Plastic responses to parents and predators lead to divergent social behaviour in sticklebacks

Population divergence in antipredator defense and behaviour occurs rapidly and repeatedly. Genetic differences, phenotypic plasticity, or parental effects may all contribute to divergence, but the relative importance of each of these mechanisms remains unknown. We exposed juveniles to parents and predators to measure how induced changes contribute to shoaling behaviour differences between two threespine stickleback species (benthics and limnetics: Gasterosteus spp). We found that limnetics increased shoaling in response to predator attacks while benthics did not alter their behaviour. Care by limnetic fathers led to increased shoaling in both limnetic and benthic offspring. Shoaling helps limnetics avoid trout and avian predation; our results suggest this adaptive behaviour is the result of a combination of paternal effects, predator-induced plasticity, and genetic differences between species. These results suggest that plasticity substantially contributes to the rapid divergence in sho...

种群在反捕食防御与行为上的分化可快速且反复发生。遗传差异、表型可塑性或亲代效应均可能推动这一分化，但这些机制各自的相对重要性仍不明确。我们将幼鱼暴露于亲代与捕食者环境中，以测定诱导性变化如何导致两种三刺鱼（底栖型与湖沼型：Gasterosteus spp.）之间的集群行为差异。研究发现，湖沼型个体在遭遇捕食者攻击时会增强集群行为，而底栖型个体的行为未发生改变。湖沼型父本的抚育可使湖沼型与底栖型后代的集群行为均增强。集群行为有助于湖沼型个体躲避鳟鱼与鸟类捕食；研究结果表明，这种适应性行为是亲代效应、捕食者诱导的可塑性以及物种间遗传差异共同作用的结果。这些结果表明，可塑性对集群行为的快速分化具有显著贡献……