Negative public information in mate choice copying helps the spread of a novel trait.

Numerous field and laboratory experiments have shown that many species have the capacity for social learning, including mate choice decisions that can be influenced by witnessing the mating decisions of others. Here we develop a numerical model of mate choice copying that follows the population genetics tradition, consisting in tracking allele frequencies in a population over time under various scenarios. In contrast to previous evolutionary models, we consider both positive social information and negative social information because many mating systems are driven by males in pursuit of a mate and female refusal of copulation may provide negative social information. The inclusion of negative social information to mate choice copying helps the spread of a novel trait, even if female innate mate choice preference is biased toward the common male type. We argue that the presence or absence of copying might simply mirror the associated cost-benefit relationship of the mating system of a given species and suggest how to test this prediction.