Notes on Terminology and Selection of Populations
Throughout the manuscript, the term “Native American ancestry” refers to estimates of genetic ancestry from indigenous Americans found across North, Central, and South America, and we distinguish this term from present-day Native Americans living in the US. We use the term “Native American” to refer to indigenous peoples of the Americas, acknowledging that some people may prefer other terms such as “American Indian.” Our estimates of African ancestry specifically aim to infer ancestry of sub-Saharan Africa and does not include ancestry from North Africa. We note that the term “Latino” has many meanings in different contexts, and in our case, we use it to refer to individuals living in the US who self-report as either “Latino” or “Hispanic.”
Our work represents a snapshot in time of genetic ancestry and identity, and future work is needed to inform the dynamic changes and forces that shape social interactions.
We note that our cohorts are likely to have ancestry from many African populations, but because of current reference sample availability, our resolution of West African ancestries is outside the scope of our study. Likewise, our estimates of Native American ancestry arise from a summary over many distinct subpopulations, but we are limited in scope because of insufficient sample sizes from subpopulations, so we currently use individuals from Central and South American together as a reference set (see Durand et al.33 for a list of populations and sample sizes).