Elucidating demographic history during the settlement of ecological communities is crucial for properly inferring the mechanisms that shape patterns of species diversity and their persistence through time. Here, we used genomic data and coalescent‐based approaches to elucidate for the first time the demographic dynamics associated with the settlement by endemic reef fish fauna of one of the most remote peripheral islands of the Pacific Ocean, Rapa Nui (Easter Island). We compared the demographic history of nine endemic species in order to explore their demographic responses to Pleistocene climatic fluctuations. We found that species endemic to Rapa Nui share a common demographic history, as signatures of population expansions were retrieved for almost all of the species studied here, and synchronous demographic expansions initiated during the last glacial period were recovered for more than half of the studied species. These results suggest that eustatic fluctuations associated with Milankovitch cycles have played a central role in species demographic histories and in the final stage of the community assembly of many Rapa Nui reef fishes. Specifically, sea level lowstands resulted in the maximum reef habitat extension for Rapa Nui endemic species; we discuss the potential role of seamounts in allowing endemic species to cope with Pleistocene climatic fluctuations, and we highlight the importance of local historical processes over regional ones. Overall, our results shed light on the mechanisms by which endemism arises and is maintained in peripheral reef fish fauna.

中文翻译：

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应对更新世的气候波动：偏远地方性暗礁鱼类的人口统计学响应。

阐明生态群落定居期间的人口历史对于正确推断影响物种多样性模式及其在时间上的持久性的机制至关重要。在这里，我们首次使用基因组数据和基于聚结的方法来阐明与太平洋最偏远的外围岛屿之一拉帕努伊（复活节岛）的地方性礁鱼动物群定居有关的人口动态。我们比较了九种特有物种的人口历史，以探讨其对更新世气候波动的人口响应。我们发现，拉帕努伊（Rapa Nui）特有的物种拥有共同的人口统计学历史，因为这里研究的几乎所有物种都获得了种群扩展的特征，在上一个冰河期开始的同步人口统计扩张过程中，超过一半被研究物种得以恢复。这些结果表明，与米兰科维奇周期相关的欣快波动在物种人口统计历史以及许多拉帕努伊礁石鱼类群落的最后阶段起着核心作用。具体来说，海平面低位导致拉帕努伊特有物种最大的珊瑚礁栖息地扩展；我们讨论了海山在允许特有物种应对更新世气候波动中的潜在作用，并且我们强调了本地历史过程对区域历史过程的重要性。总体而言，我们的结果阐明了地方性礁鱼动物区系中特有物种产生和维持的机制。