title: Mating portfolios: bet-hedging, sexual selection and female multiple mating.
abstract: Polyandry (female multiple mating) has profound evolutionary and ecological implications. Despite considerable work devoted to understanding why females mate multiply, we currently lack convincing empirical evidence to explain the adaptive value of polyandry. Here, we provide a direct test of the controversial idea that bet-hedging functions as a risk-spreading strategy that yields multi-generational fitness benefits to polyandrous females. Unfortunately, testing this hypothesis is far from trivial, and the empirical comparison of the across-generations fitness payoffs of a polyandrous (bet hedger) versus a monandrous (non-bet hedger) strategy has never been accomplished because of numerous experimental constraints presented by most 'model' species. In this study, we take advantage of the extraordinary tractability and versatility of a marine broadcast spawning invertebrate to overcome these challenges. We are able to simulate multi-generational (geometric mean) fitness among individual females assigned simultaneously to a polyandrous and monandrous mating strategy. Our approaches, which separate and account for the effects of sexual selection and pure bet-hedging scenarios, reveal that bet-hedging, in addition to sexual selection, can enhance evolutionary fitness in multiply mated females. In addition to offering a tractable experimental approach for addressing bet-hedging theory, our study provides key insights into the evolutionary ecology of sexual interactions.
authors.affiliation: Doñana Biological Station, Spanish Research Council CSIC, c/Americo Vespucio, s/n, Isla de la Cartuja 41092, Sevilla, Spain Centre for Evolutionary Biology, University of Western Australia, School of Animal Biology M092, Nedlands 6009, Western Australia paco.garcia@ebd.csic.es paco.garcia@uwa.edu.au.
authors.forename: Francisco
authors.identifier: http://orcid.org/0000-0001-9515-9038
authors.initials: F
authors.lastname: Garcia-Gonzalez
authors.affiliation: Laboratory of Entomology, Faculty of Agriculture, Kagawa University, Ikenobe 2393, Miki-cho, Kita-gun, Kagawa 761-0795, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Yasui
authors.affiliation: Centre for Evolutionary Biology, University of Western Australia, School of Animal Biology M092, Nedlands 6009, Western Australia.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Evans
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D052586:Mating Preference, Animal; D012617:Sea Urchins / Q000502:physiology*
keywords: Heliocidaris erythrogramma armigera; evolution of polyandry; geometric mean fitness; post-copulatory sexual selection; promiscuity; stochasticity