Anyone who has taken 10th grade biology remembers that one of the most persuasive arguments for the theory of descent by modification is based on the existence of putative vestigial structures in organisms, and one of the most popular examples of an evolutionary vestige is the human appendix. Vestigial structures are the remnants of structures that at one time had some function but because of changing needs, no longer do. Other examples are arm hair, the coccyx, wisdom teeth, hip bones in whales, junk DNA, and so on. Charles Darwin himself cited the appendix as evidence that the human species changes and evolves because it was thought that the appendix was a structure which no longer served any purpose.
Well, whatever the status and usefulness of other vestigial structures to evolutionary theory, the human appendix is now being quietly retired.
Science Daily reports:The lowly appendix, long-regarded as a useless evolutionary artifact, won newfound respect two years ago when researchers at Duke University Medical Center proposed that it actually serves a critical function. The appendix, they said, is a safe haven where good bacteria could hang out until they were needed to repopulate the gut after a nasty case of diarrhea, for example.
Now, some of those same researchers are back, reporting on the first-ever study of the appendix through the ages. Writing in the Journal of Evolutionary Biology, Duke scientists and collaborators from the University of Arizona and Arizona State University conclude that Charles Darwin was wrong: The appendix is a whole lot more than an evolutionary remnant. Not only does it appear in nature much more frequently than previously acknowledged, but it has been around much longer than anyone had suspected.
"Maybe it's time to correct the textbooks," says William Parker, Ph.D., assistant professor of surgical sciences at Duke and the senior author of the study. "Many biology texts today still refer to the appendix as a 'vestigial organ.'"
Jonathan Wells argued in his book Icons of Evolution that textbooks are filled with certain evidences of evolution which enjoy the status of classic proofs in the world of evolutionary biology but which are, in fact, based on false, and even falsified, data. The Piltdown man was an early example which comes to mind, as does the peppered moth, and Ernst Haeckel's fraudulent drawings of embryos that seemed to support the notion that embryonic development recapitulated evolutionary history. Junk DNA is no longer on the list because functions performed by this material are being discovered with increasing frequency.
Despite the fact that so many of these icons have been discredited some textbooks still present them to students as solid evidence for Darwinian evolution. It'll be interesting to see how long it takes before the appendix joins the expanding list of evolutionary vestiges that aren't really vestigial at all.
RLC
