Slashdot Mirror
Is Middle Age Evolution's Crowning Achievement?
Hugh Pickens writes "Reproductive biologist David Bainbridge writes that with the onset of wrinkles, love handles, and failing eyesight we are used to dismissing our fifth and sixth decades as a negative chapter in our lives. However recent scientific findings show just how crucial middle age has been to the success of our species and that with the probable existence of lots of prehistoric middle-aged people, natural selection had plenty to work on. 'We lead an energy-intensive, communication-driven, information-rich way of life, and it was the evolution of middle age that supported this,' writes Bainbridge, adding that middle age is a controlled and preprogrammed process, not of decline, but of development. 'When we think of human development, we usually think of the growth of a fetus or the maturation of a child into an adult. Yet the tightly choreographed transition into middle age is a later but equally important stage in which we are each recast into yet another novel form' — resilient, healthy, energy-efficient and productive. 'The middle aged may not have been able to outrun the prey, but they were really good at working out where it might be hiding and dividing up the spoils afterwards.' Although some critics say that middle age is a construct of the middle aged, Bainbridge asserts that one key role of middle age is the propagation of information. 'All animals inherit a great deal of information in their genes; some also learn more as they grow up. Humans have taken this second form of information transfer to a new level. We are born knowing and being able to do almost nothing. Each of us depends on a continuous infusion of skills, knowledge and customs, collectively known as culture, if we are to survive. And the main route by which culture is transferred is by middle-aged people showing and telling their children — as well as the young adults with whom they hunt and gather — what to do.'"
My very limited understanding was that evolution really could only work if the survivors were of reproductive age. If they are great at surviving and making children then it would work, otherwise not.
Ah.. fine I read the article:
"The probable existence of lots of prehistoric middle-aged people means that natural selection had plenty to work on. Those with beneficial traits would have been more successful at nurturing their children to reproductive age and helping provide for their grandchildren, and hence would have passed on those traits to their descendants. As a result, modern middle age is the result of millennia of natural selection."
So really it's grandparents that this article is really getting at. Middle aged for the purpose of having your offspring's offspring survive. That actually makes sense.
It's a match made in, er, evolution:
Little children love to hear the same story repeatedly, over and over, using exactly the same words.
Old folks repeat the same stories over and over, and if they get the words wrong, the children correct them.
Perfection.
I read a little blurb years ago by a guy who was in the peace core in the Caribbean. In a little village, 200 people or so. There was one really old guy who was eighty or some such. He was long past being able to do much more than gossip and look after small children. Till the day they heard over the radio that a hurricane was coming. Most people didn't really know what a hurricane was, but he did. He'd been through one when he was a young man. And all these years later he knew what to do. He had young men go into the forrest and bring back logs, showed them how to brace the insides of homes. To board up the windows, block the doors. Use rope to tie down the roof. Ordered families to just abandon badly constructed huts. Cut down and remove trees that were likely to come down. People were busy and a little grumpy but did what they were told. Hurricane hit in the middle of the night, 120 mile an hour winds. Most of the poorly constructed houses got knocked down, the ones that were reinforced survived and the people in them. No one died, not in that village. Some other villages, they didn't do anything, and houses fell down, people died.
So the thing is, the old man had already passed on his genes. By living long he was also able to use and pass on hard won knowledge and thus insure that his children. grand children and great grand children survived.