The evolution of leks through female choice

It is generally acknowledged that female preferences for mating in large groups of displaying males could cause the evolution of leks. Recent hypotheses differ on what selective advantage would accrue to females with such preferences, but they agree on the need for some such advantage if these preferences are to select for larger lek sizes. A model developed here, adapted from models of female preferences for individual male traits, shows that female preferences for larger leks can evolve and be maintained without any direct selective advantage. Like the individual choice models, it also demonstrates a number of arbitrary or non-adaptive features inherent in such systems. Most notably, instead of a single optimal outcome, there may exist a curve of possible equilibria. These equilibria can be stable or unstable depending on the nature of the female preferences.