The award of the 2012 Nobel Prize in Economic Sciences to the two main founders of matching theory, Alvin E. Roth and Lloyd S. Shapley, corroborates the fundamental importance and specificity of this theoretical framework. Yet matching theory has been largely ignored in the biological sciences, notwithstanding the potential provided by this approach to address mate choice and sexual selection. Here, we propose to use matching theory to explore the role played by sexual selection in the origin of species. We will consider the hamlets (Hypoplectrus spp), brightly coloured reef fishes from the tropical western Atlantic, as a marine model system. Preliminary data suggest that this approach has the potential to challenge current paradigms about speciation and, in the longer term, open up an entirely new research area. In the midst of a global extinction crisis, an understanding of speciation - the only counterbalancing force to extinction - is not only a fundamental question, but also a pressing issue.
