Why We Age. – Review

Why We Age. – Review – book reviews

T.B.L. Kirkwood

Why We Age Steven N. Austad

New York: John Wiley and Sons. 244pp, 19.99 [pounds sterling]

Steven Austad is a comparative zoologist who, over the past decade, has focused his research on biological problems of ageing. A particularly significant contribution has been to test a prediction of evolutionary theory that animal populations subject to lower levels of extrinsic mortality will tend to evolve longer life spans. This prediction is clearly fulfilled in many instances when one species is compared with another. Bats, for instance, are much longer-lived than rats, and tortoises are famed for their longevity. Wings and hard shells are adaptations which clearly reduce extrinsic risks. However, Austad sought and found evidence that even within a species the same prediction holds true. He discovered that an island population of opossums, free from predators, lived longer and appeared to age more slowly than their cousins on the mainland.

Written in an engaging style, Why We Age surveys the biology of ageing from a zoological standpoint. Myths of remote, long-lived human communities are cheerfully exploded, genetic theories expounded, and the rate-of-living theory explored and found wanting. Menopause is examined from an evolutionary standpoint and explanations are offered for the life-extending effects of calorie restriction in rodents. Plenty of anecdotal material enlivens the text.


Professor of Biological Gerontology, Manchester

COPYRIGHT 1998 Oxford University Press

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