In biology, an adaptation, also called an adaptive trait, is a trait with a current functional role in the life of an organism that is maintained and evolved by means of natural selection. Adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation. Adaptations enhance the fitness and survival of individuals. Organisms face a succession of environmental challenges as they grow and develop and are equipped with an adaptive plasticity as the phenotype of traits develop in response to the imposed conditions. The developmental norm of reaction for any given trait is essential to the correction of adaptation as it affords a kind of biological insurance or resilience to varying environments.
In behavioral ecology, an adaptive behavior is a behavior which contributes directly or indirectly to an individual's survival or reproductive success and is thus subject to the forces of natural selection.[1] Examples include favoring kin in altruistic behaviors, female selection of the most fit male, and defending a territory or harem from rivals.
Conversely, a non-adaptive behavior is a behavior or trait that is counterproductive to an individual's survival or reproductive success. These might include altruistic behaviors which do not favor kin, adoption of unrelated young, and being a subordinate in a dominance hierarchy.
Adaptations are commonly defined as evolved solutions to recurrent environmental problems of survival and reproduction.[2] Individual differences commonly arise through both heritable and nonheritable adaptive behavior. Both have been proven to be influential in the evolution of species adaptive behaviors, although heritable adaptation remains a controversial subject.[2]