Friday, September 17, 2010

Senter strikes again!

Good grief, Phil, slow down will you? First, it was a clever paper on the intermediacy of Australopithecus afarensis ("Lucy") in American Biology Teacher, which I commented on here. Then it was his baraminology paper in Journal of Evolutionary Biology that showed that dinosaurs and birds should be considered members of the same baramin (I intend to formally respond to very soon, but in the meantime, you can read my initial impressions here). Now, he's got a new paper in the latest Reports of the NCSE called "Vestigial structures exist even within the creationist paradigm." He's becoming quite the creationism scholar, cranking out three significant papers in the last year. He makes me look lazy in comparison!

The basic message of the new paper is that vestigial organs are not "useless" but merely reduced. He ably refutes creationists' (mostly Bergman's) arguments against vestigial organs, but then he points out that even within created kinds there are examples of vestigial organs, like extra toe bones in fossil horses or the vestigial eyes of cave salamanders. I pretty much agree with him 100%, and I'm glad someone finally spelled this out so well. I could add to his list of intrabaraminic vestigial organs the reduced wings of the flightless cormorant and the reduced wings of many flightless insects. The standard creationist argument about vestigial organs is not only wrong but also self-defeating. I've sort of addressed this issue before, but not nearly so well as Phil's article.

I do have one trifle of a disagreement with one of his points. Phil wrote,
While it is true that Darwin (1872) assumed that rudimentary structures are useless, modern biologists do not make this assumption and therefore do not employ uselessness as a criterion for recognizing a vestigial structure.
He wrote that in the context of refuting creationist contentions that "vestigiality" equates to "functionless." If only Phil were right about that, but it's my experience that evolutionary biologists are extremely sloppy when describing vestigial structures. Some examples
  • "A vestigial structure is a useless or rudimentary version of a body part that has an important function in other, closely allied, species." - Freeman & Herron, Evolutionary Analysis, 4th ed, p. 42.
  • "Vestigial characters. The adaptations of organisms have long been, and still are, cited by creationists as evidence of the Creator's wise beneficence, but no such claim can be made for the features, displayed by almost every species, that served a function in the species' ancestor, but do so no longer." - Futuyma, Evolution, 2nd ed., pp. 50-51.
  • "Vestigial organs Organs or structures that appear to be small and functionless but can be shown to be homologous with ancestral organs and structures that were larger and functional." - Hall & Hallgrimsson, Strickberger's Evolution, 4th ed., p. 733.
And so on. These aren't just your average, workaday evolutionary biologists either. It's Doug Futuyma and Brian Hall emphasizing the uselessness of vestigial organs. With quotes like these, it's no wonder that creationists get hung up on functionality as the ultimate refutation of vestigial organs. I think evolutionary biologists (and anticreationist apologists) would do very well to adopt Phil's more precise discussion of vestigiality as the gold standard.

Otherwise, an excellent paper. Thanks, Phil.

Senter. 2010. Vestigial organs exist even within the creationist paradigm. RNCSE 30(4):18,23-26.

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