Results of principal component analysis (PCA) generated from microsatellite data in PCA-GEN. The first two principle component factors (PC1 and PC2) plotted here account for 63.7% of the total variance (per axis inertia: PC1 = 47.38, PC2 = 16.32). These two factors are highly significant based on statistical tests with 1000 randomizations. Colors are coded as in Figure 2. Note that the North China group symbols cannot be fully seem due to overlapping.