> - hominoids = hylobatids + hominids-pongids
> -- hominids = Afr.apes/humans = HPG
> -- pongids = Asian great apes = orangs               Marc

>         And hominins = apiths, homos, and other bipedal folks. ; ) --
Mario

Ayayay. Please, no, Mario! Hominins in that sense is nonsense (due to
anthropocentric thinking): chimps & gorillas & perhaps even orangs had
climbing-wading ancestors IMO, and even Oreopith (ca.8 Ma Italy) was
possibly partly bipedal. All hominids are/were waders-climbers, IOW, there's
nothing that binds apiths exclusively to Homo. Apiths IMO are simply
primitive hominids that are gradually evolving into chimp or gorilla
direction: less wading, more knuckle-walking, longer arms, thinner enamel,
higher iliac bones, etc.

-- Marc

> - hominoids = hylobatids + hominids-pongids
   > -- hominids = Afr.apes/humans = HPG
   > -- pongids = Asian great apes = orangs               Marc

   >         And hominins = apiths, homos, and other bipedal folks. ; ) --
   Mario

   Ayayay. Please, no, Mario! Hominins in that sense is nonsense (due to
   anthropocentric thinking): chimps & gorillas & perhaps even orangs had
   climbing-wading ancestors IMO, and even Oreopith (ca.8 Ma Italy) was
   possibly partly bipedal. All hominids are/were waders-climbers, IOW, there's
   nothing that binds apiths exclusively to Homo. Apiths IMO are simply
   primitive hominids that are gradually evolving into chimp or gorilla
   direction: less wading, more knuckle-walking, longer arms, thinner enamel,
   higher iliac bones, etc.                     -- Marc

           Sorry, Marc. I don't agree. Do you know maybe if Marcel is of similar
oppinion? -- Mario

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

>B. Meehan, 1977. Hunters by the seashore. J. of Human Evolution 6:363-370.
>
>> >>> IMO human ancestors once fed for a considerable part on shellfish
(see
>our tool use, thick enamel, handiness, thick skeleton in erectus...).
>
>> >> Yes, but also on crabs and other crustacea, on fish (perch species,
>stingrays etc), octopi, dugong, seabirds, seabird eggs, marine and
>freshwater turtles, marine turtle eggs, small mammals etc. I think what
made
>our ancestors so succesfull is precisely the fact that they exploited such
>diverse resources: if one of those seasonally or temporarily ran out, they
>switched to other food items. No problem.
>
>> >Yes, that's well possible. I only wonder whether we have always been so
>omnivorous or whether there was once a more-aquatic=diving phase (as
>suggested by our anatomy IMO), and how much difference there was between
>male (deeper diving?) & female (more beach-combing?) food gatherings.
>
>> I don't know if we have always been omnivores. Interesting question.
>
>They must surely have been durophagous: the early hominids-pongids ca.15 Ma
>probably had thick enamel & possibly already used tools. There seems to a
>parallel in capuchin monkeys, who feed on hard-shelled foods, eg, nuts &
>(the coastal populations) mangrove oysters. And in sea-otters: also
>thick-enameled, with molars resembling those of apiths (Walker) &
>tool-using, feeding on mussels, clams, abalones, urchins... Humans, orangs,
>most Miocene hominids-pongids ca.15-8 Ma (except, eg, Dryopith) & apiths
>have thick enamel (chimps intermediate, gorillas thin), but AFAIK gibbons
>don't use tools & have thin enamel (this doesn't say everything: gorillas
>also have thin enamel & don't use tools, but their ancestors probably had
>thick enamel & used tools). Capuchins are rel.small monkeys, this suggests
>the early durophagous phase (coastal forest IMO, cf. Miocene fossils) not
>unlikely began after the great/lesser ape split, and possibly before body
>enlargement (if gibbons did not become smaller again later), IOW, the
>sequence might be:
>- arboreal cf. NW monkeys, cf. +- howler locomotion, but frugivorous?
>- arboreal + (some?) swimming: tail loss & suspensory cf. sloths to reach
>other trees in flooded season,
>- durophagous cf.mangrove capuchins thick enamel, tools: at about or after
>great/lesser ape split?
>- larger size: hominids-pongids + wading, Tethys coasts ca.16-8 Ma,
>- early hominids Med.coasts, lake Chad...: frequent wading, diet incl. nuts
>& possibly oysters etc.,
>- early Homo Med.+Ind.Ocean coasts + diving, loss of climbing ca.2 Ma,
>- sapiens walking, loss of wading ca.300 ka?
>OTOH, the complete loss of a tail, the drastic reorganisation of the body
>build in hominoids & the long gestation period in gibbons could suggest
>there once existed a considerable semi-aquatic phase in early hominoids
>(much more swimming ca.20 Ma & perhaps other aquatic acitivities than in
>sloths)? In that case durophagy came after body enlargement (although the
>capuchin example suggests durophagy might have predated body enlargement).
>
Yes, likely.

>BTW, we can try to extend the sequence in the other direction, see the
>recent find of Carpolestes simpsoni, eg,
>- arboreal frugivore (some body enlargement) ca.40 Ma?
>- insectivore (full binocularity) ca.50 Ma?
>- terminal branch frugivore (grasping hands, nails) ca.60 Ma?
>
>Who is Carpolestes simpsoni?
>

Do these abundant reef communities have other
>predators? What were possible food competitors for our ancestors?
>
>> I think the way Homo uses coastal resources is quite unique. The only
>competitor I can think of is the (probably) estuarine otter Enhydrion, that
>is extinct now. "It is interesting to note that among the Pliocene fossils
>of southern Asia is a giant mollusc- and crab-eating otter called
Enhydrion,
>which was larger than the Pacific Sea Otter. Anatomically, Enhydrion was
>internediate between the African Clawless otter Aonyx and the Sea Otter,
and
>it may also have occupied an intermediate ecological niche. Sea otters must
>have had fresh water antecedents similar to Aonyx and Enhydrion. The
>inducement that would have drawn a tropical riverine animal into temperate
>and eventually arctic seas would have been the enormous resources of
>estuarines and rivermouth sea shores. Here, there were abundant molluscs,
>crabs, crayfish, turtles and other easily harvested but tough-shelled
>animals. Given that these resources are still abundant, why has this otter
>become extinct while its marine and its African (freshwater) cousins
>survive? A necessary prerequisite of gigantism is a large and reliable food
>source, and gigantism can be a form of insurance against predators and
>competitors. Where humans are the predator and competitor, large size
>becomes a liability and it is quite possible that Enhydrion was one more
>'naive' casualty of humans when they took to exploiting river and estuary
>resources in a big way." (Jonathan Kingdon, 1993). It's also interesting to
>note that Enhydrion occurred in East Africa, e.g. in the Plio-Pleistocene
>Turkana Basin. Well, makes you think.
>
>Yes! OTOH otters are fast (eg, little SC fat) & have a carnivore &
>small-sized past, but humans are slow & rather fat & have an
>omni-frugivorous-durophagous & large-sized past. And at least one study
>suggests erectus's diet (Pithecanthr.IV enamel) included coarse, though
>foods: "tooth wear patterns show clearly that Java man was mainly
vegetarian
>and specialized in foods of little nutritional value" (P-F.Puech 1983
"Tooth
>wear, diet, and the artifacts of Java man" Curr.Anthrop.24:381-2). I asked
>P-F which foods that could have been, but he couldn't tell. Perhaps incl.
>cattails (cf. neandertals) or cane parts?


