There is no scientific way of determining race or ethnicity. Assumptions about this scientific basis were debunked in the early 20th century, whereas journals on eugenics truly believed in this so-called science in the 19th century, some of which was called Social Darwinism toward the late 19th century, but even that was unrelated to Darwin's research. In short, it is not possible to scientifically determine a single race or ethnicity with the help of science or gene analysis, mainly because we're all mixed. Even those of us with ancestors known for consanguinity have mixed ethnic genes. There are no bundles of genes for only whites or blacks or whatever. One can find more by searching: scientific basis for race, or scientific basis for ethnicity (if searching respectable sources). This is a popular subject recently because extremist groups want to promote racism and division for political and financial gain (for the .01%). But there will never be a concensus among scientists on which genes constitute one race or another.