Premium
DECOUPLING OF RAPID AND ADAPTIVE EVOLUTION AMONG SEMINAL FLUID PROTEINS IN HELICONIUS BUTTERFLIES WITH DIVERGENT MATING SYSTEMS
Author(s) -
Walters James R.,
Harrison Richard G.
Publication year - 2011
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.2011.01351.x
Subject(s) - heliconius , biology , sexual selection , mating , evolutionary biology , mate choice , mating system , zoology , mimicry
Reproductive proteins often diverge rapidly between species. This pattern is frequently attributed to postmating sexual selection. Heliconius butterflies offer a good opportunity to examine this hypothesis by contrasting patterns of reproductive protein evolution between clades with divergent mating systems. Pupal‐mating Heliconius females typically mate only once, limiting opportunity for postmating sexual selection. In contrast, adult‐mating females remate throughout life. Reproductive protein evolution is therefore predicted to be slower and show little evidence of positive selection in the pupal‐mating clade. We examined this prediction by sequencing 18 seminal fluid protein genes from a dozen Heliconius species and a related outgroup. Two proteins exhibited d N /d S > 1, implicating positive selection in the rapid evolution of at least a few Heliconius seminal fluid proteins. However, contrary to predictions, the average evolutionary rate of seminal fluid proteins was greater among pupal‐mating Heliconius . Based on these results, we suggest that positive selection and relaxed constraint can generate conflicting patterns of reproductive protein evolution between mating systems. As predicted, some loci may show elevated evolutionary rates in promiscuous taxa relative to monandrous taxa resulting from adaptations to postmating sexual selection. However, when monandry is derived (as in Heliconius ), the opposite pattern may result from relaxed selective constraints.