TY - JOUR A1 - Breitkopf, Hendrik A1 - Onstein, Renske E. A1 - Cafasso, Donata A1 - Schlüter, Philipp M. A1 - Cozzolino, Salvatore T1 - Multiple shifts to different pollinators fuelled rapid diversification in sexually deceptive Ophrys orchids JF - New phytologist : international journal of plant science N2 - 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. KW - Andrena KW - diversification rates KW - Eucera KW - Ophrys KW - pollination syndrome KW - pollinator shift KW - sexual deception (SD) KW - species radiation Y1 - 2015 U6 - https://doi.org/10.1111/nph.13219 SN - 0028-646X SN - 1469-8137 VL - 207 IS - 2 SP - 377 EP - 389 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Breitkopf, Hendrik A1 - Schlüter, P. M. A1 - Xu, S. A1 - Schiestl, Florian P. A1 - Cozzolino, S. A1 - Scopece, G. T1 - Pollinator shifts between Ophrys sphegodes populations: might adaptation to different pollinators drive population divergence? JF - Journal of evolutionary biology N2 - Local adaptation to different pollinators is considered one of the possible initial stages of ecological speciation as reproductive isolation is a by-product of the divergence in pollination systems. However, pollinator-mediated divergent selection will not necessarily result in complete reproductive isolation, because incipient speciation is often overcome by gene flow. We investigated the potential of pollinator shift in the sexually deceptive orchids Ophrys sphegodes and Ophrys exaltata and compared the levels of floral isolation vs. genetic distance among populations with contrasting predominant pollinators. We analysed floral hydrocarbons as a proxy for floral divergence between populations. Floral adoption of pollinators and their fidelity was tested using pollinator choice experiments. Interpopulation gene flow and population differentiation levels were estimated using AFLP markers. The Tyrrhenian O.sphegodes population preferentially attracted the pollinator bee Andrena bimaculata, whereas the Adriatic O.sphegodes population exclusively attracted A.nigroaenea. Significant differences in scent component proportions were identified in O.sphegodes populations that attracted different preferred pollinators. High interpopulation gene flow was detected, but populations were genetically structured at species level. The high interpopulation gene flow levels independent of preferred pollinators suggest that local adaptation to different pollinators has not (yet) generated detectable genome-wide separation. Alternatively, despite extensive gene flow, few genes underlying floral isolation remain differentiated as a consequence of divergent selection. Different pollination ecotypes in O.sphegodes might represent a local selective response imposed by temporal variation in a geographical mosaic of pollinators as a consequence of the frequent disturbance regimes typical of Ophrys habitats. KW - adaptation KW - ecotypes KW - floral scent KW - gene flow KW - Ophrys KW - orchids KW - pollinator shift KW - sexual deception KW - speciation Y1 - 2013 U6 - https://doi.org/10.1111/jeb.12216 SN - 1010-061X SN - 1420-9101 VL - 26 IS - 10 SP - 2197 EP - 2208 PB - Wiley-Blackwell CY - Hoboken ER -