Re: A Specification for a
Paul Crowley (Paul@crowleyp.demon.co.uk)
Fri, 27 Oct 95 01:21:09 GMT
In article <60.3801.7295.0N1FAB63@canrem.com>
j#d#.moore@canrem.com "J. Moore" writes:
> What I said was unwarranted was the assumption that it happened
> during the transition from CA to hominid.
Sorry. I think I must have missed your "during the transition"
> That hair loss is something which we want to investigate is a given.
> We see no evidence that it happened during the transition, however,
However, I'd like to step back further and say that while we have no
fossil evidence, it is parsimonious to assume that all the features
that make a species distinctive appeared at the point of speciation,
if they were not present in the CA. So it's parsimonious to assume
that knuckle-walking appeared in the CA of the gorilla and the chimp
when it split off from other apes; that social behaviour and an
omnivorous diet appeared when chimps split off.
Nakedness is a most distinctive feature; so is bipedalism. Both
would seem to represent very particular adaptions to a new form of
life. Our job is to identify that form of life. We know large
brains came later. Maybe, if we could link nakedness with large
brains we could escape the problem; but until we have such an
explanation, a link with bipedalism can be (weakly) assumed.
> since we see that in our own late-arriving species, there is
> considerable variation in this characteristic. This would suggest
> that it happened pretty recently, or possibly that it's a trait that
> comes and goes extremely quickly.
I don't buy "late-arriving species". It's too hypothetical.
IMO the simplest (i.e. most parsmonious) explanation of the
regional variation in hair is that it is caused by solely by the
recent movements of races to colder climates. These are known.
Hair provides insulation and would have good selective value in
those climates. With luck DNA evidence will soon come on this.
Paul.
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