Evolution of unique skull morphology and function in Lagomorphs: a combined effect of locomotion and mastication?

背景：哺乳动物已经进化出不同的颅面形态，以适应广泛的生态位。然而，驱动颅骨进化的因素和进化变化的机制尚不完全清楚。现代狐尾类动物（兔子和野兔）的头骨与其他哺乳动物相比有很大的不同，因为它在结构上专门用于颅内运动或颅运动。虽然颅骨运动在爬行类等脊椎动物中很常见，但leporids是唯一一种进化出这种特殊颅骨修饰的哺乳动物。早期的研究表明，在与运动相关的冲击过程中，颅骨运动作为一种减震机制来消散动能。然而，这还没有经过检验。在这个项目中，我们将研究影响高度修饰的leporid头骨进化的内在和外在因素，包括功能（生物力学），生态和环境因素（气候）方面，并关注宏观进化尺度过程，以更好地了解最不寻常和最成功的哺乳动物群体之一。目的：我们的目标是通过应用复杂的计算方法，如有限元分析、x射线双平面分析（运动学）和几何形态计量学，探索饮食、运动、进化史和其他因素（如气候）如何影响lagomorph头骨形状和功能的进化。新颖性：由于计算分析的结果，对不同分类群的形态和功能进行检查和量化的能力，而不是单纯地限定，已经大大提高了。我们将结合尖端技术来了解最常见和最成功的哺乳动物群体之一的高度修饰和独特的颅骨特征的演变。时效性：最近对生物多样性价值的认识需要对形态多样性进行分析，这有助于我们对生态学、保护和进化的理解。这是一个理想的时机，汇集先进的方法来考虑对头骨进化的各种影响，如生态学，系统发育约束和功能，如何塑造哺乳动物的多样化，特别是足形动物的成功。

Background: Mammals have evolved diverse craniofacial morphology to adapt to a wide range of ecological niches. However, the factors driving skull evolution and the mechanisms of evolutionary change are not fully understood. The skull of modern leporid lagomorphs (rabbits and hares) is highly modified from other mammals as it is structurally specialised for providing intracranial movement, or cranial kinesis. While cranial kinesis is common in vertebrates such as reptiles, leporids are the only mammals to have evolved this specialised cranial modification. Early studies have suggested that cranial kinesis functions as a shock-absorbing mechanism to dissipate kinetic energy during impacts associated with locomotion. However, this has not been tested. In this project, we will examine intrinsic and extrinsic factors impacting the evolution of the highly modified leporid skull, encompassing aspects of function (biomechanics), ecology, and environmental factors (climate) and focusing on macroevolutionary-scale processes, to get a better understanding of one of the most unusual and successful mammal groups.Objectives: Our objective is to explore how diet, locomotion, evolutionary history, and other factors (e.g. climate) influence the evolution of lagomorph skull shape and function, through the application of sophisticated computational methods such as finite element analysis, x-ray biplanar analysis (kinematics) and geometric morphometrics. Novelty: The ability to examine and quantify, rather than purely qualify, morphology and function across taxa has greatly increased as a result of computational analyses. We will combine cutting edge technology to understand the evolution of a highly modified and unique cranial feature in one of the most common and successful mammal groups. Timeliness: Recent recognitions of the value of biodiversity require analysis of the morphological diversity which informs our understanding of ecology, conservation and evolution. This is an ideal time to bring together advanced methods to consider how the various influences on skull evolution, such as ecology, phylogenetic constraint and function, have shaped the diversification of mammals, and the success of lagomorphs in particular.