Differentiation in putative male sex pheromone components across and within populations of the African butterfly Bicyclus anynana as a potential driver of reproductive isolation. Issue 17 (29th July 2016)

• Record Type: Journal Article
• Authors: Bacquet, Paul M. B.; de Jong, Maaike A.; Brattström, Oskar; Wang, Hong‐Lei; Molleman, Freerk; Heuskin, Stéphanie; Lognay, George; Löfstedt, Christer; Brakefield, Paul M.; Vanderpoorten, Alain; Nieberding, Caroline M.
• Is Part Of: Ecology and evolution. Volume 6:Issue 17(2016:Sep.)
• Page Start: 6064
• Page End: 6084
• Publication Date: 2016-07-29
• Subjects: Lepidoptera -- male sex pheromone -- mitochondrial introgression -- population divergence -- reproductive isolation -- speciation; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.2298
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Sexual traits are often the most divergent characters among closely related species, suggesting an important role of sexual traits in speciation. However, to prove this, we need to show that sexual trait differences accumulate before or during the speciation process, rather than being a consequence of it. Here, we contrast patterns of divergence among putative male sex pheromone (pMSP) composition and the genetic structure inferred from variation in the mitochondrial cytochrome oxidase 1 and nuclear CAD loci in the African butterfly Bicyclus anynana (Butler, 1879) to determine whether the evolution of "pheromonal dialects" occurs before or after the differentiation process. We observed differences in abundance of some shared pMSP components as well as differences in the composition of the pMSP among B. anynana populations. In addition, B. anynana individuals from Kenya displayed differences in the pMSP composition within a single population that appeared not associated with genetic differences. These differences in pMSP composition both between and within B. anynana populations were as large as those found between different Bicyclus species. Our results suggest that "pheromonal dialects" evolved within and among populations of B. anynana and may therefore act as precursors of an ongoing speciation process. Abstract : Strong divergence of sexual traits between species is often seen as a cue that they trigger reproductive isolation and speciation. As trait divergence can alternatively be a consequence of speciation, it is important to compare genetic and phenotypic divergence to know which arose first. We observed that the putative male sex pheromone in the butterfly Bicyclus anynana diverged among and within wild‐caught African populations despite no or low genetic differentiation. Sex pheromone composition may therefore act as a precursor of reproductive isolation and speciation in this butterfly group.