The Genetic Ancestry of African Americans, Latinos, and European Americans across the United States

TLDR

North America has been shaped by ongoing mixing of Native Americans, European settlers, and Africans for the past 500 years, forming the early history of the United States. The study examined the genetic ancestry of 5,269 African Americans, 8,663 Latinos, and 148,789 European Americans who are 23andMe customers. Analysis of these participants revealed that the legacy of historical interactions is reflected in the genetic ancestry of present‑day Americans. The results show pervasive mixed ancestry with asymmetrical male and female contributions, regional differences tied to historical events such as Spanish colonization and European immigration, and fine‑scale ancestry variation that informs the relationship between racial and ethnic identities and genetic ancestry.

Abstract

Over the past 500 years, North America has been the site of ongoing mixing of Native Americans, European settlers, and Africans (brought largely by the trans-Atlantic slave trade), shaping the early history of what became the United States. We studied the genetic ancestry of 5,269 self-described African Americans, 8,663 Latinos, and 148,789 European Americans who are 23andMe customers and show that the legacy of these historical interactions is visible in the genetic ancestry of present-day Americans. We document pervasive mixed ancestry and asymmetrical male and female ancestry contributions in all groups studied. We show that regional ancestry differences reflect historical events, such as early Spanish colonization, waves of immigration from many regions of Europe, and forced relocation of Native Americans within the US. This study sheds light on the fine-scale differences in ancestry within and across the United States and informs our understanding of the relationship between racial and ethnic identities and genetic ancestry.