While many studies consider this continental admixture, few account for the genetically distinct sources of ancestry within Africa – the continent with the highest genetic variation.
A careful inspection of the results detects clusters where grouped individuals have multiple sources of ancestry, especially those in the Middle East and Central-South Asia.
By using a systematic approach to understand the source of African ancestry we have shown that genetically distinct African populations contributed differently to the genetic pool of geographically distinct American populations of African descent.
With no additional source of European ancestry besides the grandfather, grandchildren of this mating should be on an average 25% European.
A potential source of heterogeneity was ancestry; therefore, groups were combined by meta-analysis in ancestral-specific groups.
However, we caution that while highly tenable, we cannot conclude definitively that this is the source of discordance between ANCESTRY MAP and ADMIXMAP, since each of these analytical programs calculates a different statistic for LD.
One potential source of bias in global ancestry estimates is due to LD driven by segregating, chromosomal inversions.
In every stocked region, stocked populations shared various proportions of ancestry with their source(s), while unstocked populations corresponded to a unique cluster (except lakes 25 and 26; Fig. 4B; Table 3).
The median percentage of miss-called SNPs across all SNPs as well as the median percentage of miss-called SNPs across SNPs of that source ancestry are shown.
Admixed chromosomes were constructed by randomly copying segments of ancestry from the selected source population chromosomes, corresponding to the ancestry assigned to the segment.
