Data from: A key ecological trait drove the evolution of biparental care and monogamy in an amphibian

Linking specific ecological factors to the evolution of parental care pattern and mating system is a difficult task of key importance. We provide evidence from comparative analyses that an ecological factor (breeding pool size) is associated with the evolution of parental care across all frogs. We further show that the most intensive form of parental care (trophic egg feeding) evolved in concert with the use of small pools for tadpole deposition and that egg feeding was associated with the evolution of biparental care. Previous research on two Peruvian poison frogs (Ranitomeya imitator and Ranitomeya variabilis) revealed similar life histories, with the exception of breeding pool size. This key ecological difference led to divergence in parental care patterns and mating systems. We present ecological field experiments that demonstrate that biparental care is essential to tadpole survival in small (but not large) pools. Field observations demonstrate social monogamy in R. imitator, the species that uses small pools. Molecular analyses demonstrate genetic monogamy in R. imitator, the first example of genetic monogamy in an amphibian. In total, this evidence constitutes the most complete documentation to date that a single ecological factor drove the evolution of biparental care and genetic and social monogamy in an animal.将特定生态因子与育幼模式（parental care pattern）及婚配制度（mating system）的演化相关联，是一项兼具关键意义与挑战性的核心研究任务。本研究通过比较分析（comparative analyses）提供证据，证实生态因子——繁殖池大小（breeding pool size）——与所有蛙类的育幼演化存在显著关联。我们进一步发现，最强化的育幼形式——营养卵投喂（trophic egg feeding）——是伴随小型水池用于蝌蚪投放（tadpole deposition）这一行为共同演化而来的，且营养卵投喂与双亲育幼（biparental care）的演化密切相关。此前针对两种秘鲁毒蛙（Ranitomeya imitator与Ranitomeya variabilis）的研究显示，二者的生活史特征高度相似，仅繁殖池大小存在差异；这一关键生态差异最终导致了育幼模式与婚配制度的分化。我们开展的野外生态实验证实，在小型水池（而非大型水池）中，双亲育幼对蝌蚪的存活至关重要。野外观察表明，使用小型水池的Ranitomeya imitator存在社会单配制（social monogamy）；分子分析则证实该物种存在遗传单配制（genetic monogamy），这是两栖动物中遗传单配制的首例报道。综上，本研究提供了迄今为止最为完整的证据链，证明单一生态因子可推动动物的双亲育幼、社会单配制与遗传单配制的协同演化。