Researchers analyze genetic material to learn about population histories

Migration throughout the years has played a role in the diversity and population of the United States. A new study analyzed the genetics of 32,000 Americans and discovered previously unrecognized subgroups and heterogeneity resulting in the most fine-scale map of American population history to date.

Researchers learned that regional differences they found fit with historical demographic patterns.

"Substantial  substructure and heterogeneity in Hispanics/Latinos, isolation-by-distance in African Americans, elevated levels of relatedness and homozygosity in Asian immigrants, and fine-scale structure in European descents," according to a recent article published in Cell.

They also looked at the geographical distribution across the South, Northeast, Midwest, and the West. They found that individuals of European descent make up 82.8 percent of the population of the Midwest. Americans of mixed ancestry, also called admixed, are mostly found in the West and the South, and those with African ancestry are most commonly found in the South. East Asians mostly live in the West, and South Asians are mostly located in the Northeast. 

Researchers aimed to “provide a framework for analyzing population structure in heterogeneous individuals,” according to the study.  It could also help researchers and doctors explore biomedical traits.

They note that one goal of the study was to look into specific populations that are commonly overlooked in existing genetic studies, like East Asians and South Asian. With more people participating in genetic programs or using direct-to-consumer genetic tests, (approximately 26 million people have taken those tests) there is a need to include a more diverse population and to explore more of those demographic histories, the researchers said. Those factors could help to prevent over generalization and also avoid making existing Eurorcentric study biases worse.

The study was conducted by Chengzhen L. Dai, Mohammad M. Vazifeh, Chen-Hsiang Yeang, Remi Tachet,  R. Spencer Wells, Miguel G. Vilar, Mark J. Daly, Carlo Ratti, and Alicia  R. Martin. They explored population histories by studying the genetics,  ancestral  birth origin, and geographic data from the National  Geographic Genographic Project.