Monday, February 9, 2009

It all comes back to evolution

It's Darwin's 200th birthday, so evolution is an even bigger topic in the media right now than usual.

That reminded me of a question I meant to pose to our posse some time ago. It has do with this book...

For those of you unfamiliar with Behe, he is one of the leading forces in the Intelligent Design movement. In other words, Creationism. He first gained notoriety with this book...

I have not read the above book, but I did read some of The Edge of Evolution.

As you guys might remember, I have always been a little uncomfortable with the complete theory of evolution. It's not something I'm happy to admit. Richard Dawkins has said, "It is absolutely safe to say that, if you meet somebody who claims not to believe in evolution, that person is ignorant, stupid or insane (or wicked, but I'd rather not consider that)." I'm not fond of the application of any of the adjectives to myself, so I tend to keep my reservations about evolution to myself.

The Edge of Evolution spoke to some of my concerns. It's been a while since I read it, but as I recall Behe basically argues that two parts of evolutionary theory are unimpeachable - natural selection and genetic passing of traits. But he then argues that on a microscopic level, many biological systems are "irreducibly complex": the molecular systems involved in even basic biological functions like flagella are incredibly complex and would fail without the existence of multiple different biological processes existing simultaneously. Behe argues that since the overall function would completely fail without the multiple processes, the sucess of the biological function, in evolutionary theory, would require all the processes to evolve simultaneously in a single organism at a single time. He then demonstrates that even if you consider all the generations of all organisms in all time, this is basically mathematically impossible.

When I cracked the book, I sort of expected a mix of Christian evangelism and pseudoscience. As a result, I was pleasantly surprised by the extent of detailed biochemistry in the book. Here is a typical passage, the likes of which made the head of a lowly trader like myself spin.

For an otherwise scientific and reasoned closet evolution skeptic like myself, his argument was very seductive. Apparently some scientists see plausibility in his arguments (see the Amazon page endoresements). Yet from what I can glean from other things I have read, "irreducible complexity" is considered a flawed argument, and moreover, there are specific flaws in many of Behe's arguments. The problem I've had is that the rebuttals I've seen are either rather scattershot (again see some of the Amazon comments) or the arguments seem to focus on details of biochemistry that are completely over my head. For example, I could not make heads or tails of this recent discussion in Behe's blog. I have not had much luck finding a comprehensive rebuttal that is still comprehensible to a layman.

What I have noticed in some comments is a complete pre-emptive dismissal of Behe's argument, because he is obviously a tool of the Creationist/Intelligent Design fanatics. See Dawkins quote above. It reminds of the tone you sometimes hear in dismissals of anyone challenging the prevailing global warming orthodoxy as they are obviously tools of the Oil Companies.

Fortunately, our readership, while limited, does have some excellent minds in the biological arena. I am curious whether, in their experience, there is any serious discussion at all of Behe's arguments or if evolutionary theory as it currently exists is considered settled law. If so, could they point me to a relatively coherent rebuttal of Behe's arguments. It's been months since I cracked his book, but his arguments continue to entice me, and if they are irretrievably flawed, I would like to understand why that is.


Thomas said...

Excellent post, Lyon. I'm glad to see some intelligent thought on the subject by a non-scientist, non-Evangelical.

I have read Behe's books, and his arguments are extremely flawed. I'll admit, however, there are some things we don't quite understand about the beginnings of evolution.

Here's a critical analysis of the irreducibly complex argument: I'd be happy to discuss in detail...

GammaBoy said...

That was excellent, "Thomas", thanks for that. Frankly, it was a bit overwhelming on a first read, but I now have something to chew on.

You piqued my curiosity. What about the beginnings of evolution are not understood?

Restless Native said...

Behe's assertion that the arguments are tentative: "lamprey has single proteins that act as Factor V/VIII (proaccelerin/anti-hemophilic factor) and Factor IX/X (Christmas factor/Stuart factor). The authors then infer that either gene or genome duplication led to separation of the factors. Although it's interesting work, Doolittle's conclusions are only suggestive (and the authors clearly say that the data are only suggestive). They found four copies of genes that are similar to Factors V/VIII, as well as to the non-clotting proteins ceruloplasmin and hephaestin (Figure 2 in their paper). They argue that only one is a real blood clotting factor and the other three aren't, but the arguments are pretty tentative," is absolutely absurd. In their ground-breaking 1997 research H. Jeblaumee and L. D'Eesñööts established categorically that genome duplication DID lead to separation of the factors.

Lt. Weinberg said...

The intelligent design folks should talk more about how life began in the first place; the formation of that first cell with the membrane, DNA capable of replicating, and enzymes to allow the cell to divide. Now that was a miracle (or at least a highly improbable event that only need occur once!)