Developmental Exaptation

Abstract

Developmental exaptation is the process through which pre-existing characteristics of the developmental program facilitate evolutionary changes in development , by providing an internal environment that is conducive to a certain change. Developmental exaptation can be manifested at all levels of the developmental process, including gene regulation, cellular behavior, tissue differentiation, mor-phogenetic movement, relative timing of developmental events, and more. Developmental exaptation can facilitate changes in highly conserved, slowly evolving genes. It is the inherent prerequisite for cases of gene or gene network co-option in the evolution of development and is probably involved in many cases of evolutionary novelties.