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Chartier M, Jabbour F, Gerber S, Mitteroecker P, Sauquet H, von Balthazar M, Staedler Y, Crane PR, Schönenberger J. The floral morphospace--a modern comparative approach to study angiosperm evolution. THE NEW PHYTOLOGIST 2014; 204:841-53. [PMID: 25539005 PMCID: PMC5526441 DOI: 10.1111/nph.12969] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Morphospaces are mathematical representations used for studying the evolution of morphological diversity and for the evaluation of evolved shapes among theoretically possible ones. Although widely used in zoology, they--with few exceptions--have been disregarded in plant science and in particular in the study of broad-scale patterns of floral structure and evolution. Here we provide basic information on the morphospace approach; we review earlier morphospace applications in plant science; and as a practical example, we construct and analyze a floral morphospace. Morphospaces are usually visualized with the help of ordination methods such as principal component analysis (PCA) or nonmetric multidimensional scaling (NMDS). The results of these analyses are then coupled with disparity indices that describe the spread of taxa in the space. We discuss these methods and apply modern statistical tools to the first and only angiosperm-wide floral morphospace published by Stebbins in 1951. Despite the incompleteness of Stebbins’ original dataset, our analyses highlight major, angiosperm-wide trends in the diversity of flower morphology and thereby demonstrate the power of this previously neglected approach in plant science.
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Affiliation(s)
- Marion Chartier
- Department of Botany and Biodiversity Research, University of
Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Florian Jabbour
- Institute of Systematics, Evolution and Biodiversity, National
Museum of Natural History, 57 rue Cuvier – CP 39, 75231 Paris Cedex 05,
France
| | - Sylvain Gerber
- Department of Earth Sciences, University of Cambridge, Downing
Street, Cambridge, CB2 3EQ, UK
| | - Philipp Mitteroecker
- Department of Theoretical Biology, Vienna University, Althanstrasse
14, 1090 Vienna, Austria
| | - Hervé Sauquet
- Laboratoire Écologie, Systématique, Évolution,
Université Paris-Sud, CNRS UMR 8079, 91405 Orsay, France
| | - Maria von Balthazar
- Department of Botany and Biodiversity Research, University of
Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Yannick Staedler
- Department of Botany and Biodiversity Research, University of
Vienna, Rennweg 14, 1030 Vienna, Austria
| | - Peter R. Crane
- Yale School of Forestry and Environmental Studies, 195 Prospect
Street, New Haven, CT 06511, USA
| | - Jürg Schönenberger
- Department of Botany and Biodiversity Research, University of
Vienna, Rennweg 14, 1030 Vienna, Austria
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Wessinger CA, Rausher MD. Ecological transition predictably associated with gene degeneration. Mol Biol Evol 2014; 32:347-54. [PMID: 25371436 DOI: 10.1093/molbev/msu298] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Gene degeneration or loss can significantly contribute to phenotypic diversification, but may generate genetic constraints on future evolutionary trajectories, potentially restricting phenotypic reversal. Such constraints may manifest as directional evolutionary trends when parallel phenotypic shifts consistently involve gene degeneration or loss. Here, we demonstrate that widespread parallel evolution in Penstemon from blue to red flowers predictably involves the functional inactivation and degeneration of the enzyme flavonoid 3',5'-hydroxylase (F3'5'H), an anthocyanin pathway enzyme required for the production of blue floral pigments. Other types of genetic mutations do not consistently accompany this phenotypic shift. This pattern may be driven by the relatively large mutational target size of degenerative mutations to this locus and the apparent lack of associated pleiotropic effects. The consistent degeneration of F3'5'H may provide a mechanistic explanation for the observed asymmetry in the direction of flower color evolution in Penstemon: Blue to red transitions are common, but reverse transitions have not been observed. Although phenotypic shifts in this system are likely driven by natural selection, internal constraints may generate predictable genetic outcomes and may restrict future evolutionary trajectories.
