Solving the Aging Puzzle

Evolution may tell us why living things—including humans—age at such diverse rates

"Steven N. Austad is lucky to have lived long enough to be an expert on aging," writes Doug Stewart in his profile of the University of Idaho gerontologist and evolutionary zoologist. Before becoming a scientist, Austad led a risky life, as pool hustler, New York City cabbie--and lion-wrestling animal trainer in Hollywood. Despite the battering Austad received at the hands (or claws) of his charges, he was young then and knew his wounds would heal. Today, writes Stewart, "that unremarkable ability of living tissue to renew itself, at least for a while, fascinates Steve Austad" more than animal training ever did.

The fact that we don't retain that ability to heal ourselves as we grow old, says Austad, is the central paradox of gerontology, currently a hotbed of research. But very little progress has been made when it comes to explaining the basic mechanisms of aging. "Virtually all research on aging is done with animals that aren't very good at it," says Austad, citing lab mice and fruit flies as prime examples. "My idea is, let's find something that's good at aging and then figure out how they do it." To that end, the former lion tamer has studied long-lived animals, from Micronesian wild mice to Sapelo Island opossums, from parakeets to flying squirrels. By analyzing the environments, life histories and genetic makeup of these animals, and comparing them with those of other populations, Austad has shed light on how evolution may have shaped, even dictated, their life spans--and, by extension, that of human beings.

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