You don’t think it would be true in reality? Predators choose the weakest member of a group to attack, do they not? I know it is a punchline in a joke and couldn’t resist, but also know it would be somewhat true in real life. There are variables, the 30 year old might indeed be stronger/faster than the 20 year old- it happens. My 60 something hubby can easily outrun all of our grandchildren in a foot race- even the ones in their teens. If they get stalked by a tiger it won’t be hubby that gets eaten...
Well, by definition, we’re all just speculating here - obviously. I’m just speculating that man’s most important predator was other men. And that that would account for the findings in the article.
I guess *another* reason why I think that I’m right is that something changed 30,000 years ago. So what would that change have been? Tigers didn’t all of a sudden get more friendly 30,000 years ago. Bacteria didn’t all of a sudden get less virulent. Etc. etc.
But what could (and I would argue did) change 30,000 years ago was human social structures and arrangements. For all sorts of reasons early humans may have changed their social model, their economic model, technology may have changed etc. etc. and for some reason or combination of reasons 30 year olds stopped getting dispatched in steel cage death matches or ostracized from the group and left to starve but instead started being kept around for various reasons.
I guess having said what I just said that it could be they were killed off by other humans OR it could have been that they were cast off by the group and left to starve or be klled.
So pre 30,000 years ago it could be when you turned 30 you were killed by other humans or it could be you were abandoned by the tribe. Either way, you were done.
Then something changed and you were kept around and allowed to survive.
My point is that if 30 years old was a death sentence 40,000 years ago but wasn’t 20,000 years ago it was likely do to a change in the ways early humans self-organized and not due to the ability to outrun the tiger.