Secondary contact and changes in coastal habitat availability influence the nonequilibrium population structure of a salmonid (Oncorhynchus keta).
Bottom Line: We investigated the population structure of chum salmon on the North Alaska Peninsula (NAP) and, using both empirical data and simulations, evaluated the effects of colonization timing and founder population heterogeneity on patterns of genetic differentiation.We screened 161 single nucleotide polymorphisms and found evidence of nonequilibrium population structure when the slope of the isolation-by-distance relationship was examined at incremental spatial scales.Our results agree with geological and archaeological data indicating that the NAP was a dynamic landscape that may have been more recently colonized than during the last deglaciation because of dramatic changes in coastal hydrology over the last several thousand years.
Affiliation: School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Seattle, WA, 98112, USA.Show MeSH
Related in: MedlinePlus
Mentions: We estimated a global FST of 0.04. Pairwise FST values ranged from 0.002 to 0.08 (Table3), and all pairwise comparisons of populations were statistically significant (α = 0.05). PCA of individual genotypic data allowed us to visualize differentiation among and between populations; we observed variation among individuals taken from the same sampling location, but recognizable groups of individuals were evident (Fig.3). Individuals from Whale Mountain Creek, Wiggly Creek, Plenty Bear River and Meshik River (sampling locations 1–4 in Table1) were grouped together and were clearly distinct from individuals from Joshua Green and Frosty Creek (sampling locations 10 and 11). These findings indicate that individuals sampled from the eastern base of the NAP are genetically distinct from individuals sampled from the western tip of the NAP.
Affiliation: School of Aquatic and Fishery Sciences, University of Washington, 1122 NE Boat Street, Seattle, WA, 98112, USA.