The myth of Junk Body Parts continues to take a pummeling from science much as its sister myth, that of Junk DNA, does. When we last visited this topic, it was human fine body hair that turned out to be useful after all (helps fend off unwanted parasites) and not just another example of “unintelligent design” or “God’s Great Mistakes” as a list endorsed by Jerry Coyne puts it. Now: the appendix.
That’s the same organ of which Discover Magazine, for one, says in its list of “Useless Body Parts“:
This narrow, muscular tube attached to the large intestine served as a special area to digest cellulose when the human diet consisted more of plant matter than animal protein. It also produces some white blood cells. Annually, more than 300,000 Americans have an appendectomy.
It’s emerging that the appendix has an important use as a kind of secure terrarium for vital “good bacteria,” to be restored to the gut after the body has been visited and flushed out by a dread intestinal disease like cholera. Well, what do you know.
The journal Clinical Gastroenterology and Hepatology has the latest confirming data in its December 2011 issue (“The Appendix May Protect Against Clostridium difficile Recurrence”) while North Carolina State University biologist Rob Dunn, blogging at Scientific American, brings some color to the story with a fine profile of researcher Bill Parker at the Duke University School of Medicine. Parker seems to have been the first to shrug off the idea that the appendix is useless:
You may have heard the appendix is vestigial, a relict of our past like the hind leg bones of a whale. Parker heard that too, he just disagrees. Parker thinks the appendix serves as a nature reserve for beneficial bacteria in our guts. When we get a severe gut infection such as cholera (which happened often during much of our history and happens often in many regions even today), the beneficial bacteria in our gut are depleted. The appendix allows them to be restored. In essence, Parker sees the appendix as a sanctuary for our tiny mutualist friends, a place where there is always room at the inn4. If he is right, the appendix nurtures beneficial bacteria even as our conscious brains and cultures tell us to kill, kill, kill them with wipes and pills.
What the researchers reporting in Clin Gastroenterol and Hepatol found, studying patients at Winthrop-University Hospital, is this:
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.
Parker’s intuition isn’t confirmed in its entirety yet but it is on its way. Of course if you’re a regular ENV reader this will come as no huge surprise. Jonathan Wells and Casey Luskin have been on top of the appendix and its secrets, and the myth of Junk Body Parts generally, going back several years.
You’ll find that to be so if you want to go back and take a look here, here and here.