There are two categories of Adaptation. One is called Obligate or Fixed Adaptation. The other is Facultative Adaptation.
Fixed adaptations are determined by predisposing factors and are fixed, no matter the environment. Facultative adaptations, on the other hand, is sensitive to environmental variation. It is often described as "If-then" set-ups. Lifestyle changes that a human being makes in order to fit into a particular environment is a prime example of Facultative Adaptation.