The Edge of Intelligent Design

I wrote a little about reviews of Intelligent Design advocate Michael Behe’s new book, The Edge of Evolution, in Behe Does it Again. And then the other day I had the chance to sit down in a bookstore and read a good chunk of the book. The combination of my lack of support for what Behe is doing and my own academic-induced poverty led me not to buy the book.

Behe’s writing’s gone downhill. Gone are the well-worded explanations of biochemical mechanisms. Edge seems to be written in a quicker, outline sort of format with lots of little headlines and even less mass under each heading than with Darwin’s Black Box, his previous book.

Having just finished reading Richard Dawkins’ The Ancestor’s Tale, it’s really interesting to contrast his heavily detailed, frequently-exampled work with Behe’s, which relies on a very few examples to make a point. Jerry Coyne, writing in The New Republic, has an excellent review of The Edge of Evolution (reposted here) which suggests the title of this post and also has a nice introduction to evolutionary biology, if you need it.

Behe testified in support of having Intelligent Design taught in public schools at a trial in Dover, Pennsylvania. The transcript is available online. Some amusing details from Coyne:

Behe’s credibility was damaged also by his admission that ID’s definition of science was so loose that it could encompass astrology, and by his fatal assertion that the plausibility of the argument for ID depends upon the extent to which one believes in the existence of God.

The most interesting thing about Behe’s argument is just how much science he finds convincing, especially for a man who would define astrology as scientific. As Coyne rightfully notes, Behe

has no problem with a 4.5-billion-year-old Earth, nor with evolutionary change over time, nor apparently with its ample documentation through the fossil record–the geographical distribution of organisms, the existence of vestigial traits testifying to ancient ancestry, and the finding of fossil “missing links” that show common ancestry among major groups of organisms. Behe admits that most evolution is caused by natural selection, and that all species share common ancestors. He even accepts the one fact that most other IDers would rather die than admit: that humans shared a common ancestor with chimpanzees and other apes.

So what does Behe not accept? Well, he doesn’t think random mutation is capable of generating the change which is then naturally selected. But, there are some problems with what he means by random. Coyne:

On the basis of much evidence, scientists have concluded that mutations occur randomly. The term “random” here has a specific meaning that is often misunderstood, even by biologists. What we mean is that mutations occur irrespective of whether they would be useful to the organism. Mutations are simply errors in DNA replication. Most of them are harmful or neutral, but a few of them can turn out to be useful. And there is no known biological mechanism for jacking up the probability that a mutation will meet the current adaptive needs of the organism…

What we do not mean by “random” is that all genes are equally likely to mutate (some are more mutable than others) or that all mutations are equally likely (some types of DNA change are more common than others). It is more accurate, then, to call mutations “indifferent” rather than “random”: the chance of a mutation happening is indifferent to whether it would be helpful or harmful.

It is important to clarify these two steps because of the widespread misconception, promoted by creationists, that in evolution “everything happens by chance.” Creationists equate the chance that evolution could produce a complex organism to the infinitesimal chance that a hurricane could sweep through a junkyard and randomly assemble the junk into a Boeing 747. But this analogy is specious. Evolution is manifestly not a chance process because of the order produced by natural selection–order that can, over vast periods of time, result in complex organisms looking as if they were designed to fit their environment. Humans, the product of non-random natural selection, are the biological equivalent of a 747, and in some ways they are even more complex.

Coyne then goes into some more specifics on Behe’s fallacious arguing in Edge, which is quite worth reading. Behe’s main examples are a handful of infectious diseases, and Coyne does an excellent job of debunking. Unfortunately, Behe is writing to an audience that is generally uneducated in science, especially molecular and evolutionary biology, and he picks examples that are complex enough that the wool can be pulled over readers’ eyes.

Scott Carrell, author of Endless Forms Most Beautiful (which I highly recommend), has a review of Behe’s The Edge of Evolution in Science, of all places. One of Behe’s main complaints, that you hardly ever get multiple binding site mutations in the same protein, is quickly demolished when Carrell notes several publish studies:

Examples of cumulative selection changing multiple sites in evolving proteins include tetrodotoxin resistance in snakes, the tuning of color vision in animals, cefotaxime antibiotic resistance in bacteria, and pyrimethamine resistance in malarial parasites–a notable omission given Behe’s extensive discussion of malarial drugresistance.

And probably one of the most telling comments of all, the question of whether Behe is incompetent or dishonest? [After discussing the huge body of quantitative analysis of binding sites on proteins that Behe ignores]:

Is it possible that Behe does not know this body of data? Or does he just choose to ignore it? Behe has quite a record of declaring what is impossible and of disregarding the scientific literature, and he has clearly not learned any lessons from some earlier gaffes. He has again gone “public” with assertions without the benefit (or wisdom) of first testing their strength before qualified experts.

In my quick perusal of The Edge of Evolution, I noticed that in the last chapter Behe quoted Carrell’s Endless Forms Most Beautiful. But, in a classic example of creationist misquotations, the quotations selected was taken completely out of context, had an ellipsis in the middle, and was basically made to say “We need to completely rethink evolution.” Of course, if you’ve read Carrell’s book, you know that he is adding new mechanisms on top of the currently understood pathways for evolution, giving us new understanding from evolutionay developmental biology. As always, the question is whether Behe actually read the book, or is choosing to be dishonest.

(Via Pharyngula)


2 Responses to The Edge of Intelligent Design

  1. ??? says:

    Coyne wrote:

    “Behe’s credibility was damaged also by his admission that ID’s definition of science was so loose that it could encompass astrology…”

    Coyne is lying. Behe didn’t argue that “ID’s definition of science ” could encompass astrology. They were talking about what is (fefinition of) “theory”. And Behe said, that astrology could be a “theory”. (And he added that it is a bad theory.)

  2. globalizati says:

    Lying? Certainly not. If you read the transcript (available here) it’s clear that by specifically claiming that astrology could be a “scientific theory” it could be part of science. Therefore, by Behe’s definition of science, astrology and intelligent design should both be included as testable theories, even though they include supernatural or mystical elements. Intelligent design is certainly a theory on the same level as astrology. And with both, their appeal to the supernatural to explain something instead of looking for real, testable mechanisms would rule them out as science by definition. If you don’t like that definition, go off on your own and make your own science, but don’t expect any credibility.

    Also, saying that event X is correlated with event Y isn’t a good theory unless some foreseeable mechanism can be proposed.. would stating that bumblebee defection affects the orbit of Jupiter make sense? Of course not. And it certainly wouldn’t be science, at least by any definition sane people use today.

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