The United States was built by immigrants. Now for the first time, a large-scale study published using genetic data voluntarily submitted to biotechnology company 23andMe sheds light into the ancestry of three groups—African-Americans, European Americans, and Latinos—and how they are woven into the country’s history.
The findings appear in the American Journal of Human Genetics. "Our study not only reveals the historical underpinnings of regional differences in genetic ancestry, but also sheds light on inconsistencies between genetic patterns and commonly accepted notions of race and ethnicity," said 23andMe geneticist Kasia Bryc in a statement.
What makes the study unprecedented is its size. The researchers examined aggregated and anonymous data from 160,000 customers who purchased 23andMe’s $99 testing kit. All of the information was submitted voluntarily. Some of the data points in include:
- About 3.5% of European Americans have 1% or more African ancestry.
- One in every 20 African-Americans carries Native American ancestry.
- More than 14% of African-Americans from Oklahoma carry at least 2% Native American ancestry, which Bryc suggests could point to the Trail of Tears migration in the 1830s.
- White Americans with African DNA were found at higher frequencies in the south. The study suggests this could be due to region-specific influences like slavery, immigration, and colonization.
- All three groups had "asymmetrical male and female ancestry contributions," with more European male and more Native American and African female ancestors. 23andMe notes that this "asymmetry is likely a legacy of slavery" and "unbalanced sex ratios in frontier settings."
In July, 23andMe received a $1.4 million grant from the National Institute of Health to help expand its genotype database. Currently, the company is working with the FDA after the administration issued a crackdown on its health testing kits last year.