Data from: Speciation has a spatial scale that depends on levels of gene flow

Area is generally assumed to affect speciation rates, but work on the spatial context of speciation has focused mostly on patterns of range overlap between emerging species rather than on questions of geographical scale. A variety of geographical theories of speciation predict that the probability of speciation occurring within a given region should (1) increase with the size of the region and (2) increase as the spatial extent of intraspecific gene flow becomes smaller. Using a survey of speciation events on isolated oceanic islands for a broad range of taxa, we find evidence for both predictions. The probability of in situ speciation scales with island area in bats, carnivorous mammals, birds, flowering plants, lizards, butterflies and moths, and snails. Ferns are an exception to these findings, but they exhibit high frequencies of polyploid and hybrid speciation, which are expected to be scale independent. Furthermore, the minimum island size for speciation correlates across groups with the strength of intraspecific gene flow, as is estimated from a meta‐analysis of published population genetic studies. These results indicate a general geographical model of speciation rates that are dependent on both area and gene flow. The spatial scale of population divergence is an important but neglected determinant of broad‐scale diversity patterns.区域面积通常被认为会影响物种形成（speciation）速率，但现有关于物种形成空间背景的研究，大多聚焦于新兴物种间的分布重叠模式，而非地理尺度相关的核心问题。多种物种形成的地理理论预测，给定区域内发生物种形成的概率应满足两项规律：其一，随区域面积增大而升高；其二，随种内基因流（intraspecific gene flow）的空间范围缩小而提升。我们通过对广泛类群（taxa）的孤立大洋岛屿上的物种形成事件开展调研，为这两项预测提供了实证支持。在蝙蝠、食肉目哺乳动物、鸟类、显花植物、蜥蜴、鳞翅目昆虫（蝶与蛾）以及蜗牛类群中，原地物种形成（in situ speciation）的概率均随岛屿面积呈正相关关系。蕨类植物是这一规律的例外，但其物种形成多依赖多倍化与杂交过程，这类物种形成机制理论上不受地理尺度的影响。此外，通过对已发表种群遗传学研究的元分析（meta-analysis）估算得到的种内基因流强度，在不同类群间与物种形成所需的最小岛屿面积呈显著相关。上述结果表明，存在一个同时依赖区域面积与基因流的普适性物种形成速率地理模型。种群分化的空间尺度是调控大尺度多样性格局的重要但被广泛忽视的决定因素。