Figure 1

Basic admixture models commonly used in population genetics. Each rectangle represents a population. Both models consider one initial ancestral population (gray color) that splits into two new populations t_split generations ago. Each of the new populations evolves without exchanging migrants for a period of time, during which genetic differentiation between them can take place as exemplified by the presence of a different color. (A) Continuous gene flow (CGF) model. The blue population contributes 4 Nm chromosome migrants to the red population from time point t_split onwards, replacing the same number of chromosomes from this population. (B) Hybrid (HI) model. At t_admixture, there is a single event of admixture, and a new hybrid population is created from m fraction of chromosome migrants from the blue population and 1-m fraction of migrants from the red population. After this event, each population continues to evolve independently. Adapted from [20].