adaptions

Adaptations, also spelled adaptions, are heritable traits that increase the fitness of an organism in a particular environment. They arise through natural selection acting on genetic variation and are distinguished from acclimation, which is reversible phenotypic change to environmental conditions, and from exaptation, where a trait evolves for one function but is later co-opted for another.

Adaptations can be structural (anatomical features), behavioral (actions that improve survival or reproduction), physiological (internal processes), or genetic (influencing development or metabolism). They result in improved survival, reproduction, or dispersal under specific ecological circumstances. The same environment can select for different adaptations in related species, and unrelated lineages can converge on similar solutions, a phenomenon known as convergent evolution.

Examples include camouflage in prey species, beak shapes in Darwin’s finches, body plans that reduce water loss in desert animals, and resistance traits such as antibiotic resistance in bacteria or industrial melanism in moths. Adaptations can accumulate gradually over many generations, but some occur rapidly in response to strong selective pressures.

Adaptive traits often involve trade-offs and constraints, with benefits in one context potentially reducing performance in another. Local adaptation can lead to population differentiation and, over time, to speciation if gene flow remains limited.