Data from: Body size evolution in mammals: complexity in tempo and mode

Body size correlates with virtually every aspect of species' biology, so understanding the tempo and mode of its evolution is of key importance in macroecology and macroevolution. Here we use body-mass data from 3473 of 4510 extant mammalian species and an almost complete species-level phylogeny to determine the best model of log(body-mass) evolution across all mammals, split taxonomically and spatially. An early-burst model fits better across all mammals than models based on either Brownian motion or an Ornstein-Uhlenbeck process, suggesting that mammals experienced a burst of morphological evolution relatively early in their history followed by slower change subsequently. We also use spatial models to investigate rates of body-mass evolution within ecoregions. These models show that around 50% of the variation in rate can be explained by just a few predictors. High estimated rates are associated with cold, low lying, species-poor, high energy, mainland ecoregions. We conclude that the evolution of mammalian body size has been influenced by a complex interplay among geography, climate and history.体型几乎与物种生物学的所有维度均存在关联，因此阐明其演化的速率与模式，在宏生态学（macroecology）与宏演化（macroevolution）研究中具有核心重要性。本研究采用4510种现存哺乳动物物种中3473种的体质量（body-mass）数据，以及近乎完整的物种水平系统发育树（species-level phylogeny），以确定横跨全部哺乳动物类群的体质量对数（log(body-mass)）演化最优模型，并按分类学与空间维度开展拆分分析。早爆发模型（early-burst model）对所有哺乳动物类群的拟合效果优于基于布朗运动（Brownian motion）或奥恩斯坦-乌伦贝克过程（Ornstein-Uhlenbeck process）的模型，这意味着哺乳动物在演化历史早期曾经历一轮形态演化爆发，后续的演化变化则趋于平缓。我们还借助空间模型探究了各生态区（ecoregions）内体质量演化的速率。此类模型显示，演化速率约50%的变异仅可通过少数预测变量加以解释。高估算演化速率与寒冷、低海拔、物种贫乏、高能量的大陆生态区显著相关。本研究最终得出结论：哺乳动物体型的演化受到地理、气候与历史因素之间复杂的相互作用共同调控。