Sorry, I made a mistake in the otter's name (and Kingdon made a mistake):
its name is Enhydriodon, not Enhydrion.
Jose

>>>> - hominoids = hylobatids + hominids-pongids,  hominids =
Afr.apes/humans = HPG,  pongids = Asian great apes = orangs
Marc

>>> And hominins = apiths, homos, and other bipedal folks. ; ) -- Mario

>> Ayayay. Please, no, Mario! Hominins in that sense is nonsense (due to
anthropocentric thinking): chimps & gorillas & perhaps even orangs had
climbing-wading ancestors IMO, and even Oreopith (ca.8 Ma Italy) was
possibly partly bipedal. All hominids are/were waders-climbers, IOW, there's
nothing that binds apiths exclusively to Homo. Apiths IMO are simply
primitive hominids that are gradually evolving into chimp or gorilla
direction: less wading, more knuckle-walking, longer arms, thinner enamel,
higher iliac bones, etc.                     -- Marc

> Sorry, Marc. I don't agree. Do you know maybe if Marcel is of similar
oppinion? -- Mario

AFAIR, Marcel has (had?) has the curious opinion that Oreopith & (some?)
apiths & Homo are hominids to the exclusion of chimps & gorillas (perhaps he
calls them hominins), but you  better ask him.

Marc

B. Meehan, 1977. Hunters by the seashore. J. of Human Evolution 6:363-370.

>>>>>> IMO human ancestors once fed for a considerable part on shellfish
(see our tool use, thick enamel, handiness, thick skeleton in erectus...).

>>>>> Yes, but also on crabs and other crustacea, on fish (perch species,
stingrays etc), octopi, dugong, seabirds, seabird eggs, marine and
freshwater turtles, marine turtle eggs, small mammals etc. I think what made
our ancestors so succesfull is precisely the fact that they exploited such
diverse resources: if one of those seasonally or temporarily ran out, they
switched to other food items. No problem.

>>>> Yes, that's well possible. I only wonder whether we have always been so
omnivorous or whether there was once a more-aquatic=diving phase (as
suggested by our anatomy IMO), and how much difference there was between
male (deeper diving?) & female (more beach-combing?) food gatherings.

>>> I don't know if we have always been omnivores. Interesting question.

>> They must surely have been durophagous: the early hominids-pongids ca.15
Ma probably had thick enamel & possibly already used tools. There seems to a
parallel in capuchin monkeys, who feed on hard-shelled foods, eg, nuts &
(the coastal populations) mangrove oysters. And in sea-otters: also
thick-enameled, with molars resembling those of apiths (Walker) &
tool-using, feeding on mussels, clams, abalones, urchins... Humans, orangs,
most Miocene hominids-pongids ca.15-8 Ma (except, eg, Dryopith) & apiths
have thick enamel (chimps intermediate, gorillas thin), but AFAIK gibbons
don't use tools & have thin enamel (this doesn't say everything: gorillas
also have thin enamel & don't use tools, but their ancestors probably had
thick enamel & used tools). Capuchins are rel.small monkeys, this suggests
the early durophagous phase (coastal forest IMO, cf. Miocene fossils) not
unlikely began after the great/lesser ape split, and possibly before body
enlargement (if gibbons did not become smaller again later), IOW, the
sequence might be:  - arboreal cf. NW monkeys, cf. +- howler locomotion, but
frugivorous?    - arboreal + (some?) swimming: tail loss & suspensory cf.
sloths to reach other trees in flooded season,    - durophagous cf.mangrove
capuchins thick enamel, tools: at about or after great/lesser ape
it?    - larger size: hominids-pongids + wading, Tethys coasts ca.16-8
     - early hominids Med.coasts, lake Chad...: frequent wading, diet incl.
nuts & possibly oysters etc.,    - early Homo Med.+Ind.Ocean coasts +
diving, loss of climbing ca.2 Ma,    - sapiens walking, loss of wading
ca.300 ka?        OTOH, the complete loss of a tail, the drastic
reorganisation of the body build in hominoids & the long gestation period in
gibbons could suggest there once existed a considerable semi-aquatic phase
in early hominoids (much more swimming ca.20 Ma & perhaps other aquatic
acitivities than in sloths)? In that case durophagy came after body
enlargement (although the capuchin example suggests durophagy might have
predated body enlargement).

> Yes, likely.

>> BTW, we can try to extend the sequence in the other direction, see the
recent find of Carpolestes simpsoni, eg,  - arboreal frugivore (some body
enlargement) ca.40 Ma?    - insectivore (full binocularity) ca.50 Ma?    -
terminal branch frugivore (grasping hands, nails) ca.60 Ma?

> Who is Carpolestes simpsoni?

The recently found plesiadapiform (primate sensu lato or perhaps dermopteran
ca.56 Ma Wyoming): JI Bloch & DM Boyer 2002 "Grasping primate origins"
Science 298:1606-1610. The fossil had long fingers & an opposable great toe
with a nail (claws on the other fingers), probably for grasping terminal
branches, to feed on fruits, nectar, buds, flowers, but it had no
postorbital bar, small & divergent orbits (ie, probably no visually directed
predation on small insects) & no leaping legs. The habitually flexed
shoulders & elbows suggest it was a vertical clinger. The find seems to
solve an old question: it suggests that terminal branch feeding (primates
s.l.) preceded visually directed predation (euprimates).


>>>> Do these abundant reef communities have other predators? What were
possible food competitors for our ancestors?

>>> I think the way Homo uses coastal resources is quite unique. The only
competitor I can think of is the (probably) estuarine otter Enhydrion, that
is extinct now. "It is interesting to note that among the Pliocene fossils
of southern Asia is a giant mollusc- and crab-eating otter called Enhydrion,
which was larger than the Pacific Sea Otter. Anatomically, Enhydrion was
internediate between the African Clawless otter Aonyx and the Sea Otter, and
it may also have occupied an intermediate ecological niche. Sea otters must
have had fresh water antecedents similar to Aonyx and Enhydrion. The
inducement that would have drawn a tropical riverine animal into temperate
and eventually arctic seas would have been the enormous resources of
estuarines and rivermouth sea shores. Here, there were abundant molluscs,
crabs, crayfish, turtles and other easily harvested but tough-shelled
animals. Given that these resources are still abundant, why has this otter
become extinct while its marine and its African (freshwater) cousins
survive? A necessary prerequisite of gigantism is a large and reliable food
source, and gigantism can be a form of insurance against predators and
competitors. Where humans are the predator and competitor, large size
becomes a liability and it is quite possible that Enhydrion was one more
'naive' casualty of humans when they took to exploiting river and estuary
resources in a big way." (Jonathan Kingdon, 1993). It's also interesting to
note that Enhydrion occurred in East Africa, e.g. in the Plio-Pleistocene
Turkana Basin. Well, makes you think.

>> Yes! OTOH otters are fast (eg, little SC fat) & have a carnivore &
small-sized past, but humans are slow & rather fat & have an
omni-frugivorous-durophagous & large-sized past. And at least one study
suggests erectus's diet (Pithecanthr.IV enamel) included coarse, though
foods: "tooth wear patterns show clearly that Java man was mainly vegetarian
and specialized in foods of little nutritional value" (P-F.Puech 1983 "Tooth
wear, diet, and the artifacts of Java man" Curr.Anthrop.24:381-2). I asked
P-F which foods that could have been, but he couldn't tell. Perhaps incl.
cattails (cf. neandertals) or cane parts?

