Darwinism

Definition

The theory of biological evolution through natural selection, originally formulated by Charles Darwin (1809–1882), in which heritable variation among individuals leads to differential survival and reproduction, gradually producing adaptation and, over sufficient time, speciation. In modern usage, the term sometimes broadly encompasses neo-Darwinism (the synthesis of natural selection with Mendelian genetics) or, more narrowly, denotes Darwin's original formulation distinct from subsequent evolutionary developments.

Etymology

Coined by Thomas Henry Huxley in April 1860, from the surname of Charles Darwin + -ism (suffix denoting a theory or school of thought).

Example

In stick insects (Phasmatodea), Darwinism explains how leaf-mimicry evolves: individuals with more leaf-like appearance survive predation at higher rates, passing cryptic coloration traits to offspring until populations become highly specialized mimics.

Synonyms

• Darwinian theory
• Darwinianism

Related Terms

• Natural selection
• neo-Darwinism
• modern evolutionary synthesis
• Adaptation
• cryptic speciation
• Lamarckism

Usage Notes

Specialists often prefer 'modern evolutionary synthesis' or simply 'evolutionary biology' for contemporary theory, reserving 'Darwinism' for historical context or to emphasize natural selection specifically. The term is sometimes misused in non-biological contexts (e.g., 'social Darwinism') or conflated with evolution generally. Contrast with Lamarckism, which proposed inheritance of acquired characteristics rather than selection on existing variation.