Research: Old People Helped Evolution

ByABC News
July 14, 2004, 11:50 AM

July 15, 2004 -- Anthropologists Rachel Caspari and Sang-Hee Lee were astounded when they saw the numbers. After spending years studying fossilized teeth in museums around the world they were finally able to document one of the most dramatic turning points in the history of human evolution.

About 32,000 years ago, the researchers found, human longevity took a giant leap upward. In fact, the number of people surviving into old age more than quadrupled during what may have been a relatively brief period of time.

Why that happened is still a bit of a mystery, although the researchers have their hunches. But the consequences are clear. Population size grew dramatically, and with more and more people around, particularly older folks with a bit of wisdom and experience, new ideas began to emerge.

More people shared the chores of raising children and gathering food, and that left more time for leisure activities. People probably began to dream more, and shared more ideas with more people. Some became artists. Others, in time, musicians.

Population reached a "critical mass," as Caspari puts it, and from all those folks sitting around the campfire sharing ideas, modern humans began to emerge. It was not just evolution. It was revolution. This old planet would never be the same again.

30-Year-Old Grandparents

Caspari, of the University of Michigan's Anthropology Museum, and Lee, of the University of California, Riverside, published their findings in a recent issue of the Proceedings of the National Academy of Sciences.

Lee, who is temporarily in South Korea as a visiting scholar at Chonnam National University, has described the events of that era as a period of "creative explosion." The research dovetails with other studies that show the importance of having elders around the campfire.

"The elders may have served the same purpose as computer hard drives serve today," Lee told the Riverside Press Enterprise. "They were the archives of vital information."