Data from: Selection is stronger in early-versus-late stages of divergence in a Neotropical livebearing fish

How selection acts to drive trait evolution at different stages of divergence is of fundamental importance in our understanding of the origins of biodiversity. Yet, most studies have focused on a single point along an evolutionary trajectory. Here, we provide a case study evaluating the strength of divergent selection acting on life-history traits at early-versus-late stages of divergence in Brachyrhaphis fishes. We find that the difference in selection is stronger in the early-diverged population than the late-diverged population, and that trait differences acquired early are maintained over time.

选择如何在分化的不同阶段驱动性状演化，是我们理解生物多样性起源的核心议题。然而，绝大多数现有研究仅聚焦于演化轨迹中的单个时间节点。在此，我们以短鳍脂鲤属（Brachyrhaphis）鱼类为研究对象开展案例研究，评估分化早期与晚期阶段下，作用于生活史性状的歧化选择（divergent selection）强度。研究结果显示，早期分化种群的选择差异强度高于晚期分化种群，且早期演化获得的性状差异可随时间得以维持。