Well past age 50, men can still impregnate women of childbearing age. That lengthy period of fertility spurred the evolution of relatively long lives in both sexes, a new study suggests.
In modern hunter-gatherer societies, a substantial number of men in their 60s and 70s continue to father children, say Stanford University biologist Shripad D. Tuljapurkar and his colleagues. A mathematical model that they describe in the August PLoS ONE indicates that, if this mating pattern had occurred throughout human evolution, it would have preserved genes that favor both male and female survival for as long as men can reproduce, until roughly age 70.
That conclusion builds on a review of mortality patterns in hunter-gatherer and other nonindustrial societies published in the June Population and Development Review. Anthropologists Michael D. Gurven of the University of California, Santa Barbara and Hillard Kaplan of the University of New Mexico in Albuquerque con