Concept

Exaptation

Summary
Exaptation and the related term co-option describe a shift in the function of a trait during evolution. For example, a trait can evolve because it served one particular function, but subsequently it may come to serve another. Exaptations are common in both anatomy and behaviour. Bird feathers are a classic example. Initially they may have evolved for temperature regulation, but later were adapted for flight. When feathers were first used to aid in flight, that was an exaptive use. They have since then been shaped by natural selection to improve flight, so in their current state they are best regarded as adaptations for flight. So it is with many structures that initially took on a function as an exaptation: once molded for a new function, they become further adapted for that function. Interest in exaptation relates to both the process and products of evolution: the process that creates complex traits and the products (functions, anatomical structures, biochemicals, etc.) that may be imperfectly developed. The term "exaptation" was proposed by Stephen Jay Gould and Elisabeth Vrba, as a replacement for 'pre-adaptation', which they considered to be a teleologically loaded term. The idea that the function of a trait might shift during its evolutionary history originated with Charles Darwin (). For many years the phenomenon was labeled "preadaptation", but since this term suggests teleology in biology, appearing to conflict with natural selection, it has been replaced by the term exaptation. The idea had been explored by several scholars when in 1982 Stephen Jay Gould and Elisabeth Vrba introduced the term "exaptation". However, this definition had two categories with different implications for the role of adaptation. (1) A character, previously shaped by natural selection for a particular function (an adaptation), is coopted for a new use—cooptation. (2) A character whose origin cannot be ascribed to the direct action of natural selection (a nonaptation), is coopted for a current use—cooptation.
About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.