I am fairly new to genomics and population genetics. And I am reading this article 'Demographic history and rare allele sharing among human populations':
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3142009/pdf/pnas.201019276.pdf
In this article they propose a demographic model in Figure 4 on page 11986. However, I am confused how does African Americans fit in this demographic model that are known to have both African and European ancestry. And if I am to consider African American population than what is the split time between the two populations, time they merge into admixed population and the admixed proportion. My apologies if it's a really basic question but, any insights would be appreciated.