Data from: Sexual selection affects the evolution of lifespan and ageing in the decorated cricket Gryllodes sigillatus

Recent work suggests that sexual selection can influence the evolution of ageing and lifespan by shaping the optimal timing and relative costliness of reproductive effort in the sexes. We use inbred lines of the decorated cricket, Gryllodes sigillatus, to estimate the genetic (co)variance between age-dependent reproductive effort, lifespan and ageing within and between the sexes. Sexual selection theory predicts that males should die sooner and age more rapidly than females. However, a reversal of this pattern may be favoured if reproductive effort increases with age in males but not in females. We found that male calling effort increased with age, whereas female fecundity decreased, and that males lived longer and aged more slowly than females. These divergent life-history strategies were underpinned by a positive genetic correlation between early-life reproductive effort and ageing rate in both sexes, although this relationship was stronger in females. Despite these sex differences in life-history schedules, age-dependent reproductive effort, lifespan and ageing exhibited strong positive intersexual genetic correlations. This should, in theory, constrain the independent evolution of these traits in the sexes and may promote intralocus sexual conflict. Our study highlights the importance of sexual selection to the evolution of sex differences in ageing and lifespan in G. sigillatus.近期研究表明，性选择（sexual selection）可通过塑造两性繁殖投入的最优时机与相对成本，影响衰老与寿命的演化。我们以装饰蟋蟀（Gryllodes sigillatus）的近交系为实验材料，估算了两性内部及两性之间，年龄依赖性繁殖投入、寿命与衰老间的遗传（共）方差。性选择理论预测，雄性的死亡时间应早于雌性，衰老速率也更快；但若雄性的繁殖投入随年龄增长而提升，而雌性并无此特征，则该性别间的衰老模式可能发生逆转。本研究发现，雄性的鸣唱投入随年龄增长而增加，而雌性的繁殖力则随年龄下降，且雄性的寿命长于雌性、衰老速率更缓慢。尽管两性的生活史策略存在上述差异，但两性早期繁殖投入与衰老速率间均存在正向遗传相关，且该相关在雌性中更强。尽管生活史时序存在上述性别差异，但年龄依赖性繁殖投入、寿命与衰老在两性间均呈现显著的正向跨性别遗传相关，从理论上讲，这会限制这些性状在两性中的独立演化，并可能促进基因座内的性冲突。本研究凸显了性选择对装饰蟋蟀（Gryllodes sigillatus）衰老与寿命性别差异演化的重要意义。