> Sorry, I made a mistake in the otter's name (and Kingdon made a mistake):
its name is Enhydriodon, not Enhydrion.     Jose

OK, thanks.

Marc

----- Original Message -----
   From: Verhaegen
   To: AAT@yahoogroups.com
   Sent: Thursday, January 23, 2003 7:03 PM
   Subject: Re: [AAT] Re: Re AAT general



   >> A few comments :   Would this be hominid (Australopithecus + homo + etc.)
   LCA (last common ancestor), or hominoid (chimps + gorillas + hominids) LCA.

   Hominoids = humans + apes (incl.gibbons). IMO we should use "hominid" for
   Homo-Pan-Gorilla-Australopith-Orrorin-Ardipith-Kenyanthr-Sahelanthr, and
   "pongid" for Pongo-Lufengpith-Gigantopith-Sivapith.

   >> Regarding habitat. Those things happen all the time for every species. In
   coastal habitat speciation can occur only because geographical separation of
   two distant points.           Regarding island. A lot of people are thinking
   about islands. I would say that island population have less evolutive
   pressures, and (AFAIK) usually goes extinct when reunited back with main
   land. I also think that even if environment isn't so small as island, when
   two similar environments go in contact, one smaller and one bigger, the
   bigger is the one who has better chance to prevail.           If you need
   island only because you need predatorless environment, you better forget it,
   and try to solve predator problem. -- Mario

   >   Thank's for your comments  Mario.      IMO the LCA will cover both
   catagories.        I am not considering Speciation. I assume that while
   there certain abilities in each case. However upon interbreeding the most
   advantageous traits will be adapted for.      There is no doubt in my mind
   that an island based population will face more complex and different
   problems than those remaining in the habitat in which they developed.
   If predators are encountered they will be taken care of or there is no
   future.       Frank

   Thanks, Frank & Mario, interesting thinking. Perhaps Mario is right when he
   thinks island populations usu.become extinct after they meet the main land
   pop? But perhaps the time the island populations were isolated is important?

   Marc

   >A few comments : Would this be hominid (Australopithecus + homo + etc.)
   LCA (last common ancestor), or hominoid (chimps + gorillas + hominids) LCA.

   >Hominoids = humans + apes (incl.gibbons). IMO we should use "hominid" for
   Homo-Pan-Gorilla-Australopith-Orrorin-Ardipith-Kenyanthr-Sahelanthr, and
   "pinged" for Pongo-Lufengpith-Gigantopith-Sivapith.

   > Regarding habitat. Those things happen all the time for every species. In
   coastal habitat speciation can occur only because geographical separation of
   two distant points. Regarding island. A lot of people are thinking
   about islands. I would say that island population have less evolutive
   pressures, and (AFAIK) usually goes extinct when reunited back with main
   land. I also think that even if environment isn't so small as island, when
   two similar environments go in contact, one smaller and one bigger, the
   bigger is the one who has better chance to prevail. If you need
   island only because you need predatorless environment, you better forget it,
   and try to solve predator problem. -- Mario

   >>A few words

   >>Thanks for your comments Mario. IMO the LCA will cover both
   categories. I am not considering Speciation. I assume that while
   they're certain abilities in each case. However upon interbreeding the most
   advantageous traits will be adapted for. There is no doubt in my mind
   that an island based population will face more complex and different
   problems than those remaining in the habitat in which they developed.
   If predators are encountered they will be taken care of or there is no
   future. Frank

   >thanks; Frank & Mario, interisting thinking. Perhaps Mario is right when he
thinks island population'susually. Become extinct after they meet the majn land
pop? But perhapsthe time the island populations were isolated is important?

   Marc

   >(I think beach-combing was not millions of years, but 1 or max.2 mill.yrs.
   Before that time they perhaps lived in coastal forests & still climbed a
   lot.)

   Marc

   Looking at Richard Little's timetable for ice ages the interglacial periods
would be well over a hundred thousand years. There was a period of about
900000years interglacial ending about 2.8Ma then another of about 400000 years
ending about 1.4Ma The more recent ones seem to have been getting shorter. I
believe Richard got his information from Oil interests I am afraid I am a
complete layman on the subject. You could well be right on the shorter period of
beachcombing in the later periods IMO it would require an extensive period of
swamp dwelling about 8 0r more million years ago. The period of coastal forest
dwelling if in Africa would have to be restricted to an isolated coastal area or
perhaps on the Arabian Peninsula, In order to escape the Baboon virus.

   Mario may well be right that eventually the island population may disappear.

   However consider the surviving islanders since the onset of the next glaciaton
have lived for thousands of generations on an expanding island. There will be no
sudden intersection with the mainland; there will first be a distance between
the island and the mainland. There will be some distance to swim to get to the
mainland. The first ones will be a few daring males. Who may meet a few
susceptible females? You have contact and the exchange of genes has begun. It
will probably be generations before confrontation between the main bodies when
one or the other is eliminated, in the mean time many casual encounters should
have occurred. The beginning of cross-fertilization.

   From this point it does not matter which side disappears, from here on it's
the genes that count.

   Consider some of the stories of ancient wars. Kill all males save all young
females.

   Also of Chimp fights.



   Frank Newbury



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

In an interview with the redaction of the French scientific Magazine "La
Recherche" [n° 361, 74-78, February 2003], professor Yves Coppens declared that
the East Side Story - a theory he has worked out since 20 years - doesn't exist
any more.
   "L' East Side Story n'existe plus" he said.
   In this scenario, the ancestors of today apes became separated from the
ancestors of australopithecines and man by the formation of the Rift Valley in
East Africa, about 8 Mya. On the one side, the climate remained wet-tropical, on
the other (Eastern) side, the climate became more and more dry... with expansion
of the savannah where the genus Australopithecus, then Homo, allegedly have
developed.
   As a matter of fact, the recent discovery of 7 My old "Toumai" [Sahelanthropus
tchadensis] far east from the Rift Valley may explain professor Coppens'
flip-flop... :-)
   In this interview, he also added that DNA-deciphering in fossil hominin bones
would badly shake our "petits arbres évolutifs" [small family trees] in next
time.
   No mention is made about a semi-aquatic stage in human evolution, although
Yves Coppens is well aware of the AAT... On the contrary, Coppens maintained
that "le fait que l'homme soit un être de savane ne peut pas être remis en
cause" [the fact that man is a savannah dweller cannot be called into question].
  Therefore in some decades, the vision we have of anthropogenesis may be
radically different of our today concept...

   Francois de Sarre  [January 27, 2003].



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

Correction in my previous e-mail : "Toumaï" [Sahelanthropus tchadensis] was
obviously found far west of the Rift Valley...
Sorry!
Francois.


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

> In an interview with the redaction of the French scientific Magazine "La
Recherche" [n° 361, 74-78, February 2003], professor Yves Coppens declared
that the East Side Story - a theory he has worked out since 20 years -
doesn't exist any more.  "L' East Side Story n'existe plus" he said.  In
this scenario, the ancestors of today apes became separated from the
ancestors of australopithecines and man by the formation of the Rift Valley
in East Africa, about 8 Mya. On the one side, the climate remained
wet-tropical, on the other (Eastern) side, the climate became more and more
dry... with expansion of the savannah where the genus Australopithecus, then
Homo, allegedly have developed.  As a matter of fact, the recent discovery
of 7 My old "Toumai" [Sahelanthropus tchadensis] far east [West, corrected
by Francois - MV] from the Rift Valley may explain professor Coppens'
flip-flop... :-)  In this interview, he also added that DNA-deciphering in
fossil hominin bones would badly shake our "petits arbres évolutifs" [small
family trees] in next time.  No mention is made about a semi-aquatic stage
in human evolution, although Yves Coppens is well aware of the AAT... On the
contrary, Coppens maintained that "le fait que l'homme soit un être de
savane ne peut pas être remis en cause" [the fact that man is a savannah
dweller cannot be called into question]. Therefore in some decades, the
vision we have of anthropogenesis may be radically different of our today
concept...  Francois de Sarre  [January 27, 2003].

