| 1. |
- Anderson, Bruce, et al.
(författare)
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Opposing effects of plant traits on diversification
- 2023
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Ingår i: iScience. - : Cell Press. - 2589-0042. ; 26:4
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Tidskriftsartikel (refereegranskat)abstract
- Species diversity can vary dramatically across lineages due to differences in speciation and extinction rates. Here, we explore the effects of several plant traits on diversification, finding that most traits have opposing effects on diversification. For example, outcrossing may increase the efficacy of selection and adaptation but also decrease mate availability, two processes with contrasting effects on lineage persistence. Such opposing trait effects can manifest as differences in diversification rates that depend on ecological context, spatiotemporal scale, and associations with other traits. The complexity of pathways linking traits to diversification suggests that the mechanistic underpinnings behind their correlations may be difficult to interpret with any certainty, and context dependence means that the effects of specific traits on diversification are likely to differ across multiple lineages and timescales. This calls for taxonomically and context-controlled approaches to studies that correlate traits and diversification.
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| 2. |
- Arroyo-Correa, Blanca, et al.
(författare)
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Bee and floral traits affect the characteristics of the vibrations experienced by flowers during buzz-pollination
- 2019
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Ingår i: Journal of Experimental Biology. - : The Company of Biologists Ltd. - 0022-0949 .- 1477-9145. ; 222:4
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Tidskriftsartikel (refereegranskat)abstract
- During buzz pollination, bees use their indirect flight muscles to produce vibrations that are transmitted to the flowers and result in pollen release. Although buzz pollination has been known for >100 years, we are still in the early stages of understanding how bee and floral characteristics affect the production and transmission of floral vibrations. Here, we analysed floral vibrations produced by four closely related bumblebee taxa (Bombus spp.) on two buzz-pollinated plants species (Solanum spp.). We measured floral vibrations transmitted to the flower to establish the extent to which the mechanical properties of floral vibrations depend on bee and plant characteristics. By comparing four bee taxa visiting the same plant species, we found that peak acceleration, root mean-squared acceleration (RMS) and frequency vary between bee taxa, but that neither bee size (intertegular distance) nor flower biomass (dry mass) affects peak acceleration, RMS or frequency. A comparison of floral vibrations of two bee taxa visiting flowers of two plant species showed that, while bee species affects peak acceleration, RMS and frequency, plant species only affects acceleration (peak acceleration and RMS), not frequency. When accounting for differences in the transmission of vibrations across the two types of flower, using a species-specific ‘coupling factor’, we found that RMS acceleration and peak displacement do not differ between plant species. This suggests that bees produce the same initial acceleration in different plants but that transmission of these vibrations through the flower is affected by floral characteristics.
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| 3. |
- Baduel, Pierre, et al.
(författare)
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The “polyploid hop” : shifting challenges and opportunities over the evolutionary lifespan of genome duplications
- 2018
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Ingår i: Frontiers in Ecology and Evolution. - : Frontiers Media S.A.. - 2296-701X. ; 6:117
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Tidskriftsartikel (refereegranskat)abstract
- The duplication of an entire genome is no small affair. Whole genome duplication (WGD) is a dramatic mutation with long-lasting effects, yet it occurs repeatedly in all eukaryotic kingdoms. Plants are particularly rich in documented WGDs, with recent and ancient polyploidization events in all major extant lineages. However, challenges immediately following WGD, such as the maintenance of stable chromosome segregation or detrimental ecological interactions with diploid progenitors, commonly do not permit establishment of nascent polyploids. Despite these immediate issues some lineages nevertheless persist and thrive. In fact, ecological modeling commonly supports patterns of adaptive niche differentiation in polyploids, with young polyploids often invading new niches and leaving their diploid progenitors behind. In line with these observations of polyploid evolutionary success, recent work documents instant physiological consequences of WGD associated with increased dehydration stress tolerance in first-generation autotetraploids. Furthermore, population genetic theory predicts both short- and long-term benefits of polyploidy and new empirical data suggests that established polyploids may act as “sponges” accumulating adaptive allelic diversity. In addition to their increased genetic variability, introgression with other tetraploid lineages, diploid progenitors, or even other species, further increases the available pool of genetic variants to polyploids. Despite this, the evolutionary advantages of polyploidy are still questioned, and the debate over the idea of polyploidy as an evolutionary dead-end carries on. Here we broadly synthesize the newest empirical data moving this debate forward. Altogether, evidence suggests that if early barriers are overcome, WGD can offer instantaneous fitness advantages opening the way to a transformed fitness landscape by sampling a higher diversity of alleles, including some already preadapted to their local environment. This occurs in the context of intragenomic, population genomic, and physiological modifications that can, on occasion, offer an evolutionary edge. Yet in the long run, early advantages can turn into long-term hindrances, and without ecological drivers such as novel ecological niche availability or agricultural propagation, a restabilization of the genome via diploidization will begin the cycle anew.
