Population genetics

Population genetics is a subfield of genetics that deals with genetic differences within and between populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and population structure.

History

Population genetics was a vital ingredient in the emergence of the modern evolutionary synthesis. Its primary founders were Sewall Wright, J.B.S. Haldane and Ronald Fisher, who also laid the groundwork for the related discipline of quantitative genetics.

Genetic variation

Genetic variation is the basis for most evolutionary change and is therefore a central concept in population genetics. Genetic variation is caused by mutation, gene flow between populations, and sexual reproduction.

Genetic drift

Genetic drift is a change in allele frequency in a population, due to random sampling. The effects of genetic drift are most pronounced in small populations, where chance events can have a large impact on the genetic makeup of the population.

Natural selection

Natural selection is the process by which certain heritable traits—those that make it more likely for an organism to survive and successfully reproduce—become more common in a population over successive generations.

Gene flow

Gene flow is the transfer of genetic variation from one population to another. If the rate of gene flow is high enough, then two populations are considered to have equivalent allele frequencies and therefore effectively be a single population.

Mathematical models

The field of population genetics is heavily reliant on mathematical models, which describe the effects of various forces on the distribution of genetic variants within and between populations.

See also

• Evolutionary biology
• Genetic drift
• Natural selection
• Gene flow
• Genetic variation