Does he still believe that human ancestors were savanna-dwellers??
incredible! Thanks a lot, Francois!

Marc

>   >(I think beach-combing was not millions of years, but 1 or max.2
mill.yrs. Before that time they perhaps lived in coastal forests & still
climbed a lot.)   Marc

>   Looking at Richard Little's timetable for ice ages the interglacial
periods would be well over a hundred thousand years. There was a period of
about 900000years interglacial ending about 2.8Ma then another of about
400000 years ending about 1.4Ma The more recent ones seem to have been
getting shorter. I believe Richard got his information from Oil interests I
am afraid I am a complete layman on the subject. You could well be right on
the shorter period of beachcombing in the later periods IMO it would require
an extensive period of swamp dwelling about 8 0r more million years ago. The
period of coastal forest dwelling if in Africa would have to be restricted
to an isolated coastal area or perhaps on the Arabian Peninsula, In order to
escape the Baboon virus.

My thinking is partly based on comparative data, which suggest IMO that the
Homo-Pan LCA (whether 8 or 4 Ma) lived in coastal forests and that Homo
became more diving & less climbing after the split, and partly on fossil
data, which suggest that ergaster-erectus ca.1.8 Ma appeared "suddenly" at
the Med.Sea & the Indian Ocean coasts (perhaps more specifically in river
deltas? cf.Mojokerto). This sudden appearance might be artificial, eg, due
to sea level changes at that time? There are indications of Homo tools in
Israel ca.2.5 Ma IIRC, there are Oldowan cultures in E.Africa ca.2.6, and
there's possibly Homo (rudolfensis) in Kenya ca.2.4 Ma (not sure about the
exact datings). IOW, Homo (a more "primitive" form than ergaster - still
climbing??) might be older than 1.8 Ma & have lived outside Africa (which
could explain the baboon virus marker). We just don't know.

Marc

Marc, you mention that possibly Homo (rudolfensis) is in Kenya ca. 2.4 Ma.
Do you have refs for this? Jose

-----Oorspronkelijk bericht-----
Van: Verhaegen <fa204466@...>
Aan: AAT@yahoogroups.com <AAT@yahoogroups.com>
Datum: maandag 27 januari 2003 20:52
Onderwerp: Re: [AAT] Re: Re AAT general


>>   >(I think beach-combing was not millions of years, but 1 or max.2
>mill.yrs. Before that time they perhaps lived in coastal forests & still
>climbed a lot.)   Marc
>
>>   Looking at Richard Little's timetable for ice ages the interglacial
>periods would be well over a hundred thousand years. There was a period of
>about 900000years interglacial ending about 2.8Ma then another of about
>400000 years ending about 1.4Ma The more recent ones seem to have been
>getting shorter. I believe Richard got his information from Oil interests I
>am afraid I am a complete layman on the subject. You could well be right on
>the shorter period of beachcombing in the later periods IMO it would
require
>an extensive period of swamp dwelling about 8 0r more million years ago.
The
>period of coastal forest dwelling if in Africa would have to be restricted
>to an isolated coastal area or perhaps on the Arabian Peninsula, In order
to
>escape the Baboon virus.
>
>My thinking is partly based on comparative data, which suggest IMO that the
>Homo-Pan LCA (whether 8 or 4 Ma) lived in coastal forests and that Homo
>became more diving & less climbing after the split, and partly on fossil
>data, which suggest that ergaster-erectus ca.1.8 Ma appeared "suddenly" at
>the Med.Sea & the Indian Ocean coasts (perhaps more specifically in river
>deltas? cf.Mojokerto). This sudden appearance might be artificial, eg, due
>to sea level changes at that time? There are indications of Homo tools in
>Israel ca.2.5 Ma IIRC, there are Oldowan cultures in E.Africa ca.2.6, and
>there's possibly Homo (rudolfensis) in Kenya ca.2.4 Ma (not sure about the
>exact datings). IOW, Homo (a more "primitive" form than ergaster - still
>climbing??) might be older than 1.8 Ma & have lived outside Africa (which
>could explain the baboon virus marker). We just don't know.
>
>Marc
>
>
>Community email addresses:
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>
>Shortcut URL to this page:
>  http://www.onelist.com/community/AAT
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>

Grist for the mill.


   Language evolved in a leap

Conflicting needs may have driven rapid development of communication.
22 January 2003

PHILIP BALL <http://www.nature.com/nsu/profiles/aboutus.html#Ball>

Speakers want few words; listeners want many.
© GettyImages

Language probably leapt, not crept, from squeaks to Shakespeare, two
physicists have calculated. Human communication, they propose, underwent
a 'phase transition', like solid ice melting to liquid water.

The richness of human languages is a fine-tuned compromise between the
needs of speakers and of listeners, explain Ramon Ferrer i Cancho and
Ricard Solé of the Universitat Pompeu Fabra in Barcelona. Just a slight
imbalance of these demands prevents the exchange of complex information,
they argue.

So languages between those of present-day humans and the limited
signalling of some animals cannot really exist. There must, at some
point, have been a switch from rudimentary to sophisticated language.

This contrasts with some linguists' view that language evolution was a
gradual affair in which new words accumulated steadily.

Greek or grunt

A language that conveyed all information unambiguously, say Ferrer i
Cancho and Solé, would have a separate word for every thing, concept or
action it referred to. Such a language would be formidably complicated
for the speaker: the green of grass, for example, would be represented
by a totally different word to the green of sea, an emerald or an oak
leaf. But it would be ideal for the listener, who wouldn't have to work
out any meanings from a word's context.

Ideal for the speaker is a language of few words, where simple, short
utterances serve many purposes. The extreme case is a language with a
single sound that conveys everything that needs saying. Some might
suggest that teenagers prefer this kind of minimal-effort tongue that
forces others to figure out what their grunts actually mean.

Ferrer i Cancho and Solé have devised a mathematical model in which the
cost of using a language depends on the balance between these
conflicting preferences1
<http://www.nature.com/nsu/030120/030120-3.html#b1>. They calculate the
properties of the lexicon that requires minimal effort for different
degrees of compromise, from exhaustive vocabularies to one-word languages.

They find that the change from one extreme to the other does not happen
smoothly. There is a jump in the amount of communication, from very
little to near-perfect, at a certain value of the relative weightings of
speaker and hearer preferences.

Human languages, say the duo, seem to sit right on this sudden change.
When it happens, the frequency of word usages develops a distinctive
mathematical form, called a power law. The power law disappears on
either side of the communication jump.

It has been known since the 1940s that human languages do indeed show
just this kind of statistical distribution of word usage - the social
scientist George Kingsley Zipf spotted the power-law behaviour. But it
has never been satisfactorily explained before, although Zipf himself
speculated that it might represent some kind of "principle of least effort".

