Figure 3.

Estimated cline in morph frequency. (a) Phase diagram of morph-frequency equilibrium with latitude l and harassment strength h. Equilibrium frequency was calculated from the equilibrium conditions (F_A = F_G) for equation (5). (b) The estimated cline (thick solid line; h = 0.288) is shown with the observed cline (data points with dashed line from Figure 1) and a steep cline (thin solid line; h = 0). The level of male harassment h that correctly predicts the width of the morph frequency cline in the wild (h = 0.288, horizontal dashed line in Figure 3a) was calculated by using the least-square fitting method (r² = 0.77, adjusted r² = 0.76).