A benign juvenile environment reduces the strength of antagonistic pleiotropy and genetic variation in the rate of senescence

1. The environment can play an important role in the evolution of senescence because the optimal allocation between somatic maintenance and reproduction depends on external factors influencing life expectancy. 2. The aims of this study were to experimentally test whether environmental conditions during early life can shape senescence schedules, and if so, to examine whether variation among individuals or genotypes with respect to the degree of ageing differs across environments. 3. We tested life-history plasticity and quantified genetic effects on the pattern of senescence across different environments within a reaction norm framework by using an experiment on the three-spined stickleback (Gasterosteus aculeatus, Linnaeus) in which F1 families originating from a wild annual population experienced different temperature regimes. 4. Male sticklebacks that had experienced a more benign environment earlier in life subsequently reduced their investment in carotenoid-based sexual signals earl...