Data from: Persistence in peripheral refugia promotes phenotypic divergence and speciation in a rainforest frog

It is well established from the fossil record and phylogeographic analyses that late Quaternary climate fluctuations led to substantial changes in species' distribution, but whether and how these fluctuations resulted in phenotypic divergence and speciation is less clear. This question can be addressed through detailed analysis of traits relevant to ecology and mating within and among intraspecific lineages that persisted in separate refugia. In a biogeographic system (the Australian Wet Tropics, AWT) with a well-established history of refugial isolation during Pleistocene glacial periods, we test whether climate-mediated changes in distribution drove genetic and phenotypic divergence in the rainforest frog, Cophixalus ornatus. We combine paleomodeling and multilocus genetics to demonstrate long-term persistence within, and isolation among, one central and two peripheral refugia. In contrast to other AWT vertebrates, the three major lineages differ in ecologically relevant morphology and in mating call, reflecting divergent selection and/or genetic drift in the peripheral isolates. Divergence in mating call, and contact zone analyses, suggest that the lineages now represent distinct species. The results show that climate shifts can promote genetic and phenotypic divergence, and potentially speciation, and direct attention towards incorporating adaptive traits into phylogeographic studies to better resolve the mechanisms of speciation.化石记录与系统地理学分析均已证实，晚第四纪的气候波动会引发物种分布的显著改变，但这类波动是否以及如何导致表型分化与物种形成，目前仍不甚明确。该问题可通过对存续于不同避难所（refugia）的种内支系内部及支系间的生态与交配相关性状开展详细分析得以解答。针对更新世冰期期间拥有明确避难所隔离历史的澳大利亚湿热带地区（Australian Wet Tropics, AWT）这一生物地理系统，本研究以雨林蛙饰纹细趾蟾（Cophixalus ornatus）为研究对象，检验气候介导的分布变化是否推动了其遗传与表型分化。我们结合古分布建模与多基因座遗传学手段，证实了1个中央避难所与2个外围避难所内部的长期存续性，以及各避难所之间的隔离性。与澳大利亚湿热带地区的其他脊椎动物不同，这3个主要支系在生态相关形态特征与求偶鸣唱方面均存在差异，这反映了外围隔离种群中的歧化选择与/或遗传漂变。求偶鸣唱的分化以及接触带分析结果均表明，这些支系目前已属于不同的物种。本研究结果显示，气候变迁可推动遗传与表型分化，并可能促成物种形成；同时，本研究也呼吁将适应性性状纳入系统地理学研究，以更精准地解析物种形成的内在机制。