Figure 1. Density plot of pairwise quellergt relatedness values generated from simulations (100 per relatedness category) based on allele frequencies from our combined GT-seq+ddRADseq dataset of 642 individuals genotyped at 322 autosomal loci. Each colour represents a different relatedness category (Full sibs = full siblings, Half sibs = half siblings, P-O = parent-offspring, Unrelated = unrelated pair).
Our STRUCTURE and DAPC analyses revealed similar patterns in population genetic structure. STRUCTURE analysis suggested an optimal value of K = 4, with ln Pr(X |K ) plateauing around K = 4 (Figure 2D) and deltaK greatest at K = 4 (Figure 2E). For the find.clusters DAPC analysis, the lowest BIC scores occurred at K = 3 and K = 4 (Figure 2C). For both these analyses, the genetic clusters at K = 4 correspond to three geographic regions typically referred to as the Hudson Complex, the Arctic Archipelago, and the Polar Basin, with an additional cluster corresponding to the subpopulation of M’Clintock Channel (Figure 2A, B, Figure 3). Barplots showing K = 3 and K = 5 are provided in Figure S6.