http://sitn.hms.harvard.edu/flash/2017/science-genetics-reshaping-race-debate-21st-century/
If separate racial or ethnic groups actually existed, we would expect to find “trademark” alleles and other genetic features that are characteristic of a single group but not present in any others. However, the 2002 Stanford study found that only 7.4% of over 4000 alleles were specific to one geographical region. Furthermore, even when region-specific alleles did appear, they only occurred in about 1% of the people from that region—hardly enough to be any kind of trademark. Thus, there is no evidence that the groups we commonly call “races” have distinct, unifying genetic identities.