Evolutionary origins of the gekkotan adhesive system

生物进化是一个由环境驱动的互动过程，生物体适应强加的变化。进化生物学家的任务是记录有机体如何以及以何种方式适应环境的挑战。在动物运动中，足部与基质之间的接触是生物与环境之间亲密而易处理关系的一个明显例子。这种相互作用可以在从宏观到纳米尺度的各个层面上进行探索。壁虎（通常统称为壁虎）以其高度发达的粘附系统而闻名，这种系统使它们能够轻松地在玻璃等表面上爬行。结合的极端强度，其反复附着和分离而不磨损或丧失性能的能力，以及其易于接合和分离，是需要深入了解的关键因素。调查技术的突破使我们能够更好地了解这些粘附能力是如何运作的，并导致了大规模的尝试，以综合模仿这些相互作用，为可能有利于人类开发的应用。壁虎是一个多样化的群体，由1000多种组成，其中大约一半缺乏或只有非常基本的粘附系统。这些“非粘性”物种为研究壁虎高度复杂的粘性系统是如何产生的，以及在什么样的环境条件下选择的提供了途径。对这种现象的进化进行调查是有用的，因为它既允许直接评估生物体与其环境之间的相互作用（“橡胶撞击道路”），也将提供如何最好地模仿系统的见解。至少从5400万年前开始，壁虎已经多次（多达10次）完善了它们的粘附系统。在这些不同的血统中，设计的相似程度允许评估对于这样一个系统的运作什么是必要的和充分的。这项研究计划的主旨是探索系统的基本计划，并研究我们如何模拟其结构和功能特性。

Organismic evolution is an interactive process driven by the environment, with organisms adjusting to imposed change. The task of the evolutionary biologist is to document how, and in what ways, the environment challenges the organism to adapt. One example of an intimate and tractable relationship between organisms and environment is evident in the contact between feet and the substrate in animal locomotion. Such an interaction can be explored at various levels, from the macro to the nano scale. Gekkotan lizards (commonly collectively referred to as geckos) are well known for their highly developed adhesive system that permits them to scale surfaces such as glass with seeming ease. The extreme strength of the bond, its ability to attach and detach repeatedly without wear or loss of capability, and its ease of engagement and disengagement, are critical factors that require deeper understanding. Breakthroughs in investigative techniques have enabled us to obtain a better understanding of how these adhesive capabilities operate, and have led to broad-scale attempts to mimic these interactions synthetically, for applications that might benefit human exploitation. Geckos are a diverse group, consisting of over 1000 species, about half of which either lack or possess only a very rudimentary adhesive system. These "non adhesive" species provide avenues to investigate how the highly complex adhesive system of geckos arose, and under what environmental circumstances it was selected for. Investigation of the evolution of such a phenomenon is useful because it both permits a direct appraisal of interaction between the organism and its environment (where the "rubber hits the road"), and will provides insights into how best to mimic the system. Gekkos have elaborated their adhesive system on several (as many as 10) occasions beginning at least 54 million years ago. The degree of similarity of design in these various lineages allows assessment of what is necessary and sufficient for the operation of such a system. The thrust of this research program explores the fundamental plan of the system and investigates how we can mimic its structural and functional properties.