Genetic admixture occurs when previously isolated populations interbreed resulting in a population that is descended from multiple sources. It can occur between species, such as with hybrids, or within species, such as when geographically distant individuals migrate to new regions. It results in

gene pool The gene pool is the set of all genes, or genetic information, in any population, usually of a particular species. Description A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can survi ...

that is a mix of the source populations.

Examples

Climatic cycles facilitate genetic admixture in cold periods and genetic diversification in warm periods. Natural

flood A flood is an overflow of water (list of non-water floods, or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are of significant con ...

ing can cause genetic admixture within populations of migrating fish species. Genetic admixture may have an important role for the success of populations that colonise a new area and interbreed with individuals of native populations.

Mapping

Admixture mapping is a method of

gene mapping Gene mapping or genome mapping describes the methods used to identify the location of a gene on a chromosome and the distances between genes. Gene mapping can also describe the distances between different sites within a gene. The essence of all ...

that uses a

population Population is a set of humans or other organisms in a given region or area. Governments conduct a census to quantify the resident population size within a given jurisdiction. The term is also applied to non-human animals, microorganisms, and pl ...

of mixed ancestry (an admixed population) to find the genetic loci that contribute to differences in diseases or other

phenotypes In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological properti ...

found between the different ancestral populations. The method is best applied to populations with recent admixture from two populations that were previously genetically isolated. The method attempts to correlate the degree of ancestry near a genetic locus with the phenotype or disease of interest. Genetic markers that differ in frequency between the ancestral populations are needed across the genome. Admixture mapping is based on the assumption that differences in disease rates or phenotypes are due in part to differences in the frequencies of disease-causing or phenotype-causing genetic variants between populations. In an admixed population, these causal variants occur more frequently on chromosomal segments inherited from one or another ancestral population. The first admixture scans were published in 2005 and since then genetic contributors to a variety of disease and trait differences have been mapped. By 2010, high-density mapping panels had been constructed for African Americans, Latino/Hispanics, and

Uyghurs The Uyghurs,. alternatively spelled Uighurs, Uygurs or Uigurs, are a Turkic peoples, Turkic ethnic group originating from and culturally affiliated with the general region of Central Asia and East Asia. The Uyghurs are recognized as the ti ...

Examples

Mapping

See also

References

Further reading