Re: Brain Development

Thu, 2 Feb 1995 20:54:20 -0600

>What made other less intelligent hominid species less advantageous and ultimate>ly extinct?

An interesting theory I heard is that homo sapiens killed them off through

On brain development in general; I believe that intelligence is one of those
traits that is selected for in many species. Dumb species don't hang around
for very long.

Also, William Calvin has an interesting theory he puts forth in _The Ascent of
Mind_ that claims human brain expansion is the result of the Ice Age. It seems
that during the last 2.5 my the brain of homo sapiens sapiens increased by 4X.
Calvin thinks this is the result of adaptation to the changing environment. The
continual abatement and advance of the ice sheets (with no less than 18 cycles
during this period) acted as a motor for encephalization. Ice would advance,
creating harsh conditions that required intelligence to cope with, and then
recede creating a rich, abundant environment that spurred fairly rapid bouts of
speciation. After several million years of this,voila! I at least think is a
more credible theory than the "direct energy from the intestines to the brain"
theory from homos starting to eat meat that was posted a few days ago.


james b.