Conventional Wisdom Suggests That Stress Accelerates Aging -- But Is It Really True?

�Evolutionary studies of ripening typically apply small, transitory animals (insects, worms, mice) under benign conditions - constant temperature and humidity, no parasites, superabundant intellectual nourishment - in the laboratory. Oddly enough, very little is known about ageing in such animals in their abrasive, stressful natural environments. Could it be that these laboratory "guinea pigs" actually age often more slowly in captive luxury than do their wild cousins?



Nori Kawasaki, Rob Brooks, and Russell Bonduriansky of the University of New South Wales, and Chad Brassil of the University of Nebraska, place out to find out, using the giant Australian stilt-legged fly Telostylinus angusticollis, a beautiful, sexually dimorphous animal that breeds on rotten mrs. Henry Wood. To identify individual flies in the wild, they wrote codes (combinations of Arabic numerals and Latin and Japanese letters) on the flies' backs victimization enamel paint, and recorded the comings and goings of marked individuals on Acacia trunks while at the same time monitoring their captive cousins in the lab.



Analysis, promulgated in the September issue of the American Naturalist, revealed hitting contrasts betwixt wild and captivity: in males, the rate of aging (deliberate as the rate of increase of mortality rate with historic period) was as least doubled greater in the wild than in the science laboratory. Curiously, raving mad females did not look to age at all. For both sexes, life expectancies in the wild were dramatically shorter than in the lab.



Evolutionary biologists have long sought to understand how environmental factors generate natural selection on the rate of aging, and in the end influence the frequencies of genes that underpin genetic variation in this trait. Much less is known about how environment affects the