Fig. 6: Simulated divergence with gene flow across the lake-stream habitat transition.

a Schematic of the stepping-stone model. Arrows indicate migration between neighboring demes. b Median frequency of the allele favored in the stream across 100 loci under selection after 1000 generations of evolution, averaged across 20 simulation replications for different combinations of migration rate and selection strength (selection coefficient s given on top of each panel). The demes are color coded as in a. In the rightmost panel, all stream demes are fixed for the stream allele hence the lines overlap.