...in that the appendix was recently discovered to have a useful function as a backup store for intestinal bacteria in case something killed off all the good stuff in your gut?
Removing the appendix would presumably take multiple mutations that would have other, possibly harmful effects as well. So it can't really happen overnight.
In order for it to happen at all the appendix needs to become so troublesome that everybody dies before they can reproduce. My son was born 3 weeks ago. My appendix could do me in tomorrow and the genes that express for it will likely go on.
In order for it to happen at all the appendix needs to become so troublesome that everybody dies before they can reproduce.
Not at all; it just needs to reduce the average number of children the average person has. Any mutation that makes it "less troublesome" on average would be favoured.
> Any mutation that makes it "less troublesome" on average would be favoured.
That's correct, but, from my understanding, revolutionary mutations are orders of magnitude less likely to happen than evolutionary mutations.
Everyone has an appendix, so there's no natural selection pressure where non-appendix people are breeding to further the spread of non-appendix humans. Just thinking out loud here - I reckon the way it would have to go would be if the appendix was a significant disadvantage, and people with a less sensitive/smaller/less prominent/something-like-that appendix were able to survive more easily or have more children on average, then you might selection pressures moving towards a less prominent and eventually no appendix.
It could happen, but it'd take a long time. Actually, one that fascinates me is what effect modern medicine and technology will have on evolution. Greater mobility is seeing children with a more mixed and diverse hereditary mix. Beyond that though, longer life cycles and better medical treatment might mean both slower and less evolution. I'd expect a lot of positive effects from interbreeding of different peoples over the next 500 years, but I reckon, sadly, that things like aggression won't be genetically bred out of us any time soon by being selected for less. Interesting stuff to think about.
Fair point. I thought it would be fun to compare the mortality rate with an issue with another organ that has slim chance of going away: the pancreas. It looks like the appendix is more-or-less a trouble-free organ in comparison. I wouldn't place any bets on the emergence of an appendix-free homo sapien offshoot any time soon.
Only with the "western" diet. You'll see much fewer cases of appendicitis amongst those who don't eat the overly-rich western diet. So in my opinion, this is cultural, not genetic.
My father had appendicitis before the age of 25, despite a relatively simple diet. His father, who lived through WWII food rationing, had appendicitis, too. He wouldn't have survived without being cut open and treated with penicillin. For obvious reasons, I wish this were caused by culture, but genetics is almost certainly at work.
