Re: Bipedalism and theorizing... was Re: Morgan and creationists
Paul Crowley (Paul@crowleyp.demon.co.uk)
Tue, 24 Sep 96 19:39:43 GMT
In article <01bba9fd$483b81a0$152470c2@jdwaters.dircon.co.uk>
jdwaters@dircon.co.uk "John Waters" writes:
> JW: Generally speaking genetic adaptions occur under one of two
> sets of conditions. The first type of condition occurs when the
> global climate changes from cool dry to warm wet. This is
> significant because there are more potential ecological niches
> in a warm wet environment. Under these conditions you get the
> radiation of specie as they adapt to these new niches.
> [snips]
>
> The marginal variant specie are typically generalistic
> omnivores. The specialist mainstream specie tend to be
> frugivores, or carnivores, or leaf eaters, or graziers.
We're really talking about all species - fauna and flora. Are
such rules well recognised? I've never heard of them. Clearly
if whole species are wiped out by drastic climatic change (such as
that at the K/T boundary) then new niches open up, enabling rapid
radiative adaptation. But does it apply to normal climate change?
> .... Secondly, you need an empty niche
> which can be colonised by the new variant specie.
This is the vital feature, which is missing from normal scenarios.
> Clearly, the Chimpanzee is a generalistic omnivore. So the first
> condition for adaptive change is satisfied. However, there is no
> empty neighbouring niche. On the equatorial side, the Ape niches
> are occupied by Gorillas and Bonobos. On the desert side the
> niche is occupied by the human specie.
How can you say this? Of terrestrial animals H.s.s. must be one
of the most water-dependent. We sweat intensively. Our faeces
are 75% water. Our water-retention mechanisms are minimal to non-
existent.
> > You can break down *any* evolutionary development and say that the
> > change in each generation would be so insignificant that it would
> > have no disadvantageous effects. That's plain cheating. You have
> > to outline the countervailing advantages.
>
> JW: I Have. An improvement in their power to weight ratio. I say
> this again and again, and you ignore it again and again.
We agree that additional helplessness for a primate infant (and
its mother) is disadvantageous. You say, however, it leads to a
better power/weight ratio. Your logic here is extremely unclear.
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.
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