The range of haplogroups across the region may reflect historical genetic admixture, perhaps as a result of invasive male migrations.
AtDNA is generally used to measure the average continent-of-ancestry genetic admixture in the entire human genome and related isolated populations.
One example of genetic admixture resulting from the introduction of an invasive species is provided by the Cuban brown anole.
And since many people have ancestors from different continents - making them a genetic admixture - the data are rarely clean-cut.
Following World War II and subsequent worldwide migrations, the current American populations' genetic admixture can be traced to all corners of the world.
There are also many peoples who are genetic admixtures of the major groups.
The study suggests that the lower genetic distance between Europe and Africa can be explained by genetic admixture.
Because the Duffy antigen is uncommon in those of Black African descent, the presence of this antigen has been used to detect genetic admixture.
According to the research, these patrilines have undergone extensive genetic admixture with the Jōmon period populations previously established in Japan.
Their genetic admixture consists of 91% European and 9% Amerindian.