  
Darwinism: Science or Philosophy
Chapter 7a
Response to William A. Dembski
K. John Morrow, Jr.
[ Previous |
Table of Contents | Next ]
This paper is a response to a presented paper.
IN CONJUNCTION WITH the other speakers, I wish to express my thanks to
the Foundation for Thought and Ethics for putting together this
symposium and bringing together people with widely differing
backgrounds to exchange views on these topics. Dr. Dembski's
presentation draws heavily on the physical sciences, reflecting his
interests and training, which are quite different from my own.
I think it's striking that a lot of the justifications for a purposeful
universe are based on analogies brought from the fields of physics and
mathematics. As I mention in my own paper (chapter 10), there is an
active area of consideration in science among physicists dealing with
the question of the purposefulness of the universe or its design on the
level of fundamental physical laws.
But my perspective on this question is quite different, and comes from
my training in the biological sciences. In order to frame an
appropriate response, I would like to describe some of my own
background, because I think it will clarify my reaction to Dr.
Dembski's presentation.
First of all, my scientific experience is in genetics and cell biology.
Over the years my research has shifted more into molecular biology. My
graduate training in Seattle included courses in plant evolution and
population genetics, and during my post-doctoral training I was
affiliated with a research institute in Italy that was largely
concerned with the study of human evolution. So I look at the question
of purpose in biological systems not so much from a philosophical point
of view as from a point of view of practical issues; that is, for the
scientists in the laboratory, how do we approach biological questions
and how does the concept of evolution allow us to understand the laws
that govern the living kingdom?
In agreement with Dr. Ruse, I am an enthusiastic supporter of the basic
precepts of Darwinism theory. My basis for this commitment is a
practical one. It has the essential qualities of a good scientific
theory; it works and it provides a framework that enables us to do very
good science. The practical value of the theory of evolution is one of
the fundamental issues that separates people at this conference, and it
deserves some further consideration.
If we look today at the events that have taken place in the past twenty
years in the area of molecular biology, the progress has been nothing
short of awe inspiring. To give just one example, AIDS was unknown
before 1980. Now, the basis of this disease is completely understood
down to the most fundamental molecular level. The virus responsible for
AIDS has been mapped to the point where we know every single molecule
that composes it. These advances could never have been made without a
knowledge of molecular biology and, I would argue, molecular biology
could not exist without the foundation of evolutionary biology on which
it rests.
Most molecular biologists working in areas outside of evolutionary
biology, such as biomedical science, don't think about evolution on a
day-to-day level. They just do their research and are not particularly
concerned with philosophical issues. Most of them are fixated on
writing grants, writing papers, jumping through the scientific hoops in
order to get the rewards that come with academic achievement. In
framing hypotheses, developing ideas, and testing models, however. they
are always working within the framework of the theory of evolution.
I will give examples from my own work. During a portion of my
scientific career I have been interested in genetic variation in tumor
cells. When we look at responses to anticancer drugs, we find that
survival of the fittest in cultured cells follows the same rules as
those used for studying fruitflies or corn plants. With some
modifications we can use the same mathematical models in both systems,
and can make useful predictions of which drugs will be most
effective.
But many subdisciplines of biology are entirely encompassed by the
paradigm of evolution. One of the interesting observations of the last
few years has been the observation that DNA molecules share sequences
of information even though they code for proteins with totally
dissimilar functions. For example, Nobel-prize-winning work done in
Dallas by Brown and Goldstein involved the receptors for low density
lipoproteins. These are proteins on the surface of cells that allow
entry to cholesterol. They are vital to normal fat metabolism. Brown
and Goldstein studied the receptor molecule and found that a portion
contains a gene sequence exactly the same as "epidermal growth factor,"
a growth stimulatory protein. There is absolutely no basis that anyone
could have made for predicting this a priori. It doesn't
really make sense why proteins should be constructed as patchwork from
other preexisting proteins. It makes very good sense, however, in terms
of the theory of evolution if we think of natural selection as taking
advantage of whatever happens to be handy at the time. In fact, the
theory of evolution predicts that molecules would be made over the same
way that anatomical structures are. They are taken advantage of by
natural selection and made over for entirely new tasks. I might also
mention parenthetically that this observation demolishes the
"unlikelihood" objection to evolution. Complex structures in biology
don't arise de novo; they evolve from pre-existing
structures.
You could argue that there is no reason why a creator couldn't do that,
too. Phillip Johnson has stated that God could design living creatures
in any fashion he wished, including the use of natural selection. But
if you accept the notion of a God who pulls out odds and ends of
biological systems and throws them together (sometimes ineptly), this
is a long ways from the omnipotent creator usually considered in this
context. If you analyze the question through the principle of Occam's
Razor, and look for the simplest hypothesis, it is easiest to envision
the process of the development of living systems through natural
selection. It makes sense. It works.
When we test hypotheses in biology, we are always asking, does this
function or property have selective value? Does a structure or molecule
increase the chances of survival for the particular organism, for the
particular living system that we happen to be investigating? If it
doesn't seem to, why not? Where does this lead us? To new, previously
unknown functions? A cornucopia of information has appeared in the last
few years in the field of molecular biology that I believe
overwhelmingly supports the principles of evolution through natural
selection.
Of course we could argue that a creator could design biological systems
any way he wants. But if we retreat into this defense, we could equally
argue that the universe began twenty minutes ago and that everything
we're looking at now was put in our heads and was built around us by a
wicked and capricious creator. We don't accept this idea, not because
it is logically inconsistent, but simply because it has no scientific
or philosophical value. It is baggage that leads us nowhere. A much
simpler hypothesis is that the universe is sensible, consistent,
and that all its properties can be logically interpreted.
I would assert that the whole reason for using the paradigm of
evolution and natural selection is because it works for biologists, and
because it has been largely responsible for the tremendous advances
we've seen and the practical consequences that have accrued from
developments in molecular biology. There may be molecular biologists
who do not subscribe to the theory of evolution, and it may be possible
for them to function creatively. But I believe that they place
themselves at a tremendous disadvantage by not using the concept of
evolution in the formulation of their hypotheses.
I have not presented a specific rebuttal to Dr. Dembski. His
presentation is thoughtful and brings forth some salient points. But we
are discussing two issues. On the one hand is the question of design
and purpose in the universe. On the other is the question of the
validity of biological evolution and natural selection, and its utility
in a purely pragmatic sense for finding out more about the world around
us and how it operates.
[ Previous |
Table of Contents | Next ]
Copyright © 1994, 1997 Foundation for Thought and Ethics.
Copies of the book Darwinism: Science or Philosophy are available from:
Foundation for Thought and Ethics
P.O. Box 830721
Richardson, TX 75083-0721
Phone: 1-800-669-3410 or 972-661-1661
Fax: 972-661-2989
Email: fte-books@juno.com
Email this to a friend
copyright
© 1995-2009
Leadership U. All rights reserved.
Updated: 14 July 2002
|