Life On a Limb: The Evolution of Locomotion in Arboreal Specialists

生态和进化生理学的一个重要目标是揭示栖息地利用差异背后的潜在机制。 对运动能力的研究在这一目标中发挥了关键作用，因为许多物种在使用不同栖息地的同时进化出了运动能力。 大多数关于运动的研究都是以相对简单的陆地栖息地为模型的（即，广泛的表面），因此对树栖物种来说在生态上是不现实的。 然而，了解如何在树栖栖息地（陡峭的斜坡，狭窄的鲈鱼直径）经常遇到的变量影响运动可以提供一般的见解专业化不同的栖息地。 巨大的形态和系统发育的蜥蜴利用树栖栖息地的多样性，使他们非常适合研究树栖运动。 我们建议建立在先前的工作与一组的八种阿诺利斯蜥蜴，因为他们的繁殖是很好的解决，这些物种已被定性为属于不同的生态形态，发生在不同的树栖生境。 在实验室研究中，这些阿诺利斯物种的短跑表现与肢体长度和表面直径相关，但实际上对肢体如何在不同表面和倾斜上使用一无所知。 因此，在实验室研究中，我们将进行三个实验：（1）检查倾斜和表面直径对三种Anolis蜥蜴的稳态速度运动学的影响。 (2)研究了8种阿诺利斯蜥蜴体表直径对稳态运动的影响。 第二个实验将为理解表面直径如何影响运动提供比较基础。 (3)研究加速度和性能如何受到一组不同Anolis物种的表面直径的影响。 总之，这些实验将揭示为什么一些变色龙物种会受到倾斜的影响，而另一些则不会。 此外，他们将提供一个有价值的联系栖息地利用和数量功能形态。 更一般地说，我们还将测试功能，形态和栖息地的使用是否在物种之间共同进化，以及在树栖环境中的运动是否与陆地环境中的运动不同。 第二个目标将通过比较拟议的实验数据，最近进行的陆生蜥蜴运动。

An important goal in ecological and evolutionary physiology is to reveal the underlying mechanisms behind differences in habitat use. Studies of locomotor capacity have played a key role in this goal because many species have evolved locomotor abilities in concert with the use of different habitats. Most studies of locomotion are modeled after relatively simple terrestrial habitats (i.e., broad surfaces), and therefore are not ecologically realistic for arboreal species. However, understanding how variables commonly encountered in arboreal habitats (steep inclines, narrow perch diameters) affect locomotion could provide general insights into specialization to different habitats. The tremendous morphological and phylogenetic diversity of lizards exploiting arboreal habitats makes them ideally suited for studying arboreal locomotion. We propose to build on prior work with a group of eight species of Anolis lizards because their phylogeny is well resolved and these species have been characterized as belonging to distinct ecomorphs that occur in different arboreal habitats. The sprinting performance of these Anolis species has been correlated with limb length and the diameters of surfaces in laboratory studies, but virtually nothing is known regarding how the limbs are used on different surfaces and inclines. Thus, in laboratory studies we will conduct three experiments: (1) Examine the effects of incline and surface diameter on the kinematics of steady-speed locomotion in three species of Anolis lizards. (2) Focus on the effects of surface diameter on the kinematics of steady-speed locomotion in 8 species of Anolis lizards. This second experiment will provide a comparative basis for understanding how surface diameter affects locomotion. (3) Study how acceleration and performance is affected by surface diameter for a group of diverse Anolis species. Together, these experiments will reveal the underlying mechanistic and behavioral bases for why some anole species are affected by incline while others are not. Further, they will provide a valuable link between habitat use and quantitative functional morphology. More generally, we will also test whether function, morphology, and habitat use have co-evolved among species, and whether locomotion in arboreal environments differs from locomotion in terrestrial environments. The second goal will be achieved by comparing data from the proposed experiments to those recently performed on terrestrial lizard locomotion.