Data from: Rapid diversification and time explain amphibian species richness at different scales in the Tropical Andes, Earth's most biodiverse hotspot

The Tropical Andes are Earth's most species-rich biodiversity hotspot for both animals and plants. Nevertheless, the ecological and evolutionary processes underlying this extraordinary richness remain uncertain. Here, we examine the processes that generate high richness in the Andes relative to other regions in South America, and across different elevations within the Andes, using frogs as a model system. We combine distributional data, a newly generated time-calibrated phylogeny for 2318 frog species, and phylogenetic comparative methods to test the relative importance of diversification rates and colonization times for explaining Andean diversity at different scales. At larger scales (among regions and families), we find that faster diversification rates in Andean clades most likely explain high Andean richness. In contrast, at smaller temporal and spatial scales (within family-level clades, within the Andes), diversification rates rarely explain richness patterns. Instead, we show that colonization times are important for shaping elevational richness patterns within the Andes, with more species found in habitats colonized earlier. We suggest that these scale-dependent patterns might apply to many other richness gradients. Recognition of this scale-dependence may help to reconcile conflicting results among studies of richness patterns across habitats, regions, and organisms.

热带安第斯山脉是全球动植物物种最为丰富的生物多样性热点区域。然而，支撑这一非凡物种丰富度的生态与演化过程仍未明确。本研究以蛙类作为模式系统，探究了相较于南美洲其他区域，安第斯山脉内部不同海拔梯度下造就高物种丰富度的相关过程。我们整合分布数据、全新构建的2318个蛙类物种时间校准系统发育树，以及系统发育比较分析方法，用以检验不同尺度下，分化速率与定殖时间在解释安第斯山脉物种多样性时的相对重要性。在大尺度下（跨区域与科间），我们发现安第斯支系更快的分化速率最有可能解释安第斯山脉的高物种丰富度。与之相反，在安第斯山脉内部的科级支系这一较小时空尺度下，分化速率极少能解释物种丰富度格局。取而代之的是，我们证实定殖时间是塑造安第斯山脉内部海拔物种丰富度格局的关键因素：越早被定殖的生境，其物种种数往往越多。我们认为，这类尺度依赖性格局或许适用于诸多其他物种丰富度梯度。认识到这种尺度依赖性，有助于调和不同生境、区域与类群间物种丰富度格局研究中存在的矛盾结论。