Principal Component Analysis
The principal component analysis showed similar population structure as the fastSTRUCTURE analysis. PC1 and PC2 explain 29.68% and 6.41% of variation, respectively, and separated the sub-Saharan African samples from the rest very clearly (Figure 5). In addition, we observed the same clustering patterns of lice in the fastSTRUCTURE results, including the same outliers (Figure 4). For example, in the PCA, Asia is subdivided into South Asia and Southeast Asia (See table 2 for details on countries that belong to each region), where the Southeast Asian cluster includes individuals from Oceania. Similarly, the main outliers detected in the fastSTRUCTURE analysis were Hungary, Mongolia and Egypt, clustering together with South Asian individuals, and all of the Algerian lice clustering with Europeans. These were also observed in the PCA clusters.