Hacker News Reader

Comment by bluepizza | Hacker News Reader

> selection pressures would tend to remove it.

A person born without an appendix has no actual advantage over a person who has one, so selection doesn't really influence it.

The human body is full of things that truly serve no function, and it's also full of detrimental things, such as genetic diseases.

As long as it does not impact reproduction, selection has no impact.

View on HN

> A person born without an appendix has no actual advantage over a person who has one

Untreated appendicitis is quite deadly. I would say there is definitely some advantage.

That's true, but untreated cardiomyopathy is potentially deadly too, yet that isn't enough pressure to cause us to not have hearts...

Good idea but bad example. Something needs to fulfill a heart's role, but we can live without an appendix just fine.

Oh sure, it was reductio ad absurdum, just pointing out that the possibility of appendicitis wasn't by itself an argument against its continued existence - I don't know anyone personally who has ever been diagnosed with it...

> just pointing out that the possibility of appendicitis wasn't by itself an argument against its continued existence

Except that yes it is an argument against it.

Your reduction breaks down because it conflates "a reason" with "all reasons".

Unless it is widespread deadly before breeding age, it doesn't make much difference.

See: dementia, cancer.

Natural selection only pushes towards the removal of things that harm reproduction, not things that harm survival at all ages. If appendicitis mostly happens after the average age of reproduction, then there's not really a big evolutionary pressure to remove the appendix. Sure the person will die of appendicitis, but if at that point they've already had all the kids they're likely to have during their life, then the appendicitis doesn't have an effect on the process of natural selection.

Reply on news.ycombinator.com