I have just posted a video about what Darwin might have thought about old age. He walked on his thinking-path (the sandwalk) every day that he could even in old age. He was pretty much an invalid when he died, but not as much of an invalid as he would have been had he not walked on his thinking path so often.
First, in the video, Darwin speculates on why walking improved his thinking. I have already summarized this in an earlier essay. Gentle walking increases blood flow to the brain. Also, thinking, like walking, is a series of steps.
Second, in the video, Darwin speculates on why old age evolved. Humans are unique among animals in having decades of post-reproductive life span. One explanation is that natural selection has provided us with whatever we need to be young, but not whatever we need to be old. But if old age is just the dumping ground of bad genes and defective body parts, why hasn’t evolution gotten rid of it?
The more likely reason that humans grow old, rather than just dying, is that old people provide important benefits to their offspring and to their tribe. Old people are repositories of knowledge and wisdom (well, knowledge, anyway) especially before books and AI. Us old people know things that young people haven’t even thought to ask about. Also, old people help to take care of the grandkids while the parents are searching for food or status. This is also the time when old people can pass on a lot of culturally important information to later generations. Finally, old people may not travel very far but they can forage for food near the camp.
Old age doesn’t seem quite so bad when Darwin explains it to you.
