What does introgression mean?
Introgression is the movement and lasting incorporation of genes from one species or population into another. It typically occurs when the two groups interbreed, producing hybrid offspring, and the hybrids repeatedly reproduce with members of the recipient population. Backcrossing can then leave selected genes from the donor group embedded in the recipient group's genome. Scientists study introgression because it can introduce useful traits, such as disease resistance or the ability to tolerate drought, and can reveal close evolutionary relationships between species. The term is also important in conservation, where gene flow between distinct populations may be monitored, and in agriculture, where genes from wild relatives may enter cultivated varieties through crossing. Although often discussed alongside hybridization and ordinary gene flow, introgression specifically emphasizes the transfer of genetic material between species or substantially differentiated populations.
nounThe transfer and stable incorporation of genes from one species or population into another through hybridization and repeated backcrossing. It is an important mechanism by which populations acquire new genetic variation.
- The transfer of genetic material from one species or population into another through hybridization and repeated backcrossing.
"Gene introgression has enabled some plant species to adapt rapidly to changing environmental conditions."
"The researchers documented extensive introgression between the two closely related plant species."
"Careful monitoring is needed to detect genetic introgression between wild populations and commercial crop varieties."
The plural is rare and is chiefly used when referring to multiple distinct cases of gene transfer.
"The populations showed several introgressions that had persisted over multiple generations."
Introgression lets evolution travel through hybrids: a species can borrow a useful gene without adopting the other species' entire identity.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does introgression come from?
The word was formed in the early 20th century from the Latin prefix intro-, meaning “in” or “into,” and forms related to Latin gradī, “to step,” also the source of gressus, “step” or “advance.” The form introgression thus conveys the movement of something into and through another population, by analogy with biological inheritance.
Related word forms
How introgression is actually used
This is specialized terminology used chiefly in evolutionary biology, population genetics, breeding, and conservation. It usually describes a process that is more selective or directional than the broader phenomenon of gene flow.