on how the facial bones would have
> > > > developed in life with smaller muscles - since
> > > > the mutation in question would only have
> > > > affected the jaw muscles.
> > > >
> > > I may not be getting your meaning here, but it seems
> > > to me that if all we have is the ongoing experience of a
> > > soft-food diet, then this seems very much like a Lamarkian
> > > explanation for a genetic change.
> >
> > Basically this particular mastication muscle gene
> > mutation (MYH16) makes no sense, unless there was
> > for example a corresponding change in the size of
> > the jaw bone (as changing the size of mastication
> > muscles, but leaving their owner with large jaws
> > does not seem a recipe for
> > reproductive success)
> >
> > > > > I've also got an uncomfortable feeling that there's a
> > > > > contradiction here somewhere that's being overlooked.....
> > > > > what advantage would be gained for a DHA-driven
> > > > > brain enlargement by losing the sagittal crest as the
> > > > > result of a MHY16 mutation, if the skull then thickened?
> > > >
> > > > On the face of it, it does seem somewhat contradictory;
> > > > then again there was something of a stasis in the
> > > > enlargement in the size of the H.e ...
> > > >
> > > > (the H.ergaster on the other hand is said to have had
> > > > a thinner skull, a skull more like that of a
> > > > modern human).
> > > >
> > >
> > > I would expect that erectus and ergaster would share
> > > the characteristics that they inherited from their littoral
> > > predecessors and differences in attritbutes would reflect
> > > the different post-littoral environments that each had to
> > > deal with.
> > >
> > > This suggests to me that H.e/e left the littoral with
> > > the thinner skulls of ergaster, while the Asian erectines
> > > developed the heavier bones for reasons that are far
> > > from obvious.
> > > >
> > > > I may be wrong but I think Marc attributes a thick
> > > > skull in H.e to a diving adaptation (but modern
> > > > humans today seem to dive pretty successful with
> > > > their thin boned domed skulls).
> > > >
> > > H.erectus was not exploiting a littoral diet.
> >
> > Agree, H.erectus was in the wrong places to be
> > a littoral dweller. H.erectus at least outside
> > of north Africa was a scavenger/hunter and
> > perhaps the prey of predators.
> >
> > > > One answer could be if H.e were prey to predators as
> > > > some have claimed then a thick skull may have increased
> > > > their chances of surviving an attack (hyenas of old in
> > > > China - are said to have specialised in cracking open
> > > > the skulls of their H.e prey).
> > > >
> > > > The Skull-Crushing Hyenas of Dragon Bone Hill
> > > >
> > > >
http://www.wired.com/wiredscience/2010/06/repost-the-skull-crushing-hyenas-of-dr\
agon-bone-hill/
> > > >
> > > ____________________________________
> > >
> > > Predation stresses would be a clear selection mechanism,
> > > but I don't think that skulls in a hyena den is the evidence
> > > in this case.....cracking open skulls to get at brains would
> > > have been done port-mortem and unlikely to have a great
> > > deal of reproductive impact. For this we'd have to assume
> > > that the survival rate from these hyena predations would
> > > be greater among those with the thicker bones.....but here
> > > we're talking about an extremely large and powerful
> > > hyena and I doubt that even the thickest of post-cranial
> > > erectine bones would have been much of a defence. In
> > > fact I'd have thought that survival rates would be highest
> > > among those with lighter bones as the only way to
> > > survive such an encounter would be not get caught.
> >
> > Or perhaps if initially a thicker skull conferred
> > some survival advantage for the H.erectus...
> >
> > They then lost out when the endless `arms race'
> > between predator and prey have moved up a notch, with
> > the hyenas not only adapting their predation skills
> > but adapting to crack open the tougher skulls of
> > their prey to get at the H.erectus brain
> > (a source of fat?).
> >
> > > > > > > Until further evidence turns up I think the most
> > > > > > > plausible null-hypothesis is that the lack of Neu5Gc
> > > > > > > freed up the Neu5Ac that otherwise would have been
> > > > > > > used to make Neu5Gc. The additional Neu5Ac was
> > > > > > > then used to create synaptic connections in the brains
> > > > > > > being enlarged by the plentiful DHA.
> > > > > >
> > > > > > Was its loss simply accident of evolution, or was it a
> > > > > > necessary step in the evolution of a relatively large
> > > > > > brain in the human lineage - I would say it was the
> > > > > > latter.
> > > > >
> > > > >
> > > > > Both.
> > > >
> > > > There may be an entirely different reason for the
> > > > both the inactivation of MYH16 and that of Neu5Gc
> > > > in the human lineage that we may have missed...both
> > > > may have result from genetic-drift, not natural selection
> > > > (positive or otherwise).
> > > >
> > > Could be I suppose. I'd given it some thought, but decided
> > > it's the explanation of last resort and that's where I left it..
> > >
> > > Rob.
> >
> > Not so certain, as genetic drift - does have the
> > advantage over `natural selection' in removing from
> > the equation convoluted and non-parsimonious
> > explanations... as it leaves a species faced with
> > a gene mutation the sole option of either adapting
> > to the change or going extinct...
> >
> > If we were take Neu5Gc as an example - the gene
> > mutation could have arose from repeated pathogen
> > infections over several generations some two to
> > three million years ago, then after another serious
> > endemic that reduced their number once more the only
> > ones that reproduced passed on the mutated gene
> > (thus eradicating in a single generation the
> > `normal' copy of the gene) leaving their successors
> > to either adapt to life without Neu5Gc or go extinct.
> >
> > Perhaps other species have been faced with this
> > choice in the past, but have failed to adapt to the
> > loss of Neu5Gc. Humans may have survived simply because
> > the mutation in the human lineage coincided with an
> > increase in the size of the brain, with an enlarged
> > brain and competitive edge perhaps compensating for
> > a compromised immune and cardiovascular system.
> >
> > Happy Christmas
> >
> > --Bill
> >
> > This post may be slightly delayed as I am having
> > new phone line installed hopefully in the next
> > couple of days (my existing phone line gave
> > up the ghost yesterday).
> >
> > --------------------------------
> >
> > > --- In AAT@yahoogroups.com, "Rob Dudman" <ausell@> wrote:
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: dons3148
> > > > To: AAT@yahoogroups.com
> > > > Sent: Sunday, December 12, 2010 11:24 PM
> > > > Subject: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> > > > Hypotheses)
> > > >
> > > > Hello Bill........
> > > > >
> > > > > > [No garhi fossils from before or after, yet here we
> > > > > > have eight more or less in the same place and from
> > > > > > the same time? Now that's odd. Maybe they died of
> > > > > > P.reich malaria and those who survived the epidemic
> > > > > > scarpered and eventually found themselves at the
> > > > > > coast.......... :-)]
> > > > >
> > > > > :)
> > > > >
> > > > > Or perhaps they were a `hunting/scavenging' or scouting
> > > > > party that fell foul of pack of predators.........
> > > > >
> > > > Wouldn't such an attack have left some evidence on
> > > > the bones? To be sure, there need be no bone trauma
> > > > for a predator to kill its prey, but eating the meat should
> > > > have left some marks.
> > >
> > > Hello Rob...
> > >
> > > > > .......(like a'piths - australopithecines - they still had
> > > > > the sagittal crest on the top of the skull, that functioned
> > > > > as muscle anchor for the jaw muscles).
> > > > >
> > > > Well yes......Bouri is dated c. 2.5 - 2.6 Mya and the
> > > > MHY16 mutation didn't happen until c. 2.4 Mya.
> > > > The Bouri date is coincident with the CMAH mutation.
> > >
> > > Yes since they had the sagittal crest, it can be said
> > > to be clear evidence that the date of the CMHA mutation
> > > was around 2.4 Mya and rule out the argument that it
> > > could have occurred at a much earlier date.
> > >
> > > > > > From what I can see, the main gripe about the
> > > > > > Bouri evidence has been related to the notion that
> > > > > > A'piths didn't/couldn't manufacture and use Mode 1
> > > > > > stone tools, so these had to have been made by
> > > > > > Homo and the only candidate has been habilis. IMO,
> > > > > > this is imposing an a-priori rule to the physical evidence
> > > > > > and thus a very poor approach to understanding that
> > > > > > evidence.
> > > > >
> > > > > Can an ancient hominid 3.4 Mya picking up a sharp
> > > > > edged stone to scrape and cut the last scraps of
> > > > > meat of the bones of a predators kill, be classed
> > > > > as a stone tool user?
> > > > >
> > > > IMO, yes.
> > > > >
> > > > > Or would this kind of behaviour be no different from
> > > > > that of any number of other species - from otters to
> > > > > chimpanzees - who use whatever is available - a twig
> > > > > a stone - to get at something edible or tasty).
> > > > >
> > > > Essentially no difference at all (IMO). Even modifying
> > > > stones into sharp-edged tools is essentially no different
> > > > to when a chimp strips leaves from a twig so that it
> > > > will fit into a termite hole. Knapping is certainly more
> > > > complicated in that it uses a tool (a hammer stone)
> > > > to make a tool, but there's no type difference in the
> > > > behaviour.
> > >
> > > Then essentially a `tool using' habilis was no
> > > different from a `tool using' gorilla using a
> > > stick to test the depth of the water it was
> > > walking through or an otter using a stone to
> > > crack open a shell...
> > >
> > > Then I would say tool use in Man as such cannot
> > > be used to define anything other the start of
> > > when the human imagination (the ability of forming
> > > mental images, sensations and concepts) kicked in
> > > (bringing an end to replicating the same
> > > stone tools over and over again).
> > >
> > > > > The habilis makes a pretty lousy candidate for
> > > > > Bouri (wrong place, wrong time for the `habilis').
> > > > > Bouri predates the earliest habilis `fossil' by
> > > > > several hundred thousand years. The older garhi
> > > > > (older by several hundred thousand years) is
> > > > > the better candidate.
> > > > >
> > > > By far the better candidate IMO, particularly given
> > > > that the garhi fossils were 'proximal' to the tools..
> > > > >
> > > > > Incidentally I think Bruce Bower for his article in
> > > > > ScienceNews came up with the best headline for this
> > > > > news story...
> > > > >
> > > > > "Ancient hominid butchers get trampled"
> > > > >
> > > > >
http://www.sciencenews.org/view/generic/id/65558/title/Ancient_hominid_butchers_\
get_trampled
> > > > >
> > > > :-)
> > > >
> > > > >
> > > > > > > > > If that had been the case Rob, then the possible
> > > > > > > > > consequences for those that had been free of the
> > > > > > > > > parasite inland for generations moving into a
> > > > > > > > > littoral habitat could have been disastrous, they
> > > > > > > > > may even literally have faced extinction (perhaps
> > > > > > > > > only the elimination of Neu5Gc in the human
> > > > > > > > > lineage, dragging them back from the brink
> > > > > > > > > of extinction?)
> > > > > > > >
> > > > > > > > Yes....that's my suggested alternative to the hair-loss
> > > > > > > > explanation for an increase in vulnerability to P.reich
> > > > > > > > that led to the Neu5Gc adaptation. Having had the
> > > > > > > > hair-loss explanation so cruelly euthanased by
> > > > > > > > yourself, the adaptation seemed rather pointless
> > > > > > > > and in need of some provenance.
> > > > > > >
> > > > > > > :)
> > > > > > >
> > > > > > > Would not say your explanation was entirely
> > > > > > > euthanized by a more recent date for hair loss
> > > > > > > in the human lineage, as relative hair loss in
> > > > > > > Man in the last million years could have mirrored
> > > > > > > the last phase in the expansion of the human
> > > > > > > brain to its current size, with AMH (modern Man)
> > > > > > > inheriting the condition from their immediate
> > > > > > > predecessors of 240,000 years ago (early H.s.s)
> > > > > > >
> > > > > > Yes, it's still a possibility I suppose, but its probability
> > > > > > has taken a definite nose-dive!
> > > > >
> > > > > Maybe not... I downloaded a copy of Hermelita Winter's
> > > > > paper that appeared in `Human Genetics' in 2000, out of
> > > > > curiosity to see how they arrived at such a recent date
> > > > > for the inactivation of the KRTHAP1 gene (hair gene)
> > > > > in the human lineage...
> > > > >
> > > > > Now I have questions about the date they came up with
> > > > > for the mutation of the hair gene.
> > > > >
> > > > > I am probably wrong - but their conclusion appears to
> > > > > be somewhat contradictory - as the date they give for
> > > > > the gene mutation predates the emergence of those
> > > > > they claim first acquired the gene mutation.
> > > > >
> > > > > They claim that only AMH living in Africa acquired
> > > > > the hair gene mutation. Yet the date they claim for
> > > > > the gene mutation predates somewhat the first
> > > > > appearance of AMH in Africa by at least 50,000
> > > > > years to 90,000 years (apparently in the authors
> > > > > view it would have been too complicated for earlier
> > > > > groups of humans living outside of Africa to have
> > > > > acquired the gene mutation!).
> > > > >
> > > > > [quote]
> > > > > "Two controversial hypotheses are currently discussed
> > > > > regarding the origin of modern humans. Both concepts
> > > > > entail an expansion approximately 1.5 million years ago
> > > > > of Homo erectus from Africa into the Old World (Tattersall
> > > > > 1997; Disotell 1999). The "multiregional continuity"
> > > > > hypothesis maintains that our lineage, from then on,
> > > > > consisted of a continual stream of populations evolving
> > > > > in all areas of the Old World, constantly linked by gene
> > > > > flow that allowed evolutionary changes in one region to
> > > > > spread into others (Tattersall 1997; Disotell 1999;
> > > > > Wolpoff 1998). By contrast, the "single African origin"
> > > > > hypothesis contends that all modern humans descended
> > > > > from a single ancestral founder population, which
> > > > > consisted of approximately 10,000 breeding adults, and
> > > > > which emerged in Africa about 200,000 years ago, staying
> > > > > relatively isolated for probably thousands of years before
> > > > > expanding into the Old World and thereby gradually
> > > > > replacing more primitive forebears from the first
> > > > > migrational wave..."
> > > > >
> > > > > (the authors clearly favour the out-of-date "out
> > > > > of Africa" hypotheses of the 1980's)
> > > > >
> > > > > (AMH - Modern humans emerged between 165,000 and
> > > > > 190,000 years ago)
> > > > >
> > > > > The paper:
> > > > >
> > > > > Human type I hair keratin pseudo gene fhHaA has
> > > > > functional orthologs in the chimpanzee and gorilla:
> > > > > evidence for recent inactivation of the human gene
> > > > > after the Pan-Homo divergence
> > > > >
> > > > > http://www.springerlink.com/content/kygkdy6cdhw1kjkw/
> > > > > _______________________________
> > > > >
> > > > Unfortunately for my idea that hairlessness could have
> > > > been a determining factor in the Neu5Gc mutation, the
> > > > timing is still way out by a couple of million years.
> > >
> > > That does seem to be the case Rob; unless some new
> > > research comes up with an earlier date for the
> > > inactivation of the hair gene that resulted in a
> > > relatively hairless species known as Man. (the
> > > habilis and H.erectus could have been as hairy
> > > as a gorilla or a chimpanzee today...)
> > >
> > > > > > For there to have been a genetic adaptation we certainly
> > > > > > require something in addition to a diet that no longer
> > > > > > needed strong jaws. It is the case that the weaker
> > > > > > jawed mutation became the norm, but in a situation
> > > > > > where all were experiencing the same diet, then the
> > > > > > diet in itself can't explain the reproductive edge
> > > > > > gained by those already with the CMAH mutation
> > > > > > to then establish it as the norm.
> > > > >
> > > > > To become the norm, I would think - those with the
> > > > > mutation would have had to over time outnumbered
> > > > > those without the mutation, and selection in general
> > > > > would have had to acted favour those with the mutation
> > > > > so unless those born without the mutation were
> > > > > bumped off - it is unlikely to have happen
> > > > > overnight, in evolutionary terms.
> > > > >
> > > > > However, there must have been something that drove
> > > > > the change, perhaps an edge in masticating some
> > > > > seafoods better than their large jawed kin......
> > > > >
> > > > > .........a smaller mouth opening may have been more
> > > > > advantageous than massive ape mouth of old when
> > > > > it came dealing with some shellfish (like the slimy
> > > > > slippery contents of oysters).
> > > > >
> > > > How 'massive' d'you think this must have been to
> > > > prevent them from tipping oysters (or whatever)
> > > > into their mouths? Even if those with 'massive' jaw
> > > > muscles found themselves at some disadvantage,
> > > > this still wouldn't explain the edge gained by those
> > > > with the smallest jaw muscles. Inbetween 'massive'
> > > > and 'smallest' would have been simply 'big' and
> > > > these too would have lost out to the weakest-
> > > > jawed.
> > >
> > > The difference in terms of comparison may have
> > > been between say the jaws, mouth size and oral
> > > cavity of a gorilla and that of an AMH (modern
> > > human) today... the former today is probably better
> > > adapted to masticating large amounts of vegetable
> > > matter than that of the average human.
> > >
> > > However, I would say that the outcome on the shore
> > > a couple o million years and more ago, may have
> > > depended more on how the facial bones would have
> > > developed in life with smaller muscles - since
> > > the mutation in question would only have
> > > affected the jaw muscles.
> > >
> > > > .....And this gives us a second candidate for this
> > > > > > reproductive edge.....bigger heads. At least this
> > > > > > doesn't suffer from the generalised rule of small
> > > > > > and weak not being sexy, but it's still not apparent
> > > > > > why larger heads per se would be sexy. But if
> > > > > > larger heads meant larger brains and larger brains
> > > > > > gave rise to more intelligent behaviour, then we
> > > > > > have a third candidate that is intuitively cogent.
> > > > > >
> > > > > > What do I mean by 'more intelligent behaviour'?
> > > > > > Well, it wasn't more success in provisioning as
> > > > > > we're assuming an abundant littoral, so I'd guess
> > > > > > that was in courting technique!
> > > > >
> > > > > :)
> > > > >
> > > > > Not all of the of H.e chose a bigger head, some seem
> > > > > to have contradicted the trend towards expanding the
> > > > > brain by favouring thick boned skulls - possibly having
> > > > > a thick skull was a positive survival advantage for
> > > > > those that hunted? (or maybe H.e courting technique
> > > > > involved head-butting a potential mate...)
> > > > >
> > > > I don't think H.e/e mating choices had anything to with
> > > > the MHY16 mutation......at c. 2.4 Mya we're dealing
> > > > with the H.e/e precursor.
> > > >
> > > > (Head-butting a potential mate? Lor', I can't see them
> > > > lasting as long as they did if that was the extent of their
> > > > charm. Anyone who has grown up in a modern urban
> > > > setting knows that (fore)head-butting is a commonplace
> > > > [and very effective] occurrence between fighting males,
> > > > but as an explanation for H.e/e thick skulls.......mmmm,
> > > > I'll leave that one in the 'pending more evidence' box.)
> > >
> > > Head-butting today, is known in a city somewhat
> > > further up the coast from here as giving someone
> > > a Glasgow kiss...
> > >
> > > It is Glasgwegien slang for headbutt - a vicious
> > > headbutt (is there another kind!)
> > > >
> > > > > I've also got an uncomfortable feeling that there's a
> > > > > contradiction here somewhere that's being overlooked.....
> > > > > what advantage would be gained for a DHA-driven
> > > > > brain enlargement by losing the sagittal crest as the
> > > > > result of a MHY16 mutation, if the skull then thickened?
> > > >
> > > > On the face of it, it does seem somewhat contradictory;
> > > > then again there was something of a stasis in the
> > > > enlargement in the size of the H.e ...
> > > >
> > > > (the H.ergaster on the other hand is said to have had
> > > > a thinner skull, a skull more like that of a
> > > > modern human).
> > > >
> > > > > > Until further evidence turns up I think the most
> > > > > > plausible null-hypothesis is that the lack of Neu5Gc
> > > > > > freed up the Neu5Ac that otherwise would have been
> > > > > > used to make Neu5Gc. The additional Neu5Ac was
> > > > > > then used to create synaptic connections in the brains
> > > > > > being enlarged by the plentiful DHA.
> > > > >
> > > > > Was its loss simply accident of evolution, or was it a
> > > > > necessary step in the evolution of a relatively large
> > > > > brain in the human lineage - I would say it was the
> > > > > latter.
> > > > >
> > > > Both.
> > > >
> > > > Rob.
> > >
> > > There may be an entirely different reason for the
> > > both the inactivation of MYH16 and that of Neu5Gc
> > > in the human lineage that we may have missed...
> > > both may have result from genetic-drift, not
> > > natural selection (positive or otherwise).
> > >
> > > What is Genetic Drift?
> > > http://www.biology.arizona.edu/evolution/act/drift/about.html
> > >
> > > Genetic drift [Wikipedia]
> > >
> > > Genetic drift is an important evolutionary process
> > > which leads to changes in allele frequencies over
> > > time. It may cause gene variants to disappear
> > > completely, and thereby reduce genetic variation.
> > > In contrast to natural selection, which makes gene
> > > variants more common or less common depending on
> > > their reproductive success,] the changes due to
> > > genetic drift are not driven by environmental or
> > > adaptive pressures, and may be beneficial, neutral,
> > > or detrimental to reproductive success. [quote]
> > >
> > > http://en.wikipedia.org/wiki/Genetic_drift
> > >
> > > _______________________________
> > >
> > > --Bill
> > >
> > > > --- In AAT@yahoogroups.com, "Rob Dudman" <ausell@> wrote:
> > > > >
> > > > >
> > > > > ----- Original Message -----
> > > > > From: dons3148
> > > > > To: AAT@yahoogroups.com
> > > > > Sent: Thursday, December 09, 2010 12:33 AM
> > > > > Subject: [AAT] Re: Neu5Gc (Was: Chimp the Hunter, Kills the Savanna
> > > > > Hypotheses)
> > > >
> > > > Hello Rob...
> > > >
> > > > > Hello Bill........
> > > > > >
> > > > > > > > On the other hand if the garhi was using tools to
> > > > > > > > butcher red-meat inland 2.5 Mya, then they would
> > > > > > > > have had to have been moving into a littoral
> > > > > > > > habitat, or in a littoral habitat at around the
