Figure 5.

Schematic representation of the directional plasticity effects on the variation in the genotypic values x. The solid line shows the log of the fitness function, and the shaded areas symbolize the distributions of phenotypes and fitness without plasticity (light shading) and with plasticity (dark shading). Directional plasticity (symbolized by an arrow) shifts the distribution of the phenotypes (mean and variance). The curvature of the log fitness function (convex in (a); concave in (b)) determines how the shift in the mean of the distribution changes the variation in log fitness from [20].