Island biodiversity has long fascinated biologists as it typically presents tractable systems for unpicking the eco‐evolutionary processes driving community assembly. In general, two recurring themes are of central theoretical interest. First, immigration, diversification, and extinction typically depend on island geographical properties (e.g., area, isolation, and age). Second, predictable ecological and evolutionary trajectories readily occur after colonization, such as the evolution of adaptive trait syndromes, trends toward specialization, adaptive radiation, and eventual ecological decline. Hypotheses such as the taxon cycle draw on several of these themes to posit particular constraints on colonization and subsequent eco‐evolutionary dynamics. However, it has been challenging to examine these integrated dynamics with traditional methods. Here, we combine phylogenomics, population genomics and phenomics, to unravel community assembly dynamics among Pheidole (Hymenoptera, Formicidae) ants in the isolated Fijian archipelago. We uphold basic island biogeographic predictions that isolated islands accumulate diversity primarily through in situ evolution rather than dispersal, and population genomic support for taxon cycle predictions that endemic species have decreased dispersal ability and demography relative to regionally widespread taxa. However, rather than trending toward island syndromes, ecomorphological diversification in Fiji was intense, filling much of the genus‐level global morphospace. Furthermore, while most endemic species exhibit demographic decline and reduced dispersal, we show that the archipelago is not an evolutionary dead‐end. Rather, several endemic species show signatures of population and range expansion, including a successful colonization to the Cook islands. These results shed light on the processes shaping island biotas and refine our understanding of island biogeographic theory.

中文翻译：

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岛屿蚂蚁群落组装的基因组学和表型学分析。

岛屿生物多样性长期以来一直使生物学家着迷，因为它通常会提供易于处理的系统来识别推动社区聚集的生态进化过程。通常，两个重复出现的主题具有重要的理论意义。首先，移民，多样化和灭绝通常取决于岛屿的地理属性（例如，面积，孤立性和年龄）。其次，定居后很容易发生可预测的生态和进化轨迹，例如适应性状综合症的进化，专业化趋势，适应性辐射以及最终的生态衰退。诸如分类群循环之类的假设利用了其中的几个主题，对殖民化和随后的生态进化动力学施加了特殊的约束。但是，用传统方法检查这些集成动力学一直是一个挑战。id（膜翅目，甲虫）蚂蚁在孤立的斐济群岛中。我们支持基本的岛屿生物地理学预测，即孤立的岛屿主要通过原地进化而不是通过扩散来积累多样性，并且种群基因组学支持分类群周期预测，即相对于区域广泛的分类群而言，特有物种降低了扩散能力和人口统计学。但是，斐济并没有趋向于岛屿综合症，而是在生态形态上非常多样化，充满了属类的全球形态空间的大部分。此外，虽然大多数特有物种的人口数量减少且散布减少，但我们表明该群岛并非进化的死胡同。相反，一些特有物种显示出种群和范围扩大的特征，包括成功地定居到库克群岛。