The Science of Admixture Percentages (Garrett Hellenthal)

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 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. This lecture was presented at Who Do You Think You Are? - Live! 2017. Please note that these videos are copyrighted to the presenter and should only be used for personal study. They are not to be used for any other purpose without the presenter's express permission. Also, please note that because this is a rapidly advancing field, the content may quickly become outdated. The DNA Lectures were sponsored by FamilyTreeDNA (www.ftdna.com) and organised by volunteers from ISOGG (International Society of Genetic Genealogy, www.isogg.org). ISOGG volunteers also provided free DNA advice and support for members of the public at the conference.