Re: Calvin

Keith Henson (
Fri, 24 Jan 1997 17:35:12 -0800 (PST)

On Fri, 24 Jan 1997, Robert Schrader wrote:

> I must admit that I haven't read Calvin's book[s] either, but it does
> seem odd that one can claim that Lucy doesn't have sufficient neurons
> for release timing. Frogs do pretty well with small brains, and so do
> bats.

Neither one is trying to throw accurately. The math involved is very
simple. Calvin's best on this subject, Ascent of Mind, is out of print,
but available on his web site:

Here is a (I hope fair use) clip from the table of contents:

7 WHIDBEY ISLAND: Ratcheting Up Brain Size_ Parts, Process, Product: the
legislative process illustrates a transformational process at work, and
illustrates what a detailed understanding of human evolutionary processes
might involve. Beach walk to an old Indian fishing village buried by a mud
slide on Whidbey Island. And a mother-and-unborn-child burial. Relatively big
heads occur with early puberty. Then stature re-enlarges in other ways. When
the resulting big heads kill their mothers, there is selection for
slower-than-average body growth rates, so the survivors are born
premature-looking. Given selection pressure resulting in juvenilization, one
gets a cycle that can be repeated many times to enlarge the brain fourfold.

_8 HAND-AX HEAVEN: The Ambitious Ape's Guide to a Bigger Brain_ 205 A
possible advantage of juvenilized bodies for throwing ability and thus
hunting. How an ape could have invented the predatory throw, using
side-of-the-barn accuracy. And how it ought to lead to something like the
Acheulean hand ax. A heaven for used hand axes, in the Pluvial ponds of the
Sahara. The growth curve for throwing, and the brain reorganization it

If this is not applicable to the recent discussions, I don't know what
might be. Keith Henson