Data from: Present-day genetic structure of Atlantic salmon (Salmo salar) in Icelandic rivers and ice-cap retreat models

Due to an improved understanding of past climatological conditions, it has
now become possible to study the potential concordance between former
climatological models and present-day genetic structure. Genetic
variability was assessed in 26 samples from different rivers of Atlantic
salmon in Iceland (total of 2,352 individuals), using 15 microsatellite
loci. F-statistics revealed significant differences between the majority
of the populations that were sampled. Bayesian cluster analyses using both
prior information and no prior information on sampling location revealed
the presence of two distinguishable genetic pools - namely, the Northern
(Group 1) and Southern (Group 2) regions of Iceland. Furthermore, the
random permutation of different allele sizes among allelic states revealed
a significant mutational component to the genetic differentiation at four
microsatellite loci (SsaD144, Ssa171, SSsp2201 and SsaF3), and supported
the proposition of a historical origin behind the observed variation. The
estimated time of divergence, using two different ABC methods, suggested
that the observed genetic pattern originated from between the Last Glacial
Maximum to the Younger Dryas, which serves as additional evidence of the
relative immaturity of Icelandic fish populations, on account of the
re-colonisation of this young environment following the Last Glacial
Maximum. Additional analyses suggested the presence of several genetic
entities which were likely to originate from the original groups detected.