Re: Are we "special"?

Paul Crowley (
Fri, 06 Dec 96 09:16:39 GMT

In article <581ned$> "Gerrit Hanenburg" writes:

> How did you arrive at the figure of ~40000 genes?

This was from a posting here on 30 Jan 1996 by Dr Holloway.
Actually prior to that I had heard a talk by Prof Steve Jones
where he quoted a figure of ~60,000.

> >It is in this area
> >that we would differ most from chimpanzees. The major changes
> >in morphology, mostly those that concerned bipedalism, would
> >have happened quickly. It is in the CNS that selection
> >operated over millions of years on millions of mutations to
> >produce the distinctive H.s.s. characteristics.
> The major differences between human and chimpanzee brains are relative
> size and the degree of interconnectivity. These differences can in
> principle be the result of differences in developmental timing
> (heterochrony) or allometric relationships.These in their turn can be
> the result of mutations in only a few (regulatory) genes. The
> differences do not require millions of mutations.

I'd agree that "millions" is too much; such a figure could not
possibly be achieved in the timescale under any evolutionary
scenario. Regulatory genes must be extensively involved.
However, the figure must be at least in the tens or thousands,
and possibly hundreds of thousands, and any figure like that
presents almost insuperable problems for a *serious* paleo-

> The basic organization of the human CNS is not dramatically different
> from that of a chimpanzee.

This is a factual, physical matter, and hopefully someday soon
we'll get a good answer from geneticists or neurologists.
However, I feel that you are quite wrong, and that there are
dramatic differences. One way of looking at it is to consider
the work our CNS does: a language-learning capacity is inbuilt,
but all attempts to establish the rules for this capacity have
made little progress. They are far to complex. One reflection
of this is the hopeless inadequacy of all language translation
programs, even though they incorporate tens of thousands of
rules and millions of lines of code.