Data from: Linking micro- and macroevolutionary perspectives to evaluate the role of Quaternary sea-level oscillations in island diversification

With shifts in island area, isolation, and cycles of island fusion-fission, the role of Quaternary sea-level oscillations as drivers of diversification is complex and not well understood. Here we conduct parallel comparisons of population and species divergence between two island areas of equivalent size that have been affected differently by sea-level oscillations, with the aim to understand the micro- and macroevolutionary dynamics associated with sea-level change. Using genome-wide datasets for a clade of seven Amphiacusta ground cricket species endemic to the Puerto Rico Bank (PRB), we found consistently deeper interspecific divergences and higher population differentiation across the unfragmented Western PRB, in comparison to the currently fragmented Eastern PRB that has experienced extreme changes in island area and connectivity during the Quaternary. We evaluate alternative hypotheses related to the microevolutionary processes (population splitting, extinction and merging) that regulate the frequency of completed speciation across the PRB. Our results suggest that under certain combinations of archipelago characteristics and taxon traits the repeated changes in island area and connectivity may create an opposite effect to the hypothesized "species pump" action of oscillating sea levels. Our study highlights how a microevolutionary perspective can complement current macroecological work on the Quaternary dynamics of island biodiversity.

随着岛屿面积、隔离程度发生变化，且岛屿经历融合-分裂循环，第四纪海平面波动作为物种分化驱动因子的作用机制复杂且尚未被充分阐明。本研究针对两块面积相当但受海平面波动影响模式不同的岛屿区域，开展种群分化与物种分化的平行比较分析，旨在阐明与海平面变化相关的微进化与宏进化动力学机制。本研究以波多黎各海台（Puerto Rico Bank, PRB）特有的7种Amphiacusta属地蟋蟀演化支为研究对象，利用其全基因组数据集（genome-wide datasets）开展分析，结果显示：与第四纪期间岛屿面积和连通性发生剧烈变化、当前已碎片化的东部PRB相比，未发生碎片化的西部PRB区域始终表现出更深的种间分化与更高的种群分化水平。我们还评估了与微进化过程（种群分裂、灭绝与融合）相关的多种备选假说，这些过程调控着PRB区域内完全成种事件的发生频率。研究结果表明，在群岛特征与类群特征的特定组合下，岛屿面积与连通性的反复变化，可能与学界假说中波动海平面的"物种泵（species pump）"效应相悖，产生相反的作用。本研究阐明了微进化视角如何能够补充当前关于岛屿生物多样性第四纪动态的宏生态学研究。