Question: Will we adapt to lose our appendix?

Martin Johnsson answered on 19 Mar 2020:

I find this interesting, because evolution sometimes comes up with what seems like pretty strange solutions … The appendix, male nipples, the fact that bivalves (that’s the group of animals that include muscles and clams) have an intestine that goes right through their hearts. Nature is sometimes a little strange. 🙂

There are a couple of things going on with the appendix.

First, it’s not entirely clear what, if any, function it serves: does it contribute to the immune system by being part of the lymphatic system, does it help repopulate the gut with good bacteria after you’ve had gastrointestinal problems? These are some of the proposed functions. I don’t know which one is the most important, and I’m not sure anyone does.

Second, the relationship between function and whether the appendix will be maintained is tricky. If it is really important to our survival and health, then it will probably be maintained. But even if it isn’t, it will only be lost if there are genetic variants, that make people not develop an appendix, and those variants become common in the human population. And that depends both on random chance and on the costs and benefits of having an appendix.

In short: it depends, and it’s an interesting evolutionary puzzle. 🙂