Convergent Evolution of Manual and Pedal Grasping Capabilities in Tetrapods

Abstract

Grasping behavior and manipulation using the hand and/or foot is wide- spread among tetrapods and can be used in various contexts in the daily life of many species. Activities such as feeding and movement through the environment may be assisted by grasping. Well-defined digits and digital musculature are synapomorphies of the tetrapod clade and from this foundation other features, such as opposable digits and tendon configurations, have evolved independently in many lineages. The evolutionary transitions leading to grasping and manipulative behaviors are complex and require better understanding. Here we survey the evolution of grasping autopodia and their forms and functions across four major tetrapod clades, revealing that the underlying morphological bases and ecological factors may differ among tetrapods. Further interdisciplinary approaches, including eco-ethology, morphology, biomechanics, ontogeny, and even genetics, relating to grasping form and function within and among tetrapods must be developed for a better understandng of the role that object/substrate/food grasping abilities play in the evolutionary success of several tetrapod lineages.