> > > > > > > > same time... is that likely?
> > > > > > >
> > > > > > > Well, garhi do seem to have vacated the African
> > > > > > > scene after c. 2.5 Mya.
> > > > > >
> > > > > > The garhi have though have seemingly retained the
> > > > > > `title' of earliest stone tool user, as a recent claim for
> > > > > > even older `tool use' some 3 Mya based on bone
> > > > > > cut marks appears to have been dismissed, with
> > > > > > the alleged `cut marks' apparently now attributed
> > > > > > to the bones simply being trampled on.
> > > > > >
> > > > > > You may recall there was a controversial claim
> > > > > > back in August this year for evidence for stone
> > > > > > tool use 3.4 Mya that was based on cut marks on
> > > > > > some bones found in the Lower Awash.
> > > > > > (The Dikika Cut Marks)
> > > > > >
> > > > > > Trampling Over The Dikika Cut Marks
> > > > > >
http://anthropology.net/2010/11/19/trampling-over-the-dikika-cut-marks/
> > > > > >
> > > > > That's a reasonably convincing rebuttal of the claim
> > > > > that the Dikika cut marks are evidence of tool use.
> > > > > However, the Bouri evidence was published over a
> > > > > decade ago and no-one (AFAIK) has yet claimed
> > > > > that these are not cut-marked bones that are 'proximal'
> > > > > to the remains of eight individual garhi.
> > > > >
> > > > > [No garhi fossils from before or after, yet here we
> > > > > have eight more or less in the same place and from
> > > > > the same time? Now that's odd. Maybe they died of
> > > > > P.reich malaria and those who survived the epidemic
> > > > > scarpered and eventually found themselves at the
> > > > > coast.......... :-)]
> > > >
> > > > :)
> > > >
> > > > Or perhaps they were a `hunting/scavenging' or scouting
> > > > party that fell foul of pack of predators. (like a'piths -
> > > > australopithecines - they still had the sagittal crest
> > > > on the top of the skull, that functioned as muscle
> > > > anchor for the jaw muscles).
> > > >
> > > > > From what I can see, the main gripe about the
> > > > > Bouri evidence has been related to the notion that
> > > > > A'piths didn't/couldn't manufacture and use Mode 1
> > > > > stone tools, so these had to have been made by
> > > > > Homo and the only candidate has been habilis. IMO,
> > > > > this is imposing an a-priori rule to the physical evidence
> > > > > and thus a very poor approach to understanding that
> > > > > evidence.
> > > >
> > > > Can an ancient hominid 3.4 Mya picking up a sharp
> > > > edged stone to scrape and cut the last scraps of
> > > > meat of the bones of a predators kill, be classed
> > > > as a stone tool user?
> > > >
> > > > Or would this kind of behaviour be no different from
> > > > that of any number of other species - from otters to
> > > > chimpanzees - who use whatever is available - a twig
> > > > a stone - to get at something edible or tasty).
> > > >
> > > > The habilis makes a pretty lousy candidate for
> > > > Bouri (wrong place, wrong time for the `habilis').
> > > > Bouri predates the earliest habilis `fossil' by
> > > > several hundred thousand years. The older garhi
> > > > (older by several hundred thousand years) is
> > > > the better candidate.
> > > >
> > > > Incidentally I think Bruce Bower for his article in
> > > > ScienceNews came up with the best headline for this
> > > > news story...
> > > >
> > > > "Ancient hominid butchers get trampled"
> > > >
> > > >
http://www.sciencenews.org/view/generic/id/65558/title/Ancient_hominid_butchers_\
get_trampled
> > > >
> > > > ___________________________________
> > > >
> > > > The `habilis' wasn't much of a hunter either, as
> > > > apparently there is evidence that it was more
> > > > prey than hunter as it appears to have been among
> > > > the favoured prey of ancient big cats like the
> > > > Dinofelis (a sabre tooth big cat about the size
> > > > of a lion). Ancient crocs too apparently liked
> > > > to snack on the unfortunate `habilis'
> > > >
> > > > Ancient Horned Crocodile Found-Ate Early Humans?
> > > >
> > > > "Crocodile bite marks had previously been found on
> > > > hominid bones from the gorge. Based on the latest
> > > > find, scientists suspect that the crocodile not only
> > > > ate our ancestors, but that it was their biggest
> > > > predator at the time. "[quote]
> > > >
> > > >
http://news.nationalgeographic.com/news/2010/02/100225-new-horned-crocodile-earl\
y-humans/
> > > >
> > > > ___________________________________
> > > >
> > > > > > > I understand that temperature is the key factor and
> > > > > > > of course increasing altitude mimics increasing
> > > > > > > latitude.
> > > > > >
> > > > > > That appears to be the case as after a bit of a
> > > > > > search this morning on the subject, it appears
> > > > > > the mosquito larvae is killed if the temp drops
> > > > > > below 15.C.
> > > > > >
> > > > > > Surprisingly though... mosquitoes themselves
> > > > > > do somehow survive in temperate climes, by
> > > > > > hibernating through the winter (among them
> > > > > > a mosquito in Alaska called the snow-mosquito!).
> > > > > >
> > > > > Given the staggering numbers of those tundra mozzies
> > > > > it's some consolation that they're not called anopheles!
> > > > > I seem to recall reading that anopheles were found
> > > > > in England during this past summer....d'you know
> > > > > anything about that?
> > > >
> > > > No... but it would not be a surprise if they were
> > > > overwintering in southern England, as apparently
> > > > there are a number of mosquito species in Britain
> > > > (there is even a mosquito recording scheme!)
> > > >
> > > > http://www.britishmosquitoes.org.uk/recordingscheme/index.html
> > > >
> > > > However, in these parts pesky midges are the
> > > > problem, not mosquitoes.
> > > >
> > > > http://www.snh.org.uk/publications/on-line/advisorynotes/29/29.htm
> > > >
> > > > ______________________________________
> > > >
> > > > > > > > If that had been the case Rob, then the possible
> > > > > > > > consequences for those that had been free of the
> > > > > > > > parasite inland for generations moving into a
> > > > > > > > littoral habitat could have been disastrous, they
> > > > > > > > may even literally have faced extinction (perhaps
> > > > > > > > only the elimination of Neu5Gc in the human
> > > > > > > > lineage, dragging them back from the brink
> > > > > > > > of extinction?)
> > > > > > >
> > > > > > > Yes....that's my suggested alternative to the hair-loss
> > > > > > > explanation for an increase in vulnerability to P.reich
> > > > > > > that led to the Neu5Gc adaptation. Having had the
> > > > > > > hair-loss explanation so cruelly euthanased by
> > > > > > > yourself, the adaptation seemed rather pointless
> > > > > > > and in need of some provenance.
> > > > > >
> > > > > > :)
> > > > > >
> > > > > > Would not say your explanation was entirely
> > > > > > euthanized by a more recent date for hair loss
> > > > > > in the human lineage, as relative hair loss in
> > > > > > Man in the last million years could have mirrored
> > > > > > the last phase in the expansion of the human
> > > > > > brain to its current size, with AMH (modern Man)
> > > > > > inheriting the condition from their immediate
> > > > > > predecessors of 240,000 years ago (early H.s.s)
> > > > > >
> > > > > Yes, it's still a possibility I suppose, but its probability
> > > > > has taken a definite nose-dive!
> > > >
> > > > Maybe not... I downloaded a copy of Hermelita Winter's
> > > > paper that appeared in `Human Genetics' in 2000, out of
> > > > curiosity to see how they arrived at such a recent date
> > > > for the inactivation of the KRTHAP1 gene (hair gene)
> > > > in the human lineage...
> > > >
> > > > Now I have questions about the date they came up with
> > > > for the mutation of the hair gene.
> > > >
> > > > I am probably wrong - but their conclusion appears to
> > > > be somewhat contradictory - as the date they give for
> > > > the gene mutation predates the emergence of those
> > > > they claim first acquired the gene mutation.
> > > >
> > > > They claim that only AMH living in Africa acquired
> > > > the hair gene mutation. Yet the date they claim for
> > > > the gene mutation predates somewhat the first
> > > > appearance of AMH in Africa by at least 50,000
> > > > years to 90,000 years (apparently in the authors
> > > > view it would have been too complicated for earlier
> > > > groups of humans living outside of Africa to have
> > > > acquired the gene mutation!).
> > > >
> > > > [quote]
> > > > "Two controversial hypotheses are currently discussed
> > > > regarding the origin of modern humans. Both concepts
> > > > entail an expansion approximately 1.5 million years ago
> > > > of Homo erectus from Africa into the Old World (Tattersall
> > > > 1997; Disotell 1999). The "multiregional continuity"
> > > > hypothesis maintains that our lineage, from then on,
> > > > consisted of a continual stream of populations evolving
> > > > in all areas of the Old World, constantly linked by gene
> > > > flow that allowed evolutionary changes in one region to
> > > > spread into others (Tattersall 1997; Disotell 1999;
> > > > Wolpoff 1998). By contrast, the "single African origin"
> > > > hypothesis contends that all modern humans descended
> > > > from a single ancestral founder population, which
> > > > consisted of approximately 10,000 breeding adults, and
> > > > which emerged in Africa about 200,000 years ago, staying
> > > > relatively isolated for probably thousands of years before
> > > > expanding into the Old World and thereby gradually
> > > > replacing more primitive forebears from the first
> > > > migrational wave..."
> > > >
> > > > (the authors clearly favour the out-of-date "out
> > > > of Africa" hypotheses of the 1980's)
> > > >
> > > > (AMH - Modern humans emerged between 165,000 and
> > > > 190,000 years ago)
> > > >
> > > > The paper:
> > > >
> > > > Human type I hair keratin pseudo gene fhHaA has
> > > > functional orthologs in the chimpanzee and gorilla:
> > > > evidence for recent inactivation of the human gene
> > > > after the Pan-Homo divergence
> > > >
> > > > http://www.springerlink.com/content/kygkdy6cdhw1kjkw/
> > > >
> > > > _______________________________
> > > >
> > > > > > > You suggest that those with little or no activated
> > > > > > > MYH16 may have had a reproductive edge over
> > > > > > > their contemporaries by being more attractive as
> > > > > > > mating partners, but again I find this difficult to
> > > > > > > sequence. This group would have been a small,
> > > > > > > handicapped minority in a species that had required
> > > > > > > strong jaws and they would have remained a small
> > > > > > > minority during the change from an inland diet to
> > > > > > > a littoral one.
> > > > > >
> > > > > > Circumstances seem to have favoured those with the
> > > > > > gene mutation as the mutation became the norm in
> > > > > > the human lineage, which may indicate there was
> > > > > > positive selection in favor of gene mutation...
> > > > > >
> > > > > > The link to diet could be that it was specifically
> > > > > > two masticatory (jaw) muscles that were affected
> > > > > > by the gene mutation, in other words two jaw muscles
> > > > > > directly involved in chewing. (So whatever they were
> > > > > > doing on the shore it involved less chewing and less
> > > > > > time spent chewing like a gorilla/chimpanzee)
> > > > > >
> > > > > > It is likely a reduction in the size of two jaw
> > > > > > muscles would influence how the jaw bones developed
> > > > > > in life, but perhaps it took a generation or two (or
> > > > > > maybe more?) for a new smaller jaw as such to become
> > > > > > the norm in the human lineage (possibly giving those
> > > > > > involved, time to adjust to their `new facial
> > > > > > configuration'?).
> > > > > >
> > > > > For there to have been a genetic adaptation we certainly
> > > > > require something in addition to a diet that no longer
> > > > > needed strong jaws. It is the case that the weaker
> > > > > jawed mutation became the norm, but in a situation
> > > > > where all were experiencing the same diet, then the
> > > > > diet in itself can't explain the reproductive edge
> > > > > gained by those already with the CMAH mutation
> > > > > to then establish it as the norm.
> > > >
> > > > To become the norm, I would think - those with the
> > > > mutation would have had to over time outnumbered
> > > > those without the mutation, and selection in general
> > > > would have had to acted favour those with the mutation
> > > > - so unless those born without the mutation were
> > > > bumped off - it is unlikely to have happen
> > > > overnight, in evolutionary terms.
> > > >
> > > > However, there must have been something that drove
> > > > the change, perhaps an edge in masticating some
> > > > seafoods better than their large jawed kin.
> > > >
> > > > > > Incidentally... the upper masticatory muscle of the
> > > > > > two mastication muscles affected by the mutation would
> > > > > > have receded from being anchored to the top of the
> > > > > > skull down to the sides of the skull.
> > > > > >
> > > > > > Perhaps this change alone removed a restraint on the
> > > > > > expansion of the human brain as the skull would no
> > > > > > longer be constrained by massive jaw muscles
> > > > > > attached and anchored to the top of the skull.
> > > > > >
> > > > > And this gives us a second candidate for this
> > > > > reproductive edge.....bigger heads. At least this
> > > > > doesn't suffer from the generalised rule of small
> > > > > and weak not being sexy, but it's still not apparent
> > > > > why larger heads per se would be sexy. But if
> > > > > larger heads meant larger brains and larger brains
> > > > > gave rise to more intelligent behaviour, then we
> > > > > have a third candidate that is intuitively cogent.
> > > > >
> > > > > What do I mean by 'more intelligent behaviour'?
> > > > > Well, it wasn't more success in provisioning as
> > > > > we're assuming an abundant littoral, so I'd guess
> > > > > that was in courting technique!
> > > >
> > > > :)
> > > >
> > > > Not all of the of H.e chose a bigger head, some seem
> > > > to have contradicted the trend towards expanding the
> > > > brain by favouring thick boned skulls - possibly having
> > > > a thick skull was a positive survival advantage for
> > > > those that hunted? (or maybe H.e courting technique
> > > > involved head-butting a potential mate...)
> > > >
> > > > > > One further complication arising from a reduction in
> > > > > > the two jaw muscles and a related reduction in the
> > > > > > jaw itself, are the teeth. Those initially born with
> > > > > > mutation may have had a mouthful of ill-fitting
> > > > > > teeth...
> > > > > >
> > > > > That's hardly going to enhance the sexual attraction
> > > > > of the smaller, weaker jaw!
> > > >
> > > > :)
> > > >
> > > > > > > ........Even today the square jaw is considered an
> > > > > > > attractive male feature....large jaws may be 'out'
> > > > > > > but 'weak-chinned' or 'chinless' is still a euphemism
> > > > > > > for 'unmasculine'.
> > > > > > > For modern females OTOH, a small, more
> > > > > > > pointed jaw-line is considered attractive and
> > > > > > > here is a gender difference that strongly suggests
> > > > > > > sexual selection. It seems that so far females have
> > > > > > > not been finding weaker jaws more attractive in
> > > > > > > potential mating partners.
> > > > > >
> > > > > > That may have been the case if the mutation had
> > > > > > affected only one sex... but this mutation of the
> > > > > > jaw mastication muscles would have affected both
> > > > > > sexes equally.
> > > > > >
> > > > > > So perhaps from a male perspective a couple of
> > > > > > million years ago, females with born smaller jaws
> > > > > > were a lot more 'attractive' than those females
> > > > > > born with 'masculine' large jaws. (thus male
> > > > > > mating choice, perhaps ensured there was
> > > > > > positive selection for the mutation)
> > > > > >
> > > > > Perhaps.
> > > > > >
> > > > > > > It had occurred to me that if the CMAH mutation
> > > > > > > was the result of a bottleneck effect created by a
> > > > > > > severe P.reich malarial epidemic and this had in some
> > > > > > > way set up the conditions where the exceptionally
> > > > > > > weak-jawed would mate more frequently, but so
> > > > > > > far it hasn't occurred to me how this could have
> > > > > > > been the case.
> > > > > >
> > > > > > Brain expansion remains an explanation for the gene
> > > > > > mutation, as only after the reduction in the size of the
> > > > > > jaw muscles in question could brain expansion have
> > > > > > become a possibility...
> > > > > >
> > > > > Yes.....on arrival at the littoral that small percentage of
> > > > > the population that were handicapped with weak jaws
> > > > > because of a genetic disorder (the CMAH mutation),
> > > > > would have been able to respond to a high DHA diet
> > > > > in a way that their stronger jawed contemporaries could
> > > > > not. I think they may have outwitted their rivals in the
> > > > > mating game.
> > > >
> > > > That seems a distinct possibility, Rob.
> > > >
> > > > One other may have been a smaller mouth as a
> > > > consequence of the changes resulting from the
> > > > mutation, an a smaller mouth opening may have
> > > > been more advantageous than massive ape mouth
> > > > of old when it came dealing with some
> > > > shellfish (like the slimy slippery
> > > > contents of oysters).
> > > >
> > > > > > > Unless an objective difference can be identified to
> > > > > > > distinguish the Neu5Gc of one species from another,
> > > > > > > then I have to say that your conclusion seems very
> > > > > > > much a guess. In my reading about Neu5Gc I've
> > > > > > > come across nothing to even hint that there's a
> > > > > > > difference in this regard between species and if
> > > > > > > there is in fact no difference, then we do need an
> > > > > > > explanation for the human immune system response.
> > > > > >
> > > > > > The way I look at this question is to do so from the
> > > > > > perspective of the human immune system, in that they
> > > > > > both represent a threat to the body.
> > > > > >
> > > > > > This after some 2.5 Mya (taking into account a few
> > > > > > genus Homo ancestors and possibly a predecessor or
> > > > > > two to genus Homo since the inactivation Neu5Gc in
> > > > > > the human lineage) can be seen as a reasonable
> > > > > > response on the part of the immune system, as
> > > > > > humans as such have evolved happily for some
> > > > > > two million of years and more without a
> > > > > > functional need for endogenous Neu5Gc.
> > > > > >
> > > > > > Not so certain the comparison with Vit.C is a valid
> > > > > > one, as Neu5Gc is basically antigenic in Man (it invokes
> > > > > > an immune response), whereas Vit.C, exogenous Vit.C is
> > > > > > something that is essential for collagen synthesis
> > > > > > (without it we would get scurvy, a condition in
> > > > > > which the body falls apart)
> > > > > >
> > > > > > All primates (apes and monkeys) have been dependent
> > > > > > on an exogenous source of Vit.C for tens of millions of
> > > > > > years.
> > > > > >
> > > > > > Vit.C inactivation as such is said to have occurred
> > > > > > in primates about 60 Mya - around the time the wet
> > > > > > and dry noses split (primates) - so it can be said
> > > > > > to be an oddity we share with our primate kin
> > > > > > (apes and monkeys).
> > > > > >
> > > > > I'd read that it was about 40 Mya, but for the
> > > > > purposes of our discussion the difference is of little
> > > > > consequence. Here's an interesting take on why
> > > > > primates ceased producing endogenous Vit. C......
> > > > >
> > > > > Vitamin C--the primate fertility factor?
> > > > > Millar J.
> > > > >
> > > > > Abstract
> > > > > The loss of the ability of primates and man to synthesise
> > > > > ascorbic acid (vitamin C) is usually seen as an evolutionary
> > > > > accident, with no benefit to the species. This paper argues
> > > > > that the loss of this biosynthetic ability has allowed vitamin C
> > > > > to act as a 'fertility factor' in primate societies. It is argued
> > > > > that the requirement for vitamin C increases with age, and
> > > > > so in times of food shortages the older members of society
> > > > > suffer higher mortality than the younger. This reduces the
> > > > > median age of the population towards the younger and
> > > > > most fertile members, and so enables the population to
> > > > > regrow rapidly when food resources are restored.
> > > > >
> > > > > http://www.ncbi.nlm.nih.gov/pubmed/1491626
> > > > > ________________
> > > >
> > > > Interesting theory, but the gene mutation as such
> > > > apparently occurred tens of millions of years ago,
> > > > just after the split from the `wet noses' that can
> > > > make their own Vit.C and before the tarsier - who
> > > > cannot make Vit.C - branched off (about 58/57 Mya).
> > > > So primates themselves, early primate society
> > > > 60 Mya was probably very different from how
> > > > primates organised themselves today. (the gene
> > > > mutation in question occurred long before the
> > > > emergence of the apes some 23/24 Mya).
> > > >
> > > > Losing the ability to turn glucose into Vit.C would
> > > > seem on the face of it is a pretty negative adaptation
> > > > (as it amount to losing something essential) for any
> > > > species, have read somewhere that the loss of the
> > > > ability to make Vit.C paralleled the loss of the
> > > > ability to break down uric acid in primates (how
> > > > those two link together is anybody's guess!).
> > > >
> > > > [quote]
> > > > "Among the animals that have lost the ability to
> > > > synthesise vitamin C are simians (specifically the
> > > > suborder haplorrhini, which includes humans), guinea
> > > > pigs, a number of species of passerine birds (but
> > > > not all of them-there is some suggestion that the
> > > > ability was lost separately a number of times in
> > > > birds), and many (probably all) major families of
> > > > bats, including major insect and fruit-eating bat
> > > > families. These animals all lack the
> > > > L-gulonolactone oxidase (GULO) enzyme, which
> > > > is required in the last step of vitamin
> > > > C synthesis, because they have a defective
> > > > form of the gene for the enzyme
> > > > (Pseudogene ΨGULO)."
> > > >
> > > > http://www.news-medical.net/health/What-is-Vitamin-C.aspx
> > > >
> > > > ____________________________________
> > > >
> > > > > > Arguably humans are only unique in one sense we
> > > > > > have a relatively large brain, so perhaps the absence
> > > > > > of endogenous Neu5Gc is somehow favourable to
> > > > > > the brain.
> > > > > >
> > > > > Until further evidence turns up I think the most
> > > > > plausible null-hypothesis is that the lack of Neu5Gc
> > > > > freed up the Neu5Ac that otherwise would have been
> > > > > used to make Neu5Gc. The additional Neu5Ac was
> > > > > then used to create synaptic connections in the brains
> > > > > being enlarged by the plentiful DHA.
> > > > >
> > > > > Rob.
> > > >
> > > > Was its loss simply accident of evolution, or
> > > > was it a necessary step in the evolution of a
> > > > relatively large brain in the human lineage -
> > > > I would say it was the latter.
> > > >
> > > > --Bill
> > > >
> > >
> >
>

