Live fast die young life history in females: evolutionary trade-off between early life mating and lifespan in female Drosophila melanogaster

Abstract

The trade-off between survival and reproduction is fundamental to life history theory. Sexual selection is expected to favour a 'live fast die young' life history pattern in males due to increased risk of extrinsic mortality associated with obtaining mates. Sexual conflict may also drive a genetic trade-off between reproduction and lifespan in females. We found significant additive genetic variance in longevity independent of lifetime mating frequency, and in early life mating frequency. There was significant negative genetic covariance between these traits indicating that females from families characterized by high levels of multiple mating early in life die sooner than females that engage in less intense early life mating. Thus, despite heritable variation in both traits, their independent evolution is constrained by an evolutionary trade-off. Our findings indicate that, in addition to the well-known male-driven direct costs of mating on female lifespan (mediated by male harassment and harmful effects of seminal fluids), females with a genetic propensity to mate multiply live shorter lives. We discuss the potential role of sexual conflict in driving the evolutionary trade-off between reproduction and lifespan in Drosophila. More generally, our data show that, like males, females can exhibit a live fast die young life history strategy.

Figure 1. Raw sire family means of longevity.

Figure 2. Sire family mean relationship between residual longevity and early life mating frequency.

Residual longevity was obtained from a linear regression of longevity on lifetime mating frequency and start date. Points and error bars correspond to sire family means and standard errors, respectively.