Figure 6.

Evolution of the mean genetic value of a population located at the extreme north of the landscape. The mean genetic value of a population located at latitude + 0.5 (dotted circle in Figure 1) was monitored under two different levels of environmental cline and three different strengths of assortative mating. All simulations were conducted under the island migration model with moderate gene flow (Nm=5.1). The red line indicates strong assortative mating (ρ=0.8), the blue line moderate assortative mating (ρ=0.3), and the black line random mating (ρ = 0). Each line represents the mean of 50 independent replicates for each evolutionary scenario.