Herbivorous ecomorphology and specialization patterns in theropod dinosaur
evolution
LE Zanno & PJ Makovicky 2011 PNAS 108:232-7
http://www.pnas.org/content/108/1/232.abstract?etoc#
free access

... we present a refined approach for assessing trophic habits in fossil
taxa, and apply the method to Coelurosauria (for which diet is
controversial).
Our findings detect 21 morphological features that exhibit statistically
significant correlations with extrinsic fossil evidence of coelurosaurian
herbivory (eg, stomach contents, gastric mill).
These traits represent quantitative, extrinsically founded proxies for
identifying herbivorous eco-morphology in fossils, and are robust despite
uncertainty in phylogenetic relationships among major coelurosaurian
subclades.
The distribution of these features suggests that herbivory was widespread
among Coelurosauria :
- 6 major subclades display morphological evidence of the diet ;
- contrary to previous thought, hyper-carnivory was rel.rare, and
potentially secondarily derived.
Given the potential for repeated, independent evolution of herbivory in
Coelurosauria, we also test for repetitive patterns in the appearance of
herbivorous traits within sub-lineages, using rank concordance analysis.
We find evidence for a common succession of increasing specialization to
herbivory in Ornithomimosauria & Oviraptorosauria, perhaps underlain by
intrinsic functional &/or developmental constraints, as well as evidence
indicating that the early evolution of a beak in Coelurosauria correlates
with an herbivorous diet.