References

     # Ferrer i Cancho, R. & Solé, R. V. Least effort and the origins of
       scaling in human language. Proceedings of the National Academy of
       Sciences USA, published online, doi:10.1073/pnas.0335980100
       (2003). |Article| <http://dx.doi.org/10.1073/pnas.0335980100>




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

Well, I had already proposed that early humans had to have already
evolved to some stage of obligate bipedalism to go forth and survive
in the savannas. It should be common knowledge by now that the
savannas did not appear until long after the earliest biped fossils
were found. It may be that ranging in the savannas may have
facilitated the evolution of what is now the modern anatomy and
locomotion, or a radical adaptation to a new environment. -- Artemis

--- In AAT@yahoogroups.com, "Marc Verhaegen" <marc.verhaegen@v...>
wrote:
> > In an interview with the redaction of the French scientific
Magazine "La
> Recherche" [n° 361, 74-78, February 2003], professor Yves Coppens
declared
> that the East Side Story - a theory he has worked out since 20
years -
> doesn't exist any more.  "L' East Side Story n'existe plus" he
said.  In
> this scenario, the ancestors of today apes became separated from the
> ancestors of australopithecines and man by the formation of the
Rift Valley
> in East Africa, about 8 Mya. On the one side, the climate remained
> wet-tropical, on the other (Eastern) side, the climate became more
and more
> dry... with expansion of the savannah where the genus
Australopithecus, then
> Homo, allegedly have developed.  As a matter of fact, the recent
discovery
> of 7 My old "Toumai" [Sahelanthropus tchadensis] far east [West,
corrected
> by Francois - MV] from the Rift Valley may explain professor
Coppens'
> flip-flop... :-)  In this interview, he also added that DNA-
deciphering in
> fossil hominin bones would badly shake our "petits arbres
évolutifs" [small
> family trees] in next time.  No mention is made about a semi-
aquatic stage
> in human evolution, although Yves Coppens is well aware of the
AAT... On the
> contrary, Coppens maintained that "le fait que l'homme soit un être
de
> savane ne peut pas être remis en cause" [the fact that man is a
savannah
> dweller cannot be called into question]. Therefore in some decades,
the
> vision we have of anthropogenesis may be radically different of our
today
> concept...  Francois de Sarre  [January 27, 2003].
>
> Does he still believe that human ancestors were savanna-dwellers??
> incredible! Thanks a lot, Francois!
>
> Marc

Mario may well be right that eventually the island population may disappear.

   However consider the surviving islanders since the onset of the next glaciaton
have lived for thousands of generations on an expanding island. There will be no
sudden intersection with the mainland; there will first be a distance between
the island and the mainland. There will be some distance to swim to get to the
mainland. The first ones will be a few daring males. Who may meet a few
susceptible females? You have contact and the exchange of genes has begun. It
will probably be generations before confrontation between the main bodies when
one or the other is eliminated, in the mean time many casual encounters should
have occurred. The beginning of cross-fertilization.

   From this point it does not matter which side disappears, from here on it's
the genes that count.

   Consider some of the stories of ancient wars. Kill all males save all young
females.

   Also of Chimp fights.                           Frank Newbury

         I actually didn't mean of any war. Look at America's discovery. Only a
handful of europeans came to North America. But those handful brought with them
diseases. Those diseases were just common european (Old World) diseases. But
indians couldn't cope with them. It was mass dieing. Those type of things I was
thinking about. Smaller community simply cannot evolve in the way larger can. --
Mario



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

AFAIR, Marcel has (had?) has the curious opinion that Oreopith & (some?)
apiths & Homo are hominids to the exclusion of chimps & gorillas (perhaps he
calls them hominins), but you  better ask him.               Marc

         : ), ok. Thanks, Marc. -- Mario

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

J Biomech 2003 Feb;36(2):249-52 Links
Optimum ratio of upper to lower limb lengths in hand-carrying of a load under
the assumption of frequency coordination.
Wang WJ, Crompton RH, Li Y & Gunther MM.
The ratio of the upper to lower limb lengths (or the intermembral index IMI) in
the earliest human ancestors is closer to that of the living chimpanzees than to
our own, although the former show undoubted adaptations to bipedality. What
biomechanical factors could then have led to the phenomenon of genus Homo? This
paper proposes and evaluates a relationship between IMI and hand-carrying.
Assuming that coordination of limb swing frequencies of the upper and lower
limbs would be the subject of positive selection, a mathematical expression was
derived and can in part explain the changes in IMI. We found that AL-288-1 (3.6
Ma), the most complete skeleton of the early hominid Australopithecus afarensis,
could only have carried loads equivalent to 15-50 % of the upper limb weight
while maintaining swing symmetry, but KNM WT-15000, Homo ergaster (1.8 Ma) and
modern  humans could both carry loads 3 times heavier than the upper limb while
maintaining swing symmetry. The carrying ability of chimpanzees would be
inferior to that of AL-288-1. The IMI of modern humans, at 68-70, is the
smallest, and is optimal for hand-carrying under our criteria. Under reduced
selection pressure for hand-carrying, but unreduced selection for mechanical
effectiveness, we might expect humans to evolve a longer upper limb, to improve
swing symmetry when unloaded.


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

Thanks, Bruce. Looks interesting. I'll possibly be able to read the whole
PNAS paper within a few weeks.

Marc
_________

> Grist for the mill.
>   Language evolved in a leap
> Conflicting needs may have driven rapid development of communication.
> 22 January 2003
> PHILIP BALL <http://www.nature.com/nsu/profiles/aboutus.html#Ball>
> Speakers want few words; listeners want many.
> © GettyImages
>
> Language probably leapt, not crept, from squeaks to Shakespeare, two
> physicists have calculated. Human communication, they propose, underwent
> a 'phase transition', like solid ice melting to liquid water.
>
> The richness of human languages is a fine-tuned compromise between the
> needs of speakers and of listeners, explain Ramon Ferrer i Cancho and
> Ricard Solé of the Universitat Pompeu Fabra in Barcelona. Just a slight
> imbalance of these demands prevents the exchange of complex information,
> they argue.
>
> So languages between those of present-day humans and the limited
> signalling of some animals cannot really exist. There must, at some
> point, have been a switch from rudimentary to sophisticated language.
>
> This contrasts with some linguists' view that language evolution was a
> gradual affair in which new words accumulated steadily.
>
> Greek or grunt
>
> A language that conveyed all information unambiguously, say Ferrer i
> Cancho and Solé, would have a separate word for every thing, concept or
> action it referred to. Such a language would be formidably complicated
> for the speaker: the green of grass, for example, would be represented
> by a totally different word to the green of sea, an emerald or an oak
> leaf. But it would be ideal for the listener, who wouldn't have to work
> out any meanings from a word's context.
>
> Ideal for the speaker is a language of few words, where simple, short
> utterances serve many purposes. The extreme case is a language with a
> single sound that conveys everything that needs saying. Some might
> suggest that teenagers prefer this kind of minimal-effort tongue that
> forces others to figure out what their grunts actually mean.
>
> Ferrer i Cancho and Solé have devised a mathematical model in which the
> cost of using a language depends on the balance between these
> conflicting preferences1
> <http://www.nature.com/nsu/030120/030120-3.html#b1>. They calculate the
> properties of the lexicon that requires minimal effort for different
> degrees of compromise, from exhaustive vocabularies to one-word languages.
>
> They find that the change from one extreme to the other does not happen
> smoothly. There is a jump in the amount of communication, from very
> little to near-perfect, at a certain value of the relative weightings of
> speaker and hearer preferences.
>
> Human languages, say the duo, seem to sit right on this sudden change.
> When it happens, the frequency of word usages develops a distinctive
> mathematical form, called a power law. The power law disappears on
> either side of the communication jump.
>
> It has been known since the 1940s that human languages do indeed show
> just this kind of statistical distribution of word usage - the social
> scientist George Kingsley Zipf spotted the power-law behaviour. But it
> has never been satisfactorily explained before, although Zipf himself
> speculated that it might represent some kind of "principle of least
effort".
>
> References
>
>     # Ferrer i Cancho, R. & Solé, R. V. Least effort and the origins of
>       scaling in human language. Proceedings of the National Academy of
>       Sciences USA, published online, doi:10.1073/pnas.0335980100
>       (2003). |Article| <http://dx.doi.org/10.1073/pnas.0335980100>

