ABSTRACT
Background One of the most signicant recent development in speciation theory has been the increased attention given to sexual selection as an evolutionary force capable of rapidly inducing reproductive isolation among populations [1]. Sexual selection is thought to have played an important role in major adaptive radiations, such as those of Hawaiian Drosophila [2,3] and East African cichlid shes [4-6]. Because many closely related species dier in sexually dimorphic male breeding color, many studies on cichlid shes from Lakes Malawi and Victoria have emphasized the possible role of female choice of male nuptial color as a driving force for speciation [5,7-10]. e observations that individual females can have preferences for dierent male color patterns and that these preferences lead to reproductive
isolation between incipient species have been used to model speciation in cichlid radiations [e.g. [11-14]]. e breakdown of assortative mating between a pair of sympatric Lake Victoria cichlid species in turbid waters [15], the breakdown of assortative mating during laboratory experiments under monochromatic light [9], and the observation that non-hybrid females prefer hybrid males that have the colors of conspecics [16] provided evidence that female mating preferences for male courtship hue are important in reproductive isolation in Lake Victoria cichlids.