Family level phylogenies reveal modes of macroevolution in RNA viruses
A Kitchen, LA Shackelton & EC Holmes 2011 PNAS 108:238-243

... the colonization of new but related host species may represent the
principle mode of macro-evolution in RNA viruses.

Genetic evidence for patrilocal mating behavior among Neandertal groups
C Lalueza-Fox cs 2011 PNAS 108:250-3 open access

The remains of 12 Hn individuals have been found at El Sidrón (Asturias,
Spain): 6 adults, 3 adolescents, 2 juveniles, 1 infant.
Archaeological, paleontological & geological evidence indicates that these
individuals represent all or part of a contemporaneous social group of Hn,
who died at around the same time, and later were buried together as a result
of a collapse of an underground karst.
We sequenced phylogenetically informative positions of mtDNA hyper-variable
regions 1 & 2 from each of the remains.
Our results show that the 12 individuals stem from 3 different maternal
lineages (7, 4 & 1 individual(s) resp.).
Using a Y-chromosome assay to confirm the morphological determination of sex
for each individual, we found :
- the 3 adult males carried the same mtDNA lineage,
- each of the 3 adult females carried different mtDNA lineages.
These findings provide evidence that Hn groups not only were small, and
characterized by low genetic diversity, but also were likely to have
practiced patrilocal mating behavior.

2010. New Homo erectus maxilla from the base of the Bapang Formation
(Central Java, Indonesia): Hominins arrive prior to 1.5 Ma in the Sangiran
Dome (Y. Zaim, Ciochon, J. M.Polanski, F. E. Grine, E. A. Bettis III, Y.
Rizal, R. G. Franciscus, R. R. Larick, M. Heizler, K. L.Eaves  & H. Marsh).
Journal of Human Evolution (in revision).

2010. Divorcing Hominins from the Stegodon-Ailuropoda Fauna: New Views on
the Antiquity of Hominins in Asia. (Ciochon).  In: Out of Africa I: The
First Hominin Colonization of Eurasia,  edited by J.G. Fleagle, J.J. Shea,
F. Grine and R.E.F. Leakey, Springer Dordrecht, pp. 111-126.

2009. Introduction to Physical Anthropology, 2009-2010 (12th edition)
(Written by R. Jurmain, L. Kilgore, W. Trevathan and Ciochon).
Cengage-Wadsworth, Belmont, CA, 587 pp.

2009. The mystery ape of Pleistocene Asia (Ciochon). Nature 459: 9110-911.

2009. Asian Homo erectus converges in time (Ciochon & E.A. Bettis III).
Nature 458: 153-154.

2009. Way out of Africa: Early Pleistocene paleoenvironments inhabitated by
Homo erectus in Sangiran Dome, Java (E. A. Bettis III, A. K. Milius, S. J.
Carpenter, R. Larick, Y. Zaim, Y.Rizal, R.L. Ciochon, S. A. Tassier-Surine,
D. Murray, Suminto, and S. Bronto) Journal of Human Evolution 56: 11-24.

2008. Assessing mandibular shape variation in Gigantopithecus and
³Indopithecus² using a geometric morphometrics approach (S.F. Miller, J.
White, and Ciochon).  American Journal of Physical Anthropology 137:
201-212.

2008. Molar enamel thickness and dentine horn height in Gigantopithecus
blacki (A.J.Olejniczak, T.M. Smith, W. Wang, R. Potts, Ciochon, O. Kullmer,
F. Schrenk and J.-J. Hublin).
American Journal of Physical Anthropology 135: 85-91.

2007. Revisiting Primate Postcrania from the Pondaung Formation of Myanmar:
The Purported Anthropoid Astragalus (G.A. Gunnell and Ciochon).  Elwyn
Simons: Symposium Honoring his Contributions to Evolutionary Biology edited
by J.G. Fleagle and C.C. Gilbert, Springer, New York, pp. 211-228.

2007. The First Skull of the Earliest Giant Panda (Changzhu Jin, Ciochon,
Wei Dong, R. M.Hunt, Jr, Jinyi Liu, M. Jaeger, and Qizhi Zhu).  Proceedings
of the National Academy of
Sciences, USA 104: 10932-10937.

2006. Our Anthropoid roots (Ciochon and G.F. Gunnell).  Natural History,
vol. 115, no. 2 (March), pgs. 54-59.

2006. The Human Evolution Source Book (Ciochon and John Fleagle).
Pearson/Prentice Hall, Upper Saddle River, New Jersey, 716 pages.


[Non-text portions of this message have been removed]

February 2004
http://www2.uiowa.edu/dragon/Natural%20History%20Magazine%20%20Feature.htm
Featured Story
Headstrong Hominids

The mysterious skulls of Java man and Peking man
may have evolved because males were
clubbing each other in fights.

Noel T. Boaz & Russell L. Ciochon
This article was adapted from Noel T. Boaz & Russell L. Ciochon ³Dragon Bone
Hill: An Ice-Age Saga of Homo erectus² Oxford UP 2004.

Ever since the 1890s, when the Dutch anatomist Eugene Dubois unearthed the
first-recorded cranium of the early, small-brained human relative now known
as Homo erectus, scholars have been struck by the unusual anatomy of its
skull. The top and sides of the cranium have thick, bony walls and a low,
wide profile. To the modern eye, this part of its skull, known as the
calotte, or skullcap, looks a lot like a cyclist's helmet ‹ low &
streamlined, designed to protect the brain, ears & eyes from impact.
In contrast, we modern humans hold our enormous, easily injured, semi-liquid
brains in relatively thin-walled bony globes. We have to buy our bicycle
helmets.

Skull of Peking man, a composite  reconstruction by G.J. Sawyer & Ian
Tattersall that is based on skull XII & other fossils discovered in China

Photo by R.Mickens,  AMNH Because Dubois discovered his fossils in Java, it
and other specimens later found in that region became popularly known as
"Java man".  In the 1920s similar fossils were discovered in China's
Longgushan Cave, c 30 miles from Beijing (then transliterated in the West as
"Peking"), and were dubbed "Peking man".  At the time, no other hominid
fossils of comparable antiquity were known, so Dubois & everyone else
initially regarded the skull's robustness ‹ its strength & thickness ‹ as
typical of early human ancestors.  Even as late as the 1940s, Franz
Weidenreich (German PA, then working at the American Museum of Natural
History) proposed that H.erectus had descended from a line of massive,
indeed gigantic ancestors, and that modern H.sapiens was the end result of a
down-scaling trend.  But as more hominid fossils have come to light, it has
become clear that the ancestors of H.erectus did not have massive bones, and
neither did H.erectus.  In fact, except for its strange skull, the skeleton
of H.erectus resembled our own ...

The skullcaps discovered in E-Asia tend to be more robust than the ones in
Africa.  Hence some PAs have regarded the African fossils as a distinct
species, which they call H.ergaster.  But one African skullcap just as
robust as any Asian specimen was discovered by Louis Leakey in Olduvai
Gorge, Tanzania. It dates from c 1.4 Ma.  And even the strapping youth known
as Turkana boy, the most complete H.erectus skeleton discovered so far,
probably would have had a thick skull when fully grown ...

Visualizing Java man: A fossil designated Sangiran 17 is the most complete
H.erectus skull discovered on Java.  Under the supervision of Hisao Baba
(Curator of Anthropology, National Science Museum in Tokyo), sculptor Yoichi
Yazawa reconstructed the individual's appearance in life.  First, a cast of
the fossil (A) was rounded out with teeth, lower jaw & chewing muscles (B).
Other soft tissues were built up (C), finally the outer skin was added (D).
Because this fossil had relatively robust features compared with some
others, it was presumed to be that of a male.

Courtesy Hisao Baba, National Science Museum, Tokyo
Many differences in hominid skulls can be accounted for by the evolution of
the brain & the chewing apparatus. Large skulls are needed to contain large
brains, and large jaws & teeth for processing tough foods need heavy-duty
skull bones to anchor massive chewing muscles. Unfortunately, neither of
these tried-and-true explanations can entirely account for the unique
attributes of the H.erectus skull. What seems more likely is that the
species badly needed some protective headgear.  Functionally, the H.erectus
skullcap is similar to the defensive carapace of a turtle ‹ indeed, some
excavators have mistaken cranial fragments of H.erectus for fossil turtle
shell.  But what special sources of traumatic injury did hominids face that
might have encouraged the evolution of such a robust skull?  We don¹t think
it was exposure to predators (which can readily attack other, more
vulnerable parts of the body), or a habit of venturing into slippery or
precarious territory where the hazards of falling were increased. In
examining the protection afforded by the H.erectus skull, we think the
evidence points to some kind of violence perpetrated within the species
itself.

Large skulls are needed to contain large  brains, and large jaws & teeth for
processing tough foods need  heavy-duty skull bones to anchor massive
chewing muscles. Unfortunately,  neither of these tried-and-true
explanations can entirely account for the  unique attributes of the
H.erectus skull. What seems more likely  is that the species badly needed
some protective headgear ...

As one might expect, the thicker the bone, the less likely it is to break on
impact.  In our most recent work we have been experimentally testing &
quantifying the advantages of thick bones.  With a 9-foot-high
guillotine-like bone-testing apparatus, we administer calibrated impacts on
1-inch circular pieces of bone from human cadavers.  Certainly thick bone
does confer a competitive advantage.  But minimizing weight and optimizing
protective value at the same time is a problem that we continue to study.

Contrast between the cranium of H.erectus (top) & that of a modern human
(middle &  bottom) is clear in cross section.  H.erectus had by far the
thicker skull, with a prominent keel along the midline and extra  bracing
along the lower sides.

Patricia J.  Wynne
The H.erectus skullcap is described technically as pachyostotic
(³thick-boned²): thick, solid layers of bone make up both its inner & outer
surfaces.  Sandwiched between them is a less strong, lattice-like layer of
bone, whose intervening spaces, in life, would have been filled with marrow
& blood.  The H.erectus skull also has a number of unique bony structures.
3 of them (a beetling brow ridge & bony thickenings on the sides & rear of
the cranium) form a bony ring starting above the eyes, extending back around
the head above the ears, and meeting on the back of the head.  The top of
the skull resembles the inverted bottom of a boat, with a thickened bony
mound that looks like the boat¹s keel extending along the midline of the
skull [see illustration right].

In the 1920s, an American surgeon named E.R. LeCount classified skull
fractures by type. A heavy blow falling directly on top of the head tends to
cave in the bone overlying the so-called superior sagittal sinus, a channel
within the meninges for venous blood draining along the midline of the
brain. LeCount hypothesized that the strongly constructed midline of the
skull is an adaptation that protects against such damage. In most H.erectus
skulls the same adaptation appears in exaggerated form as the so-called
sagittal keel.

... Contrary to what one might predict, the H.erectus skull is not
particularly thick at the pterion ...






[Non-text portions of this message have been removed]

> Very interesting Marc. Before I don't think H erectus would be much aquatic
> (at least compared to H sapiens), but seems you got some evidences.
> - Evidence = POS, coastal/saline paleo-environment,... any more?

Yes IMO:
- He-like people appeared "suddenly" at Ain-Hanech, Dmanisi, Mojokerto etc c
1.8 Ma.  High sea levels then?? (Dmanisi at the Black-Caspian Sea connection
then.)
- Colonisation of Flores > 18 km overseas.
- Appearance of an external nose = incipient aquaticness?
- Keeling = stabilisation during swimming?
- Skull flattening (hydrodynamic).
- Brain enlargement = DHA?
- Ear exostoses in Peking He (in Hs, typical of divers & surfers - by
repeated wetting & drying in cold water & wind?  In guinea-pigs elicited by
irrigation with water colder than c 17°C).
- Always shellfish in paleo-milieu (see Stephen Munro's list, and see also
Joosten's paper below).

(Some "aquatic" adaptations appear fast & early in evolution (eg,
pachyostosis), other might appear after a long time, eg, gradually larger
brains?)

> - What do other PAs say about their heavy bones? Any hypotheses from them?
> Or more importantly, do they even discribe H.erectus as "pachyosteosclerotic"?

The term POS is from marine biology (see comments below).
The terminology is still confusing: if the medulla is narrower, the density
of the total bone is higher, of course, but the bone tissue itself can also
be denser.
In our papers we discern:
1) pachyostosis = thick compared to joints,
2) osteosclerotic = dense = more calcium/volume of cortex,
3) medullar stenosis = narrow marrow canal.
As in most incipient aquatics, many He bones show 1) & 3), probably also 2)
but this is more difficult to know for sure (see other mail).
De Buffrénil says Sirenia initially had 1) before 2) &/or 3), but his is
possibly not universal in incipient aquatics.

POS animals don't have all their bones POS.  The distribution of POS bones
is important for stabilisation in water (eg, seacows have very heavy ventral
parts of their ribs, this compensates for the large dorsal lungs, this
combination stabilises the animals pronogradely).

Hn seems to have had a heavy skeleton dorsally, but more lightly-built bones
ventrally, even lighter than in Hs: very large frontal sinuses & remarkably
slender claviculas & pubis (this suggests IMO they spent more time in fresh
water than He, and they often back-floated?  as you know, I now think that
Hn might seasonally have trekked inland from the coasts along rivers).


> - Some marine mammals (e.g. cetaceans) have *secondarily* reduced bone
> density, i.e. they had heavy bones before, but evolved lighter bones for
> faster movement together with: (a) lung compression during deep dive, (b)
> bigger and fewer red blood cells and (c) higher haemoglobin concentration to
> store more oxygen in blood.

Yes, fast & deep swimmers can even have (secondarily) more lightly-built
bones than terrestrials.

> Now H erectus have heavier-than-normal bones, and H sapiens have
> lighter-than-normal bones,

No, Hs & (at least some) apiths has slightly thicker bones than expected for
their size (compared to other primates & terrestrial mammals), but He had
bones that were perhaps >3 times heavier (twice as thick + narrower marrow +
probably denser bone tissue) than expected.

> can we say that we also have *secondarily* reduced
> bone density like the cetaceans?

I had the same thought, but AFAIK all secondarily-light-boned aquatics are
strongly adapted to fast & deep swimming, which can't be said of Homo.
More likely IMO, our slightly-heavy-boned skeleton is a relic of POS.

