Date: Tue, 21 Apr 1998 11:38:48 -0700 (PDT)
From: Matt Dennis <corwin3083-AT-yahoo.com>
Subject: Re: The Survival Of The Fittest Floom







---"Steven E. Callihan" <callihan-AT-callihan.seanet.com> wrote:
>
> Matt Dennis wrote:

> >Also, for those of you who can't imagine species evolving suddenly,
> >try reading about Stephen Jay Gould's theory of punctuated
> >equilibrium. If you study evolutionary history, you will notice that
> >after each great extinction, as new niches have opened up for
> >occupation, new animals have evolved, relatively suddenly, to fill
the
> >gap. It really isn't that hard to imagine.
> 
> A species that is adapted solely to a single habitat is liable to be
at a
> greater risk of extinction if that babitat disappears or is radically
> altered. Generally, evolution is the exception. Extinction is the
rule. The
> problem, in other words, is that it is a very low probability that
exactly
> the right mutation would show up at exactly the right place and
time--the
> odds are against it, in other words. That doesn't mean that it doesn't
> happen once in a blue, blue moon, but just that we shouldn't count
on it.
> The higher probability, by far, I think, is that every evolution,
whereby
> one species diverges from another involves a multiplicity of mutations
> (changes to the genetic code) over a fairly extensive period of
time. The
> advantage, in evolutionary terms, would go to those species that
contain a
> variety of different subtypes (such as the different kinds of Darwin's
> finches, for instance).
> 
> Best,
> 
> Steve

It doesn't matter whether the odds are against "just the right
mutation showing up at just the right time." The point is that it does
happen. Look at the incredible variety of life that exists on this
planet now; then remember the great extinctions that have happened at
the end of every era. Not only have just the right mutations shown up,
but they have shown up more than once!

-Matt
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