Figure 2: Joint evolution of male competitiveness and female preferences based on male resources.
After 1,000 generations of evolution in the absence of female choice (p=0, resulting in a dynamics as in Fig. 1), female preferences are allowed to evolve. In the standard version of the model, female always evolve a strong preference for males with high-quality resources (p>0), thereby favouring males of higher competitiveness. In case of small variation in resource quality ((a); Rlow=0.8, Rhigh=1.2) polymorphism gives way to large-amplitude cycles in male competitiveness. In case of large variation ((b); Rlow=0.2, Rhigh=1.8) the cycles disappear and male competitiveness evolves to a maximal level.
