Biased Hybridization and Its Impact on Adaptive Introgression

• Published in: Trends in ecology & evolution (Amsterdam) Vol. 36; no. 6; pp. 488 - 497
• Main Author: Pfennig, Karin S.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2021
• Subjects: adaptive radiation; admixture; conservation; gene flow; rapid adaptation; sexual selection; gene flow; conservation; admixture; rapid adaptation; adaptive radiation; sexual selection
• ISSN: 0169-5347; 1872-8383
• DOI: 10.1016/j.tree.2021.02.010

Gene exchange between species can influence ecological and evolutionary processes ranging from population rescue to adaptive radiation. Genomic tools have provided new insights into the prevalence and nature of gene exchange between species. However, much remains unknown of how ecological, behavioral, and evolutionary factors determine what genetic variation moves between species in the first place. In particular, more research is needed that evaluates whether such factors bias gene flow from one species to another, and whether any such biases affect how genetic variation from another species is ultimately retained in the genome of a given species. Addressing this issue is crucial in a changing world where hybridization and introgression might determine which species succeed and which become extinct. Interbreeding between species, hybridization, often occurs in specific habitats or by particular individuals. Consequently, gene flow between species could consist of a nonrandom sample of the segregating variation in the hybridizing species.This biased gene flow can ultimately influence which alleles, if any, undergo introgression into the genome of the recipient species, especially if it determines patterns of genetic and phenotypic variation that are exposed to natural selection.Understanding how hybridization and introgression enable rapid adaptation is crucial for preserving biodiversity. Explicitly considering how the evolutionary and ecological causes of hybridization bias gene flow and thereby influence the unfolding and detection of introgression will contribute to this understanding.