Common evolutionary trends underlie the four-bar linkage systems of sunfish and mantis shrimp

Comparative biomechanics offers an opportunity to explore the evolution of disparate biological systems that share common underlying mechanics. Four-bar linkage modelling has been applied to various biological systems such as fish jaws and crustacean appendages to explore the relationship between biomechanics and evolutionary diversification. Mechanical sensitivity states that the functional output of a mechanical system will show differential sensitivity to changes in specific morphological components. We document similar patterns of mechanical sensitivity in two disparate four-bar systems from different phyla: the opercular four-bar system in centrarchid fishes and the raptorial appendage of stomatopods. We built dynamic linkage models of 20 centrarchid and 36 stomatopod species and used phylogenetic generalized least squares regression (PGLS) to compare evolutionary shifts in linkage morphology and mechanical outputs derived from the models. In both systems, the kinematics of the fou...比较生物力学（Comparative biomechanics）为探究共享底层力学机制的不同生物类群的演化提供了契机。四杆连杆建模（four-bar linkage modelling）已被应用于鱼类颌骨、甲壳类附肢等多种生物系统，以探究生物力学与演化多样化之间的关联。机械敏感性（Mechanical sensitivity）理论指出，机械系统的功能输出会对特定形态组分的变化表现出差异化敏感性。本研究记录了来自不同门类的两类迥异四杆系统中相似的机械敏感性模式：分别为棘臀鱼科鱼类的鳃盖四杆系统，以及口足类动物的捕食附肢。我们构建了20种棘臀鱼科鱼类与36种口足类动物的动态连杆模型，并采用系统发育广义最小二乘回归（PGLS），对比分析了模型推导的连杆形态与机械输出的演化变化。在两类系统中，四杆的运动学...