> Not to mention H sapiens also fulfill the
> above (a), (b) and (c) when compared to chimps.
> Happy New Year!

Happy 2011, Chak!

--marc



>> 1)    H.erectus is pachyosteosclerotic.
>> 2)    All pachyosteosclerotic animals are aquatic.
>> ergo: H.erectus is aquatic.
>> _____
>> Some commments:
>> 1)
>> Pachy-osteo-sclerosis (POS) means that the bones are
>> - denser than expected (high calcium content = osteo-sclerosis),
>> - thicker (compared to joint size = pachy-ostosis) &
>> - with narrower bone marrow canal (medullary stenosis).
>> These 3 features make the bone heavier.
>> Heavier bones are not stronger, to the contrary, eg, seacows (heaviest bones
>> known) have very brittle bones.
>> For terrestrial mammals there's an optimum between calcium & collagen
>> content & medulla size etc that makes the bones strong & supple enough & not
>> too brittle.
>> Some erectus bones have more POS than others.  The skull (esp.occiput =
>> posterior part), femora, humeri, pelvis (except perhaps the pubic part =
>> anterior part) etc are 2 or 3 times as heavy as is the case in comparable
>> terrestrial animals, eg, in most erectus the skull is twice as thick, the
>> diploe (medulla) is thinner, and the bone is denser.
>> Of all primates, only H.erectus & relatives ("archaic" spp) are known to
>> have POS.  Neandertals are intermediate in this respect between He & Hs.
>> H.sapiens doesn't have POS, or only to a very small degree.
>> 2)
>> All tetrapods with POS are aquatic (google pachyosteosclerosis).
>> The reverse is not true: many aquatic mammals (esp.Cetacea & fast swimmers)
>> have lightly built skeletons, lighter than terrestrial mammals (support is
>> less necessary in the water than outside).
>> But slow aquatics in shallow waters, esp.sea water, that dive for sessile
>> foods, typically have POS.  POS is most commonly seen in incipient aquatics,
>> often semi-aquatic, but the fully aquatic seacows have extreme POS.  Which
>> bones show most POS depends on the life-& swimming style, eg, bottom-walkers
>> often have dense leg bones (legs down, sea-otter, hippo), pronograde divers
>> often have dense ribs (seacow), dense skulls are seen in head-down divers
>> (seacow, walrus).
>> That the ventral skeleton (paranasal region, pubis) in erectus is less dense
>> than the dorsal part might suggest they back-floated parttime.
>> Committed aquatics lose POS.  AFAIK the only exception are seacows (very
>> slow), presumably to compensate for their large lungs (shallow-diving
>> mammals typically have very large lungs, but deep diving spp have rel.small
>> lungs).
>> POS not necessarily means fulltime aquaticness, but at least requires a
>> strong dependence on aquatic life, typically slow diving in salt water for
>> plants or slow prey that live on the bottom.
>> POS exclude fast running, of course: typical cursorials have very lightly
>> built skeletons (Arabic horse, greyhound, Kenyan long-distance runners):
>> endurance running hypotheses on erectus are nonsense.
>> AFAWK all erectus fossils have been found next to salt/brackish water (eg,
>> google econiche homo, see table), at least from Mojokerto 1.8 Ma to Eritrea
>> c 125 ka (eg, Joordens below), with the exception of KNM-OL-45500
>> (discussion below).  They have been found on islands that only could be
>> reached oversea.  All fossil evidence confirms that erectus is no exception
>> among pachyostotic animals.
>> In a Hs adult, the skeleton comprises c 14 % of the total body Wt (c 1/7).
>> Presumably, erectus had thick SC fat layers (eg, 1/5 of body Wt instead of c
>> 1/7, with specific gravity of fat tissue = c 0.92) & rel.large lungs (say c
>> 3.5 instead of 2.5 litres in normally filled lungs).
>> Some very rough estimations & calculations:
>> Specific gravities (densities):
>> - SC fat tissue   0.92  (fat alone c 0.9)
>> - lung tissue     0.55  (air c 0.0015)
>> - compact bone    1.85  (but denser in He)
>> - cancellous bone 1.08
>> dm3 in Hs of 70 kg:
>> - fat tissue         10    (male vs female)
>> - mean lung volume    2.5  (partly inflated)
>> - compact bone        7    (most of the bone)
>> - cancellous bone     3    (medulla)
>> dm3 in He:
>> - fat tissue         14   (cf aquatic)
>> - mean lung volume    3.5 (shallow aquatic)
>> - compact bone       10   (often twice as thick)
>> - cancellous bone     2.5
>> Difference in kg in He compared to Hs of 70 kg:
>> - SC fat     - 0.40
>> - lung       - 0.45
>> - compact bone     + 4 (thicker & denser bone)
>> - cancellous bone  - 0.05
>> Sum 3.4 kg, ie, c 2.38 % heavier (vs Hs 70 kg)
>> (large uncertainties = lung, bone & fat tissues).
>> I don't know whether freshwater mammals are generally somewhat heavier or
>> lighter (specific gravity) than terrestrial mammals, eg, hippos
>> (bottom-walkers, AFAIK heavy skeletons)? tapirs?
>> Sea water is c 2.4 % heavier than fresh water (but can be much denser in
>> shallow tropical marine or saline "enclaves" (evaporation) where possibly
>> some He might have lived preferably).
>> The high bone density of He suggests a marine/saline milieu, but if their
>> lungs or SC fat were much larger (well possible IMO), a brackish milieu or a
>> combination of fresh & salt waters could also have been possible (see
>> Joordens paper below).
>> POS can evolve & disappear in rel.short time spans (a few 100s or 1000s of
>> years? = secular trend):
>> - The small skull OL-45500 (Olorgesailie, Kenya, c 1 Ma?, ass.x Acheulian
>> handaxes) had He-like features (eg, well-developed post-toral sulcus +
>> shelf-like morphology, wide convex inter-orbital region, short temporal
>> squama + flat superior border, mid-line keeling of frontal bone), but thin
>> cranial bones overall.  R.Potts cs.2004 Sci.305:75-78: "Fossils found by
>> sieving of the sandy silt adhering to the frontal bone include amphibian
>> bones and a single tooth of the rodent Otomys sp., which inhabits thick
>> grasses in and around modern East African swamps, lakes and rivers..." =
>> freshwater dweller?
>> - OTOH some Hs fossils (Kow Swamp) had archaic features & heavy skeletons
>> when they lived near lakes where they consumed mussels. When the shellfish
>> there became extinct c 19 ka, the lake was abandoned. --marc
>> _____
>> Relevance of aquatic environments for hominins:
>> A case study from Trinil (Java, Indonesia)
>> JCA Joordens cs.2009 JHE 57:656-671 doi 10.1016/j.jhevol.2009.06.003
>>     ... we provide ecological context for the current debate on modernity
>> (or not) of aquatic resource exploitation by hominins. We use the H.erectus
>> site of Trinil as a case study to investigate how research questions on
>> possible dietary relevance of aquatic environments can be addressed. Faunal
>> & geochemical analysis of aquatic fossils from Trinil Hauptknochenschicht
>> (HK) fauna demonstrate that Trinil at 1.5 Ma contained near-coastal rivers,
>> lakes, swamp forests, lagoons & marshes with minor marine influence,
>> laterally grading into grasslands.  Trinil HK environments yielded at least
>> 11 edible mollusc spp & 4 edible fish spp that could be procured with no or
>> minimal technology.  We demonstrate that, from an ecological point of view,
>> the default assumption should be that omnivorous hominins in coastal
>> habitats with catchable aquatic fauna could have consumed aquatic resources.
>> The hypothesis of aquatic exploitation can be tested with taphonomic
>> analysis of aquatic fossils associated with hominin fossils.  We show that
>> midden-like characteristics of large bivalve shell assemblages containing
>> Pseudodon & Elongaria from Trinil HK indicate deliberate collection by a
>> selective agent, possibly hominin.
>> ______
>> Skeleton weight allometry in aquatic and terrestrial vertebrates
>> WW Reynolds 1977 Hydrobiologia 56:35-37 doi 10.1007/BF00023283
>>     The relation of skeleton Wt to body Wt with increasing size is compared
>> for aquatic & terrestrial vertebrates.  Due to the buoyancy of water, the
>> skeleton weights of aquatic vertebrates (fishes & whales) vary in nearly
>> direct proportion (exponent 1.0) to body Wt ; the skeletons of terrestrial
>> vertebrates occupy an increasingly greater proportion of total body Wt as
>> size increases (exponent >1) due to the necessity of supporting their Wt on
>> land.
>> _____
>> Density of fresh and embalmed human compact and cancellous bone
>> PL Blanton & NL Biggs 1968 AJPA 29:39?4 doi?0.1002/ajpa.1330290113
>>     This investigation was undertaken to determine the densities of
>> - fresh human compact & cancellous bone (marrow constituents intact),
>> - compact & cancellous bone taken from embalmed cadavers.
>> The density of 107 bone specimens was determined on the basis of the Wt &
>> volume of each specimen. Mean density results were:
>> - fresh compact bone     1.85,
>> - fresh cancellous bone  1.08,
>> - embalmed compact bone    1.85,
>> - embalmed cancellous bone 1.09.
>> Embalming did not appear to have altered the density of either compact or
>> cancellous bone.
>> It was observed also that the densities of several bone specimens taken from
>> the same area of one bone varied greatly.

Mitochondrial Population Genomics Supports a Single Pre-Clovis Origin with a
Coastal Route for the Peopling of the Americas
NJR Fagundes cs 2008 Am.J.hum.Gen.82:583-592 doi 10.1016/j.ajhg.2007.11.013

It is well accepted that the Americas were the last continents reached by
modern humans, most likely through Beringia.
However, the precise time & mode of the colonization of the New World remain
hotly disputed issues.

Native American populations exhibit almost exclusively 5 mtDNA haplogroups
(A­D & X).
Haplogroups A­D are also frequent in Asia, suggesting a NE-Asian origin of
these lineages.
However, the differential pattern of distribution & frequency of haplogroup
X led some to suggest that it may represent an independent migration to the
Americas.

Here we show, by using 86 complete mt genomes, that all Native American
haplogroups (incl.X) were part of a single founding population, thereby
refuting multiple-migration models.
A detailed demographic history of the mtDNA sequences estimated with a
Bayesian coalescent method indicates a complex model for the peopling of the
Americas, in which the initial differentiation from Asian populations ended
with a moderate bottleneck in Beringia during the LGM c 23-19 ka. Toward the
end of the LGM, a strong population expansion started c 18 ka, and finished
c 15 ka.
These results support a pre-Clovis occupation of the New World, suggesting a
rapid settlement of the continent along a Pacific coastal route.

Mitochondrial Population Genomics Supports a Single Pre-Clovis Origin with a
Coastal Route for the Peopling of the Americas
NJR Fagundes cs 2008 Am.J.hum.Gen.82:583-592 doi 10.1016/j.ajhg.2007.11.013

It is well accepted that the Americas were the last continents reached by
modern humans, most likely through Beringia.
However, the precise time & mode of the colonization of the New World remain
hotly disputed issues.

Native American populations exhibit almost exclusively 5 mtDNA haplogroups
(A­D & X).
Haplogroups A­D are also frequent in Asia, suggesting a NE-Asian origin of
these lineages.
However, the differential pattern of distribution & frequency of haplogroup
X led some to suggest that it may represent an independent migration to the
Americas.

Here we show, by using 86 complete mt genomes, that all Native American
haplogroups (incl.X) were part of a single founding population, thereby
refuting multiple-migration models.
A detailed demographic history of the mtDNA sequences estimated with a
Bayesian coalescent method indicates a complex model for the peopling of the
Americas, in which the initial differentiation from Asian populations ended
with a moderate bottleneck in Beringia during the LGM c 23-19 ka. Toward the
end of the LGM, a strong population expansion started c 18 ka, and finished
c 15 ka.
These results support a pre-Clovis occupation of the New World, suggesting a
rapid settlement of the continent along a Pacific coastal route.

The Gravettian burial known as the Prince (“Il Principe�):
new evidence for his age and diet
PB Pettitt, M Richards, R Maggi & V Formicola 2003
Antiquity
http://findarticles.com/p/articles/mi_hb3284/is_295_77/ai_n28995837/

The famous upper Palaeolithic (Gravettian) burial with shell ornaments known
as “Il Principe� was discovered in Italy 60 years ago.
Here the authors present recent scientific research on his skeleton, leading
to new assessments of the date of the burial & indications of diet.

“Il Principe� is the nickname given to a spectacular Mid Upper Palaeolithic
(Gravettian) burial discovered at Arene Candide, Italy in 1942.
Arene Candide is a large cave located c 90 m above sea level on the slope of
the Caprazoppa promontory (Ligurian coast near Finale Ligure, Savona).
The cave is named after a dune of white siliceous sand of aeolian origin,
banked against the wall of the promontory, today destroyed by quarrying
activity.
Systematic excavation of its rich deposit was carried out at the beginning
of the 1940s by Bernabò Brea & Cardini, who exposed a stratigraphic sequence
which ranged from the Upper Palaeolithic to historical times, and included
many burials of Late Epigravettian & Neolithic date.
The burial of “Il Principe� (Arene Candide 1) came to light on 1.5.42,
during the excavation of a sondaggio (test core) into the Pleistocene
deposits, shortly before the excavations were interrupted by the war.
The skeleton of an adolescent male, spectacularly ornamented, hence “Il
Principe�, was found at a depth 6.70 m in a bed of red ochre, its head
surrounded by 100s of perforated shells & canines of deer, probably
originally forming a kind of cap.
Shells (Ciprea sp.), pendants of mammoth ivory, 4 perforated “bâtons de
commandement� of elk antler, 3 of which were decorated with thin radial
striations around the hole & a 23 cm long flint blade held in the right hand
were additional components of the extraordinary ornamentation of this
specimen (Fig.1).
... the result shows that the burial was emplaced between 23.820-23.060 ka
...

Dietary information

The C & N stable isotope values of the extracted & dated collagen provide us
with information on the diet of ‘Il Principe’.
Stable isotope analyses provides information on protein sources in diets
over the last years of life, and is particularly well suited to
distinguishing between marine & terrestrial protein sources.
The δ13C value of –17.6 & the associated δ15N value of 12.6 % are indicative
of a contribution of marine foods to the diet.
If we use Holocene end-point values of –20 ± 1 % for a 100 % terrestrial
diet, and –12 ± 1 for a 100 % marine diet, the ‘Il Principe’ values
indicate
that c 20-25 % of dietary protein is from marine protein, probably from the
Mediterranean.
This links in well with a larger study of Gravettian humans from Eurasia
which have also been dated directly using the AMS radio-C technique
(Richards et al. 2001) in which evidence for the use of aquatic resources
was indicated for a number of individuals through stable isotope analyses
...