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Rodrigues LC, Rodrigues M. Flowers visited by hummingbirds in the open habitats of the southeastern brazilian mountaintops: species composition and seasonality. BRAZ J BIOL 2014; 74:659-76. [DOI: 10.1590/bjb.2014.0097] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 05/09/2013] [Indexed: 11/22/2022] Open
Abstract
The hummingbird-visited plant community located on the open-habitat mountaintop of the Espinhaço Range was studied for two years (from August 2007 to July 2009) in Serra do Cipó National Park, Southeastern Brazil (19° 15′ S and 43° 31′ W). The floral characteristics and flowering period of the hummingbird-visited plants was monthly recorded along trails located in three vegetation types: (1) typical campos rupestres (TCR), (2) open fields (OPF), and (3) capões de mata(CAM). Hummingbird visitation was observed in 51 plant species, 22 ornithophilous and 29 non-ornithophilous species. The TCR showed the greatest number of species visited (N = 38), followed by the OPF (N = 18) and CAM (N = 17). Six species of hummingbirds were recorded visiting flowers: Augastes scutatus, Campylopterus largipennis, Colibri serrirostris, Chlorostilbon lucidus, Eupetomena macroura and Phaethornis pretrei. This study demonstrates that the species richness and the number of ornithophilous species visited by the hummingbirds at the study site are more similar to hummingbird-plant communities of the Atlantic Forest than to those of the Cerrado communities and other Brazilian highland open-habitat communities. The plant families most visited by hummingbirds were Bromeliaceae and Asteraceae. Although the Asteraceae family is rarely used as a food resource for hummingbirds in other high and lowland communities, in the study site this family is used mainly by the endemic hummingbird Augastes scutatus. We found a large overlap of flowering throughout the year among the species visited by the hummingbirds. Thus, the nectar availability supports these resident hummingbirds. The present study also showed that the studied hummingbird-plant community is composed of many species endemic to the campos rupestres of the Espinhaço Range, some of which are considered to be in danger of extinction, thus constituting a unique and threatened community. Thus, understanding hummingbird-plant pollination dynamics becomes fundamental to the conservation of the campos rupestres.
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Affiliation(s)
- LC Rodrigues
- Universidade Federal de Minas Gerais – UFMG, Brazil
| | - M Rodrigues
- Universidade Federal de Minas Gerais – UFMG, Brazil
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Cane JH, Dunne R. Generalist Bees Pollinate Red-flowered Penstemon eatonii: Duality in the Hummingbird Pollination Syndrome. AMERICAN MIDLAND NATURALIST 2014. [DOI: 10.1674/0003-0031-171.2.365] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Boberg E, Alexandersson R, Jonsson M, Maad J, Ågren J, Nilsson LA. Pollinator shifts and the evolution of spur length in the moth-pollinated orchid Platanthera bifolia. ANNALS OF BOTANY 2014; 113:267-75. [PMID: 24169591 PMCID: PMC3890388 DOI: 10.1093/aob/mct217] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS Plant-pollinator interactions are thought to have shaped much of floral evolution. Yet the relative importance of pollinator shifts and coevolutionary interactions for among-population variation in floral traits in animal-pollinated species is poorly known. This study examined the adaptive significance of spur length in the moth-pollinated orchid Platanthera bifolia. METHODS Geographical variation in the length of the floral spur of P. bifolia was documented in relation to variation in the pollinator fauna across Scandinavia, and a reciprocal translocation experiment was conducted in south-east Sweden between a long-spurred woodland population and a short-spurred grassland population. KEY RESULTS Spur length and pollinator fauna varied among regions and habitats, and spur length was positively correlated with the proboscis length of local pollinators. In the reciprocal translocation experiment, long-spurred woodland plants had higher pollination success than short-spurred grassland plants at the woodland site, while no significant difference was observed at the grassland site. CONCLUSIONS The results are consistent with the hypothesis that optimal floral phenotype varies with the morphology of the local pollinators, and that the evolution of spur length in P. bifolia has been largely driven by pollinator shifts.
