Vestigial organs are those parts of our body that evolution has rendered obsolete. In other words, they’re hangers on in our genetic code from a previous era where we actually needed them. An example of this would be the human appendix. Scientists long believed that the appendix was a vestigial organ, a part of the digestive tract that helped to secrete special enzymes that broke down high-cellulose food (plants). However, when we first tied rocks to sticks and started hunting, our diet became more diverse, and the appendix was eventually phased out. However, new evidence shows that the appendix may not be as vestigial as we once thought.

A recent article by Robert Dunn in Scientific American explores the study of a maybe-useful human appendix as a storehouse of beneficial bacteria. Human bodies have tons of bacteria in them, and most of it is good for us. In fact, if you were to take a picture of a person, and then remove them but leave the bacteria, you would clearly see the person’s silhouette. Nasty thought, huh? Some of that helpful bacteria is in our gut and our digestive tract, and when we get an infection or virus of some kind, that beneficial bacteria can be wiped out. The alternative view of the appendix is that when that happens, the appendix jumps into action, secreting the stockpiled bacteria back into the gut.

To study this scientists went back and looked at records of individuals that had suffered from gut infections of the kind that would wipe out all of the beneficial bacteria in the digestive tract (like Cholera, for example). They then compared that data to whether or not the person had received an appendectomy at some point prior to infection. They then looked at mortality rates and recovery rates of people that still had their appendix as compared to people who didn’t.

The results are inconclusive, at best. Part of the problem is that much of this data had to come from third world countries, where cholera and other infectious diseases are more common. However, those countries are also not famous for their medical record-keeping, particularly for a trivial operation like an appendectomy. However, it should be noted that in a specific study of one particular hospital, recurrence of the gut infection occurred in 48% of patients without their appendix, and only 11% of patients with their appendix. Of course, there are enough variables in this kind of study to negate any positive correlations.

To my thinking, it simply goes back to natural law. “Nature suffers no excess of neither form nor function.” Vestigial might just be another word for, “we haven’t figured that one out yet.”