Center for Studies in Physics and Biology, Rockefeller University, New York, NY 10065, USA.
All Souls College, University of Oxford, Oxford, OX1 4AL, UK.
Integr Comp Biol. 2021 Sep 8;61(2):710-722. doi: 10.1093/icb/icab097.
Terrestrial animals must often negotiate heterogeneous, varying environments. Accordingly, their locomotive strategies must adapt to a wide range of terrain, as well as to a range of speeds to accomplish different behavioral goals. Studies in Drosophila have found that inter-leg coordination patterns (ICPs) vary smoothly with walking speed, rather than switching between distinct gaits as in vertebrates (e.g., horses transitioning between trotting and galloping). Such a continuum of stepping patterns implies that separate neural controllers are not necessary for each observed ICP. Furthermore, the spectrum of Drosophila stepping patterns includes all canonical coordination patterns observed during forward walking in insects. This raises the exciting possibility that the controller in Drosophila is common to all insects, and perhaps more generally to panarthropod walkers. Here, we survey and collate data on leg kinematics and inter-leg coordination relationships during forward walking in a range of arthropod species, as well as include data from a recent behavioral investigation into the tardigrade Hypsibius exemplaris. Using this comparative dataset, we point to several functional and morphological features that are shared among panarthropods. The goal of the framework presented in this review is to emphasize the importance of comparative functional and morphological analyses in understanding the origins and diversification of walking in Panarthropoda. Introduction.
陆地动物经常需要应对异质且多变的环境。因此，它们的运动策略必须适应广泛的地形，以及不同的速度，以实现不同的行为目标。在果蝇中的研究发现，步幅协调模式（ICPs）随步行速度平稳变化，而不是像脊椎动物那样在不同步态之间切换（例如，马在小跑和疾驰之间切换）。这种连续的步幅模式意味着不需要为每个观察到的 ICP 分别设置独立的神经控制器。此外，果蝇的步幅模式谱包括昆虫在向前行走过程中观察到的所有典型协调模式。这提出了一个令人兴奋的可能性，即果蝇中的控制器对于所有昆虫，甚至可能更普遍地对于所有节肢动物步行者都是通用的。在这里，我们调查并整理了一系列节肢动物物种在向前行走时的腿部运动学和腿部协调关系的数据，以及最近对缓步动物 Hypsibius exemplaris 的行为研究数据。使用这个比较数据集，我们指出了节肢动物之间共有的几个功能和形态特征。本综述中提出的框架的目标是强调比较功能和形态分析在理解节肢动物行走起源和多样化的重要性。引言。
