Phenotypic Plasticity

CORE DEFINITION

Phenotypic plasticity refers to the differences in phenotype (behavior, morphology, physiology) exhibited by an organism in response to unique environments. These differences encompass all types of environmentally induced changes, including morphological, physiological, behavioral, and phenological variations. Such changes may be permanent or temporary over the organism's lifetime. Originally, the term was used to describe the influence of development on morphological traits, but now it is more broadly applied to describe phenotypic differences resulting from environmental changes, such as acclimatization (adaptation) and learning. The phenomenon where environmental differences induce discontinuous phenotypes is also known as non-genetic polymorphism. Generally, phenotypic plasticity is more important for relatively sessile organisms such as plants. For most mobile organisms like animals, they can move away from unfavorable environments. Nevertheless, mobile organisms also exhibit a certain degree of phenotypic plasticity, at least in some aspects. The pea aphid (Acyrthosiphon pisum) demonstrates significant phenotypic plasticity: its reproductive mode can switch between asexual and sexual reproduction, and it can develop wings when the colony becomes too dense.