To further explore European substructure we examined additional PCs in the initial all European participant set after excluding the SNPs within the Chromosome 8 inversion. The distribution of individuals in the first two vectors in the entire group did not change. However, the third vector now showed clusters corresponding to population affiliation (Figure 6). However, this PC accounts for only very small amount of the population variation within our different sample sets (see Table 1). Although PC4 showed marginal evidence for clustering by the ANOVA test there was little apparent correlation with self-identified ancestry. Additional PCs did not show evidence for substructure by ANOVA, or a significant split half reliability test.
