AdaptationWhen selective pressures are placed on populations, natural selection causes certain traits to become more βfitβ than others. The variations with the greatest survival value will become more common in each successive generation. Genetic traits that give organisms a better chance at survival will be selected for, and traits that reduce the fitness of individuals will be selected against. This process is known as adaptation. Although there are many different definitions of this word, it has a specific meaning in evolutionary theory, and refers to genetics. Adaptation is a change in the genetics of a population with time. An individual cannot change its genetic makeup. Therefore, in evolutionary terms, an individual cannot adapt, only a population can.
Recall that earlier we defined evolution as a change with time, and here we are applying the same definition to adaptation. Evolution is used more often to describe the accumulation of changes or the formation of a new species via the processes of natural selection and adaptation.