Data from: The predictability and magnitude of life-history divergence to ecological agents of selection: a meta-analysis in livebearing fishes

Environments causing variation in age-specific mortality – ecological agents of selection – mediate the evolution of reproductive life-history traits. However, the relative magnitude of life-history divergence across selective agents, whether divergence in response to specific selective agents is consistent across taxa and whether it occurs as predicted by theory, remains largely unexplored. We evaluated divergence in offspring size, offspring number, and the trade-off between these traits using a meta-analysis in livebearing fishes (Poeciliidae). Life-history divergence was consistent and predictable to some (predation, hydrogen sulphide) but not all (density, food limitation, salinity) selective agents. In contrast, magnitudes of divergence among selective agents were similar. Finally, there was a negative, asymmetric relationship between offspring-number and offspring-size divergence, suggesting greater costs of increasing offspring size than number. Ultimately, these results provide strong evidence for predictable and consistent patterns of reproductive life-history divergence and highlight the importance of comparing phenotypic divergence across species and ecological selective agents.

可导致年龄特异性死亡率产生变异的环境，即生态选择因子，介导了繁殖生活史性状的演化。然而，不同选择因子间生活史分化的相对强度、特定选择因子所引发的分化在不同类群间是否保持一致，以及该分化是否符合理论预测，这些问题在很大程度上仍未得到探索。本研究以花鳉科（Poeciliidae）胎生鱼类为研究对象，通过荟萃分析评估了后代大小、后代数量以及二者间权衡关系的分化情况。研究发现，生活史分化在部分选择因子（捕食压力、硫化氢）下呈现出一致性且具备可预测性，但在其余选择因子（种群密度、食物限制、盐度）下则并非如此。相较而言，不同选择因子间的分化强度却较为相似。最后，后代数量分化与后代大小分化之间呈现出负向不对称关系，这表明增加后代大小所付出的进化成本要高于增加后代数量。综上，本研究结果为繁殖生活史分化存在可预测且一致的模式提供了有力证据，并凸显了跨物种与跨生态选择因子比较表型分化的重要性。