NEW BOOK'S ESSAYS DEFTLY COUNTER INTELLIGENT DESIGN

Saturday, August 28, 2004

The last time I wrote a column that mentioned evolution, a reader complained on his Web log that probably 20 percent of my columns were on that topic. (Though he was kind enough to describe himself as a fan, on that particular topic he is not.) That turns out to be wrong, as it happens; I asked our archives to find anything with my byline containing the word "evolution," and there are 15, over seven years. Not all of them are columns, and not all of them are about biology, but 4 percent is pretty close. And why not? I write about things I'm interested in, I'm interested in science and evolutionary biology is a particularly fascinating part of science. It's a very active field, so there's always something new to write about.

That would be reason enough to make it a frequent topic, but in addition there's the fact that it is politically important because many people believe evolutionary biology is wrong, or at least incomplete. Some of them are actively seeking to replace it in school science curriculums with what they believe, and since I think they're wrong, I don't want them to be able to do that.

And that's why I think it would be good if lots of people read a new volume of essays, Why Intelligent Design Fails: A Scientific Critique of the New Creationism. The editors are Matt Young, who teaches physics at the Colorado School of Mines, and Taner Edis, who teaches physics at Truman State University in Kirkland, Mo. The essays are focused on explaining why the claims of intelligent design proponents are scientifically unsound, and they are accessible to people who are not experts in science.

One argument for intelligent design is that some biological structures are "irreducibly complex," meaning that they couldn't have evolved because they have interdependent parts. Unless all the parts are present, none of them is useful, so natural selection wouldn't have selected them, and a designer of some kind must have intervened.

That argument was advanced by biochemist Michael Behe in Darwin's Black Box, and among his examples are bacterial flagella and the complex system that regulates blood clotting.

One difficulty with this claim is that it isn't useful. Unless there's some way to identify what the designer did and when, the claim makes no testable predictions, so it isn't scientific. Note that "testable" is not the same as "experimental." We can't do experiments on stars, but astronomy is a science nonetheless. The second difficulty is that the claim is false. Ian Musgrave of the University of Adelaide, in his essay about the evolution of bacterial flagella, lays out a possible path relying on the structural similarity of the flagellum to the organelles bacteria use for secretion. The path consists of small enough steps that natural selection obviously could take them.

Note that to refute the claim of irreducible complexity it is not necessary to demonstrate that natural selection did take exactly those steps. "Just so" stories, called that after Rudyard Kipling's children's books, often turn out to be wrong in their particulars. But the claim is a universal claim: No possible path to this outcome exists. A universal claim is disproved by a single counterexample, in this case of something that is possible.

William Dembski, who [at the time this was written] worked with the Science and Religion Project at Baylor University, is a leading advocate of intelligent design and has written several books on the subject. As it happens, I heard Dembski speak last year at a conference I went to. At that time I didn't recognize his name, but I followed my usual practice at conferences, which is to take notes both because I might want to write about the speech, and to keep my mind from wandering. I was about two sentences in when I realized what he was saying was complete nonsense. Two of the book's chapters explain why, one on his misuse of what are called "no free lunch" theorems to claim that evolution cannot create complex, specified information, and the other on his arguments about probability.

Victor Stenger, a professor emeritus of physics at the University of Hawaii, and an adjunct professor of philosophy at the University of Colorado at Boulder, is also president of Colorado Citizens for Science (www.coloradocfs.org). He tackles the idea that the universe is fine-tuned for our existence, so it must have been designed that way.

"The fine-tuning argument would tell us that the sun radiates light so that we can see where we are going," Stenger says. "In fact, the human eye evolved to be sensitive to light from the sun. The universe is not fine-tuned for humanity. Humanity is fine-tuned to the universe."

There's lots more worth reading. And if you want to write to tell me why I'm wrong, please make sure first that your argument is not among those so deftly refuted in this book.