Darwinism: Science or Philosophy

Chapter 7a
Response to William A. Dembski

K. John Morrow, Jr.

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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.

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