GARD 1.5 range shapefiles used in: Global diversity patterns are explained by diversification rates at ancient, not shallow, timescales

Explaining global species richness patterns is a “Holy Grail” of ecology and evolution. These richness patterns are often attributed to spatial variation in diversification rates (speciation minus extinction). Surprisingly, prominent studies of birds, fish, and angiosperms reported higher diversification rates at higher latitudes (mismatched with richness). Yet these studies only examined diversification rates at relatively recent timescales. Here, we quantify global richness patterns among lizard and snake species (10,213; 94%) and explore their underlying causes. We found that diversification rates at more recent timescales in squamates also show mismatched patterns of rates and richness. However, diversification rates at deeper timescales were positively related to richness. These observations may help resolve the paradoxical results of previous studies. Remarkably, these diversification patterns are largely unrelated to climate. Instead, higher tropical richness is related to ancien...

阐释全球物种丰富度格局是生态学与进化生物学领域的「圣杯」级研究课题。这类物种丰富度格局通常被归因于分化速率（即物种形成速率减去灭绝速率）的空间异质性。令人意外的是，针对鸟类、鱼类和被子植物（Angiosperms）的多项具有影响力的研究均报道，高纬度地区的分化速率更高——这与物种丰富度的分布格局相悖。但此类研究仅考察了相对较近时间尺度下的分化速率。本研究对蜥蜴与蛇类共10213个物种（占现存类群的94%）的全球物种丰富度格局进行了定量分析，并探讨其背后的成因。研究发现，有鳞类（Squamata）在更近时间尺度下的分化速率同样呈现出速率与丰富度分布不匹配的格局；然而，更深时间尺度下的分化速率则与物种丰富度呈正相关关系。上述发现或有助于解决以往研究中出现的矛盾结论。值得注意的是，此类分化格局在很大程度上与气候无关；相反，热带地区更高的物种丰富度与古...