The Science of Admixture Percentages
As DNA collections continue to emerge, representing individuals sampled from ever more locations, genetic ancestry testing companies are able to provide increasingly precise and detailed information about customers’ ancestry. Typically these companies compare customers’ DNA to that of individuals sampled from different geographic locations, and then provide percentage breakdowns reflecting which of these locations contain a similar genetic make-up as the customer. But what do these percentages mean? Garrett Hellenthal explains some of the methodology behind the numbers, including recent computational advances, and discusses how to interpret (and how not to over-interpret) the results.
Garrett Hellenthal is a statistical geneticist at University College London, whose primary work involves identifying the factors that contribute to the genetic variation among worldwide human groups.