Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA.
W.M. Keck Science Department, Claremont McKenna, Scripps, and Pitzer Colleges, Claremont, CA 91711, USA.
Integr Comp Biol. 2019 Aug 1;59(2):443-455. doi: 10.1093/icb/icz092.
Terrestrial animals move in complex habitats that vary over space and time. The characteristics of these habitats are not only defined by the physical environment, but also by the photic environment, even though the latter has largely been overlooked. For example, numerous studies of have examined the role of habitat structure, such as incline, perch diameter, and compliance, on running performance. However, running performance likely depends heavily on light level. Geckos are an exceptional group for analyzing the role of the photic environment on locomotion as they exhibit several independent shifts to diurnality from a nocturnal ancestor, they are visually-guided predators, and they are extremely diverse. Our initial goal is to discuss the range of photic environments that can be encountered in terrestrial habitats, such as day versus night, canopy cover in a forest, fog, and clouds. We then review the physiological optics of gecko vision with some new information about retina structures, the role of vision in motor-driven behaviors, and what is known about gecko locomotion under different light conditions, before demonstrating the effect of light levels on gecko locomotor performance. Overall, we highlight the importance of integrating sensory and motor information and establish a conceptual framework as guide for future research. Several future directions, such as understanding the role of pupil dynamics, are dependent on an integrative framework. This general framework can be extended to any motor system that relies on sensory information, and can be used to explore the impact of performance features on diversification and evolution.
陆生动物在空间和时间上都在复杂的栖息地中移动。这些栖息地的特征不仅由物理环境决定，还由光环境决定，尽管后者在很大程度上被忽视了。例如，许多研究已经研究了栖息地结构（如坡度、栖木直径和顺应性）对奔跑性能的作用。然而，奔跑性能可能高度依赖于光水平。壁虎是分析光环境对运动影响的一个特殊群体，因为它们从夜间祖先中独立进化出了几种昼行性，它们是视觉导向的捕食者，而且种类非常多样。我们的初步目标是讨论在陆生栖息地中可能遇到的各种光环境，如白天与黑夜、森林中的树冠覆盖、雾和云。然后，我们回顾了壁虎视觉的生理光学，包括一些关于视网膜结构的新信息、视觉在运动驱动行为中的作用，以及在不同光照条件下对壁虎运动的了解，然后展示光照水平对壁虎运动性能的影响。总的来说，我们强调了整合感觉和运动信息的重要性，并建立了一个概念框架，作为未来研究的指南。几个未来的方向，如理解瞳孔动态的作用，都依赖于一个综合的框架。这个通用框架可以扩展到任何依赖感觉信息的运动系统，并用于探索性能特征对多样化和进化的影响。