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Gómez JM, Muñoz-Pajares AJ, Abdelaziz M, Lorite J, Perfectti F. Evolution of pollination niches and floral divergence in the generalist plant Erysimum mediohispanicum. ANNALS OF BOTANY 2014; 113:237-49. [PMID: 23965614 PMCID: PMC3890381 DOI: 10.1093/aob/mct186] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 06/21/2013] [Indexed: 05/23/2023]
Abstract
BACKGROUND AND AIMS How generalist plants diverge in response to pollinator selection without becoming specialized is still unknown. This study explores this question, focusing on the evolution of the pollination system in the pollination generalist Erysimum mediohispanicum (Brassicaceae). METHODS Pollinator assemblages were surveyed from 2001 to 2010 in 48 geo-referenced populations covering the entire geographic distribution of E. mediohispanicum. Bipartite modularity, a complex network tool, was used to find the pollination niche of each population. Evolution of the pollination niches and the correlated evolution of floral traits and pollination niches were explored using within-species comparative analyses. KEY RESULTS Despite being generalists, the E. mediohispanicum populations studied can be classified into five pollination niches. The boundaries between niches were not sharp, the niches differing among them in the relative frequencies of the floral visitor functional groups. The absence of spatial autocorrelation and phylogenetic signal indicates that the niches were distributed in a phylogeographic mosaic. The ancestral E. mediohispanicum populations presumably belonged to the niche defined by a high number of beetle and ant visits. A correlated evolution was found between pollination niches and some floral traits, suggesting the existence of generalist pollination ecotypes. CONCLUSIONS It is conjectured that the geographic variation in pollination niches has contributed to the observed floral divergence in E. mediohispanicum. The process mediating this floral divergence presumably has been adaptive wandering, but the adaptation to the local pollinator faunas has been not universal. The outcome is a landscape where a few populations locally adapted to their pollination environment (generalist pollination ecotypes) coexist with many populations where this local adaptation has failed and where the plant phenotype is not primarily shaped by pollinators.
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Affiliation(s)
| | | | | | - J. Lorite
- Departamento de Botánica, Universidad de Granada, E-18071 Granada, Spain
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Abstract
Ecological networks of two interacting guilds of species, such as flowering plants and pollinators, are common in nature, and studying their structure can yield insights into their resilience to environmental disturbances. Here we develop analytical methods for exploring the strengths of interactions within bipartite networks consisting of two guilds of phylogenetically related species. We then apply these methods to investigate the resilience of a plant-pollinator community to anticipated climate change. The methods allow the statistical assessment of, for example, whether closely related pollinators are more likely to visit plants with similar relative frequencies, and whether closely related pollinators tend to visit closely related plants. The methods can also incorporate trait information, allowing us to identify which plant traits are likely responsible for attracting different pollinators. These questions are important for our study of 14 prairie plants and their 22 insect pollinators. Over the last 70 years, six of the plants have advanced their flowering, while eight have not. When we experimentally forced earlier flowering times, five of the six advanced-flowering species experienced higher pollinator visitation rates, whereas only one of the eight other species had more visits; this network thus appears resilient to climate change, because those species with advanced flowering have ample pollinators earlier in the season. Using the methods developed here, we show that advanced-flowering plants did not have a distinct pollinator community from the other eight species. Furthermore, pollinator phylogeny did not explain pollinator community composition; closely related pollinators were not more likely to visit the same plant species. However, differences among pollinator communities visiting different plants were explained by plant height, floral color, and symmetry. As a result, closely related plants attracted similar numbers of pollinators. By parsing out characteristics that explain why plants share pollinators, we can identify plant species that likely share a common fate in a changing climate.
