To all,



In our continuing exploration of whether behavior can or cannot be
inherited, here are results from a group of Swedish-Norwegian researchers.
Apparently, genetic modifications do take place in young chickens' brains.



Regards,

Gerry



_____

From: evolutionary-psychology@yahoogroups.com
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Subject: [SPAM] [evol-psych] Swedish chickens challenge Darwin




Swedish chickens challenge Darwin


Published: 16th April 2007 17:51 CET
Online: http://www.thelocal <http://www.thelocal.se/7015/> .se/7015/

http://www.thelocal <http://www.thelocal.se/7015/> .se/7015/

Darwin's theory of evolution has been dealt a stinging blow by a group of
Swedish-Norwegian researchers. The group, led by Professor Per Jensen from
Linköping University, has launched a challenge to Darwin's notion that
behaviour cannot be inherited.

In a study published by scientific journal PLoS ONE, the group found that
the young of domestic hens exposed to high levels of stress displayed
similar behavioral anomalies despite growing up in a stress free
environment.

Furthermore, genetic modifications in the young chickens' brains were
similar to those developed by their parents as a result of stress.

Per Jensen is keen to stress that the results do not mean that Darwin was
wrong.

"But we have seen that an animal population can quickly adjust to new
environmental conditions by passing on modified patterns of expression to
their young. This was not considered possible in the classical theory of
evolution," he said in a statement released by Linköping University.

The researchers observed two groups of chickens, one of which was exposed to
a stressful environment. Their daily rhythm was disrupted, making it
difficulty for the animals to judge when they were to be fed and when they
should sleep. The stressed environment proved seriously detrimental to their
learning ability when compared to the other group.

When the researchers studied the young of both groups, they found that the
young of stressed hens had the same learning difficulties as their parents.
These chickens also grew at a faster rate and were more dominant than the
young of the group not exposed to stress.

"What is interesting is that the chickens themselves did not experience any
stress. From the moment the egg was laid, they were treated exactly the same
as the control animals. The differences must result from the brains of the
chickens with stressed parents developing differently," said Per Jensen.

The researchers examined the expression levels of 9,000 genes in one part of
the parents' brains to see if a genetic link could be established. They
found that these levels fluctuated in the genes of the stressed animals,
becoming either more or less active.

The young of the stressed animals displayed the same genetic changes.

According to the researchers, the parent's experiences had altered the
function of the genes in the brains of their young, whose behaviour was also
affected. This suggests that the behavioural changes were inherited by
genetic means.

Paul O'Mahony (paul.omahony@ <mailto:paul.omahony@...>
thelocal.se/08 656 6513)