is reduction in variance for most ancestry PCs for the genetic based super population assignments. Specifically, of the 10 PCs constructed variances were smaller for all 10 PCs in the EUR, 8 in the AFR, 8 in EAS, 7 in SAS but only 2 in the AMR group. Variance reduction was statistically significant via the sign-test for the EUR (p = 0.0008), AFR (p = 0.029), and EAS super population groups (p = 0.029). Although 7 of 10 PC variances were smaller in the SAS group, the reduction did not reach statistical significance (p = 0.103). Plots of the first three PCs for each self-reported census race and super-population assignments showing the reduced variance can be seen in Figure 2.
