Sunday, March 14, 2010
To be vestigial, or not to be vestigial. That is the question.
Throughout the first chapter in the book, Jerry Coyne explains the premise behind vestigial organs: that is, organs that are no longer of use to animals and are just evolutionary leftovers which have not been completely phased out of the body plan. The most prominent of such examples would obviously be the human appendix, which, simply, is thought to do nothing in the human colon. However, when reading an article on Wikipedia about the "Vermiform Appendix," it becomes clear that the appendix may actually serve a useful function. That function, at the risk of sounding gross, is thought to be the "safehouse" for healthy bacteria which help clean the colon after an episode of diarrhea. This begs the question, are all vestigial organs really useless in their current forms? Do they possibly serve some use that is insignificant yet still there? Also, when in the many phases of evolution would one finally call an organ vestigial? That is, when is something finally considered useless?