To avoid statistical biases during population structure analysis and IBS score computations, SNPs with Pearson’s correlation coefficients (r2) higher than 0.8 were rejected. Due to the absence of a genetic scaffold, a chromosomal location-based SNP filtering, as implemented in common GWAS packages, such as PLINK v.1.9 , was replaced by iterative SNP filtering. Pairwise Pearson’s r2 across SNPs were computed and, at each step during the iteration, the SNP correlated (r2 > 0.8) with the most number of other SNPs was rejected. The iteration stopped when no remaining SNPs were correlated (all pairwise r2 < 0.8). This procedure left 3220 SNPs out of original 5838 SNPs. Filtered SNPs were then used to compute IBS scores, namely pairwise Pearson’s correlation coefficients (r2), between individuals. Here again iterative filtering was applied across trees to prune individuals with IBS > 0.1875. Out of 506 trees, 327 passed IBS-based filtering.