Population genetics is a sub-field of genetics and evolutionary biology which examines genetic change over time within and between populations.

Research in population genetics examines patterns of mutation, gene flow, migration, selection and genetic drift.

Researchers use sophisticated computational methods to study the demographic histories of populations. One isolation-with-migration example diagrammed here displays a history that includes two population splits with subsequent gene flow among all three contemporary population samples. It becomes more challenging to disentangle the signals of population splitting and migration for older demographic models; however, as population-level genomic datasets grow, these analyses become tractable.