Polymorphism

Polymorphism ^[1] in biology is when two or more clearly different phenotypes exist in the same population of a species.^[2] The words forms or morphs are sometimes used.^[3]

Polymorphism is common in nature. The most common example is sexual dimorphism, which occurs in many organisms. Another example is sickle-cell anaemia.

In order to be classified as such, morphs must occupy the same habitat at the same time and belong to a population with random mating.^[4]

1. ↑ Greek: πολύ = many, and μορφή = form, figure, silhouette
2. ↑ Cite error: The named reference Ford1975 was used but no text was provided for refs named (see the help page).
3. ↑ Polymorphism as described here involves morphs of the phenotype. The term is also used somewhat differently by molecular biologists to describe certain point mutations in the genotype, such as SNPs (see also RFLPs). This usage is not discussed on this page.
4. ↑ Ford E.B. 1965. Genetic polymorphism. Faber & Faber, London.