Population Structure
At K=2, fastSTRUCTURE results show a clear separation of lice collected
in Africa from the rest of the regions, including a few admixed samples
in Asia (Figure 4). As the number of K increases, the genetic clusters
start to separate the samples by continents and further subdividing into
sub-continents. Out of the 10 K-values tested, the optimum value of K
for this dataset was K=5. The five genetic clusters (Figure 4) separate
out individuals as follows: Sub-Saharan African (orange cluster),
Southeast Asian and Oceanian (dark blue cluster), South Asia (green
cluster), Central and South America (maroon cluster), and Europe with
the majority of North America (light blue cluster). There are a few
exceptions to these general categorizations of individuals. Some that
stand out are samples from Hungary, Egypt, Mongolia, Turkey, and Israel.
Both fastSTRUCTURE and ADMIXTURE analyses produced identical results.
Therefore, we only report fastSTRUCTURE results on the overall genetic
population structure.