Many Americans who identify as European actually carry African ancestry just as many Americans who identify as African carry European ancestry, finds an extensive new genetic analysis.
DNA tells no lies, so the findings, published in the American Journal of Human Genetics, reveal just what a melting pot of different racial and ethnic groups exists in the United States.
"Our study not only reveals the historical underpinnings of regional differences in genetic ancestry, but also sheds light on the complex relationships between genetic ancestry and self-identified race and ethnicity," study author Katarzyna Bryc of 23andMe and Harvard Medical School said in a press release.
Bryc and her team studied DNA sequence variations called "single-nucleotide polymorphisms" in the genomes of more than 160,000 African Americans, Latinos and European Americans. Study participants provided saliva samples, where the DNA sequence variations were found.
The researchers found that more than 6 million Americans who self-identify as European likely carry African ancestry. As many as 5 million self-described European Americans might have at least 1% Native American ancestry, according to the study.
The researchers also determined that regional ancestry differences reflect historical events in the U.S., such as waves of immigration. For example, Scandinavian ancestry is found in trace proportions in most states, but it makes up about 10% of ancestry in European Americans living in Minnesota and the Dakotas.
The scientists also discovered that people identify roughly with the majority of their genetic ancestry.
Nevertheless, racial lines appear to be more blurred than previously thought.
"These findings suggest that many individuals with partial African and Native American ancestry have 'passed' into the white community, thereby undermining the use of cultural labels that separate individuals into discrete, non-overlapping groups," Bryc said.
She added, "Taken together, our results suggest that genetic ancestry can be leveraged to augment historical records and inform cultural processes shaping modern populations."
Tags: ANCESTRY, GENETICS, RACE, U.S., US & World