Feeding ecology has a stronger evolutionary influence on functional morphology than on body mass in mammals

Ecological specialization is a central driver of adaptive evolution. However, selective pressures may uniquely affect different ecomorphological traits (e.g., size and shape), complicating efforts to investigate the role of ecology in generating phenotypic diversity. Comparative studies can help remedy this issue by identifying specific relationships between ecologies and morphologies, thus elucidating functionally-relevant traits. Jaw shape is a dietary correlate that offers considerable insight on mammalian evolution, but few studies have examined the influence of diet on jaw morphology across mammals. To this end, I apply phylogenetic comparative methods to mandibular measurements and dietary data for a diverse sample of mammals. Especially powerful predictors of diet are metrics that capture either the size of the angular process, which increases with greater herbivory, or the length of the posterior portion of the jaw, which decreases with greater herbivory. The size of the angular...

生态特化是适应性进化的核心驱动因子。然而，选择压力会对不同的生态形态性状（ecomorphological traits）产生独特影响，这使得探究生态在表型多样性产生过程中所扮演角色的研究变得复杂。比较研究可通过识别生态与形态之间的特定关联来解决这一问题，进而阐明具有功能相关性的性状。颌骨形态是与食性相关的特征，能够为哺乳动物演化提供重要见解，但目前鲜有研究探讨全哺乳动物类群中食性对颌骨形态的影响。为此，本研究将系统发育比较方法（phylogenetic comparative methods）应用于涵盖多样类群的哺乳动物下颌测量数据与食性数据。能够有效预测食性的关键指标包括：随植食性程度升高而增大的角突（angular process）尺寸，以及随植食性程度升高而减小的下颌后部长度。角突的……