Data from: Rapid diversification and time explain amphibian 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地区（biodiversity hotspot）。然而，造就这一非凡物种丰富度的生态与进化过程仍不明朗。本研究以蛙类为模式类群，探究了安第斯山脉相较于南美洲其他区域、以及安第斯山脉内部不同海拔梯度下高物种丰富度的形成机制。本研究整合了分布数据、新构建的涵盖2318个蛙类物种的时间校准系统发育树（time-calibrated phylogeny），以及系统发育比较分析方法（phylogenetic comparative methods），以检验分化速率（diversification rates）与定殖时间（colonization times）在解释不同尺度下安第斯山地多样性格局中的相对重要性。在大尺度下（区域间与科间），我们发现安第斯支系（clades）中更快的分化速率最可能解释安第斯山脉的高物种丰富度。与之相反，在较小的时空尺度下（安第斯山脉内部的科级支系间），分化速率几乎无法解释物种丰富度格局。取而代之的是，我们发现定殖时间对塑造安第斯山脉内部的海拔梯度丰富度格局至关重要：越早被定殖的生境中物种数量越多。我们认为这类依赖于尺度的格局可能广泛适用于其他众多丰富度梯度研究。认识到这种尺度依赖性，有助于调和不同生境、区域与类群间丰富度格局研究中存在的矛盾结论。