Sexual dimorphism in wing pigmentation promotes rapid species diversification in Zygoptera but not Anisoptera

Abstract

Sexual selection has long been thought to promote speciation, but evidence is inconclusive. In Odonata - which includes dragonflies and damselflies-, wing pigmentation has been found to be influenced by sexual selection. Past evidence shows that wing pigmentation in males is a driver of speciation in damselflies. However, whether sexual dimorphism per se is associated with species diversification rates has not been tested. Here we test whether wing pigmentation sexual dimorphism influences diversification rates in a supertree of 1,260 species, the most comprehensive phylogeny inferred for the group. We find that male wing pigmented sexual dimorphism is associated with higher species diversification rates in damselflies but not in dragonflies. This study presents the first evidence of the role of species sexual dimorphism in species diversification in a clade identified as amarker of habitat quality. In the face of accelerating biodiversity loss, uncovering diversification drivers is of pressing importance.