A pheromone by any other gene would smell as sweet

Reproductive isolation is the result of either the inability to produce viable and fertile offspring or the avoidance of mating altogether. While these mechanisms can evolve either over time via genetic drift or natural selection, the genetic result is usually a complex set of traits that are often linked. Explaining how reproductive isolation proceeds from the initiation of divergence to the complete prevention of mating is often a difficult task, as the underlying genes for traits associated with reproductive isolation can change via molecular evolution and subsequent protein coding alterations or through alterations of gene expression regulation. In this issue of Molecular Ecology, Treer, Maex, VanBocxlaer, Proost, and Bossuyt (2017) use transcriptomic, proteomic and phylogenetic analyses to show that species-specific sex pheromones are the result of gradual sequence divergence on the same set of proteins in two closely related newt species (Ichthyosaura alpestris and Lissotriton helveticus). This study shows that salamander pheromone systems provide an enticing opportunity to connect the evolution of reproductive isolation to the changes in genes that underlie a key phenotype.