Ray Audette writes:
>The onset of the glaciers was the boom time.  At the peek of the ice age the
>temperate zones contained very large areas of steppe-tundra.  The
>Pleistocene Megafauna and the humans who preyed on them would be at their
>maximum populations at this time.
>
>When the ice receded was the time of stress.

Ok, I may have that part backwards.  Honestly, I don't have my reference
handy (_The Ascent of Mind_), and I haven't read Cohen's book which
you cite, so I can't really say one way or the other.

However, regardless of which phase of the ice ages is seen as boom time and
which is seen as the time of stress, so long as we believe that there
were alternating times of relaxation and constriction of environmental
pressures then the "boom-time/neoteny/enlargement" theory of human
encephalization is still reasonable.

I still very much would like to hear the counterarguments both
to this theory and to the Expensive Tissue Hypothesis.

>Cohen, Mark Nathan "The Food Crisis in Prehistory: Overpopulation and the
>Origins of Agriculture" in the bibliography at my site.

Incidently, this book is also out of print (according to amazon.com).

-Bruce