Moore Michael P, Riesch Rüdiger, Martin Ryan A
Department of Biology, Case Western Reserve University, Cleveland, OH, 44106, USA.
School of Biological Sciences, Royal Holloway, University of London, Egham, TW20 0EX, UK.
Ecol Lett. 2016 Apr;19(4):435-42. doi: 10.1111/ele.12576. Epub 2016 Feb 15.
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.
导致特定年龄死亡率发生变化的环境——选择的生态因子——介导了生殖生活史特征的进化。然而，不同选择因子之间生活史差异的相对大小、对特定选择因子的响应差异在不同分类群中是否一致，以及这种差异是否如理论预测的那样发生，在很大程度上仍未得到探索。我们通过对胎生鱼类（花鳉科）进行荟萃分析，评估了后代大小、后代数量以及这些性状之间的权衡差异。生活史差异在某些（捕食、硫化氢）但并非所有（密度、食物限制、盐度）选择因子中是一致且可预测的。相比之下，不同选择因子之间的差异幅度相似。最后，后代数量和后代大小差异之间存在负向、不对称的关系，这表明增加后代大小的成本高于增加后代数量的成本。最终，这些结果为生殖生活史差异的可预测和一致模式提供了有力证据，并突出了比较不同物种和生态选择因子之间表型差异的重要性。