N Rohland cs 2010 Publ Libr Sci Biol 8(12):e1000564  
Genomic DNA sequences from mastodon and wooly mammoth reveal deep speciation
of forest and savanna elephants

... we generated 39,763 bp of aligned nuclear DNA sequence across 375 loci
for
* African savanna elephant,
* African forest elephant,
* Asian elephant,
* the extinct American mastodon &
* the woolly mammoth.

Our data establish:
* the Asian elephant is the closest living relative of the extinct mammoth
in the nuclear genome, extending previous findings from mtDNA analyses ;
* savanna & forest elephants, which some have argued are the same species,
are as or more divergent in the nuclear genome as mammoths & Asian
elephants, which are considered to be distinct genera, thus resolving a
long-standing debate about the appropriate taxonomic classification of the
African elephants.
We document a much larger effective population size in forest elephants
compared with the other elephantid taxa, likely reflecting species
differences in ancient geographic structure & range, & differences in life
history traits such as variance in male reproductive success.

______


AUTHOR SUMMARY

The living  elephants are the last survivors of a once highly successful
mammalian order, the Proboscidea, which includes extinct species such as the
iconic woolly mammoth Mammuthus primigenius & the American mastodon Mammut
americanum.
Despite numerous studies, the phylogenetic relationships of the modern
elephants to the woolly mammoth, as well as the taxonomic status of the
African elephants of the genus Loxodonta, remain controversial.
This is in large part due to the fact that both the woolly mammoth & the
American mastodon (the closest outgroup to elephants & mammoths available
for genetic studies) are extinct, posing considerable technical hurdles for
comparative genetic analysis.

We have used a combination of modern DNA sequencing & targeted PCR
amplification, to obtain a large data set for comparing American mastodon,
woolly mammoth, Asian elephant, African savanna elephant & African forest
elephant.

We unequivocally establish that the Asian  elephant is the sister species to
the woolly mammoth.
A surprising finding from our study is that the divergence of African
savanna & forest elephants ‹ which some have argued to be 2 populations of
the same species ‹ is about as ancient as the divergence of Asian elephants
& mammoths.  Given their ancient divergence, we conclude that African
savanna & forest elephants should be classified as 2 distinct species.

> Marc, I have a slight precision to add:

Hi P-F    :-)

> Heavier bones are not stronger, the skull development has been different.

Yes, marble disease (& other "osteopetroses") is very brittle (too much
calcium vs collagen etc.?).
Also, flat domes as in He skulls (platycephaly) are less strong than rounder
vaults as in Hs (cf helmet).

> Since I am concerned with odontology, I think you must join the tooth
> development that produces different morphologies (very characteristic in
> neanderthals).     Amitiés PF

Hn has, eg,
A) taurodont cheek teeth,
B) shovel-like incisors &
C) a retro-molar space.

A) + larger pulpa + longer-growing teeth = herbivorous adaptation as in
other mammals with larger pulpas? more attrition?
B) = for strengthening? biting what?
C) has to do with hydrodynamic nose+midface-lengthening + skull-flattening
(platycephaly)?

--marc

----- Original Message -----
From: "Heather Twist" <HeatherTwist@...>
To: <AAT@yahoogroups.com>
Sent: Sunday, January 02, 2011 8:02 PM
Subject: Re: [AAT] Live fast, die young? Maybe not.... (Was: Neu5Gc Chimp
the Hunter, Kills the Savanna Hypotheses)


Bird metabolism is faster than a mouse, and they often live harder
lives (they don't usually live in holes most of the day). Yet a 90-year-
old albatross can still fly. It's like the difference between annuals
and perennials in plants: mice have a "stop" mechanism that will make
them die no matter what. Birds don't, nor do most fish.

That annual/perennial comparison was interesting. Has anyone speculated on
the respective advantages of those two modes?

Elaine

On Wed, Jan 5, 2011 at 11:57 AM, Elaine Morgan <elaine@...>wrote:

>
>
>
> ----- Original Message -----
> From: "Heather Twist" <HeatherTwist@... <HeatherTwist%40gmail.com>>
> To: <AAT@yahoogroups.com <AAT%40yahoogroups.com>>
> Sent: Sunday, January 02, 2011 8:02 PM
> Subject: Re: [AAT] Live fast, die young? Maybe not.... (Was: Neu5Gc Chimp
> the Hunter, Kills the Savanna Hypotheses)
>
> Bird metabolism is faster than a mouse, and they often live harder
> lives (they don't usually live in holes most of the day). Yet a 90-year-
> old albatross can still fly. It's like the difference between annuals
> and perennials in plants: mice have a "stop" mechanism that will make
> them die no matter what. Birds don't, nor do most fish.
>
> That annual/perennial comparison was interesting. Has anyone speculated on
> the respective advantages of those two modes?
>
> Elaine
>
In terms of this group, there is another interesting thing: Mouse and bovine
milk, and presumably most mammal milk, is mainly GC. But elephant, human,
and whale milk is AC. ). That might relate AC to an aquatic adaption too.
  Whales and elephants live longer than most mammals also. So of all the
mammals, the only ones found to have AC in their milk just happen to be
aquatic-adapted ones?

I can't find a clear reference for pork or hippos: Pigs are mixed with AC
and GC in their bodies, but I don't know about their milk.

The one other mammal that has mainly AC in immunoglobulin is guinea pigs,
which are an artificial animal bred to live with humans, and are
longer-lived than many rodents. Cats, dogs, rabbits, and rats have *some*
AC, and those are animals that also live with humans.

http://books.google.com/books?id=TA_5gsNtx2cC&pg=PA52&lpg=PA52&dq=neu5ac+guinea+\
pigs&source=bl&ots=NsH1Zj6yp2&sig=ASVYoz4IfQ0pTvnyf00CEa1Aehc&hl=en&ei=k9skTdzgI\
5S8sAOOrsW_AQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCUQ6AEwAg#v=onepage&q\
&f=false


Guinea pigs live 5-8 years, as opposed to 2-3 for pet rats and about 1 year
for mice.

Among rodents, the longest-lived rodents are in general the water-swimming
or flying ones: beavers and nutria and bats live longer than mice and rats.
My theory is that aging has to do with mobility and food supply. Animals
that are tied to one location need to have aging, because they can easily
out-produce their food supply. But animals that can easily move to new
feeding grounds don't need aging. Mice often live their entire lives in a
very small area, and they have very short lifespans. Rats move around more,
but they still keep to one geographic area, and they live longer. Beavers
and bats have a far wider feeding area, and they live the longest. Guinea
pigs always live with human beings, so presumably they get fed as much as
they want, but they were also a food source so probably weren't kept around
all that long.

But anything that lives in the water has a more varied food supply, because
there tends to be more food in the water and it replenishes itself faster.
Where grass only grows fast at one time during the year, seaweed can grow
several feet a day, and it's difficult to eat local fish faster than they
can reproduce. So there isn't so much of a need for a short lifespan.

It looks like there isn't all that much research yet on sialic acid though.
I'm guessing some interesting stuff is going to come out of this.

>
>
--
Heather Twist
http://eatingoffthefoodgrid.blogspot.com/


[Non-text portions of this message have been removed]

Thanks a lot, Heather, very interesting ­ there¹s still a lot to be
discovered.

About life expectancy: it¹s usu.believed that spp that live long have few
predators (top of food chain) or can easily escape predators (eg, fly away:
birds a bats). No wonder whales, elephants & humans live long. It¹s not
necessarily connected to aq.life.
Spp that have a lot of predators have to live fast, breed early & have large
offsprings.

Possibly cavioids (guinea-pig, capibara...) are/were semi-aq.

--marc

_____


>> Bird metabolism is faster than a mouse, and they often live harder
>> lives (they don't usually live in holes most of the day). Yet a 90-year-
>> old albatross can still fly. It's like the difference between annuals
>> and perennials in plants: mice have a "stop" mechanism that will make
>> them die no matter what. Birds don't, nor do most fish.
>> That annual/perennial comparison was interesting. Has anyone speculated on
>> the respective advantages of those two modes?  Elaine

> In terms of this group, there is another interesting thing: Mouse and bovine
> milk, and presumably most mammal milk, is mainly GC. But elephant, human,
> and whale milk is AC. ). That might relate AC to an aquatic adaption too.
>  Whales and elephants live longer than most mammals also. So of all the
> mammals, the only ones found to have AC in their milk just happen to be
> aquatic-adapted ones?
> I can't find a clear reference for pork or hippos: Pigs are mixed with AC
> and GC in their bodies, but I don't know about their milk.
> The one other mammal that has mainly AC in immunoglobulin is guinea pigs,
> which are an artificial animal bred to live with humans, and are
> longer-lived than many rodents. Cats, dogs, rabbits, and rats have *some*
> AC, and those are animals that also live with humans.
> http://books.google.com/books?id=TA_5gsNtx2cC&pg=PA52&lpg=PA52&dq=neu5ac+guine
> a+pigs&source=bl&ots=NsH1Zj6yp2&sig=ASVYoz4IfQ0pTvnyf00CEa1Aehc&hl=en&ei=k9skT
> dzgI5S8sAOOrsW_AQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCUQ6AEwAg#v=one
> page&q&f=false
> Guinea pigs live 5-8 years, as opposed to 2-3 for pet rats and about 1 year
> for mice.
> Among rodents, the longest-lived rodents are in general the water-swimming
> or flying ones: beavers and nutria and bats live longer than mice and rats.
> My theory is that aging has to do with mobility and food supply. Animals
> that are tied to one location need to have aging, because they can easily
> out-produce their food supply. But animals that can easily move to new
> feeding grounds don't need aging. Mice often live their entire lives in a
> very small area, and they have very short lifespans. Rats move around more,
> but they still keep to one geographic area, and they live longer. Beavers
> and bats have a far wider feeding area, and they live the longest. Guinea
> pigs always live with human beings, so presumably they get fed as much as
> they want, but they were also a food source so probably weren't kept around
> all that long.
> But anything that lives in the water has a more varied food supply, because
> there tends to be more food in the water and it replenishes itself faster.
> Where grass only grows fast at one time during the year, seaweed can grow
> several feet a day, and it's difficult to eat local fish faster than they
> can reproduce. So there isn't so much of a need for a short lifespan.
> It looks like there isn't all that much research yet on sialic acid though.
> I'm guessing some interesting stuff is going to come out of this.

The "few predators" part makes sense also, esp. for mammals ... some
animals, like wolves, regulate their birth rate too.

But in terms of birds, reptiles, and fish though, pretty much all of them
age similarly, the ones at the bottom of the food chain and the ones at the
top. However, the ones at the bottom get predated on constantly so it's not
obvious what the average life span is. Individuals don't show age in the
same way mammals do. These animals age more like apple trees do: an
individual apple tree will just keep going and going until it gets bark rot
or some such.

So in terms of something like a sea turtle: most of the babies get eaten. If
one makes it to adulthood, it just keeps getting bigger and bigger and lives
for centuries. With mice, most of the mice get eaten in the first year too,
but if it doesn't get eaten, it will die anyway because its body stops
working, in a rather dramatic way. Humans and whales seem somewhere in the
middle: we don't age in the same way as apes (women go into menopause about
the time a female ape would die of old age), but we don't "keep going" like
a sea turtle or a chicken. I don't know how dolphins age: I haven't seen
anything that shows arthritis or wrinkly skin in an old dolphin or whale
though. Dolphins have a fair number of predators though.

But regardless of WHY they live longer, the thing about whales, elephants
and humans is that they are among the apparent few mammals that use neu5Ac
in their milk rather than the neu5Gc version. So my question is: is that
coincidental to their being long lived? Or to their being aquatic? Or both
(i.e. it's easier to be long-lived if you are aquatic)? Or it's just a
strange coincidence?

It's also interesting because among fish, the only fish that is listed as
having a fair amount of GC is salmon, and those are the one fish I know of
that at least in some species has a truncated lifespan.

Interesting that guinea pigs may once have been semi-aquatic. Guinea pigs
are one of the few mammals besides humans and primates that don't synthesize
vitamin C, presumably because their owners fed them fruit scraps?


On Wed, Jan 5, 2011 at 3:34 PM, Marc Verhaegen <m_verhaegen@...>wrote:

>
>
> Thanks a lot, Heather, very interesting ­ there¹s still a lot to be
> discovered.
>
> About life expectancy: it¹s usu.believed that spp that live long have few
> predators (top of food chain) or can easily escape predators (eg, fly away:
> birds a bats). No wonder whales, elephants & humans live long. It¹s not
> necessarily connected to aq.life.
> Spp that have a lot of predators have to live fast, breed early & have
> large
> offsprings.
>
> Possibly cavioids (guinea-pig, capibara...) are/were semi-aq.
>
> --marc
>
> _____
>
>
> >> Bird metabolism is faster than a mouse, and they often live harder
> >> lives (they don't usually live in holes most of the day). Yet a 90-year-
> >> old albatross can still fly. It's like the difference between annuals
> >> and perennials in plants: mice have a "stop" mechanism that will make
> >> them die no matter what. Birds don't, nor do most fish.
> >> That annual/perennial comparison was interesting. Has anyone speculated
> on
> >> the respective advantages of those two modes? Elaine
>
> > In terms of this group, there is another interesting thing: Mouse and
> bovine
> > milk, and presumably most mammal milk, is mainly GC. But elephant, human,
> > and whale milk is AC. ). That might relate AC to an aquatic adaption too.
> > Whales and elephants live longer than most mammals also. So of all the
> > mammals, the only ones found to have AC in their milk just happen to be
> > aquatic-adapted ones?
> > I can't find a clear reference for pork or hippos: Pigs are mixed with AC
> > and GC in their bodies, but I don't know about their milk.
> > The one other mammal that has mainly AC in immunoglobulin is guinea pigs,
> > which are an artificial animal bred to live with humans, and are
> > longer-lived than many rodents. Cats, dogs, rabbits, and rats have *some*
> > AC, and those are animals that also live with humans.
> >
> http://books.google.com/books?id=TA_5gsNtx2cC&pg=PA52&lpg=PA52&dq=neu5ac+guine
> >
> a+pigs&source=bl&ots=NsH1Zj6yp2&sig=ASVYoz4IfQ0pTvnyf00CEa1Aehc&hl=en&ei=k9skT
> >
> dzgI5S8sAOOrsW_AQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCUQ6AEwAg#v=one
> > page&q&f=false
> > Guinea pigs live 5-8 years, as opposed to 2-3 for pet rats and about 1
> year
> > for mice.
> > Among rodents, the longest-lived rodents are in general the
> water-swimming
> > or flying ones: beavers and nutria and bats live longer than mice and
> rats.
> > My theory is that aging has to do with mobility and food supply. Animals
> > that are tied to one location need to have aging, because they can easily
> > out-produce their food supply. But animals that can easily move to new
> > feeding grounds don't need aging. Mice often live their entire lives in a
> > very small area, and they have very short lifespans. Rats move around
> more,
> > but they still keep to one geographic area, and they live longer. Beavers
> > and bats have a far wider feeding area, and they live the longest. Guinea
> > pigs always live with human beings, so presumably they get fed as much as
> > they want, but they were also a food source so probably weren't kept
> around
> > all that long.
> > But anything that lives in the water has a more varied food supply,
> because
> > there tends to be more food in the water and it replenishes itself
> faster.
> > Where grass only grows fast at one time during the year, seaweed can grow
> > several feet a day, and it's difficult to eat local fish faster than they
> > can reproduce. So there isn't so much of a need for a short lifespan.
> > It looks like there isn't all that much research yet on sialic acid
> though.
> > I'm guessing some interesting stuff is going to come out of this.
>
>
>



--
Heather Twist
http://eatingoffthefoodgrid.blogspot.com/


[Non-text portions of this message have been removed]

Those PAs still dream about our ancestors as blood-thursty violent beasts....

