Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
Microevolution refers to small-scale evolutionary changes that happen within a population over relatively short periods of time. These changes involve alterations in allele frequencies and are responsible for variation within a single species.
The gene pool is the total collection of genes (alleles) present in a population at any given time. It includes all the genetic variations available for natural selection to act upon.
Genetic drift refers to random changes in allele frequencies within a population. It is more pronounced in small populations and can lead to the loss or fixation of certain alleles over time.
Gene flow is the movement of genes (alleles) from one population to another through migration or interbreeding. It can increase genetic diversity within a population and reduce genetic differences between populations.