> Marc, you mention that possibly Homo (rudolfensis) is in Kenya ca. 2.4 Ma.
Do you have refs for this? Jose

I just looked it up. B.Wood 1992 "Old bones match old stones"
Nat.355:678-679 on Beds of Chemeron KNM-BC-1, and 1993 "Rift on the record"
Nat.365:789-790 on Uraha U-501 (zie mijn boek p.166): Wood thinks BC-1
(Kenya ca.2.4 Ma) as well as UR-501 (Malawi ca.2.5-2.4 Ma) might perhaps
belong to the species of KNM-ER-1470, or at least to Homo.

Marc
_____

> >My thinking is partly based on comparative data, which suggest IMO that
the Homo-Pan LCA (whether 8 or 4 Ma) lived in coastal forests and that Homo
became more diving & less climbing after the split, and partly on fossil
data, which suggest that ergaster-erectus ca.1.8 Ma appeared "suddenly" at
the Med.Sea & the Indian Ocean coasts (perhaps more specifically in river
deltas? cf.Mojokerto). This sudden appearance might be artificial, eg, due
to sea level changes at that time? There are indications of Homo tools in
Israel ca.2.5 Ma IIRC, there are Oldowan cultures in E.Africa ca.2.6, and
there's possibly Homo (rudolfensis) in Kenya ca.2.4 Ma (not sure about the
exact datings). IOW, Homo (a more "primitive" form than ergaster - still
climbing??) might be older than 1.8 Ma & have lived outside Africa (which
could explain the baboon virus marker). We just don't know.    Marc

http://www.pnas.org/cgi/content/abstract/0334222100v1

T.Nishimura 2003 "Comparative morphology of the hyo-laryngeal complex in
anthropoids: two steps in the evolution of the descent of the larynx"
Primates 44:41-9

Dr Nishimura was so kind as to send me a pdf of his paper. Looks very
interesting, see abstract below. If somebody wants to read the paper, please
let me know.

Marc
_______

The descent of the larynx is a key phenomenon not only in postnatal
development, but also in the evolution of human speech. The positional
change of the larynx is affected by the descent of the hyoid bone in
relation to the mandible and cranial base, and that of the laryngeal
framework in relation to the hyoid bone. The phylogeny of the spatial
configuration of the hyo-laryngeal complex is one of the most important
sources of information for elucidating the evolution of laryngeal descent.
In the present study, the anatomy of the complex was examined in various
species of anthropoids to compare the configuration, the shape of the
basihyal and thyroid cartilage, and the length of the lateral thyrohyoid
ligaments. Non-human hominoids share most features with humans, while
cercopithecoids and ceboids have anatomical features that sharply contrast
to humans, except for the form of the thyroid cartilage in ceboids. The
laryngeal framework in hominoids is well separated from and assured of
mobility independent of the hyoid. In cercopithecoids and ceboids, it is, by
contrast, locked into and tied tightly with the hyoid so that the
hyo-laryngeal complex acts as a functional unit. This spatial configuration
is considered to be significantly related to the mechanism that prevents
aspiration, including epiglottic movement and vestibular closure. Non-human
hominoids are inferred to share the mechanism with human adults, not with
cercopithecoids and ceboids, although their larynx is located as high as the
latter. Consequently, it is hypothesized that the descent of the larynx
evolved in two steps. The first step would have been descent of the thyroid
in relation to the hyoid for the evolution of the mechanism preventing
aspiration, which occurred in the common ancestor of hominoids. The second
step, descent of the hyoid within the neck, occurred during hominid
evolution for human speech.

> T.Nishimura 2003 "Comparative morphology of the hyo-laryngeal complex in
anthropoids: two steps in the evolution of the descent of the larynx"
Primates 44:41-9:     The descent of the larynx is a key phenomenon not only
in postnatal development, but also in the evolution of human speech. The
positional change of the larynx is affected by the descent of the hyoid bone
in relation to the mandible and cranial base, and that of the laryngeal
framework in relation to the hyoid bone. The phylogeny of the spatial
configuration of the hyo-laryngeal complex is one of the most important
sources of information for elucidating the evolution of laryngeal descent.
In the present study, the anatomy of the complex was examined in various
species of anthropoids to compare the configuration, the shape of the
basihyal and thyroid cartilage, and the length of the lateral thyrohyoid
ligaments. Non-human hominoids share most features with humans, while
cercopithecoids and ceboids have anatomical features that sharply contrast
to humans, except for the form of the thyroid cartilage in ceboids. The
laryngeal framework in hominoids is well separated from and assured of
mobility independent of the hyoid. In cercopithecoids and ceboids, it is, by
contrast, locked into and tied tightly with the hyoid so that the
hyo-laryngeal complex acts as a functional unit. This spatial configuration
is considered to be significantly related to the mechanism that prevents
aspiration, including epiglottic movement and vestibular closure. Non-human
hominoids are inferred to share the mechanism with human adults, not with
cercopithecoids and ceboids, although their larynx is located as high as the
latter. Consequently, it is hypothesized that the descent of the larynx
evolved in two steps. The first step would have been descent of the thyroid
in relation to the hyoid for the evolution of the mechanism preventing
aspiration, which occurred in the common ancestor of hominoids. The second
step, descent of the hyoid within the neck, occurred during hominid
evolution for human speech.

I just read the paper.

Nishimura describes the evol.steps:
1) thyroid descent in the hominoid LCA,
2) hyoid descent in H.sapiens (unknown in fossils).

I doubt his interpretations:
1) monkeys don't aspirate foods,
2) humans can speak well with undescended larynges.

Hypothesis 1:
1) for phonation cf. song in gibbons)??
2) for suction feeding??

Hypothesis 2:
1) suction feeding??
2) correlated with basicranial flexion??

Other ideas??

Marc

Marc,
     Nishimura's interesting article raises a tangential set of
questions. In The Aquatic Ape Hypothesis, Elaine argued that the larynx
descended as a breathing adaptation in an aquatic environment, noting
that several other aquatic species also have such structure, whereas few
terrestrial ones do. Separately, Philip Lieberman argues, for example in
Eve Spoke, that a Neanderthal's larynx was no more descended than a
human infant's and, as a result, could not articulate as well as humans,
particularly being inable to make some critical phonemes.
     Here are the questions: Is there a consensus among the AAT group
that the larynx descended as an aquatic adaptation? If so, doesn't
Lieberman's argument, if true, imply that there must have been at least
some further aquatic adaptation, and hence considerable aquatic
involvement, since the LCA of Homo sapiens and Neanderthal about 250K
ya? And if this is true, how does it fit with your perspective (if I
have it right) that the most aquatic phase for hominids was erectus?
     Bruce Stevens


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

>     Nishimura's interesting article raises a tangential set of questions.
In The Aquatic Ape Hypothesis, Elaine argued that the larynx descended as a
breathing adaptation in an aquatic environment

Well, she thought (not any more?) that it facilitated breathing (eg, wider
opening, less resistance to breathing).

