The Skeptical Biochemist: Is There an Edge to Evolution? Part 1
An Analysis of Michael Behe’s book, The Edge of Evolution
In the 12th century, the Danish king set aside a large area of forest along the eastern coast of the island of Zealand, as a Royal Hunting grounds. The area was fenced-off a few hundred years later, and is now open to the public. Fortunately for me, I live close to the “Deer Park,” and early in the morning, before many people get out of bed, I go for a run there. I am often truly impressed by what I see in nature, such as the majestic stare of a stag looking at me, as I go by, or the noise and sight of a flock of geese flying overhead. As an individual, I have no problem saying that what we see around us can point towards transcendence – there is grandeur and beauty. When discussing the Intelligent Design movement with my oldest brother, Steve, he asked me what was wrong with the idea that we can see God in nature—that is, that the goodness and design we see around us is surely an argument pointing towards God. I told him I don't have problems with this line of thinking. Having thought about this some, I realized that this idea is very common in the Bible, and for example Jesus often seemed to point to this in parables. However, as a scientist, I am deeply skeptical of claims that one can use science to somehow ‘prove’ God exists (or to ‘prove’ there is no God, for that matter). In 1661, around the same time the Danish king fenced-off the area around the “Deer Park,” one of the first chemists, Robert Boyle, wrote a book called The Sceptical Chemist. (Hence the title of this review.) Boyle was a devout Christian as well as a very good scientist; I will come back to Boyle later.
This brings me to mention the target audience of this review. Of course anyone can read this, but it is intended mainly for educated readers who are interested in the science/religion dialogue, and in particular are interested in Intelligent Design, and either have read or want to read The Edge of Evolution: The Search for the Limits of Darwinism, by Michael Behe (Free Press, New York, 2007). I have heard from some of my friends and family that they find this book “convincing” from a scientific point of view. Before I go into a discussion of the book, I want to give the reader a bit more perspective about myself. I grew up in Springdale, Arkansas, and am the youngest of five children. Some (not all) of the members of my family are “young earth creationists,” that is, they think that the world is less than 10,000 years old. I first heard of Mike Behe about 25 years ago, when I was a Ph.D. student, working on showing that alternative DNA helical structures could exist inside of living cells. Behe had published a paper with Gary Felsenfeld, showing that methylation of certain DNA sequences could greatly facilitate the formation of left-handed Z-DNA, and that Z-DNA did not like to be wrapped around the nucleosome. Probably for most people, that last sentence doesn't make much sense, but for me, this was a paper that I was very fond of, as these results pointed in the direction of perhaps some sort of biological meaning. I eventually got my Ph.D. (in biochemistry/molecular biology from the University of Cincinnati College of Medicine), did a post-doc at the Institute of Molecular Medicine, Oxford University, and about 12 years ago moved to Denmark, where I have been the leader of the comparative microbial genomics group at CBS (the Center for Biological Sequence analysis, a bioinformatics center in the Department of Systems Biology, at the Technical University of Denmark).
Now that I've laid down my philosophical and personal perspective I can get on with the review. I feel that this is a necessary background as, after I reviewed Darwin's Black Box more than 10 years ago, I was accused by several readers of being critical of Behe not based on the science, but because I “wanted to promote atheism,” which is certainly not the case. I will struggle to give what is written in Edge of Evolution a fair hearing - let's see how well the scientific evidence supports what is written in the book.
First, I want to start on a positive note - there are (at least) two things that I liked about the book:
Behe does a good job of describing the logical outcome of thinking in contemporary molecular biology. For example, IF in fact DNA is really some sort of computer code, where did this information come from, how is it maintained, and Who wrote it? IF in fact the mutational frequency of DNA is in the range of 1 change per hundred million base-pairs (that is, the DNA polymerase incorporates the “wrong” base about once ever hundred million times), then how can we explain the incredible diversity we see around us?
Behe is writing from the point of view of a non-materialist. Thus, he seems to think that there is more to the world than what we see around us, and this is in contrast to many other vocal atheistic scientists
I will now make my way through the text, in order of the chapters. In my opinion, the book starts well, and then begins to veer off in strange directions - but I'm getting ahead of myself.
Chapter 1 - The Elements of Darwinism
I agree with Behe when he says that “Darwin's theory has to be sifted carefully, because it's actually a mixture of several, unrelated, entirely separate ideas”: random mutation, natural selection, and common descent. He then goes on to say that of the latter, “in brief, the evidence for common descent seems compelling,” but that he feels “random mutation is extremely limited.” Later in this chapter, he states “Evolution from a common ancestor, via changes in DNA, is VERY well supported. It may or may not be random.” [page 12, emphasis in the original] This will in fact be the main focus of the rest of the book - whether “random mutation” alone can generate enough diversity on which natural selection can work , in order for evolution to occur. So just to flesh this out a bit—in Behe's defense, clearly he is not a “young earth” creationist, who thinks that the world is less than 10,000 years old. He has no problem with the world being about 4.5 billion years old, and life slowly evolving from the first single-cell bacteria appearing almost as soon as fossils could form, through another 4 billion years as mostly single-celled or tiny microscopic organisms, and the very recent appearance of larger plants and animals a bit less than a half-billion years ago. This is all fine and accepted to be true—it is just the MECHANISM for how this might have happened that is being considered. Just as a minor point, one thing in this chapter that is stated as fact, isn't quite right in my opinion—“By far the most critical aspect of Darwin's multifaceted theory is the role of random mutation. Almost all of what is novel and important in Darwinian thought is concentrated in this third concept.” Perhaps this is true today, but certainly when Darwin published his Origin of Species, the critical novel, important and new idea, in contrast to the current thought, was that of common descent—in fact Darwin hadn't a clue about HOW diversity was generated, but the whole point of his book was to demonstrate the evidence for natural selection and change of species (common descent) over time, in contrast to the idea that each individual species had been recently created by God, a few thousand years ago. And common descent, Behe admits, is supported by “compelling evidence”—so we are in agreement here. Evolution has happened over billions of years, and there is “compelling evidence” for evolution by common descent.
In my next post we will examine where Behe and I part company.
David Ussery is an associate professor of comparative microbial genomics at the Center for Biological Sequence Analysis at the Technical University of Denmark and on the faculty at the University in Oslo, Norway. Ussery is the co-author of Computing for Comparative Microbial Genomics and has authored or co-authored 130 articles for science and professional journals. He is also a frequent public speaker on the topic of bacterial genomics.