A 2000 km genetic wake yields evidence for northern glacial refugia and hybrid zone movement in a pair of songbirds.

ABSTRACT: Hybrid zones are natural experiments that expose the forces maintaining species differences. But for cases where a trait of one of the hybridizing pair appears shifted into the range of the other, the underlying mechanism can be difficult to infer. For example, hybridization between hermit warbler (Dendroica occidentalis) and Townsend's warbler (Dendroica townsendi) is restricted to narrow hybrid zones in Washington and Oregon, yet hermit mtDNA can be found in phenotypically pure Townsend's populations up to 2000 km north along the Pacific coast. This could reflect introgression of selectively favoured hermit mitochondria north across the hybrid zones, or a neutral genetic wake left behind following southern zone movement. Hermit mitochondrial haplotypes in populations of coastal Townsend'

SUBMITTER: Krosby M 

PROVIDER: S-EPMC2660942 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature