# Heritable Variation > **Machine-Evolution Nexus:** [[articles/Digital Darwinism and the Invisible World of Machine Evolution|Digital Darwinism and the Invisible World of Machine Evolution]] places this concept within the history and governance of substrate-independent evolution. **Domain:** Evolution / Inheritance **Doc Type:** Canonical Wiki Node **Maturity:** Developed ## Definition Heritable variation is transmissible difference among descendants: variants differ from one another, and at least some of those differences can pass into later generations. ## Machine-Evolution Context It supplies the variation on which selection can act. In digital systems it may arise through copy errors, mutation operators, recombination or altered executable descriptions. ## Continuity and Evidence Boundary Variation alone is not evolution, and change to a running instance is not necessarily heritable. The modification must enter the channel that produces descendants. ## Relationships [[wiki/Heredity|Heredity]], [[wiki/Mutation|Mutation]], [[wiki/Genetic Recombination|Genetic Recombination]], [[wiki/Differential Reproductive Success|Differential Reproductive Success]] ## Sources / Provenance - Richard Lewontin, “The Units of Selection” (1970); standard population-genetics usage.