From: Terry M. Gray (email@example.com)
Date: Thu Sep 12 2002 - 21:50:26 EDT
> If we can establish that
>the current structure that exists today could not have evolved for some
>reason, we need not worry about evidence for its evolution. ... In
>the end, if they
>hypothetically proved beyond doubt that the flagella could not evolve, then
>the evidence you want has never existed for the flagella and your
>considerations are a diversion.
This points out my fundamental beef with the ID folks as it concerns
biology and possibly pre-biotic evolution. There are confident
assertions based on all too uncertain probability calculations that
"flagella could not evolve" (and thus allowing the dismissal of the
various circumstantial evidences suggesting that they did). Believe
it or not, I'm open to ID, i.e. we may very well hit a brick wall
with respect to possible evolutionary explanations. I just don't see
that we're anywhere close to being able to say that. In my opinion we
have to know a lot more than we do in order to say that such and such
couldn't have happened.
I've pointed out earlier that most of the genome research is oriented
toward medicine and agriculture: comparative mammalian genomics,
comparative bacteriological genomics, and comparative plant genomics.
The fundamental cell biology features of mammal and plants are
basically the same and so the comparative work there doesn't tell us
beans about the origin of various primitive eukaryotic features. I'm
not sure that comparing various modern strains of bacteria is going
to get too far either. Basically, I'm saying the same thing that Tim
said. Comparative genomics of various protists will get us somewhere,
I think, as will comparative genomics of archaea. At the same time,
I'm not afraid to say that the evidence may be gone--that a lot of
the formative cell biology structures came into being prior to the
rise of "modern" genomes. I don't say this just to give an "it must
have evolved" answer, but the reality is that we may not be able to
find the answer in modern organisms.
This is why I went to the evolution of cooperative binding of oxygen
in hemoglobin when I first encountered Behe's arguments. I wanted to
show that an irreducibly complex structure/function like hemoglobin
could evolve. (Now if you're going to say, as Mike does, that if it
evolved then it apparently wasn't irreducibly complex, then you're
just being tautological.) Hemoglobin is irreducibly complex because
the function is a function of the whole (kind of like a
mousetrap)--there is no cooperative binding of oxygen without the
whole (at least the alpha-beta dimer). Oxygen binding is not the
function of hemoglobin--cooperative oxygen binding is. This is an
example of a recently obtained function, i.e. cooperative oxygen
binding. But a reasonably plausible account can be given as to how
non-cooperative oxygen binding to simple cooperative oxygen binding
to full hemoglobin like oxygen binding came into being. When we know
as much comparative stuff about flagella as we do about hemoglobin,
I'll begin to listen to some of these ID arguments (if the lack of an
evolutonary account is not forthcoming given that evidence).
Otherwise, we're just looking at pulsars and calling them "little
green men" because we don't know of anything that could "naturally"
create that pattern.
-- _________________ Terry M. Gray, Ph.D., Computer Support Scientist Chemistry Department, Colorado State University Fort Collins, Colorado 80523 firstname.lastname@example.org http://www.chm.colostate.edu/~grayt/ phone: 970-491-7003 fax: 970-491-1801
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