Data from: 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
early in the breeding season, and consequently senesced at a slower rate
later in the season, compared to those that had developed under harsher
conditions. This plasticity of ageing was genetically determined. Both
antagonistic pleiotropy and genetic variation in the rate of senescence
were evident only in the individuals raised in the harsher environment. 5.
The experimental demonstration of genotype-by-environment interactions
influencing the rate of reproductive senescence provides interesting
insights into the role of the environment in the evolution of
life-histories. The results suggest that benign conditions weaken the
scope for senescence to evolve, and that the dependence on the environment
may maintain genetic variation under selection.