Coexistence in Sympatry With Gene Flow Before Speciation Has Completed.

ABSTRACT: Incipient species often coexist in sympatry before complete reproductive isolation has evolved between them. How do they persist in the face of hybridization and gene flow? The challenge is more acute than ordinary ecological coexistence not only because gene flow erodes and recombines genetic differences, but also because selection against hybrids can destabilise population sizes. We estimated gene flow and selection against hybrid genotypes between sympatric limnetic and benthic species of threespine stickleback in two British Columbia lakes. First-generation hybrids are present at a rate of about 2%. To estimate selection, we compared the frequency distribution of ancestry proportions between juvenile and adult samples. We also used genomic simulation with assortative mating in an ecolo

SUBMITTER: Schluter D 

PROVIDER: S-EPMC12617059 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature