Data from: Assembling a species–area curve through colonization, speciation and human-mediated introduction

Aim: The fundamental biogeographical processes of colonization, speciation and extinction shape island biotas in space–time. On oceanic islands, area and isolation affect these processes and resulting biodiversity patterns. In the Anthropocene, a new human-mediated colonization dynamic is altering insular ecosystems world-wide. Here, we test predictions about the roles of archipelago area and isolation in structuring ant diversity patterns through effects on both natural and anthropogenic biogeographical processes. Location: Tropical Pacific islands. Methods: We compiled a comprehensive data set of ant faunal compositions across tropical Pacific archipelagos. Using regression analysis we evaluated the bivariate and interactive effects of area and isolation on the number of colonizing lineages, native species, endemic species, exotic species and total richness in the archipelago. Results: There is a strong species–area effect and a much more modest isolation effect on total ant species richness across the Pacific archipelagos. The number of colonizing lineages of each archipelago is strongly driven by the isolation of the archipelago. Endemic species are present in large archipelagos of low and intermediate isolation. The most remote archipelagos are nearly devoid of endemic lineages and their ant faunas are largely composed of Pacific Tramp species and exotics brought from outside the Pacific region. Main conclusions: The prominent species–area curve in Pacific ants emerged over time through multiple processes. The colonization of lineages is determined primarily by isolation, with few or no lineages reaching remote archipelagos. Cladogenesis mediates the isolation effect and increases the area effect through the differential radiation of lineages in large archipelagos. In the Anthropocene, the assembly of the species–area relationship has accelerated dramatically through human-mediated colonization. Overall, our results support a view that species–area curves reflect regulating limits on species richness that scale with area, but that multiple biogeographical processes can occur to achieve these limits.

研究目标：定殖、物种形成与灭绝这三大核心生物地理学过程，塑造了岛屿生物群的时空分布格局。在大洋岛屿中，岛屿面积与隔离度会影响上述过程，并最终决定生物多样性模式。在人类世（Anthropocene），由人类介导的全新定殖动态正在全球范围内改变岛屿生态系统。本研究旨在检验关于群岛面积与隔离度，如何通过作用于自然与人为生物地理学过程，进而调控蚂蚁多样性格局的相关预测。
研究区域：热带太平洋岛屿。
研究方法：本研究整合了横跨热带太平洋各群岛的蚂蚁区系组成综合数据集。通过回归分析，我们评估了面积与隔离度的单变量及交互作用，对群岛内定殖谱系数、本土物种数、特有物种数、外来物种数以及总物种丰富度的影响。
研究结果：太平洋群岛的蚂蚁总物种丰富度存在显著的物种-面积效应，而隔离度效应则相对微弱。各群岛的定殖谱系数量主要受其隔离度驱动。特有物种多见于隔离度处于中等与较低水平的大型群岛。最为偏远的群岛几乎无特有谱系分布，其蚂蚁区系主要由太平洋漫游物种（Pacific Tramp species）以及源自太平洋以外的外来物种构成。
主要结论：太平洋蚂蚁类群显著的物种-面积关系，是通过多重过程逐步形成的。谱系定殖主要受隔离度调控，仅有极少数谱系能够抵达偏远群岛。分支成种（cladogenesis）介导了隔离度效应，并通过大型群岛内谱系的差异化辐射，强化了面积效应。在人类世（Anthropocene），由人类介导的定殖过程极大加速了物种-面积关系的构建。总体而言，本研究结果支持如下观点：物种-面积曲线反映了随面积缩放的物种丰富度调控上限，但实现此类上限的生物地理学过程存在多重路径。