Why Does Human Post-Reproductive Longevity Exist?

Human life span is quite unusual in that it includes a prolonged post-reproductive period in females and the existence of menopause. This is observed in some other species in captivity, provided with the benefits of life-long veterinary care, but in the wild very few species indeed share this characteristic with us. Of these, killer whales are the nearest to us in the evolutionary tree of life. None of our closer relatives, such as other primates, experience menopause. They are in addition short-lived in comparison to our length of life. Chimpanzees and gorillas top out at 50-60 years of age in captivity, and a decade or more less in the wild. Much of current thinking on the topic of unusual human longevity, at least when compared with our primate cousins, centers on our intelligence and capacity for culture as the originating difference. This allows older people to contribute materially to the success of their descendants, and this applies selection pressure to extended life: those with the capacity to live longer prosper, and some new balance of biological mechanisms is reached under the hood as a result. This view of the recent evolutionary past is known as the grandmother hypothesis, and ties together the existence of menopause, exceptional longevity, and the well-known disparity between male and female life spans. You can look back in the Fight Aging! archives for a pointer to a good open access paper on this topic. You might consider the paper linked below as a readin...
Source: Fight Aging! - Category: Research Authors: Tags: Medicine, Biotech, Research Source Type: blogs