Fig. 2.

Fitness sets in a niche space defined by dark and light matching indices, displayed as contour plots of the phenotypes of all moths in all lineages from the 50th through the 100th generations. Data resulting from selection on each of the three experimental backgrounds are contrasted with the results of a nonselective, control process. Note that both the disjunct and mottled treatments produced bimodal, concave fitness sets with peak densities of moths along the axes, dividing the population into dark and light specialists. The speckled treatment produced a mostly convex fitness set that was more cryptic than the controls but not significantly dimorphic.