Fig. 2.

Clustering of populations based on their genetic diversity was performed by using standard principal component (PC) analysis using the correlation matrix of the original variables. Per-locus estimates of expected heterozygosity (27), allele richness (28), and variance in allele size for the STR loci were used for each population (Table 2). Coordinates are the first (vertical) and second (horizontal) PCs. The first PC represented overall diversity because its eigenvector’s loadings were positive and similar in magnitude (data not shown). The first PC alone accounted for 40% of the total variation, and together with the second PC, 53% of the total variation was captured. Brz Rio, Brazil Rio; Brz Sao, Brazil Sao Paulo; Argen, Argentina; Brz Par, Brazil Parana; Venezu, Venezuela; C. Amer, Central America; Brz Amaz, Brazil Amazon; MidEast, Middle East.