John Eley wrote:
  It occurred to me that the fat
> storage properties of insulin may have been an adaptation which allowed
> human to store enough fat during the late summer months to get through
> the winter when food would be more difficult to obtain.  Any thoughts?

Interestingly, it may have been the lenth of winter rather than it's severity that led Neanderthals to be
replaced by Cromagnons. The later's much smaller muscle mass (lower resting metabolism)would allow them to
store fat faster as the steepe-tundra migrated to the poles during the very warm (for an ice-age) first half
(113-72 thousand years ago)of the last period of glaciation, resulting in winters that were not as severe but
lasted longer.  These temperate latitude winters were also much darker having longer nights when any additional
insulation would be very welcome.

This migration first introduced man to temperate wolves (who became our dogs).  When the steppe-tundra again
migrated closer to the equator, this man/dog predator became the dominant predator on the planet.  The new
tools made practical by this new association are perhaps the best evidence of this change.  The geographically
smaller although more lush steppe that remained was quickly overcome by these new humans, trigering some
speculate, the pleistocene extinctions.  Although we didn't need the ability to store fat as much, it came with
the neoteny package which allowed us our enviable position on the food chain.

When the steppe-tundra disapeared completely at the end of the last ice-age (12,000 years ago), sea levels rose
and the last of the pleistocene mega-fauna became extinct (we chased them almost all the way to the poles).
Man needed a new food source and the serpent offered Eve "Fruit of the Tree of Knowledge" (aka Neolithic
Revolution).

Ray Audette
Author "NeanderThin"