Re: Brain Development

Sat, 4 Feb 1995 17:04:00 PST

Holloway has already pointed out the factual problem with the claim:

"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."

(which is a statement previously posted as a brief synopsis of a longer
argument by Calvin (?) on the ice age as a driving mechanisim for increase in
brain size in hominids).

In addition to factual problems, this type of argument tries to convert
association (actually, it is even wrong on the association as Holloway notes,
but even if it were not factually wrong...) into causation without
establishing a plausible causal mechanism. As stated, the argument applies
equally to ANY species, hence EVERY species subjected to the rigors of the
Ice Age should demonstrate "rapid bouts of speciation" and development of
intelligence. Failing that, at most there is association (assuming the
argument was not factually incorect) and no causal link between ice ages and
change in hominid brain size.

D. Read