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Population genetics
Population genetics is the study of variation within populations of individuals, and the forces which shape it. This involves studying changes in the frequencies of genetic variation in populations over space and time.
Some of the major forces that shape variation in natural populations are: mutation, selection, migration and random genetic drift. When a new mutation arises, it may be beneficial to the organism; deleterious (harmful) to the organism; or it may be neutral (have no effect on the fitness of the organism). Generally, beneficial and deleterious mutations are subject to natural selection, typically leading to increases and decreases in their allele frequency, respectively.
Allele frequencies are also influenced by random genetic drift. This process explains the chance fluctuation in allele frequencies from one generation to another due to independent assortment in meiosis. This is the major force acting on neutral variants.
Modern population genetics makes use of increasing amounts of genome-scale data. It is a very large field with multiple applications. For example, data from genome-scale population genetics studies has been used to:
You can browse population genetics data in Ensembl. Learn more about this in the Population Genetics section our course Ensembl: Browsing chordate genomes.