6/29/2007

BEHE: 'IRRELEVANT COMPLEXITY'?


Michael Behe’s got a new book out, and both Michael Ruse and Ken Miller were underwhelmed, to put it mildly. * In fact, one gets the impression that they not only found Behe unpersuasive, but when comparing Behe's latest with an earlier work, "Darwin’s Black Box", they were distinctly disappointed. Perhaps it’s because Behe pretty much abandons the argument for which he’s best-known ("irreducible complexity", or IC) and, instead, has essentially gone backwards, reviving bogus probability arguments after the fashion of Fred Hoyle.

Why has this happened? Perhaps it’s because Behe was embarrassed by the evidence presented in the Dover trial by folk like Dr. Miller, who memorably demonstrated how Behe's favorite alleged example of IC (the bacterial flagellum) could've evolved from different arrangements of protein with different functions. Perhaps it was because, under oath, Behe was presented with a large pile of publications that covered the general topic of molecular evolution, literature that "Darwin's Black Box" attempted to suggest did not exist.

Or, more poignantly, perhaps it is because there is something like a revolution underway in comparative genomics which is providing, as Sean Carroll has phrased it, forensic evidence for molecular evolution. Here’s a particularly good example of the kind of thing that gives Michael Behe and the rest of the folks hollering ‘irreducible complexity’ fits: a highly-detailed and through account of the putative evolutionary relationships of a particular family of proteins, the globins.

The study in question ("A phylogenomic profile of globins", by Vinograd, et. al,) appears on-line and compares 330 different prokaryote and eukaryote genomes. The massive bibliography takes up nearly eight full pages and contains 147 citations. At the end of the study, there are several graphic displays of the data relationships, including a very neat and easy-to-follow Venn diagram on page 31. The broadest conclusion of the study is that there is a clear pattern of molecular evolution within this family of proteins, which in the prokaryotic genomes are neither as widely-distributed nor share the same functions as in eukaryotes. More specifically, the results support the claim that (quoting from page 3) "since the hemoglobins in organisms other than animals are enzymes or sensors, it is likely that the evolution of an oxygen transport function accompanied the emergence of multicellular animals."

I think an objective observer would be forced to conclude that Dr. Behe’s claim that there "has never been a meeting, or a book, or a paper on details of the evolution of complex biochemical systems" (Darwin’s Black Box, pg. 179) is manifestly false, and it can be expected that even more detailed accounts of molecular evolution are probably just around the corner. The more detail provided by observations, the less inference required, to the point where the whole complexity objection becomes irrelevant.
b
Has 'irreducibly complexity' become irrelevant? Darwin knew nothing about the bacterial flagellum, much less molecular evolution, but he surely would've recognized the general form of Behe's argument. Darwin observed, "If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find out no such case."
b
And, indeed, when Dr. Behe first looked at things like molecular cascades and the flagellum he may have persuaded himself that he had discovered such cases, things which to his rather limited understanding of biology seemed complex, and irreducibly so. Suggestively, Behe's new book essentially abandons this tack, as if he no longer has confidence in the specifics of his pet examples. The irreducibility of no structure, no protein, no process seems demonstrable. With Darwin, we can find no such case.

Behe, M. Darwin's Black Box: The Biochemical Challenge to Evolution. Free Press. New York. 1996.

Behe, M. The Edge of Evolution: The Search for the Limits of Darwinism. Free Press. New York. 2007.

Carroll, S. "God As Genetic Engineer." Science, Vol. 316. no. 5830, pp. 1427 - 1428. June 8, 2007.

Carroll, S. The Making of the Fittest: DNA and the Ultimate Forensic Record of Evolution. W.W. Norton. New York. 2006.

Darwin, C. On the origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life. London: John Murray, 1859.

Kitzmiller v. Dover Area School District. Trial transcript: Day 12 (October 19), PM Session, Pt. 1 URL: http://www.talkorigins.org/faqs/dover/day12pm.html


Miller, K. "The Flagellum Unspun: The Collapse of "Irreducible Complexity". 2002. URL: http://www.millerandlevine.com/km/evol/design2/article.html

Miller, K. "Falling Over The Edge." Nature 447, pg. 1055 - 1056, June 27 2007.

Ruse, M. "Design? Maybe. Intelligent? We have our doubts." The Globe and Mail. June 2, 2007.

Vinograd, et al. "A phylogenomic profile of globins", in BMC Evolutionary Biology, Vol. 6, No. 31, April 7, 2007. URL: http://www.biomedcentral.com/1471-2148/6/31/abstract

(* = regrettably, as Ruse and Miller's reviews are up-to-the-minute, they aren't free. A quick gloss of Ruse's review is available here, however, along with similar reviews from Sean Carroll and Jerry Coyne. Miller's review is summarized here. )

2 comments:

Stanton said...

He's going backwards closer to Hoyle's arguments?
So, does this mean his third book is going to be about why Archaeopteryx can't exist?

Scott Hatfield . . . said...

I think, if I read you right, that the 'devolution' of his arguments will next lead him to declare that evolution is a tautology, or sump'n.