Several theories predict that rates of phenotypic evolution should be related to the rate at which new lineages arise. However, drawing general conclusions regarding the coupling between these fundamental evolutionary rates has been difficult due to the inconsistent nature of previous results combined with uncertainty over the most appropriate methodology with which to investigate such relationships. Here we propose and compare the performance of several different approaches for testing associations between lineage-specific rates of speciation and phenotypic evolution using phylogenetic data. We then use the best-performing method to test relationships between rates of speciation and body size evolution in five major vertebrate clades (amphibians, birds, mammals, ray-finned fish and squamate reptiles) at two phylogenetic scales. Our results provide support for the long-standing view that rates of speciation and morphological evolution are generally positively related at broad macroevolutionary scales, but they also reveal a substantial degree of heterogeneity in the strength and direction of these associations at finer scales across the vertebrate tree of life.

一些理论预测，表型进化的速度应该与新谱系出现的速度有关。然而，由于先前结果的不一致性质以及调查这种关系的最合适方法的不确定性，很难得出关于这些基本进化速率之间耦合的一般结论。在这里，我们提出并比较了使用系统发育数据测试谱系特定物种形成率和表型进化之间关联的几种不同方法的性能。然后，我们使用性能最佳的方法在两个系统发育尺度上测试五种主要脊椎动物进化枝（两栖动物、鸟类、哺乳动物、鳍鱼和有鳞爬行动物）的物种形成率和体型进化之间的关系。