Figure 2From: Geographic stratification of linkage disequilibrium: a worldwide population study in a region of chromosome 22Principal components analysis plots based on the r2 values obtained for neighbouring markers. Populations with more than three missing r2 values were excluded in the analysis (Surui, San, Non-Austronesian (NAN) Melanesian, Colombian, Karitiana, Pima and Papuan). 42.1% and 18.9% of the variance is explained by the first and second components, respectively. The plot of the two first components pools the populations into two groups: East Asia and European/Western Eurasians. African populations are scattered due their lack of a single linkage disequilibrium pattern. Note that four Native American populations were excluded from the analysis and only one such population (Mayans, from Mexico) could be included.Back to article page