Simulation results for the evolution of multiple preferences for arbitrary male traits. This figure shows the parameter space, in terms of costs of competition (γ) and strength of female preference (α), where a single preference for an arbitrary trait fixes (gray), both preferences fix (white), and both preferences are lost (black). Top panel is for successive preference introduction, bottom panel shows simultaneous preference introduction. For a preference to fix, preference strength must be sufficiently high, and costs must be relatively low. Introducing preferences successively increases the parameter space where multiple preferences may coexist.