Re: [BULK] - Is evolution really the central theory for all of biology?

From: <douglas.hayworth@perbio.com>
Date: Tue Sep 13 2005 - 16:47:14 EDT

Ted and the fellow readers,

I have challenged colleagues in the past (fellow evolutionary biology and
ecologist graduate students) with the same question Skell poses. I think it
is at least instructive to ask the question so that we think about what we
mean when we accept or quote Dobzhansky's statement.

I would concede that many individual research endeavors in biology don't
involve direct application of the evolutionary idea or context. After all,
when you're focused at a very mechanistic level (i.e., trying to isolate or
describe a protein interaction or a biochemical pathway, etc.) most of your
energy and thought concerns how to use available tools to "see" and
"measure" the object, not on how the object got to be the way it is rather
than some other way. However, the importance of an idea is not measured by
the amount of time spent specifically thinking about it.

It is the historical perspective that provides so much more depth of
meaning to a given static structure or function. So Watson and Crick
describe the structure of DNA, and a static survey of living creatures
indicates that DNA (or RNA) is ubiquitous as the molecular basis for all,
but it is only by incorporating the historical and evolutionary concepts of
inheritance and mutation (descent with modification) that we can appreciate
how dynamic, complex and robust the NA-based system of life is. Without the
assumption that time is a dimension of reality worth considering, many
scientific "discoveries" become less interesting and meaningful, and we
would not be able to make nearly as good predictions about how knowledge of
a process in one organism relates to another.

If current biology research proceeded without any knowledge that evolution
has occurred (i.e., without appreciation for evolution as a unifying
concept), there likely would be whole schools of research devoted to what
we know would be futile endeavors, such as trying to determine how given
systems are optimally designed. What reality check would we have to tell us
that most structures are only "optimal" within a certain context (e.g.,
based on mutation and natural selection)?

For my dissertation, I studied variation in the noncoding (intergenic
spacer) portion of the multicopy ribosomal DNA. Without the historical
perspective, there would not be any logical way to understand this
variation. Certain mutational processes have been characterized
mechanistically, such as unequal crossing over, replicative transposition,
gene amplification and gene conversion. Only by examining real variation
among different populations of the same species and among related species
under the assumption that they are related to each other phylogenetically
can we hope to understand which and how those processes cause the variation
we observe today. This in turn can feed back to understanding those
mechanisms better (e.g., which ones are more frequent).

Therefore, I think that the evolutionary perspective is more foundational
to nearly every biologist's research than a survey like Skell's suggests on
the surface. Regardles of what they consciously and explicity incorporated
into their research, most of those scientists would not have thought to
research the same things in the same way and (therefore) would not have
made the same kind of contributions to science if they had developed their
research interests and specific studies entirely without the general
assumption of evolution.

If evolution really occurred, then all current biological entities are
products of that process and it is somewhat meaningless to attempt
generalization about mechanisms and structures without evaluating the
dimension of time.

I don't think that came out as eloquently as I wanted, but it'll have to
do.

Douglas

I urged Phil to publish his observations somewhere,
and this past month they did appear in "The Scientist" (29 August, p. 10),
under the title, "Why Do We Invoke Darwin?"

I am interested to hear what ASAers think of this provocative little piece.
I've placed it below.

Ted
******

By: Philip S. Skell
The Scientist
August 29, 2005
Received on Tue Sep 13 16:49:33 2005

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