By Don Sapatkin PHILADELPHIA - Emmanuel Skordalakes scrutinized the genetic makeup of pigs and cows and rats and hundreds of other creatures before the red flour beetle, an eighth-of-an-inch-long pest found in Southern kitchens, delivered the breakthrough scientists had sought for more than a decade.

PHILADELPHIA _ As if gray hair, brittle bones and wrinkles weren't bad enough, scientists say that as you age the very DNA in your trillions of cells starts to fray, unravel and disintegrate. Now there may be something you can do to slow the inevitable _ exercise.