# Population Genetics
**Domain:** Evolution / Mathematics / Genomics
**Doc Type:** Canonical Discipline Node
**Maturity:** Foundational
## Definition
**Population genetics** studies how allele frequencies and genetic variation change under mutation, selection, drift, migration, recombination and population structure.
## Nexus Context
The field turns evolution into a quantitative population process. [[articles/The Evolutionary Roots of Silicon Valley|The Evolutionary Roots of Silicon Valley]] links Berkeley molecular evolution with Stanford work by Luigi Luca Cavalli-Sforza and Marcus Feldman on human population history, cultural transmission and gene–culture interaction.
Machine-learning analogies should remain bounded. Populations are not merely candidate solutions, fitness is not always a scalar objective and drift has no necessary engineering purpose. But population thinking contributes three vital ideas to machine systems: distributions rather than representative individuals, historical dependence and the difference between selection and chance.
## Continuity Context
Population-level ancestry cannot settle individual identity. A reference genome or haplogroup locates someone inside distributions and lineages; it does not reconstruct their mind.
## Sources / Provenance
- Daniel L. Hartl and Andrew G. Clark, _Principles of Population Genetics_.
- Stanford Marcus Feldman profile: https://profiles.stanford.edu/marcus-feldman
## See Also
[[wiki/Natural Selection|Natural Selection]], [[wiki/Haplogroup|Haplogroup]], [[wiki/Cultural Transmission|Cultural Transmission]], [[wiki/Population Modeling|Population Modeling]]