Correlations with Population Proportions
We find that levels of Native American and African ancestry in 23andMe customers in each state are significantly correlated with the proportion of African Americans and Latinos in each state (Figures S11–S13). For example, levels of African ancestry in European Americans and Latinos in a state are highly correlated with proportion of African Americans in each state (both p values < 10−4). Levels of Native American ancestry in European Americans and Latinos in a state are highly correlated with proportion of Latinos in each state (p values < 10−6 and < 10−2, respectively).