<snip>
SJ
> This is a point Phil
> Johnson has made: "...the evidence for Darwinian macroevolutionary
> transformations is most conspicuously absent just where the fossil
evidence
> is most plentiful- among marine invertebrates. (These animals are
plentiful
> as fossils because they are so frequently covered in sediment upon death,
> whereas land animals are exposed to scavengers and to the elements.) If
the
> theory were true, and if the correct explanation for the difficulty in
finding
> ancestors were the incompleteness of the fossil record, then the evidence
> for macroevolutionary transitions would be most plentiful where the record
> is most complete." (Johnson P.E., "Defeating Darwinism by Opening
> Minds", 1997, p60)]
Chris
Not necessarily. Evolution proceeds much more slowly in stable environments
and/or with non-recombinant reproduction than it does in cases where
environments are much less stable and/or where DNA recombination occurs
during reproduction. To determine whether Johnson had any valid point at all
would require determination of details that he does not seem concerned to
bother with. I guess this is because he suspects they would not support his
claims. Evolution is *definitely* not to be regarded as always proceeding at
a constant rate (by any measure that I can think of). This
"uniformitarianism" was one of Darwin's biggest mistakes.
Since the *main* function of selection is actually the restriction or
*prevention* of evolution, it is not hard to understand that, in a stable,
steady, undersea environment, once organisms got locally optimized for their
niche in the environment, nearly *any* genetic variation would be culled
out. Eventually, of course, even such protected environments will change, as
tectonic plates move, as ice ages come and go, and as evolution in other
areas "bleeds" new species into such environments, and so on. But, for long
periods of time, many such environments appear to have been remarkably
steady-state. These are exactly the environments in which we would *not*
expect to see the most evidence for evolution, because they are the
environments in which evolution would be at its very slowest, perhaps doing
nothing more than a little genetic drift and the accumulation of
mainly-inactive genetic material that has "found out" how to get itself
reproduced without having to do any morphological "work."
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