Skip to main content
U.S. flag

An official website of the United States government

An introduced and a native vertebrate hybridize to form a genetic bridge to a second native species

January 1, 2008

The genetic impacts of hybridization between native and introduced species are of considerable conservation concern, while the possibility of reticulate evolution affects our basic understanding of how species arise and shapes how we use genetic data to understand evolutionary diversification. By using mitochondrial NADH dehydrogenase subunit 2 (ND2) sequences and 467 amplified fragment-length polymorphism nuclear DNA markers, we show that the introduced white sucker (Catostomus commersoni) has hybridized with two species native to the Colorado River Basin - the flannelmouth sucker (Catostomus latipinnis) and the bluehead sucker (Catostomus discobolus). Hybrids between the flannelmouth sucker and white sucker have facilitated introgression between the two native species, previously isolated by reproductive barriers, such that individuals exist with contributions from all three genomes. Most hybrids had the mitochondrial haplotype of the introduced white sucker, emphasizing its pivotal role in this three-way hybridization. Our findings highlight how introduced species can threaten the genetic integrity of not only one species but also multiple previously reproductively isolated species. Furthermore, this complex three-way reticulate (as opposed to strictly bifurcating) evolution suggests that seeking examples in other vertebrate systems might be productive. Although the present study involved an introduced species, similar patterns of hybridization could result from natural processes, including stream capture or geological formations (e.g., the Bering land bridge). ?? 2008 by The National Academy of Sciences of the USA.

Publication Year 2008
Title An introduced and a native vertebrate hybridize to form a genetic bridge to a second native species
DOI 10.1073/pnas.0712002105
Authors D.B. McDonald, T.L. Parchman, M.R. Bower, W.A. Hubert, F.J. Rahel
Publication Type Article
Publication Subtype Journal Article
Series Title Proceedings of the National Academy of Sciences of the United States of America
Index ID 70000266
Record Source USGS Publications Warehouse