Re: Bipedalism and theorizing... was Re: Morgan and creationists

John Waters (jdwaters@dircon.co.uk)
28 Sep 1996 18:17:45 GMT

Part 2.

> In any case, I'm sure that "a better power/weight ratio" is a
> chimera. How could, say, chimps or dogs or dolphins achieve
a
> better power/weight ratio? They are each as well adapted to
their
> current environment as is possible. They are each the result
of
> millions of years of evolutionary weeding-out. Insofar as the
> real world allows, they have an optimum power/weight ratio.
>
> Perhaps you are saying that certain populations adapted to a
> different environment. If that's the case, say so. The
power/
> weight thing seems to me a distraction.
>
> Paul.

JW: You will be aware that within any specie there can be a
variation of individual characteristics. For example, at the
recent Olympic Games in Atlanta there were champion shot
putters, sprinters and marathon runners. Each had a different
physiology in terms of bone size, muscle twitch etc.

If the human environment changed in a way which favoured
marathon running as the sole means of survival, the Shot Putters
and Sprinters would gradually die out. This is a process known
as natural selection. The remaining population would all have
the
marathon runner€s physiology.

Notice that there has been no genetic adaptation here. It is
purely a process of selection. Of course the genes would still
retain the basic codes which would allow the specie to produce
shot putters and sprinters in the future. In each generation, a
minority of the population would be born with these
characteristics.

So, if a change occurs in the environment of chimps, dolphins or
dogs, which requires an improvement in their power to weight
ratio, this might be achieved solely by the selective process.
If a greater change was required, this would be dependent upon
genetic variation and selection.

According to the Neutral Theory of Genetic Evolution genetic
mutations occur at random in each new generation of specie. If
the mutations are advantageous they will improve the survival
and reproduction possibilities of the individuals concerned.
Over many generations this will lead to a preponderance of such
mutations in the specie€s gene pool.

( Paul, I will continue my reply to your questions in Part 3.
Post.)

John.