Re: Alex's gibbon-like CA

Paul Crowley (
Sun, 12 Nov 95 12:43:28 GMT

In article <482psm$> "Benjamin H. Diebold" writes:

> Paul Crowley ( wrote:
> [snip]
> : occurred. Environmental change would have had no bearing on such
> : small groups. I'm sure that PA thought emphasises the climatic change
> : largely because of a complete dearth of better ideas.
> This seems an astonishing claim. Why on earth should you believe that
> environmental change would have no bearing on small groups?

You've lifted it quite out of context. Partly it was a reference
to a discussion on the effects of major climatic change.

My point is that billions of species have been created. Only a
very small proportion could be thought to be the result of major
climatic change. Yet that explanation is always the first to be
pulled out of the hat - in particular for hominid speciation.
So, in principle, we have to be suspicious whenever we see it.
Almost invariably it's a case of "Well, I can't think of anything
else so it must have been the result of a change in climate".

Secondly, I was referring to the period of hominid evolution when
brains expanded and language developed. How many beneficial
mutations did that involve? 10,000? Each of them had to spread
throughout the whole population. So it had to be small and
localized, or as I said: a lot of choke points. Major climatic
change would have had no significant effect on this process. Even
in the broadest sense, it is hard to see how any environmental
change could have had a substantial influence.