Experimental evolution of aging, growth, and reproduction in fruitflies

We report in this paper an evolutionary experiment on Drosophila that teste d life-history theory and the evolutionary theory of aging. As theory predi cts, higher extrinsic mortality rates did lead to the evolution of higher i ntrinsic mortality rates, to shorter lifespans. and to decreased age and si ze at eclosion; peak fecundity also shifted earlier in life. These results confirm the key role of extrinsic mortality rates in the evolution of growt h, maturation, reproduction, and aging, and they do so with a selection reg ime that maintained selection on fertility throughout life while holding po pulation densities constant.