polymorfism

Polymorfism, often written polymorphism in English, is a term used across several disciplines to denote the presence of multiple distinct forms within a single system or lineage. The root from Greek poly- meaning “many” and morphe meaning “form” describes a shared composition or underlying mechanism expressed in different ways.

In biology, genetic polymorphism refers to the occurrence of two or more discrete phenotypes or alleles in a population at appreciable frequency. This variation can influence traits such as coloration, metabolism, or disease resistance and plays a central role in evolution and population genetics. Classic examples include ABO blood groups in humans and color morphs in some species.

In chemistry and materials science, polymorphism describes substances that share the same chemical formula but crystallize into different structures. Different crystal forms can have distinct properties such as solubility, melting point, or stability, which is important for pharmacology and materials engineering. Carbon exists as graphite and diamond as polymorphs; pharmaceutical compounds often exhibit multiple polymorphs with implications for efficacy and manufacturability.

In computer science, polymorphism is the ability of a single interface or operation to work with multiple data types. It underpins object-oriented design and generic programming. There are several forms: subtype polymorphism (inheritance-based), parametric polymorphism (generics), and ad-hoc polymorphism (function or operator overloading). Dynamic versus static binding also shapes how and when the particular form is chosen at run time or compile time. Polymorphism enables code reuse, abstraction, and extensibility.