> , noting that several other aquatic species also have such structure

I don't think she did. In fact, cetaceans have "ascended" larynges
(intranasal).

> , whereas few terrestrial ones do. Separately, Philip Lieberman argues,
for example in Eve Spoke, that a Neanderthal's larynx was no more descended
than a human infant's

He can't possibly know (cartilages don't fossilize, and if they did
(thyroids sometimes ossify partly), there's no bony connection with the
skull base). His reasoning was that neandertals had no (or less) basicranial
flexion, thant apes have no basicranial flexion, so if apes have descended
larynges, neandertals should also have descended larynges IHO. This is
obviously wrong in several respects.

> and, as a result, could not articulate as well as humans, particularly
being inable to make some critical phonemes.

Again wrong: we now know humans can speak with ascended larynges.

>   Here are the questions: Is there a consensus among the AAT group that
the larynx descended as an aquatic adaptation?

I don't think so, but I can't speak for others. For our view (with Roger
Crinion & Stephen Munro) see
http://groups.yahoo.com/group/AAT/files/Phon.abilities--ill.30.12.00.doc
Roger is the one who knows most on the comparative anatomy of the pharynx &
larynx. In short, we think descended larynges (in rest) might suggest
suction feeding.


> If so, doesn't Lieberman's argument, if true, imply that there must have
been at least some further aquatic adaptation, and hence considerable
aquatic involvement, since the LCA of Homo sapiens and Neanderthal about
250K ya? And if this is true, how does it fit with your perspective (if I
have it right) that the most aquatic phase for hominids was erectus?
Bruce Stevens

Lieberman is wrong of course. As for erectus, we don't know the place of
their larynges. Nishimura describes: 1) descended thyroid in the hominoid
LCA, 2) descended hyoid in H.sapiens (unknown in fossils). I see at least 2
possibilities: 1) for phonation (but deer & dogs have descended larynges on
when calling) & 2) for suction feeding (IMO present in erectus, and perhaps
much earlier)? Or else: 1) for suction feeding (thiswould imply that the
early hominoids were suction feeders!) & 2) correlated with basicranial
flexion (only sapiens, ie, post-aquatic)??

Marc

>> Marc, you mention that possibly Homo (rudolfensis) is in Kenya ca. 2.4
Ma.
>Do you have refs for this? Jose
>
>I just looked it up. B.Wood 1992 "Old bones match old stones"
>Nat.355:678-679 on Beds of Chemeron KNM-BC-1, and 1993 "Rift on the record"
>Nat.365:789-790 on Uraha U-501 (zie mijn boek p.166): Wood thinks BC-1
>(Kenya ca.2.4 Ma) as well as UR-501 (Malawi ca.2.5-2.4 Ma) might perhaps
>belong to the species of KNM-ER-1470, or at least to Homo.
>Marc


Thanks Marc!
Jose

"Algis Kuliukas" <algis@...> wrote in message
news:77a70442.0301301639.290de456@....

> I just did it in our pool and the results are interesting. I'm 182cm tall
and my hip height is 99cm. Bending down to pick a stone off the bottom of
the pool was easy (without loosing contact with the bottom) up until a water
depth of 113 cm. Then, suddenly it became impossible and the feet came away
from the surface as soon as my head dipped below the surface.
Interesting. But what does it show? That extant apes couldn't simultaneously
walk bipedally with their head under water at depths greater than 1.14 x hip
height? I don't think anyone who is open to the AAH would see that as
damning evidence against it.     1) I suggest a good part (probably most) of
the foraging of food of the earliest bipeds would have been above the water
surface vegetation.     2) The depth of water I envisage them moving in is
at the most about this depth. If it were much deeper, they'd have swam.
3) Even if they did forage for food at the bottom in these depths it is
inlikely that they'd try to walk at the same time. Rather like chimps feed
posturally from franches in an upright manner but thet get down on all fours
to move to the next branch.         So, thanks for an interesting idea. I
think the wading model comes out of it as strong as ever.     Algis Kuliukas

I don't read most, but luckily I read this. Thanks, Algis.
1) Yes, wading apiths could probably be compared to humans or chimps
collecting water lilies or lowland gorillas feeding on "aquatic herbaceous
vergatation".
2) Yes, I guess these plants (sedges, AHV, water lilies, cattails etc.)
mostly grow in water less deep than ca.1 m.
3) Yes, they probably didn't collect bottom foods. It's only with Homo that
we see indications of bottom feeding (heavy skeleton, elaborate stone tool
use & handiness, fossils & tools amid shellfish & corals), but like all
human populations collecting shellfish, they swam of course.

Marc

Marc,
     Thanks for your thoughts on the HS/HN larynx question. Your
responses to Lieberman's points were interesting and I was curious
whether your conclusions are based on having read his work or on my
description. If the latter, you might want to check out his book. In it,
he has some comparative casts of oral cavities representing modern and
archaic HS (both adult and infant) and HN.
     Also, you mentioned that humans can speak with ascended larynges.
How has this been determined? Does the larynx not descend in some
individuals?
     Regards,
     Bruce Stevens

> >>     Nishimura's interesting article raises a tangential set of
questions. In The Aquatic Ape Hypothesis, Elaine argued that the larynx
descended as a breathing adaptation in an aquatic environment

> >Well, she thought (not any more?) that it facilitated breathing (eg,
wider opening, less resistance to breathing).

> I still think that.

OK.

> >> , noting that several other aquatic species also have such structure

> >I don't think she did.

> Yes I did. I know of two - dugong and sealion. Negus makes it clear. The
only counter-argument I have heard is that Negus did not have the state of
the art equipment we have today so maybe he was wrong. The answer to that is
that the people who do have the equipment, unlike Negus, have never even
tried to look at the larynx of these creatures.

I don't know whether Negus made this clear. After Jan Wind's death I bought
his copy of Negus "Compar.anatomy...Larynx" with some annotations of Jan &
correspondence of Negus & Jan: p.77: "In the Walrus and the Californian Sea
Lion, both carnivorous but microsmatic, there is only a very small and
insignificant epiglottis, but with no disability in powers of swallowing
(Figs. 32, 88). The Dugong and the Manatee are also unprovided with more
than a very small and low epiglottis" - the Figs are not very clear to me,
but the all these aquatic species have small epiglottises, whereas human
have well-developed ones I believe.


> > In fact, cetaceans have "ascended" larynges.

> They also have blow holes. They obviously followed a different path.

Well possible, but why?

> >> , whereas few terrestrial ones do. Separately, Philip Lieberman argues,
for example in Eve Spoke, that a Neanderthal's larynx was no more descended
than a human infant's
.....

> I agree with Marc about Lieberman.

> >>   Here are the questions: Is there a consensus among the AAT group that
the larynx descended as an aquatic adaptation?

> I wouldn't think so.

> >I don't think so, but I can't speak for others. For our view (with Roger
Crinion & Stephen Munro) see
http://groups.yahoo.com/group/AAT/files/Phon.abilities--ill.30.12.00.doc
Roger is the one who knows most on the comparative anatomy of the pharynx &
larynx. In short, we think descended larynges (in rest) might suggest
suction feeding.

