The Useless Appendix and Other Darwinian Myths
At the Center for Science & Culture's Facebook page, a commenter asks how we would respond to a graphic that is making the Internet rounds, humorously imagining a dialogue between God and an angel. It's a conversation about "intelligent design," with the angel playing the role of the skeptic and challenging God to explain some puzzling human anatomical features. The short dialogue includes this exchange:
Angel: What about this weird bag thing?This is the stuff that urban legends are made of. The human appendix's job isn't to "explode." In fact, it performs important immune functions. We've discussed this many times before here on ENV (see here, here, here, or here), but to reiterate, a 2007 news article stated:
God: That's the appendix.
Angel: What does it do?
God: It explodes.
Angel: Really? That's all?
God: Pretty much.
The appendix "acts as a good safe house for bacteria," said Duke surgery professor Bill Parker, a study co-author. Its location -- just below the normal one-way flow of food and germs in the large intestine in a sort of gut cul-de-sac -- helps support the theory, he said. Also, the worm-shaped organ outgrowth acts like a bacteria factory, cultivating the good germs, Parker said. That use is not needed in a modern industrialized society, Parker said. If a person's gut flora dies, it can usually be repopulated easily with germs they pick up from other people, he said. But before dense populations in modern times and during epidemics of cholera that affected a whole region, it wasn't as easy to grow back that bacteria and the appendix came in handy.Additionally, Loren G. Martin, professor of physiology at Oklahoma State University, lists various likely functions for the appendix. Writing on Scientific American's website, he includes these examples:
- being "involved primarily in immune functions"
- "function[ing] as a lymphoid organ, assisting with the maturation of B lymphocytes (one variety of white blood cell) and in the production of the class of antibodies known as immunoglobulin A (IgA) antibodies."
- helping with "the production of molecules that help to direct the movement of lymphocytes to various other locations in the body"
- "suppress[ing] potentially destructive humoral (blood- and lymph-borne) antibody responses while promoting local immunity"
- Additionally, it is "an important 'back-up' that can be used in a variety of reconstructive surgical techniques"
Likewise, a few months back David Klinghoffer reported that researchers in the journal Clinical Gastroenterology and Hepatology found:
Individuals without an appendix were four times more likely to have a recurrence of Clostridium difficile, [a pathogen common in hospitals,] exactly as Parker's hypothesis predicted. Recurrence in individuals with their appendix intact occurred in 11% of cases. Recurrence in individuals without their appendix occurred in 48% of cases.In other words, the appendix performs important immune-related functions. Thus, the appendix is not there to occasionally explode. With the appendix increasingly considered to be an important organ that you wouldn't want to lose, researchers have also found that antibiotics can cure many cases of appendicitis (see Eriksson et al., 2006 ). Just as we would treat -- and not simply remove -- an infected kidney, it is now possible to treat -- and not simply remove -- an infected appendix.
As for that dialogue between God and an angel, what it tells us is that lots of folks out there who reject intelligent design do so because they believe Darwinian urban legends -- an example being this argument that our appendix, no better than a useless vestigial organ, proves that human beings are the product of blind, unguided Darwinian evolution. The more we learn about such arguments, the more we learn how vestigial they are.