Monday, September 18, 2006

God of the gaps

I faithfully peruse Science and Nature each week, the two premier science journals. Many of the research reports are over my head, so the tendency is to skip quickly past "In situ structure of the complete Treponema primitia flagellar motor" (Nature, August 31, 2006).

Big mistake. Buried in the tech talk is a thing of astonishing interest: the first detailed representation of a bacterial flagellar motor, the nanomachine that spins the whiplike appendage that propels a bacterium through an aqueous medium.

The darn thing looks exactly like the electric motor that spins your washing machine: a stator and rotor, made of 25 different proteins. It is about a thousand times smaller than the period at the end of this sentence, and rotates at speeds up to 300 cycles per second. Not only that, it can rotate in either direction!

Michael Behe, the creationist author of Darwin's Black Box, used the flagellar motor as a premier example of intelligent design -- and he didn't know the half of it. Now that we have a picture of the gizmo, well, it sure looks designed, and the lazy explainer will jump to that conclusion. Of course, saying "a designer did it" says nothing; it's just a phony way of saying "I don't know." No one yet knows the detailed steps by which natural selection contrived so marvelous a device, but we know of no reason in principle why it could not have happened, and plausible scenarios have been offered by biologists. Now that we do know what a flagellar motor looks like, we can be sure that plucky young graduate students will be working out its antecedents -- a rather more exciting prospect that simply throwing up one's hands and invoking divinity.

In the famous Dover, Pennsylvania, trial challenging the teaching of intelligent design in public school science classes, Eric Rothschild, chief counsel for the plaintiffs, said in his summation: "Thankfully, there are scientists who do search for answers...By contrast, Professor Behe and the entire intelligent design movement are doing nothing to advance scientific or medical knowledge and are telling future generations of scientists, don't bother."