Data from: Sex-dependent evolution of life-history traits following adaptation to climate warming

1. Thermodynamic processes increase metabolic rate and decrease longevity at high temperatures in ectotherms. However, how sustained long-term increase in temperature affects the evolution of longevity is poorly understood. 2. Stress theory of ageing predicts that increased longevity is positively genetically correlated with resistance to different types of environmental stressors implying that evolutionary trajectories of ageing may be mediated by correlative selection for robust phenotypes under thermal stress. 3. Here, we test this hypothesis by using replicate populations of the seed beetle Callosobruchus maculatus, evolving under two thermal environments: ancestral 30 °C and incremental increase towards novel 36 °C. 4. Beetles evolving under climate warming became larger, more fecund and lived longer than the beetles evolving under 30 °C across both environments. However, the increase in longevity was partly due to parental effects because after two generations of acclimatization it persisted only in males. 5. Our results support the hypothesis that evolution of stress resistance confers increased longevity through positive pleiotropy but demonstrate that such effects can be sex specific. These findings suggest that sex differences can evolve as correlated responses to selection under environmental change.

1. 热过程会提升变温动物（ectotherms）在高温环境下的代谢率，并缩短其寿命。然而，长期持续的温度升高如何影响寿命的进化，目前仍知之甚少。
2. 衰老的应激理论（stress theory of ageing）预测，寿命延长与对不同类型环境胁迫因子（environmental stressors）的抗性存在正向遗传相关，这意味着衰老的进化轨迹可能受到热胁迫下稳健表型（robust phenotypes）的相关选择所介导。
3. 本研究以豆象（Callosobruchus maculatus）的重复种群为实验材料，在两种热环境下开展进化选择实验：其一为祖先适应的30℃恒温环境，其二为逐步升温至新型36℃的渐变热环境。
4. 相较于在30℃环境下进化的豆象种群，经气候变暖模拟环境驯化进化的豆象，在两种测试环境下均表现出个体更大、繁殖力更强、寿命更长的表型。不过，寿命延长的效应部分源于亲本效应：仅在雄性个体中，经过两代驯化适应后，该延寿效应仍可维持。
5. 本研究结果支持“胁迫抗性的进化可通过正向多效性（positive pleiotropy）延长寿命”这一假说，但同时证实此类效应存在性别特异性。上述研究结果表明，性别差异可作为环境变化下选择的相关响应而发生进化。