Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil.
Département Adaptations du Vivant, UMR Mécanismes adaptatifs et évolution (MECADEV) Muséum National d'Histoire Naturelle/CNRS, Paris, France.
Syst Biol. 2020 Sep 1;69(5):962-972. doi: 10.1093/sysbio/syaa015.
Birds can use different types of gaits to move on the ground: they either walk, hop, or run. Although velocity can easily explain a preference for running, it remains unclear what drives a bird species to favor hopping over walking. As many hopping birds are relatively small and arboreal, we wanted to test the link between size, arboreality, and hopping ability. First, we carried out ancestral character state reconstructions of size range, hopping ability, and habitat traits on over 1000 species of birds. We found that both hopping ability and arboreality were derived and significantly correlated traits in avian evolution. Second, we tested the influence of hopping ability on the morphology of the lower appendicular skeleton by quantifying the shape differences of the pelvis and the three long bones of the hind limbs in 47 avian species with different habitats and gait preferences. We used geometric morphometrics on 3D landmarks, digitized on micro-computed tomography (micro-CT) and surface scans of the pelvis, femur, tibiotarsus, and tarsometatarsus. Locomotion habits significantly influence the conformation of the pelvis, especially at the origin of hip and knee muscle extensors. Interestingly, habitat, more than locomotion habits, significantly changed tarsometatarsus conformation. The morphology of the distal part of the tarsometatarsus constrains digit orientation, which leads to a greater ability to perch, an advantageous trait in arboreality. The results of this work suggest an arboreal origin of hopping and illuminate the evolution of avian terrestrial locomotion.[Anatomy; avian; gait; leg; lifestyle; pelvis; tree-dwelling.].
它们要么行走、跳跃，要么奔跑。虽然速度很容易解释为什么鸟类更喜欢奔跑，但仍不清楚是什么驱使某些鸟类物种更喜欢跳跃而不是行走。由于许多跳跃鸟类相对较小且生活在树上，我们想测试大小、树栖性和跳跃能力之间的联系。首先，我们对 1000 多种鸟类的体型范围、跳跃能力和栖息地特征进行了祖先特征状态重建。我们发现，跳跃能力和树栖性在鸟类进化中都是衍生的，并且是显著相关的特征。其次，我们通过量化 47 种具有不同栖息地和步态偏好的鸟类的下肢附肢骨骼的形状差异，测试了跳跃能力对下肢附肢骨骼形态的影响。我们使用了基于 3D 标记的几何形态测量学，这些标记是在微计算机断层扫描（micro-CT）和骨盆、股骨、胫骨和跗跖骨的表面扫描上数字化的。运动习惯显著影响骨盆的形态，特别是在髋关节和膝关节伸肌的起源处。有趣的是，与运动习惯相比，栖息地更显著地改变了跗跖骨的形态。跗跖骨远端的形态限制了趾的方向，这导致了更有利于树栖的栖息能力。这项工作的结果表明跳跃起源于树栖生活，并阐明了鸟类陆地运动的进化。[解剖学；鸟类；步态；腿部；生活方式；骨盆；树栖。]
