Heritability of lifespan is largely sex-limited in Drosophila

Males and females differ with respect to lifespan and rate of aging in most animal species. Such sexual dimorphism can be associated with a complex genetic architecture, where only part of the genetic variation is shared between the sexes. To the extent this is true for lifespan and aging is not known, since studies of lifespan have given contradictory results and because aging has not been studied from this perspective. Here we investigate the additive genetic architecture of lifespan and aging in Drosophila melanogaster. We find substantial amounts of additive genetic variation for both traits, and that more than three quarters of this variation is available for sex-specific evolutionary change. This result shows that the sexes have a profoundly different additive genetic basis for these traits, which has several implications. First it translated into an, on average, three times higher heritability of lifespan within compared to between the sexes. Second, it implies that the sexes are...