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| 4. |
- Brito, Vinicius Lourenço Garcia, et al.
(författare)
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Biomechanical properties of a buzz-pollinated flower
- 2020
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Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 7:9
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Tidskriftsartikel (refereegranskat)abstract
- Approximately half of all bee species use vibrations to remove pollen from plants with diverse floral morphologies. In many buzz-pollinated flowers, these mechanical vibrations generated by bees are transmitted through floral tissues, principally pollen-containing anthers, causing pollen to be ejected from small openings (pores or slits) at the tip of the stamen. Despite the importance of substrate-borne vibrations for both bees and plants, few studies to date have characterized the transmission properties of floral vibrations. In this study, we use contactless laser vibrometry to evaluate the transmission of vibrations in the corolla and anthers of buzz-pollinated flowers of Solanum rostratum, and measure vibrations in three spatial axes. We found that floral vibrations conserve their dominant frequency (300 Hz) as they are transmitted throughout the flower. We also found that vibration amplitude at anthers and petals can be up to greater than 400% higher than input amplitude applied at the receptacle at the base of the flower, and that anthers vibrate with a higher amplitude velocity than petals. Together, these results suggest that vibrations travel differently through floral structures and across different spatial axes. As pollen release is a function of vibration amplitude, we conjecture that bees might benefit from applying vibrations in the axes associated with higher vibration amplification.
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| 5. |
- Cooley, Hazel, et al.
(författare)
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Buzz-pollinated crops : A global review and meta-analysis of the effects of supplemental bee pollination in tomato
- 2021
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Ingår i: Journal of Economic Entomology. - : Oxford University Press. - 0022-0493 .- 1938-291X. ; 114:2, s. 505-519
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Tidskriftsartikel (refereegranskat)abstract
- Buzz-pollinated plants require visitation from vibration producing bee species to elicit full pollen release. Several important food crops are buzz-pollinated including tomato, eggplant, kiwi, and blueberry. Although more than half of all bee species can buzz pollinate, the most commonly deployed supplemental pollinator, Apis mellifera L. (Hymenoptera: Apidae; honey bees), cannot produce vibrations to remove pollen. Here, we provide a list of buzz-pollinated food crops and discuss the extent to which they rely on pollination by vibration-producing bees. We then use the most commonly cultivated of these crops, the tomato, Solanum lycopersicum L. (Solanales: Solanaceae), as a case study to investigate the effect of different pollination treatments on aspects of fruit quality. Following a systematic review of the literature, we statistically analyzed 71 experiments from 24 studies across different geopolitical regions and conducted a meta-analysis on a subset of 21 of these experiments. Our results show that both supplemental pollination by buzz-pollinating bees and open pollination by assemblages of bees, which include buzz pollinators, significantly increase tomato fruit weight compared to a no-pollination control. In contrast, auxin treatment, artificial mechanical vibrations, or supplemental pollination by non-buzz-pollinating bees (including Apis spp.), do not significantly increase fruit weight. Finally, we compare strategies for providing bee pollination in tomato cultivation around the globe and highlight how using buzz-pollinating bees might improve tomato yield, particularly in some geographic regions. We conclude that employing native, wild buzz pollinators can deliver important economic benefits with reduced environmental risks and increased advantages for both developed and emerging economies.
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| 6. |
- Da Re, Daniele, et al.
(författare)
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Global analysis of ecological niche conservation and niche shift in exotic populations of monkeyflowers (Mimulus guttatus, M. luteus) and their hybrid (M. × robertsii)
- 2020
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Ingår i: Plant Ecology & Diversity. - : Taylor & Francis Group. - 1755-0874 .- 1755-1668. ; 13:2, s. 133-146
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Tidskriftsartikel (refereegranskat)abstract
- Background Hybridisation associated with biological invasions may generate new phenotypic combinations, allowing hybrids to occupy new ecological niches. To date, few studies have assessed niche shifts associated with hybridisation in recently introduced populations while simultaneously characterising the niche of parental species in both native and introduced ranges.Aims Here, we compared (1) the ecological niche of a novel hybrid monkeyflower,M. xrobertsii, with the niches of its two parental taxa (M. guttatus, M. luteus), and (2) the ecological niches of native (Americas) and introduced parental populations (Europe and New Zealand).Methods We assembled >13,000 geo-referenced occurrence records and eight environmental variables and conducted an ecological niche model analysis using maximum entropy, principal component and niche dynamics analysis.Results We found no evidence of niche shift in the hybrid, which may result in potential competition between parental and derived taxa in the introduced range.M. guttatusshowed niche conservatism in introduced populations in Europe, but a niche shift in New Zealand, whileM. luteusshowed a niche shift in Europe.Conclusions The comparison of native and non-native populations of parental taxa, suggests that whether invasions result in niche shifts or not depends on both taxon and geographic region, highlighting the idiosyncratic nature of biological invasions.
