In evolution, a maladaptation (/ˌmælædæpˈteɪʃən/) is a trait that is (or has become) more harmful than helpful, in contrast with an adaptation, which is more helpful than harmful. All organisms, from bacteria to humans, display maladaptive and adaptive traits. Like adaptation, maladaptation may be viewed as occurring over geological time, or within the lifetime of one individual or a group.
Maladaptation can arise when adaptations to environmental challenges have unintended harmful effects by either decreasing the current fitness of the organism or creating new risks which may decrease survivability. This could be caused by changes in trait distribution from genetic loading, exogenous environmental changes in the fitness landscape, or feedback in eco-plasticity, altering the fitness landscape.
