Getting Ever Older/How Long Have You Got?; The Quest to Beat Aging; Scientific American Presents; by Kathryn Brown; 8 Page(s)

Forget growing old gracefully. For centuries, graying adults have tried all kinds of things to live longer: prayers, yogurt, mystical hot springs-even injections of goat-testicle extracts. Despite it all, the maximum human life span hasn't budged. At best, the statistics say, you can hope to reach about 120 years of age-and precious few actually do.

But don't throw out those birthday candles just yet. Some scientists now say they're about to trump Father Time. Working in the lab, biologists have already reared worms, fruit flies, mice and yeast that live twice as long as normal, thanks to mutations in a mere handful of genes. Other researchers are peering into the increasing molecular disorder that characterizes aging in humans, from damaged DNA to misbehaving cells. And physiologists are finding out why some people do get to celebrate their 100th birthdays. The oldest-known human, Jeanne Calment of France, recently died at 122, leaving researchers to marvel at the possibilities of long life. "Who's to say we couldn't go 10 or 20 years longer?" asks Caleb E. Finch, director of neurogerontology at the University of Southern California.