Data from: The evolution of cooperation: interacting phenotypes among social partners

Models of cooperation among nonkin suggest that social assortment is important for the evolution of cooperation. Theory predicts that interacting phenotypes, whereby an individual’s behavior depends on the behavior of its social partners, can drive such social assortment. We measured repeated indirect genetic effects (IGEs) during cooperative predator inspection in eight populations of Trinidadian guppies (Poecilia reticulata) that vary in their evolutionary history of predation. Four broad patterns emerged that were dependent on river, predation history, and sex: (i) current partner behavior had the largest effect on focal behavior, with fish from low-predation habitats responding more to their social partners than fish from high-predation habitats; (ii) different focal/partner behavior combinations can generate cooperation; (iii) some high-predation fish exhibited carryover effects across social partners; and (iv) high-predation fish were more risk averse. These results provide the first large-scale comparison of interacting phenotypes during cooperation across wild animal populations, highlighting the potential importance of IGEs in maintaining cooperation. Intriguingly, while focal fish responded strongly to current social partners, carryover effects between social partners suggest generalized reciprocity (in which one helps anyone if helped by someone) may contribute to the evolution of cooperation in some, but not all, populations of guppies.非亲属间合作的理论模型表明，社会选型（social assortment）对合作的演化至关重要。理论预测，互作表型（interacting phenotypes）——即个体行为取决于其社交伙伴的行为——可驱动此类社会选型的形成。我们在8个具有不同捕食演化历史的特立尼达孔雀鱼（*Poecilia reticulata*）种群的合作捕食者检查行为中，测量了重复间接遗传效应（indirect genetic effects, IGEs）。研究得出了四项与河流环境、捕食历史以及性别相关的核心规律： （1）当前伙伴的行为对受试个体行为的影响最为显著，来自低捕食压力生境的孔雀鱼相较于高捕食压力生境的个体，对其社交伙伴的行为响应更强； （2）不同的受试/伙伴行为组合均可促成合作行为； （3）部分高捕食压力生境的孔雀鱼表现出跨社交伙伴的遗留效应； （4）高捕食压力生境的孔雀鱼风险规避性更强。 本研究首次针对野生动物种群间合作过程中的互作表型开展了大规模对比分析，凸显了间接遗传效应在维持合作行为方面的潜在重要性。值得注意的是，尽管受试个体对当前社交伙伴的响应十分强烈，但社交伙伴间的遗留效应表明，广义互惠（generalized reciprocity，即个体若曾获得他人帮助，则会帮助任意其他个体）或许在部分而非全部孔雀鱼种群中推动了合作行为的演化。