Figure 1

PCA plots of YRI, CHB and CEU carried out using 500 re-samples of rSNPs from HapMap taking at random 10,000 (1A), 1,000 (1B) and 500 (1C) SNPs. Only one of the re-samples is highlighted in color; the results for the remaining 499 re-samples are indicated in grey with the aim of illustrating the variability on ancestry estimates associated to the random sub-sets of SNPs. The box-plots (right panels) indicate the European, Asian and African ancestries in CEU, CHB, and YRI, respectively, as obtained in the different re-samples. A statistical summary of these box-plots is given in Table 1.