Figure 2.

Evolution of the strength of host mate choice, g, in the presence of a nonevolving STI. Solid lines correspond to continuously stable strategies (CSSs), dashed lines to unstable strategies which act as evolutionary repellers, and circles to branching points, in the presence (black; $\zeta =0.1$) and absence (gray; $\zeta =0$) of host costs, with $m_S(g)=1-\zeta g$. The component of mate choice specific to infected individuals is as described in the text. Only one type of virulence (mortality or sterility) is assumed to occur in each panel with mate choice of infected individuals based on: (A) fixed sterility virulence, $v(\beta )=0.9$; (B) fixed mortality virulence, $\frac{v(\beta )}{\kappa }=0.5$; (C) variable sterility virulence, $v(\beta )=1-f(\beta )=\beta \eta$; and (D) variable mortality virulence, $v(\beta )=\alpha (\beta )=\beta \kappa$. Remaining parameters as described in Figure 1, except $\kappa =8$.