Which cues are sexy? The evolution of mate preference in sympatric species reveals the contrasted effect of adaptation and speciation

Abstract

AbstractMate preferences have a strong effect on adaptation and speciation. In turn, these two evolutionary processes can generate contrasted selective pressures acting on the evolution of preferences. In sympatric species, trait distributions are shaped by similar selective pressures, thus independently promoting similar adaptive traits in different species. When preference targets such adaptive traits, the trait similarity between species may induce heterospecific matings. The evolution of preference for adaptive traits thus likely depends on the ecological interactions between species. Using a mathematical model, we study the evolution of preference towards adaptivevs. neutral traits shared by sympatric species. We specifically investigate whether preference for several traits might emerge, despite sensory trade-off. We also test whether preference toward cues linked to adaptationvs. species recognition may preferentially evolve. Our mathematical approach reveals the key role of sensory trade-offs and opportunity costs favouring the evolution of preferences targeting adaptive traits rather than traits relevant to species recognition. Our model thus highlights that the evolution of preferences for different traits in sympatric species depends on within-species mating opportunities but also on the niche overlap between species, tuning the heterospecific interactions.