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.

Adaptation (stylized as Adaptation., with the period included) is a 2002 American comedy-drama metafilm directed by Spike Jonze and written by Charlie Kaufman. The film is based on Susan Orlean's non-fiction book The Orchid Thief, with numerous self-referential events added. The film stars Nicolas Cage as Charlie and Donald Kaufman, and Meryl Streep as Susan Orlean, Chris Cooper as John Laroche, with Cara Seymour, Brian Cox, Tilda Swinton, Ron Livingston and Maggie Gyllenhaal in supporting roles.