Data from: Selection on learning performance results in the correlated evolution of sexual dimorphism in life-history

The evolution of learning can be constrained by trade-offs. As male and female life-histories often diverge, the relationship between learning and fitness may differ between the sexes. However, because sexes share much of their genome, intersexual genetic correlations can prevent males and females from reaching their sex-specific optima resulting in intralocus sexual conflict (IaSC). To investigate if IaSC constraints sex-specific evolution of learning we selected Caenorhabditis remanei nematode females for increased or decreased olfactory learning performance and measured learning, lifespan (in mated and virgin worms), reproduction and locomotory activity in both sexes. Males from downward-selected female lines had higher locomotory activity and longer virgin lifespan but sired fewer progeny than males from upward-selected female lines. In contrast, we found no effect of selection on female reproduction and downward-selected females showed higher locomotory activity but lived shorter as virgins than upward-selected females. Strikingly, selection on learning performance led to the reversal of sexual dimorphism in virgin lifespan. We thus show sex-specific trade-offs between learning, reproduction and lifespan. Our results support the hypothesis that selection on learning performance can shape the evolution of sexually dimorphic life-histories via sex-specific genetic correlations.学习能力的演化往往会受到权衡效应的约束。由于雌雄两性的生活史通常存在分化，学习与适合度（fitness）之间的关联可能因性别而异。然而，由于两性共享大部分基因组，性间遗传相关（intersexual genetic correlations）可能会阻碍雌雄两性达到其性别特异性的最优表型，进而引发基因座内性冲突（intralocus sexual conflict, IaSC）。 为探究基因座内性冲突是否会制约学习能力的性别特异性演化，我们以雷氏隐杆线虫（Caenorhabditis remanei）为研究对象，对其雌性个体进行选择，使其嗅觉学习性能（olfactory learning performance）提升或降低，并测定了两性的学习能力、寿命（涵盖交配与未交配个体）、繁殖能力以及运动活性。 相较于来自向上选择雌性株系的雄性个体，来自向下选择雌性株系的雄性运动活性更高、未交配寿命更长，但产生的后代数量更少。与之相反，我们未发现选择处理对雌性繁殖能力存在显著影响；向下选择的雌性运动活性更高，但作为未交配个体的寿命短于向上选择的雌性。 尤为引人注目的是，针对学习性能的选择导致了未交配寿命的两性异形（sexual dimorphism）发生逆转。综上，我们证实了学习能力、繁殖能力与寿命之间存在性别特异性的权衡效应。本研究结果支持如下假说：对学习性能的选择可通过性别特异性遗传相关，塑造具有两性异形特征的生活史演化。