Sexual selection and the evolution of secondary sexual traits: Sex comb evolution in Drosophila

Rhonda R. Snook, Nelly A. Gidaszewski, Tracey Chapman, Leigh W. Simmons

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)

Abstract

Sexual selection can drive rapid evolutionary change in reproductive behaviour, morphology and physiology. This often leads to the evolution of sexual dimorphism, and continued exaggerated expression of dimorphic sexual characteristics, although a variety of other alternative selection scenarios exist. Here, we examined the evolutionary significance of a rapidly evolving, sexually dimorphic trait, sex comb tooth number, in two Drosophila species. The presence of the sex comb in both D. melanogaster and D. pseudoobscura is known to be positively related to mating success, although little is yet known about the sexually selected benefits of sex comb structure. In this study, we used experimental evolution to test the idea that enhancing or eliminating sexual selection would lead to variation in sex comb tooth number. However, the results showed no effect of either enforced monogamy or elevated promiscuity on this trait. We discuss several hypotheses to explain the lack of divergence, focussing on sexually antagonistic coevolution, stabilizing selection via species recognition and nonlinear selection. We discuss how these are important, but relatively ignored, alternatives in understanding the evolution of rapidly evolving sexually dimorphic traits.
Original languageEnglish
Pages (from-to)912-918
Number of pages7
JournalJournal of Evolutionary Biology
Volume26
Issue number4
DOIs
Publication statusPublished - 1 Apr 2013

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