# Mutation Rate
> **Machine-Evolution Nexus:** [[articles/Digital Darwinism and the Invisible World of Machine Evolution|Digital Darwinism and the Invisible World of Machine Evolution]] places this node within the history and governance of substrate-independent evolution.
**Domain:** Evolution / Population Genetics
**Doc Type:** Canonical Wiki Node
**Maturity:** Developed
## Definition
Mutation rate is the frequency at which heritable changes arise per replication, site, genome or unit of time.
## Nexus Context
In digital evolution it can be controlled experimentally. Low rates limit exploration; excessive rates can erase inherited organization; intermediate regimes shape robustness and evolvability.
## Evidence Boundary
Comparisons require a declared denominator and error model. A software update rate is not a mutation rate unless changes enter a reproducing lineage.
## Relationships
[[wiki/Mutation|Mutation]], [[wiki/Survival of the Flattest|Survival of the Flattest]], [[wiki/Mutational Robustness|Mutational Robustness]], [[wiki/Evolvability|Evolvability]]
## Sources / Provenance
- Population genetics; Wilke et al. (2001).