The population is composed of members of the same species that simultaneously live and interact in the same area. When individuals in a
population breed, they pass down their genes to their offspring. Many of these genes are polymorphic, meaning that they occur in multiple variants. Such variations of a gene are referred to as alleles. The collective set of all the alleles within a population is known as the gene pool.
While
some alleles of a given gene might be observed commonly, other variants may be encountered at a much lower frequency. Gene pools are not static. The frequency and occurrence of alleles in a gene pool may change over time. For instance, allele frequencies change due to random mutations, natural selection, migration, and chance.
Population
genetics examines genetic variation within and between populations, and
changes in allele frequencies across generations. Population
geneticists use mathematical models to investigate and predict allele
frequencies in populations.