"We have to keep in mind what these admixture [ethnicity] tests do: they take the DNA of living people - us, the test takers - and they compare it to the DNA of other living people - people whose parents and grandparents and, sometimes, even great grandparents all come from one geographic area. Then they try to extrapolate backwards into time."
Click here to read the entire blog in The Legal Genealogist written by Judy Russell.