The most common objection to the logic of evolutionary health is that paleolithic humans had short lifespans, presumably because they were in poor health. This fallacy has been demolished many times over, but I have another argument to add to the pile. The popular notion that paleolithic humans lived long enough to reproduce then died is flatly contradicted by the existence of evolved grandparenting behavior.
Grandparenting behavior seems to be a cultural universal. Parents want their grown children to produce offspring, and they seem to care a lot about it. Grandparents enjoy lavishing their love on their grandchildren. The grandmother on the mothers’s side tends to invest a lot in helping out with the baby (for good evolutionary reasons).
This implies that these behaviors have evolved, which in turn means that grandparents must have had a sizable impact on their grandchildrens’s genetic success. So it must have been fairly common for people to live long enough to become grandparents. Conclusion: paleolithic humans routinely lived long enough to see their grandchildren grow up. They lived long enough to reproduce and see their children reproduce.
So how old would that have been? A conservative estimate would be that the grandparent had their child at 16 and this child had the grandchild at 16 as well. The grandparent would be 32 at the birth of the grandchild. Since grandparenting behavior extends past infancy, let’s take a conservative estimate of 4 years. So we can expect that it was common for our paleolithic ancestors to live at least to 36.
Taking a more realistic estimate, we could assume that the average age of childbirth is 22 and that grandparents were around until their grandchildren were on average 6 years old. That brings the figure up to 50. And an average age of 50 is nothing to scoff at. I’m not sure how late the evolved grandparenting behaviors last, so 6 is still a conservative figure. In fact, with generations of 16 years, one could be a great-grandparent at 48.
Just another argument that puts the lie to the notion of a short-lived paleolithic ancestry.
Long live paleo man!