Fig. 3

Propagation of the A-type under selective migration when \({R}_{in}=50\). Each panel depicts the \(7\times 7\) metapopulation grid. Bubbles indicate the spatial location of groups. The proportion of A-types in a group is represented by hue, with \(\pi =0\) (an S-type group) indicated in white and \(\pi =1\) (an A-type group) in black. Bubble diameter is proportional to the logarithm of group size. Starting from a single A-type group, the A-type can propagate across the metapopulation by selective migration as depicted, but not by random migration