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| 7. |
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| 8. |
- De Luca, P. A., et al.
(författare)
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Does body size predict the buzz-pollination frequencies used by bees?
- 2019
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 9:8, s. 4875-4887
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Tidskriftsartikel (refereegranskat)abstract
- Body size is an important trait linking pollinators and plants. Morphological matching between pollinators and plants is thought to reinforce pollinator fidelity, as the correct fit ensures that both parties benefit from the interaction. We investigated the influence of body size in a specialized pollination system (buzz-pollination) where bees vibrate flowers to release pollen concealed within poricidal stamens. Specifically, we explored how body size influences the frequency of buzz-pollination vibrations. Body size is expected to affect frequency as a result of the physical constraints it places on the indirect flight muscles that control the production of floral vibrations. Larger insects beat their wings less rapidly than smaller-bodied insects when flying, but whether similar scaling relationships exist with floral vibrations has not been widely explored. This is important because the amount of pollen ejected is determined by the frequency of the vibration and the displacement of a bee's thorax. We conducted a field study in three ecogeographic regions (alpine, desert, grassland) and recorded flight and floral vibrations from freely foraging bees from 27 species across four families. We found that floral vibration frequencies were significantly higher than flight frequencies, but never exceeded 400Hz. Also, only flight frequencies were negatively correlated with body size. As a bee's size increased, its buzz ratio (floral frequency/flight frequency) increased such that only the largest bees were capable of generating floral vibration frequencies that exceeded double that of their flight vibrations. These results indicate size affects the capacity of bees to raise floral vibration frequencies substantially above flight frequencies. This may put smaller bees at a competitive disadvantage because even at the maximum floral vibration frequency of 400Hz, their inability to achieve comparable thoracic displacements as larger bees would result in generating vibrations with lower amplitudes, and thus less total pollen ejected for the same foraging effort.
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| 9. |
- Helmstetter, Andrew J., et al.
(författare)
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Trait‐dependent diversification in angiosperms : Patterns, models and data
- 2023
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Ingår i: Ecology Letters. - : John Wiley & Sons. - 1461-023X .- 1461-0248. ; 26:4, s. 640-657
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Tidskriftsartikel (refereegranskat)abstract
- Variation in species richness across the tree of life, accompanied by the incredible variety of ecological and morphological characteristics found in nature, has inspired many studies to link traits with species diversification. Angiosperms are a highly diverse group that has fundamentally shaped life on earth since the Cretaceous, and illustrate how species diversification affects ecosystem functioning. Numerous traits and processes have been linked to differences in species richness within this group, but we know little about their relative importance and how they interact. Here, we synthesised data from 152 studies that used state-dependent speciation and extinction (SSE) models on angiosperm clades. Intrinsic traits related to reproduction and morphology were often linked to diversification but a set of universal drivers did not emerge as traits did not have consistent effects across clades. Importantly, SSE model results were correlated to data set properties - trees that were larger, older or less well-sampled tended to yield trait-dependent outcomes. We compared these properties to recommendations for SSE model use and provide a set of best practices to follow when designing studies and reporting results. Finally, we argue that SSE model inferences should be considered in a larger context incorporating species' ecology, demography and genetics.
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| 10. |
- Huang, Wen, et al.
(författare)
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Bumblebees' flower preferences are associated with floral abundance and buzz frequency when buzz-pollinating co-flowering plants
- 2024
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Ingår i: Entomologia generalis. - : E. Schweizerbart'sche Verlagsbuchhandlung. - 0171-8177. ; 44:1, s. 133-141
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Tidskriftsartikel (refereegranskat)abstract
- Buzz-pollination is used by some bees to expel pollen through vibrating flowers. Yet, little is known about the determinants influencing bee preferences among buzz-pollinated flowers. We studied five co-flowering, nectarless species of Pedicularis (Orobanchaceae) buzz-pollinated by bumblebees in an alpine meadow, to investigate bumblebees' flower preferences in response to fluctuations of floral abundance across five years. We also recorded and analyzed the buzzing frequencies produced by the three dominant bumblebee specie. Our results indicate that Bombus friseanus and B. lepidus visited different Pedicularis flowers using similar buzz frequencies and displayed an abundance-dependent flower preference across years. These two bumblebee species had staggered phenologies with distinct timing of peak abundances across the five years. In contrast, B. festivus used lower fundamental buzz frequencies, had a constant flower preference across years, but used different buzz frequencies across Pedicularis species. Although the amount of pollen released after bumblebee visitation varied across Pedicularis species, we found that after a single visit all bumblebees deposited similar amounts of pollen on stigmas. Our study indicates that bumblebees' flower preferences is sometimes, but not always, modulated by floral abundance, and that at least one bumblebee species was observed to produce buzzes of different frequencies in different plant species. Competition for floral resources among bumblebees and for pollination services among co-flowering Pedicularis species may structure plant-pollinator interactions and affect species coexistence.
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