Allele frequencies and trajectories over time in an example simulation. A) Grid of simulated populations. B) Trajectory of an allele that originated in population (1,2) in generation 8. Limits of each y-axis are 0 (new allele not present) and 1 (new allele fixed). The x-axis limits are 0 to 1000 generations. C) Heat maps of the allele frequency in each population at six time points.