You don't have to regenerate parts to live long enough to have offspring. You can do it at like 15 years old. So evolution isn't going to help in that regard much.
Living for a long time after you have children is incredibly useful from the standpoint of genetic fitness. After all, grandparents play an important role in pretty much every human culture. And a grandparent with all their body parts is a whole lot more useful than one without.
The counterpoint being that in resource-scarce evolutionary environments, every grandparent (or even parent) that stays around is consuming resources that could instead go toward creating+maintaining an additional child.
That's assuming that they consume more resources than they extract from the environment. And then there's also that grandparents can use the power and influence they've accumulated to benefit their grandchildren.
There are plenty of species where the male dies during mating, and squillions more where the male isn't around after mating.
Evolution only requires that you get to reproduction, however that happens. It doesn't require that you're happy, sad, whatever, just that you reproduce.
> Evolution only requires that you get to reproduction, however that happens. It doesn't require that you're happy, sad, whatever, just that you reproduce.
It requires that your offspring actually survive as well. Humans are, at least historically, exceptionally well-equipped to influence the survival of their offspring.
Humans also take figuratively forever to be self-sufficient. Herd animals are born with the ability to walk, for example. Humans take about 10 years before they can be taught to be even somewhat self-sufficient, which is a ridiculously long time in comparison to others.
So, given that humans are sexually mature before they're fully self-sufficient, that enhanced ability to support their offspring is not all advantage - it's actually required for the propagation of the species. If older folks weren't taking care of the younger ones, none of them would reach reproductive age.
A 7 or 8 year old can hunt if you were to teach them to do so. An 8 year olds has conceived. So it's possible to do it at a much younger age if you have no choice.
While it may sound callous, if that 8-year-old did not produce viable offspring that could mature to reproductive age themselves, she is irrelevant to evolution. Conception is not synonymous with viable offspring.
As for the 8-year-old hunter, just how self-sufficient can they be? Procuring their own weapons, transporting their own carcasses, preparing healthy meals multiple times per day on an ongoing basis... the idea that you could just loose a 7-8 year old into the woods with a weapon and they'd survive in an ongoing sense is a bit far-fetched. Teaching someone to sneak, track, and point a gun is not the same as them being self-sufficient.
>Living for a long time after you have children is incredibly useful from the standpoint of genetic fitness. After all, grandparents play an important role in pretty much every human culture.
In the time scale that matters to evolution, grandparents played absolutely no role for the Homo Sapiens, and neither did culture.
I don't think that's at all likely. We've had fire and had the physiological adaptations enabling speech for well over a million years. We've been manufacturing complex tools such as spears with stone tips for about half a million years, to Homo heidelbergensis. Even Ergaster had lifespans allowing survival to an age where grandchildren could reach adulthood, allowing for skills transfer.
Do you have children? Raising children is hard. And it's a lot less hard when you have other adults to help. Historically, those would be grandparents and aunts/uncles. But aunts/uncles would probably have children of their own.
Nobody's saying that grandparents being alive are a prerequisite for grandchildren. But anybody with kids will tell you that grandparents are tremendously helpful in raising children.
Evolution is statistical in nature, not binary. Grandparents just have to be useful in raising grandchildren for them to be favored by natural selection. They don't need to be strictly necessary.