Fig. 2.

Schematic of the admixture model. Source populations $S_1$ and $S_2$ contribute to an admixed population H. The members of H in generation g draw parents from the populations of generation $g-1$ from $S_1$ with probability $s_{1,g-1}$, from H with probability $h_{g-1}$, and from $S_2$ with probability $s_{2,g-1}$. Two parents are drawn independently. Random variable $H_{\alpha ,g}$ denotes the random autosomal ancestry fraction from population α (1 for $S_1$, 2 for $S_2$) in an individual in population H in generation g.