Observed autosomal heterozygosity (including both polymorphic and
monomorphic sites) varied across all populations. Sub-Saharan African
countries had the highest heterozygosity values observed (Figure 2).
Asian and South American countries had the second highest heterozygosity
estimates, followed by North American and European countries (Figure 2).
Across all the countries, the observed heterozygosity was lower than the
expected heterozygosity for all populations. Tajima’s D values for each
continent ranged from -0.0001-0.0003, indicating no demographic changes
within populations among continents (Figure S4).
Hierarchical population structure analysis (AMOVA) revealed significant
variation partitioned at each population hierarchical level (Table 3).
The variation among continents was 25%, among countries within
continents was 21%, among individuals within countries was 24% and
lastly the individual variation among all individuals was 29%.
FST values between continents were also relatively high.
The highest FST values were found between Africa vs
non-African countries and Oceania vs Europe (0.441) (Table 4). Low
FST values between Asia and other continents suggest
that it is the least differentiated continent relative to others. We
also observed the lowest FST values between
geographically proximal continents (e.g.: between North and South
America; between Asia and Oceania). The pairwise-FSTvalues between countries further explains the overall continental
differentiation patterns in Table 4.
Table 3: Global AMOVA
results as a weighted average across all polymorphic loci the SNP
dataset. Significant p values (p<0.00005) are indicated by an
asterisk (*)