Baret and Lints [Gerontology 1993;39:252-259] have ques tioned the interpretation of artificial selection experiments for increased longevity in Drosophila. They suggest that such experiments cannot demonstrate the genetic determination of longevity, because line differences in mean longevity are con-founded with erratic temporal variations in life span. Using 15,000 flies from selected and control lines developed by Luckinbill and Clare [Heredity 1985;55:9-19], we show here that when lines are tested simultaneously in a carefully controlled environment, they exhibit markedly different average life spans: Selected males live 20 days longer than controls, and selected females live 10 days longer. These and other observations leave no doubt about the existence of heritable variation influencing longevity in Drosophila.
- Genetic variation