- Genetic drift is a mechanism of evolution. It refers to random fluctuations in the frequencies of alleles from generation to generation due to chance events. Genetic drift can cause traits to be dominant or disappear from a population. The effects of genetic drift are most pronounced in small populations.
Definition from: Talking Glossary of Genetic Terms from the National Human Genome Research Institute
- Random changes in gene frequency especially in small populations when leading to preservation or extinction of particular genes.
Definition from: Merriam-Webster's Medical Dictionary by Merriam-Webster Inc.
See also Understanding Medical Terminology.