Without genetic variation, some key mechanisms of evolutionary change like natural selection and genetic drift cannot operate.
There are three primary sources of new genetic variation:
- Mutations are changes in the information contained in genetic material. (For most of life, this means a change in the sequence of DNA.) A single mutation can have a large effect, but in many cases, evolutionary change is based on the accumulation of many mutations with small effects.
- Gene flow is any movement of genetic material from one population to another (e.g., through migration) and is an important source of genetic variation.
- Sex can introduce new gene combinations into a population. This genetic shuffling is another important source of genetic variation.
Learn more about genetic variation in context:
- The genes that lie beneath: The work of Leslea Hlusko, a research profile.
- Aloha, spider style! The work of Rosemary Gillespie, a research profile.
- Genetic variation helps rescue endangered panthers, a news brief.
Find lessons, activities, videos, and articles that focus on genetic variation.
Reviewed and updated June, 2020.