Principal component analysis (PCA), together with a biplot, of 14 West-African population samples, (a) inclusively and (b) exclusively the Ghanaian C1 population sample, based on the Y-SNP frequencies using the phylogeny given in S3 Fig.

<p>The cumulative proportion of plot (a) is 0.92 for the first two principal components (PC1: 0.83; PC2: 0.09), and of plot (b) is 0.81 for the first two principal components (PC1: 0.45; PC2: 0.36). The nomenclature and the references of the population samples are available in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0141510#pone.0141510.s012" target="_blank">S1 Table</a>.