Fine, but did they find any evidence of skull damage due to clubbing or other
attacks?  If no, their arguement is not supported by evidence.

Chak


--- In AAT@yahoogroups.com, Marc Verhaegen <m_verhaegen@...> wrote:
>
> February 2004
> http://www2.uiowa.edu/dragon/Natural%20History%20Magazine%20%20Feature.htm
> Featured Story
> Headstrong Hominids
>
> The mysterious skulls of Java man and Peking man
> may have evolved because males were
> clubbing each other in fights.
>
> Noel T. Boaz & Russell L. Ciochon
> This article was adapted from Noel T. Boaz & Russell L. Ciochon ³Dragon Bone
> Hill: An Ice-Age Saga of Homo erectus² Oxford UP 2004.
>
> Ever since the 1890s, when the Dutch anatomist Eugene Dubois unearthed the
> first-recorded cranium of the early, small-brained human relative now known
> as Homo erectus, scholars have been struck by the unusual anatomy of its
> skull. The top and sides of the cranium have thick, bony walls and a low,
> wide profile. To the modern eye, this part of its skull, known as the
> calotte, or skullcap, looks a lot like a cyclist's helmet ‹ low &
> streamlined, designed to protect the brain, ears & eyes from impact.
> In contrast, we modern humans hold our enormous, easily injured, semi-liquid
> brains in relatively thin-walled bony globes. We have to buy our bicycle
> helmets.
>
> Skull of Peking man, a composite  reconstruction by G.J. Sawyer & Ian
> Tattersall that is based on skull XII & other fossils discovered in China
>
> Photo by R.Mickens,  AMNH Because Dubois discovered his fossils in Java, it
> and other specimens later found in that region became popularly known as
> "Java man".  In the 1920s similar fossils were discovered in China's
> Longgushan Cave, c 30 miles from Beijing (then transliterated in the West as
> "Peking"), and were dubbed "Peking man".  At the time, no other hominid
> fossils of comparable antiquity were known, so Dubois & everyone else
> initially regarded the skull's robustness ‹ its strength & thickness ‹ as
> typical of early human ancestors.  Even as late as the 1940s, Franz
> Weidenreich (German PA, then working at the American Museum of Natural
> History) proposed that H.erectus had descended from a line of massive,
> indeed gigantic ancestors, and that modern H.sapiens was the end result of a
> down-scaling trend.  But as more hominid fossils have come to light, it has
> become clear that the ancestors of H.erectus did not have massive bones, and
> neither did H.erectus.  In fact, except for its strange skull, the skeleton
> of H.erectus resembled our own ...
>
> The skullcaps discovered in E-Asia tend to be more robust than the ones in
> Africa.  Hence some PAs have regarded the African fossils as a distinct
> species, which they call H.ergaster.  But one African skullcap just as
> robust as any Asian specimen was discovered by Louis Leakey in Olduvai
> Gorge, Tanzania. It dates from c 1.4 Ma.  And even the strapping youth known
> as Turkana boy, the most complete H.erectus skeleton discovered so far,
> probably would have had a thick skull when fully grown ...
>
> Visualizing Java man: A fossil designated Sangiran 17 is the most complete
> H.erectus skull discovered on Java.  Under the supervision of Hisao Baba
> (Curator of Anthropology, National Science Museum in Tokyo), sculptor Yoichi
> Yazawa reconstructed the individual's appearance in life.  First, a cast of
> the fossil (A) was rounded out with teeth, lower jaw & chewing muscles (B).
> Other soft tissues were built up (C), finally the outer skin was added (D).
> Because this fossil had relatively robust features compared with some
> others, it was presumed to be that of a male.
>
> Courtesy Hisao Baba, National Science Museum, Tokyo
> Many differences in hominid skulls can be accounted for by the evolution of
> the brain & the chewing apparatus. Large skulls are needed to contain large
> brains, and large jaws & teeth for processing tough foods need heavy-duty
> skull bones to anchor massive chewing muscles. Unfortunately, neither of
> these tried-and-true explanations can entirely account for the unique
> attributes of the H.erectus skull. What seems more likely is that the
> species badly needed some protective headgear.  Functionally, the H.erectus
> skullcap is similar to the defensive carapace of a turtle ‹ indeed, some
> excavators have mistaken cranial fragments of H.erectus for fossil turtle
> shell.  But what special sources of traumatic injury did hominids face that
> might have encouraged the evolution of such a robust skull?  We don¹t think
> it was exposure to predators (which can readily attack other, more
> vulnerable parts of the body), or a habit of venturing into slippery or
> precarious territory where the hazards of falling were increased. In
> examining the protection afforded by the H.erectus skull, we think the
> evidence points to some kind of violence perpetrated within the species
> itself.
>
> Large skulls are needed to contain large  brains, and large jaws & teeth for
> processing tough foods need  heavy-duty skull bones to anchor massive
> chewing muscles. Unfortunately,  neither of these tried-and-true
> explanations can entirely account for the  unique attributes of the
> H.erectus skull. What seems more likely  is that the species badly needed
> some protective headgear ...
>
> As one might expect, the thicker the bone, the less likely it is to break on
> impact.  In our most recent work we have been experimentally testing &
> quantifying the advantages of thick bones.  With a 9-foot-high
> guillotine-like bone-testing apparatus, we administer calibrated impacts on
> 1-inch circular pieces of bone from human cadavers.  Certainly thick bone
> does confer a competitive advantage.  But minimizing weight and optimizing
> protective value at the same time is a problem that we continue to study.
>
> Contrast between the cranium of H.erectus (top) & that of a modern human
> (middle &  bottom) is clear in cross section.  H.erectus had by far the
> thicker skull, with a prominent keel along the midline and extra  bracing
> along the lower sides.
>
> Patricia J.  Wynne
> The H.erectus skullcap is described technically as pachyostotic
> (³thick-boned²): thick, solid layers of bone make up both its inner & outer
> surfaces.  Sandwiched between them is a less strong, lattice-like layer of
> bone, whose intervening spaces, in life, would have been filled with marrow
> & blood.  The H.erectus skull also has a number of unique bony structures.
> 3 of them (a beetling brow ridge & bony thickenings on the sides & rear of
> the cranium) form a bony ring starting above the eyes, extending back around
> the head above the ears, and meeting on the back of the head.  The top of
> the skull resembles the inverted bottom of a boat, with a thickened bony
> mound that looks like the boat¹s keel extending along the midline of the
> skull [see illustration right].
>
> In the 1920s, an American surgeon named E.R. LeCount classified skull
> fractures by type. A heavy blow falling directly on top of the head tends to
> cave in the bone overlying the so-called superior sagittal sinus, a channel
> within the meninges for venous blood draining along the midline of the
> brain. LeCount hypothesized that the strongly constructed midline of the
> skull is an adaptation that protects against such damage. In most H.erectus
> skulls the same adaptation appears in exaggerated form as the so-called
> sagittal keel.
>
> ... Contrary to what one might predict, the H.erectus skull is not
> particularly thick at the pterion ...
>
>
>
>
>
>
> [Non-text portions of this message have been removed]
>

--- In AAT@yahoogroups.com, "ChakAzul" <albert.chak@...> wrote:
>
>
> Those PAs still dream about our ancestors as blood-thursty violent beasts....
>
> Fine, but did they find any evidence of skull damage due to clubbing or other
attacks?  If no, their arguement is not supported by evidence.
>
> Chak
>





Chak

From the article:


"Franz Weidenreich was trained as a medical doctor,
and worked most of his career in medical institutions
in Germany. He even served briefly as a medic in the
German army during the First World War. Doubtless,
then, he had more than a passing familiarity with
the devastating effects of head trauma—a familiarity
that became invaluable when he began to analyze the
skulls of Peking man.

In those fossil specimens he identified a number of
depressed fractures that had subsequently healed. In
other words, half a million years or so after these
hominids had sustained massive blows to the head,
Weidenreich had suddenly stumbled on evidence that
could still reveal not only the kind of trauma that
resulted, but also, because the trauma victims had
survived, the protective value of their skulls.
Tragically, the original fossils of Peking man were
lost during the Japanese invasion of China in the
Second World War. Fortunately, careful casts of the
excavated remains had been made before the war, and
so we were still able to re-examine the head
trauma systematically.

Some of the damage Weidenreich first attributed to
hominids he later ascribed to carnivores. Other damage
was clearly geological: some bones have been crushed
by overlying sediment, others bear the impressions
of rocks pushed into them as they themselves turned
to stone. But in the end, Weidenreich classified
some ten depressions or defects in the skulls as
having been caused by blows from other hominids.
We agree. The damage closely matches in size, form,
and even location the healed depressed fractures
seen in human skulls today [see photo below]."


Headstrong Hominids

http://www2.uiowa.edu/dragon/Natural%20History%20Magazine%20%20Feature.htm


________________________________




It is perhaps more likely that modern humans (AMH) evolved
from the thinner skulled H.ergaster in north Africa...  an
is unrelated to these thick skulled hominids.



Homo ergaster: (definition )
H. ergaster may be distinguished from H. erectus by
its thinner skull-bones and lack of an obvious
supraorbital sulcus.

Homo ergaster:
https://www.msu.edu/~heslipst/contents/ANP440/ergaster.htm



--Bill







> --- In AAT@yahoogroups.com, Marc Verhaegen <m_verhaegen@> wrote:
> >
> > February 2004
> > http://www2.uiowa.edu/dragon/Natural%20History%20Magazine%20%20Feature.htm
> > Featured Story
> > Headstrong Hominids
> >
> > The mysterious skulls of Java man and Peking man
> > may have evolved because males were
> > clubbing each other in fights.
> >
> > Noel T. Boaz & Russell L. Ciochon
> > This article was adapted from Noel T. Boaz & Russell L. Ciochon ³Dragon Bone
> > Hill: An Ice-Age Saga of Homo erectus² Oxford UP 2004.
> >
> > Ever since the 1890s, when the Dutch anatomist Eugene Dubois unearthed the
> > first-recorded cranium of the early, small-brained human relative now known
> > as Homo erectus, scholars have been struck by the unusual anatomy of its
> > skull. The top and sides of the cranium have thick, bony walls and a low,
> > wide profile. To the modern eye, this part of its skull, known as the
> > calotte, or skullcap, looks a lot like a cyclist's helmet ‹ low &
> > streamlined, designed to protect the brain, ears & eyes from impact.
> > In contrast, we modern humans hold our enormous, easily injured, semi-liquid
> > brains in relatively thin-walled bony globes. We have to buy our bicycle
> > helmets.
> >
> > Skull of Peking man, a composite  reconstruction by G.J. Sawyer & Ian
> > Tattersall that is based on skull XII & other fossils discovered in China
> >
> > Photo by R.Mickens,  AMNH Because Dubois discovered his fossils in Java, it
> > and other specimens later found in that region became popularly known as
> > "Java man".  In the 1920s similar fossils were discovered in China's
> > Longgushan Cave, c 30 miles from Beijing (then transliterated in the West as
> > "Peking"), and were dubbed "Peking man".  At the time, no other hominid
> > fossils of comparable antiquity were known, so Dubois & everyone else
> > initially regarded the skull's robustness ‹ its strength & thickness ‹ as
> > typical of early human ancestors.  Even as late as the 1940s, Franz
> > Weidenreich (German PA, then working at the American Museum of Natural
> > History) proposed that H.erectus had descended from a line of massive,
> > indeed gigantic ancestors, and that modern H.sapiens was the end result of a
> > down-scaling trend.  But as more hominid fossils have come to light, it has
> > become clear that the ancestors of H.erectus did not have massive bones, and
> > neither did H.erectus.  In fact, except for its strange skull, the skeleton
> > of H.erectus resembled our own ...
> >
> > The skullcaps discovered in E-Asia tend to be more robust than the ones in
> > Africa.  Hence some PAs have regarded the African fossils as a distinct
> > species, which they call H.ergaster.  But one African skullcap just as
> > robust as any Asian specimen was discovered by Louis Leakey in Olduvai
> > Gorge, Tanzania. It dates from c 1.4 Ma.  And even the strapping youth known
> > as Turkana boy, the most complete H.erectus skeleton discovered so far,
> > probably would have had a thick skull when fully grown ...
> >
> > Visualizing Java man: A fossil designated Sangiran 17 is the most complete
> > H.erectus skull discovered on Java.  Under the supervision of Hisao Baba
> > (Curator of Anthropology, National Science Museum in Tokyo), sculptor Yoichi
> > Yazawa reconstructed the individual's appearance in life.  First, a cast of
> > the fossil (A) was rounded out with teeth, lower jaw & chewing muscles (B).
> > Other soft tissues were built up (C), finally the outer skin was added (D).
> > Because this fossil had relatively robust features compared with some
> > others, it was presumed to be that of a male.
> >
> > Courtesy Hisao Baba, National Science Museum, Tokyo
> > Many differences in hominid skulls can be accounted for by the evolution of
> > the brain & the chewing apparatus. Large skulls are needed to contain large
> > brains, and large jaws & teeth for processing tough foods need heavy-duty
> > skull bones to anchor massive chewing muscles. Unfortunately, neither of
> > these tried-and-true explanations can entirely account for the unique
> > attributes of the H.erectus skull. What seems more likely is that the
> > species badly needed some protective headgear.  Functionally, the H.erectus
> > skullcap is similar to the defensive carapace of a turtle ‹ indeed, some
> > excavators have mistaken cranial fragments of H.erectus for fossil turtle
> > shell.  But what special sources of traumatic injury did hominids face that
> > might have encouraged the evolution of such a robust skull?  We don¹t think
> > it was exposure to predators (which can readily attack other, more
> > vulnerable parts of the body), or a habit of venturing into slippery or
> > precarious territory where the hazards of falling were increased. In
> > examining the protection afforded by the H.erectus skull, we think the
> > evidence points to some kind of violence perpetrated within the species
> > itself.
> >
> > Large skulls are needed to contain large  brains, and large jaws & teeth for
> > processing tough foods need  heavy-duty skull bones to anchor massive
> > chewing muscles. Unfortunately,  neither of these tried-and-true
> > explanations can entirely account for the  unique attributes of the
> > H.erectus skull. What seems more likely  is that the species badly needed
> > some protective headgear ...
> >
> > As one might expect, the thicker the bone, the less likely it is to break on
> > impact.  In our most recent work we have been experimentally testing &
> > quantifying the advantages of thick bones.  With a 9-foot-high
> > guillotine-like bone-testing apparatus, we administer calibrated impacts on
> > 1-inch circular pieces of bone from human cadavers.  Certainly thick bone
> > does confer a competitive advantage.  But minimizing weight and optimizing
> > protective value at the same time is a problem that we continue to study.
> >
> > Contrast between the cranium of H.erectus (top) & that of a modern human
> > (middle &  bottom) is clear in cross section.  H.erectus had by far the
> > thicker skull, with a prominent keel along the midline and extra  bracing
> > along the lower sides.
> >
> > Patricia J.  Wynne
> > The H.erectus skullcap is described technically as pachyostotic
> > (³thick-boned²): thick, solid layers of bone make up both its inner & outer
> > surfaces.  Sandwiched between them is a less strong, lattice-like layer of
> > bone, whose intervening spaces, in life, would have been filled with marrow
> > & blood.  The H.erectus skull also has a number of unique bony structures.
> > 3 of them (a beetling brow ridge & bony thickenings on the sides & rear of
> > the cranium) form a bony ring starting above the eyes, extending back around
> > the head above the ears, and meeting on the back of the head.  The top of
> > the skull resembles the inverted bottom of a boat, with a thickened bony
> > mound that looks like the boat¹s keel extending along the midline of the
> > skull [see illustration right].
> >
> > In the 1920s, an American surgeon named E.R. LeCount classified skull
> > fractures by type. A heavy blow falling directly on top of the head tends to
> > cave in the bone overlying the so-called superior sagittal sinus, a channel
> > within the meninges for venous blood draining along the midline of the
> > brain. LeCount hypothesized that the strongly constructed midline of the
> > skull is an adaptation that protects against such damage. In most H.erectus
> > skulls the same adaptation appears in exaggerated form as the so-called
> > sagittal keel.
> >
> > ... Contrary to what one might predict, the H.erectus skull is not
> > particularly thick at the pterion ...
> >
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>

