title: Multiple shifts to different pollinators fuelled rapid diversification in sexually deceptive Ophrys orchids.
abstract: Episodes of rapid speciation provide unique insights into evolutionary processes underlying species radiations and patterns of biodiversity. Here we investigated the radiation of sexually deceptive bee orchids (Ophrys). Based on a time-calibrated phylogeny and by means of ancestral character reconstruction and divergence time estimation, we estimated the tempo and mode of this radiation within a state-dependent evolutionary framework. It appears that, in the Pleistocene, the evolution of Ophrys was marked by episodes of rapid diversification coinciding with shifts to different pollinator types: from wasps to Eucera bees to Andrena and other bees. An abrupt increase in net diversification rate was detected in three clades. Among these, two phylogenetically distant lineages switched from Eucera to Andrena and other bees in a parallel fashion and at about the same time in their evolutionary history. Lack of early radiation associated with the evolution of the key innovation of sexual deception suggests that Ophrys diversification was mainly driven by subsequent ecological opportunities provided by the exploitation of novel pollinator groups, encompassing many bee species slightly differing in their sex pheromone communication systems, and by spatiotemporal fluctuations in the pollinator mosaic.
authors.affiliation: Department of Biology, University of Naples Federico II, Naples, Italy.|Institute of Biochemistry and Biology, Biodiversity Research/Systematic Botany, University of Potsdam, Potsdam, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Breitkopf
authors.affiliation: Institute of Systematic Botany, University of Zurich, Zurich, Switzerland.
authors.forename: Renske E
authors.initials: RE
authors.lastname: Onstein
authors.affiliation: Department of Biology, University of Naples Federico II, Naples, Italy.
authors.forename: Donata
authors.initials: D
authors.lastname: Cafasso
authors.affiliation: Institute of Systematic Botany, University of Zurich, Zurich, Switzerland.
authors.forename: Philipp M
authors.initials: PM
authors.lastname: Schlüter
authors.affiliation: Department of Biology, University of Naples Federico II, Naples, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cozzolino
mesh_terms: D000818:Animals; D001516:Bees; D044822:Biodiversity; D005075:Biological Evolution; D004463:Ecology; D035264:Flowers; D029595:Orchidaceae / Q000235:genetics*; D010675:Pheromones; D010802:Phylogeny; D054817:Pollination
chemical_list: D010675:Pheromones
keywords: Andrena; Eucera; Ophrys; diversification rates; pollination syndrome; pollinator shift; sexual deception (SD); species radiation