Figure 3.—

Population differentiation in a hierarchical island model for two groups of two demes. Polymorphism data was generated by coalescent simulations using the ms program (Hudson 2002). To calculate F_ST for the simulated data sets we imported the output of ms into ProSeq v3 (Filatov 2002). The simulations assumed that all demes were of equal size with θ = 2 and 10 sequences were sampled from each deme. Gene flow was 5 times higher for demes within a group (4Nm = 0.5) than between the 2 groups (4Nm = 0.1). Going backward in time, at time T (measured in N_e generations) all 4 demes merge into a single deme. Dots represent differentiation between demes within a group of demes and triangles represent differentiation between groups of demes.