Did You Know? Ancestry is Not So Black and White

Data from the 2010 census showed that about 13% of people living in the United States self-identify as African American, but from a genetic point of view, ethnicity isn’t so black and white. Most African Americans have genetic ancestry tracing back to both Africa and Europe but the exact proportion can vary widely. And conversely, many Americans who consider themselves of completely European descent may actually have some African ancestry as well.

A study published a few years ago found that the average amount of DNA in an African American’s genome that could be traced back to West Africa was about 77%, but ranged from as little as one percent to as much as 99%.

At 23andMe, researchers have looked at the genetic ancestry of about 78,000 customers likely to consider themselves as entirely of European ancestry and found that somewhere between three to four percent of those people have “hidden” African ancestry ranging from 0.5 to 0.75 percent. These findings suggest that this group of customers have an African ancestor who lived about six generations, or about 200 years, ago.

The United States is often referred to as a “melting pot” and although African Americans comprise the largest racial minority, this country is also home to many other genetically mixed groups. Indeed, Americans with ties to Latin America typically have DNA deriving from Native American, European and sometimes African populations. By studying genetic ancestry, researchers can break down the proportion of a person’s DNA that traces to different parts of the world and learn more about our unique and interconnected histories.

February is Black History Month — stay tuned for more posts!

Did you know? provides tidbits of information about genetics (in humans and in other animals) and explains how DNA relates to both ancestry and health.