TY - JOUR T1 - Coevolution of male and female mate choice can destabilize reproductive isolation JF - bioRxiv DO - 10.1101/246355 SP - 246355 AU - Thomas G. Aubier AU - Hanna Kokko AU - Mathieu Joron Y1 - 2018/01/01 UR - http://biorxiv.org/content/early/2018/06/14/246355.abstract N2 - Sexual interactions play an important role in generating reproductive isolation with clear consequences for speciation. Despite increasing empirical evidence of premating isolation caused by mutual mate choice, theoretical developments have focused on the evolution of mate preferences in each sex separately. Here, using a population genetics model, we investigate the joint evolution of female and male mate choice (phenotype matching rule) under polygyny in a context of emerging reproductive isolation. We show that the evolution of female preferences increases the mating success of males with reciprocal preferences. Consequently, selection favouring mutual mate choice may be common. However, in turn, the evolution of male preferences weakens indirect selection favouring female preferences. Therefore, with weak genetic drift, the coevolution of female and male mate choice leads to periodic episodes of random mating with increased hybridization rate. Thus, counterintuitively, the process of establishing premating isolation proves very fragile if both sexes can contribute to assortative mating. Our predictions sheds new light on the evolutionary dynamics of reproductive isolation and encourages further research on the lability of isolating barriers. (<250 words) ER -