> The Many Human Faces and Homo erectus:
> http://pfpuech.newsvine.com/_news/2010/12/31/5742126-the-many-human-face\s
> Considering that the Denisovans point to consider the eventuality of a
> new type of Human concerns the evidence needed to check for the presence
> of significant data in the evolution of species of Homo.
> That is why paleoanthropologists are always looking at odd fossils,
> trying to figure how one can classify all the fossil specimens;
> In an attempt to recognise and delimit species in the fossil record
> -that is not done today for Denisovans- tooth morphology dated about 450
> 000 years was studied.
> A research concerning Pithecanthropus has already heighten the challenge
> of understanding modern human origin. The scanty robust remains from
> Java and equally scanty ones from Europe may be interpreted as relics of
> an early radiation of Pithecanthropus, or as a result of regional
> migrations during the Mindel-Riss interglacial period, when weather was
> humid and warm.
> http://independent.academia.edu/pfpuech/
> <http://pfpuech.newsvine.com/_news/2010/12/31/5742126-the-many-human-fac\
> es?threadId=3017930#comments
> Briwnys : « Recent advances in paleogenetics, such as the sequencing
> of archaic genomes like the Neanderthals and the Denisovans, have raised
> the startling possibility that all members of the genus Homo to which
> humans belong, from Homo erectus to Homo sapiens sapiens, are, in
> reality - Homo erectus. That includes anatomically modern humans. Us.
> Until these recent advances in genetics, species were designated by
> morphology, which means, by the form and structure of their physical
> shape. Now, genomic analysis has discovered that the human gene pool and
> genetic structure predates anatomically modern humans. This conclusion
> supports human evolution models that incorporate interbreeding between
> divergent branches of the genus Homo although the data cannot establish
> when the interbreeding may have occurred. It may be that the modern
> human physical type arose first and interbreeding was a consequence of
> the rapid expansion of the population. This is most likely since the
> relative isolation of African populations from Eurasian populations is
> reflected in the lack of the archaic admixture of genes in most of the
> population remaining in Africa that is otherwise present throughout the
> rest of the world. Alternatively, the modern human physical appearance
> may, itself, be the by-product of interbreeding. In either case, while
> the majority of the anatomically modern human genome may descend from a
> single population in Africa, the evolutionary lineage leading to modern
> humans did not develop in reproductive isolation from other, more
> archaic, human subpopulations and, thus, anatomically modern humans
> cannot be considered a distinct biological species compared to those
> so-called archaic species once thought to be extinct.
> Between 1 and 4 % of the genetic material of populations outside Africa
> matches the Neanderthal genome. In today's population of five billion,
> that is the equivalent of a genetic heritage from at least five million
> individuals. Far from being extinct, Neanderthal lives on in modern
> form. And that is not the only archaic source of our modern genetic
> heritage. As much as 10 % of our ancestral genes is not traceable to
> anatomically modern humans from Africa. Other recent discoveries point
> to at least two and possibly more archaic forms that arose in Eurasia,
> not the least of which may be Homo erectus itself. The polymorphic
> variations that were once thought to identify different species are now
> known to be the result of interaction between genetically determined
> characteristics and adaptations to specific environmental conditions. In
> essence, what in the past appeared to be the different species
> identified by conventional anthropology are actually only variations
> that identify progressive stages of transformation and adaptation within
> the evolutionary history of a single species. »

Yes, if Hs & Hn can produce fertile offspring, it's possible that also
erectus, ergaster, georgicus, modjokertensis, floresiensis, antecessor,
heidelbergensis, pekinensis etc belong to the same (chrono)species (=
possibly interbreeding), but more important IMO than nomenclature (eg, "Homo
sapiens erectus" etc.) is that we know which fossil(s) we're talking about.

-marc

--marc

Grehan & Schwartz 2009 (supplementary notes)
Fr.Ss are found in most large-bodied hominoids (Schwartz 1987).
Fr.Ss derived from the max.Ss are documented for Po, Lufeng-, Siva-&
Ouranopith (Brown & Ward 1988).
The S configuration in Hispanopith is also similar to that described for
Pongo ; a max.expanded S is recorded in Rudapith RUD (Schwartz 1997).
CT scans of apiths StW-505 & Sts-5 also appear to show the max.S extending
inter-orbitally (Schwartz pers.observ., no info on other apiths).
The HPG fr.S is often treated as an apomorphic character state, but it's not
unique : the derivation of fr.S from ethm.cells occurred in a wide variety
of fossil apes (Rossie 2004).
In Hs, fr.S development is more variable than in PG.
In Pp, the fr.S is usu.absent.
In Hs, the fr.S originates from
- a fr.recess of the middle meatus,
- a groove within that recess,
- the anterior terminal recess of the sulcus semi-lunaris &
- occasionally a groove situated above the ethm.bulla & below the middle
concha.
In PG, it develops as a diverticulum from the supra-bullar groove (Cave &
Haines 1940, Schwartz 1986).

Fr.S derived from expansion of the ethmoid: a variety of Oligo-& Miocene
fossils incl.Aegypto-, Ankara-, Moroto-, Oreo-, Otavipithecus, Proconsul &
Turkanapith also have a fr.S (Rossie 2004) ; ethmo-fr.Ss may not be unique
to HPG (Rossie cs 2002).
Fr.Ss are also absent from Hf (illustr.Brown cs 2004), they are usu.small or
absent in Pp (also later overlooked by Strait & Grine 2004).
Fr.Ss occur in Po as extensions of the max.Ss (Schwartz 1984).
CT scans of apiths StW-505 & Sts-5 show the max.S extending up through the
inter-orbital region, as in Po & Si rather than HPG (JH Schwartz
pers.comm.).

Fr.S (character 111) is present in a variety of fossil apes.

> Those PAs still dream about our ancestors as blood-thursty violent beasts....
> Fine, but did they find any evidence of skull damage due to clubbing or other
> attacks?  If no, their arguement is not supported by evidence.  Chak

Yes, Chak, I sent this not in the first place for the far-fetched
head-banging hypothesis (in fact, denser skulls were probably brittler, not
stronger), but I was trying to find evidence that He's skeleton was not only
thicker (more pachyostotic) but also denser.

--marc

>> http://www2.uiowa.edu/dragon/Natural%20History%20Magazine%20%20Feature.htm
>> Featured Story - Headstrong Hominids  2004
>> The mysterious skulls of Java man and Peking man
>> may have evolved because males were clubbing each other in fights.
>> Noel T. Boaz & Russell L. Ciochon
>> This article was adapted from Noel T. Boaz & Russell L. Ciochon ³Dragon Bone
>> Hill: An Ice-Age Saga of Homo erectus² Oxford UP 2004.
>> Ever since the 1890s, when the Dutch anatomist Eugene Dubois unearthed the
>> first-recorded cranium of the early, small-brained human relative now known
>> as Homo erectus, scholars have been struck by the unusual anatomy of its
>> skull. The top and sides of the cranium have thick, bony walls and a low,
>> wide profile. To the modern eye, this part of its skull, known as the
>> calotte, or skullcap, looks a lot like a cyclist's helmet ‹ low &
>> streamlined, designed to protect the brain, ears & eyes from impact.
>> In contrast, we modern humans hold our enormous, easily injured, semi-liquid
>> brains in relatively thin-walled bony globes. We have to buy our bicycle
>> helmets.
>> Skull of Peking man, a composite  reconstruction by G.J. Sawyer & Ian
>> Tattersall that is based on skull XII & other fossils discovered in China
>> Photo by R.Mickens,  AMNH Because Dubois discovered his fossils in Java, it
>> and other specimens later found in that region became popularly known as
>> "Java man".  In the 1920s similar fossils were discovered in China's
>> Longgushan Cave, c 30 miles from Beijing (then transliterated in the West as
>> "Peking"), and were dubbed "Peking man".  At the time, no other hominid
>> fossils of comparable antiquity were known, so Dubois & everyone else
>> initially regarded the skull's robustness ‹ its strength & thickness ‹ as
>> typical of early human ancestors.  Even as late as the 1940s, Franz
>> Weidenreich (German PA, then working at the American Museum of Natural
>> History) proposed that H.erectus had descended from a line of massive,
>> indeed gigantic ancestors, and that modern H.sapiens was the end result of a
>> down-scaling trend.  But as more hominid fossils have come to light, it has
>> become clear that the ancestors of H.erectus did not have massive bones, and
>> neither did H.erectus.  In fact, except for its strange skull, the skeleton
>> of H.erectus resembled our own ...
>> The skullcaps discovered in E-Asia tend to be more robust than the ones in
>> Africa.  Hence some PAs have regarded the African fossils as a distinct
>> species, which they call H.ergaster.  But one African skullcap just as
>> robust as any Asian specimen was discovered by Louis Leakey in Olduvai
>> Gorge, Tanzania. It dates from c 1.4 Ma.  And even the strapping youth known
>> as Turkana boy, the most complete H.erectus skeleton discovered so far,
>> probably would have had a thick skull when fully grown ...
>>
>> Visualizing Java man: A fossil designated Sangiran 17 is the most complete
>> H.erectus skull discovered on Java.  Under the supervision of Hisao Baba
>> (Curator of Anthropology, National Science Museum in Tokyo), sculptor Yoichi
>> Yazawa reconstructed the individual's appearance in life.  First, a cast of
>> the fossil (A) was rounded out with teeth, lower jaw & chewing muscles (B).
>> Other soft tissues were built up (C), finally the outer skin was added (D).
>> Because this fossil had relatively robust features compared with some
>> others, it was presumed to be that of a male.
>>
>> Courtesy Hisao Baba, National Science Museum, Tokyo
>> Many differences in hominid skulls can be accounted for by the evolution of
>> the brain & the chewing apparatus. Large skulls are needed to contain large
>> brains, and large jaws & teeth for processing tough foods need heavy-duty
>> skull bones to anchor massive chewing muscles. Unfortunately, neither of
>> these tried-and-true explanations can entirely account for the unique
>> attributes of the H.erectus skull. What seems more likely is that the
>> species badly needed some protective headgear.  Functionally, the H.erectus
>> skullcap is similar to the defensive carapace of a turtle ‹ indeed, some
>> excavators have mistaken cranial fragments of H.erectus for fossil turtle
>> shell.  But what special sources of traumatic injury did hominids face that
>> might have encouraged the evolution of such a robust skull?  We don¹t think
>> it was exposure to predators (which can readily attack other, more
>> vulnerable parts of the body), or a habit of venturing into slippery or
>> precarious territory where the hazards of falling were increased. In
>> examining the protection afforded by the H.erectus skull, we think the
>> evidence points to some kind of violence perpetrated within the species
>> itself.
>>
>> Large skulls are needed to contain large  brains, and large jaws & teeth for
>> processing tough foods need  heavy-duty skull bones to anchor massive
>> chewing muscles. Unfortunately,  neither of these tried-and-true
>> explanations can entirely account for the  unique attributes of the
>> H.erectus skull. What seems more likely  is that the species badly needed
>> some protective headgear ...
>>
>> As one might expect, the thicker the bone, the less likely it is to break on
>> impact.  In our most recent work we have been experimentally testing &
>> quantifying the advantages of thick bones.  With a 9-foot-high
>> guillotine-like bone-testing apparatus, we administer calibrated impacts on
>> 1-inch circular pieces of bone from human cadavers.  Certainly thick bone
>> does confer a competitive advantage.  But minimizing weight and optimizing
>> protective value at the same time is a problem that we continue to study.
>>
>> Contrast between the cranium of H.erectus (top) & that of a modern human
>> (middle &  bottom) is clear in cross section.  H.erectus had by far the
>> thicker skull, with a prominent keel along the midline and extra  bracing
>> along the lower sides.
>>
>> Patricia J.  Wynne
>> The H.erectus skullcap is described technically as pachyostotic
>> (³thick-boned²): thick, solid layers of bone make up both its inner & outer
>> surfaces.  Sandwiched between them is a less strong, lattice-like layer of
>> bone, whose intervening spaces, in life, would have been filled with marrow
>> & blood.  The H.erectus skull also has a number of unique bony structures.
>> 3 of them (a beetling brow ridge & bony thickenings on the sides & rear of
>> the cranium) form a bony ring starting above the eyes, extending back around
>> the head above the ears, and meeting on the back of the head.  The top of
>> the skull resembles the inverted bottom of a boat, with a thickened bony
>> mound that looks like the boat¹s keel extending along the midline of the
>> skull [see illustration right].
>>
>> In the 1920s, an American surgeon named E.R. LeCount classified skull
>> fractures by type. A heavy blow falling directly on top of the head tends to
>> cave in the bone overlying the so-called superior sagittal sinus, a channel
>> within the meninges for venous blood draining along the midline of the
>> brain. LeCount hypothesized that the strongly constructed midline of the
>> skull is an adaptation that protects against such damage. In most H.erectus
>> skulls the same adaptation appears in exaggerated form as the so-called
>> sagittal keel.
>>
>> ... Contrary to what one might predict, the H.erectus skull is not
>> particularly thick at the pterion ...
>>
>>
>>
>>
>>
>>
>> [Non-text portions of this message have been removed]
>>
>
>
>
>
>