Figure 6.—

Six time slices of an example simulation in a two-dimensional range, showing initial establishment and expansion of types and the beginning of mixing (which happens much slower than expansion). The population was composed of a 60 × 60 grid of demes with 1000 individuals in each. Different colors correspond to different types, and white is the ancestral type; when more than one color occupies a deme, the colors are mixed, so that eventually, if all colors spread to all demes, the entire population will be gray.