Genetic Study Offers Diverse View of Recent US Population History

(CN) – Researchers have constructed one of the most comprehensive genetic studies ever conducted in the United States, one that seeks to shed some much-needed light on the complexity of America’s genetic history.

The study, published Thursday in the American Journal of Human Genetics, details how researchers gathered genetic information from over 32,000 individuals with a host of different backgrounds and ethnicities. Genetic experts then used this vast collection of genetic data to form what they dubbed the National Geographic Genographic Project, an exhaustive look into the ancestral histories of thousands of individuals and numerous ethnic groups.

They found the genetic backgrounds of Americans today are far more complex – and diverse – than was previously believed.

One of the most notable findings revealed by the study is the surprisingly elaborate genetic history of Latinos and Hispanics. Researchers found Latinos and Hispanics maintain genetic population structures far more diverse than thought, with many Latino and Hispanic groups having African, Native American and even European ancestry.

Researchers also found that those of Asian descent – a group often underrepresented in genetic studies – show strong traces of what is known as homozygosity. This means that Asian Americans show notable evidence of common relatedness with another, a genetic footprint typically associated with ancestral intermarrying between kin.

One discovery that surprised researchers is the genetic population spread of those with European ancestry. While previous research has shown that most genetic population groups tend to stay clustered around specific geographic areas, many Europeans are spread around the country seemingly at random. Irish descendants, for instance, are well represented in New England, but those with Finnish heritage are most common across the country in the Pacific Northwest.

The study notes these discoveries prove the web of genetic history and our ancestral background is an intricate and detailed creature, one that is far less cut-and-dried than many would assume.

Alicia Martin, a study co-author from the Broad Institute of MIT and Harvard, says the findings show the value of a broader and more inclusive perspective when it comes to how we look at genetic history. She hopes the research will encourage just that.

“We have inferred U.S. demographic history at fine scale by combining genetic, geospatial, and multigenerational birth record data,” Martin said with the release of the study. “This provides important lessons for the future: if we want genetic technologies to benefit everyone, we need to rethink our current approach for genetic studies because they typically miss a huge swath of American – and more broadly human – diversity.”

Researchers say that a large part of why this study produced such detailed results is because they focused on detailed, intimate data sets as opposed to large and broad ones. Rather than gather genetic information from as many Americans has possible, scientists instead chose to focus on a concentrated number of participants who were able to provide large amounts of background data. This allowed researchers to collect data on birthplaces, participants’ postal codes and even ethnic information on participants’ grandparents.

By focusing on deep and detailed data instead of broad and general data, researchers were able to pull back the curtain on American’s genetic history far more effectively than previous genetic studies.

They say, however, that these findings are not limited to just anthropologic interests. These genetic discoveries could have meaningful roles in the fields of health and medicine, as they could offer health care professionals entirely new genetic perspectives to consider when making care-related decisions.

“We expect our findings to be most applicable for studies of human history and potentially to provide context for conducting genetic studies such as those that may be used in precision medicine,” Martin said in an email.

While the discoveries revealed by this research effort are already significant, researchers say many others are forthcoming. As more participants come forward to share their ancestral histories and scientists expand their research gaze to include as many groups and people as possible, the breadth of America’s diversity and ancestral past will become clearer.

%d bloggers like this: