Living Long in the Tooth: Grandparents may have rocked late Stone Age

A memorable senior moment may have occurred toward the end of the Stone Age. Around 30,000 years ago, the number of people surviving long enough to become grandparents dramatically increased, altering the social landscape and provoking major cultural innovations, according to two anthropologists.

Their analysis of fossil teeth from human ancestors indicates that Homo sapiens from the late Stone Age—but not Neandertals or other members of our evolutionary family—exhibited a sharp rise in the population of individuals older than 30 years.