> This confirms: no consensus on this.     Elaine

OK.

Marc

> Marc,     Thanks for your thoughts on the HS/HN larynx question. Your
responses to Lieberman's points were interesting and I was curious whether
your conclusions are based on having read his work or on my description. If
the latter, you might want to check out his book. In it, he has some
comparative casts of oral cavities representing modern and archaic HS (both
adult and infant) and HN.

Reconstructions of casts (with larynx etc.), based on his ideas of the
correlation of basicranial flexion & laryngeal descent (for which
supposition there's no good basis IMO). I have no doubt basicranial flexion
(HN was intermediate between HE & HS in this respect) is for walking fully
upright (post-aquatic - to direct the eyes to where you're walking), so
basing a reconstruction on such ideas probably gives wrong results.

>    Also, you mentioned that humans can speak with ascended larynges.  How
has this been determined? Does the larynx not descend in some individuals?
Regards,     Bruce Stevens

Yes, some pathological cases IIRC, but you better ask Elaine. Comes from
work of Tecumseh Fitch IIRC. It was believed that because humans can speak &
have descended larynges, lar.descent was necessary for speech - a logical
mistake.

Marc

News item:

http://news.bbc.co.uk/1/hi/sci/tech/2709797.stm

Regarding the Sterkfontein fossil... "Dr Clarke goes further. He argues that the
fact the hominid was not a knuckle-walker suggests chimps and humans are not as
closely related as we thought. It pushes the last common ancestor of chimps and
humans much further back in history, he says. [...] 'The suggestion in
reconstructions and in the scientific literature that human ancestors were
transformed into an upright position from a knuckle-walking ancestor is not
supported by
this new and important addition to the fossil record.' "
Of most interest is the number of interviewees who accept that knuckle-walking
evolved separately in chimps and gorillas after the split from the human line:
"Professor Chris Stringer of London's Natural History Museum says the idea that
humans and chimps derive from a knuckle-walking common ancestor is 'not a
majority view'. The peculiar gait of chimps and gorillas could have developed
after the three lines diverged, he says.
"Dr Robin Crompton, of the University of Liverpool, agrees. He says there is
'very strong' genetic evidence that we are closely related to chimps (and
bonobos). 'It is likely that the common ancestor of the African apes, including
ourselves, was arboreal,' he told BBC News Online. 'In my view, knuckle-walking
and vertical climbing - up and down tree trunks - are a specialisation of chimps
and gorillas after humans split off from them.' "
I'd therefore like to repost from an earlier post of mine:    > [...] 
Dryopithecus, a putative hominine ancestor according to Begun, shows no
adaptation for knuckle-walking (Kordos & Begun, 2002). It specialized in
suspensory locomotion and would just as easily have > walked bipedally on the
ground as in any other way (ie much like orangs do). And of the other two
members of that overall Eurasian grouping, we have no postcrania for the
gorilla-like Ouranopithecus while Oreopithecus is bipedal anyway. Finally the
"Did knuckle walking evolve twice?" paper covering chimpanzees and gorillas has
been around for ages [1].     From my own perspective, the foramen magnum on
Sahelanthropus still looks like that ape was rather erect in posture, while Dr
Hawks suggested on palanthsci that the fossil reminds him of Ouranopithecus. So
just perhaps chimps are rather more derived in their own specialized direction
than we have suspected up till now. For the rest we have a whole bunch of rather
erect gorilla-like brachiators.     Conclusion: just perhaps this whole business
of "explaining" bipedalism is a silly project to begin with. Perhaps we really
need to worry rather more about explaining knuckle-walking, a rather dangerous
evolutionary strategy if one wants to retain full flexibility of the hands and
wrists for brachiation or other reasons. Such other reasons might even include
facility with a greater range of non-preserving wooden tools, fibroconstructive
techniques or the like. Before anyone hoots with derision, please bear in mind
that orangs are now found to be cultured fellows, and along with chimps are
significantly more encephalized than Macaca, while the australopithecines are
more encephalized still (Williams, 2002). So when exactly did the
culture-encephalization ratchet begin notching its way upwards?     [1] Dainton,
M., and G.A. Macho. 1999. Did knuckle walking evolve twice? J. Human Evol.
36:171-194.  Harry (Skeptical1)


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

The BBC News website is currently covering this story at
http://news.bbc.co.uk/1/hi/sci/tech/2709797.stm
and has linked recent stories on new hand fossils found at the same
site. Anyone on this list agree with the finders interpretation or
the  other comments?
Friday, 31 January, 2003, 05:37 GMT

Fossil find stirs human debate
"This Sterkfontein individual was a climber in the trees and bipedal
on the ground" Dr Ron Clarke

The fossil of an early human-like creature (hominid) from southern
Africa is raising fresh questions about our origins. Remains from the
Sterkfontein Caves near Johannesburg suggest our ancestors were less
chimp-like than we thought. The revelation follows the discovery of
missing bones from a 3.5 million-year-old skeleton found in 1998.
Fragments of pelvis, upper leg, ribs and backbone have recently been
dug out of the rock, allowing scientists to piece together its gait.
The anatomy of the hominid, a member of the genus Australopithecus,
raises some interesting questions.
   Its bone structure shows it did not walk like modern chimps, using
the knuckles of its hands. It probably walked on two legs when it was
on the ground but spent much of the time climbing trees, says Dr Ron
Clarke, of the University of the Witwatersrand, who discovered the
fossil. Dr Clarke goes further. He argues that the fact the hominid
was not a knuckle-walker suggests chimps and humans are not as
closely related as we thought.

It pushes the last common ancestor of chimps and humans much further
back in history, he says.  Dr Clarke sets out his position in the
South African Journal of Science, which publishes the latest data.
"My conclusion from the limb proportions and the morphology of the
foot and of the hand is that this Sterkfontein individual was a
climber in the trees (using its powerful thumb in a vice-like grip)
and bipedal on the ground," he says. "It would appear, therefore,
that the strong opposable thumb evolved in the human ancestral stock
for grasping branches. Then, in the mainly terrestrial subsequent
descendants in the form of Homo, it was to prove useful for tool-
making and manipulation.

"The suggestion in reconstructions and in the scientific literature
that human ancestors were transformed into an upright position from a
knuckle-walking ancestor is not supported by this new and important
addition to the fossil record."

Fresh debate

Other experts in human evolution are more circumspect. Professor
Chris Stringer of London's Natural History Museum says the idea that
humans and chimps derive from a knuckle-walking common ancestor
is "not a majority view".
The peculiar gait of chimps and gorillas could have developed after
the three lines diverged, he says.
Dr Robin Crompton, of the University of Liverpool, agrees. He says
there is "very strong" genetic evidence that we are closely related
to chimps (and bonobos).
"It is likely that the common ancestor of the African apes, including
ourselves, was arboreal," he told BBC News Online.
"In my view, knuckle-walking and vertical climbing - up and down tree
trunks - are a specialisation of chimps and gorillas after humans
split off from them."

Sterkfontein is probably the richest site on Earth for the fossils of
early hominids, and the ancient cave system is now part of a World
Heritage Site. Some 600 hominid fossils from the Sterkfontein Caves
have now been collected and classified. The early humans they
represent are thought to have fallen to their deaths in the caves
when the limestone complex first broke the surface.