Sex-specific effects of natural and sexual selection on the evolution of life span and ageing in Drosophila simulans

1. Variation in the strength of age-dependent natural selection shapes differences in ageing rates across species and populations. Likewise, sexual selection can promote divergent patterns of senescence across the sexes. However, the effects of these processes on the evolution of ageing have largely been considered independently, and interactions between them are poorly understood.

2. We use experimental evolution to investigate how natural and sexual selection affect life span and ageing in Drosophila simulans.

3. Replicate populations were evolved under lifetime monogamy (relaxed sexual selection) or lifetime polyandry (elevated sexual selection) and at one of two temperatures, 25 °C (relaxed natural selection) or 27 °C (enhanced natural selection), in a fully factorial design. We measured longevity in 150 individually housed flies taken from each of three replicate populations per selection regime.

4. We found that natural and sexual selection affected the evolution of life ...