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Affiliation(s)
- Nicole E Rafferty
- Department of Zoology, University of Wisconsin, Madison, Wisconsin 53706, USA.
| | - Anthony R Ives
- Department of Zoology, University of Wisconsin, Madison, Wisconsin 53706, USA
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Johnson KA. Are there pollination syndromes in the Australian epacrids (Ericaceae: Styphelioideae)? A novel statistical method to identify key floral traits per syndrome. ANNALS OF BOTANY 2013; 112:141-9. [PMID: 23681546 PMCID: PMC3690994 DOI: 10.1093/aob/mct105] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Convergent floral traits hypothesized as attracting particular pollinators are known as pollination syndromes. Floral diversity suggests that the Australian epacrid flora may be adapted to pollinator type. Currently there are empirical data on the pollination systems for 87 species (approx. 15 % of Australian epacrids). This provides an opportunity to test for pollination syndromes and their important morphological traits in an iconic element of the Australian flora. METHODS Data on epacrid-pollinator relationships were obtained from published literature and field observation. A multivariate approach was used to test whether epacrid floral attributes related to pollinator profiles. Statistical classification was then used to rank floral attributes according to their predictive value. Data sets excluding mixed pollination systems were used to test the predictive power of statistical classification to identify pollination models. KEY RESULTS Floral attributes are correlated with bird, fly and bee pollination. Using floral attributes identified as correlating with pollinator type, bird pollination is classified with 86 % accuracy, red flowers being the most important predictor. Fly and bee pollination are classified with 78 and 69 % accuracy, but have a lack of individually important floral predictors. Excluding mixed pollination systems improved the accuracy of the prediction of both bee and fly pollination systems. CONCLUSIONS Although most epacrids have generalized pollination systems, a correlation between bird pollination and red, long-tubed epacrids is found. Statistical classification highlights the relative importance of each floral attribute in relation to pollinator type and proves useful in classifying epacrids to bird, fly and bee pollination systems.
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Navarro-Pérez ML, López J, Fernández-Mazuecos M, Rodríguez-Riaño T, Vargas P, Ortega-Olivencia A. The role of birds and insects in pollination shifts of Scrophularia (Scrophulariaceae). Mol Phylogenet Evol 2013; 69:239-54. [PMID: 23756207 DOI: 10.1016/j.ympev.2013.05.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 05/17/2013] [Accepted: 05/31/2013] [Indexed: 10/26/2022]
Abstract
The mixed vertebrate-insect pollination system is rare in Holarctic plants. Phylogenetic relationships of 116 Scrophularia taxa were investigated based on two plastid (ndhF and trnL-trnF) and one nuclear (ITS) DNA regions. A wider time-calibrated analysis of ndhF sequences of the Lamiales revealed that Scrophularia diverged as early as in the Miocene (<22 Ma). Results of maximum-likelihood optimizations supported wasp pollination as the ancestral pollination system from which other systems derived (hoverfly, mixed vertebrate-insect and bird systems). Four origins for a mixed vertebrate-insect (MVI) pollination system were inferred, in which two western Mediterranean species (S. sambucifolia and S. grandiflora) and two island species (the Tirrenian S. trifoliata and the Canarian S. calliantha) were involved. S. calliantha is the only species in which a more complex MVI system, including pollination by the lizard Gallotia stehlini, has evolved. In addition, bird (hummingbird) floral traits found in the New Mexican S. macrantha appear to have been independently acquired. In contrast, we failed to find evidence for an ancient role of hummingbirds in the evolution of European Scrophularia. Indeed, paleontological data revealed that extinction of European hummingbirds (30-32 Ma) occurred earlier than the divergence of European MVI lineages of Scrophularia. In conclusion, our results showed that a role of birds in pollination of Scrophularia may not have been effective in the Miocene-Pliocene, but bird pollination that shows its origin in the Pliocene-Pleistocene is still operating independently in different islands and continents.
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Affiliation(s)
- María L Navarro-Pérez
- Área de Botánica, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s.n., 06006 Badajoz, Spain.
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Sakai S, Kawakita A, Ooi K, Inoue T. Variation in the strength of association among pollination systems and floral traits: evolutionary changes in the floral traits of Bornean gingers (Zingiberaceae). AMERICAN JOURNAL OF BOTANY 2013; 100:546-55. [PMID: 23425560 DOI: 10.3732/ajb.1200359] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
UNLABELLED PREMISE OF THE STUDY Diversification of floral traits in angiosperms is often attributed to have been driven by adaptations to pollinators. Nevertheless, phylogenetic studies on the relationships among evolutionary changes in floral traits and pollination systems are still limited. We examined the relationships between floral trait changes and pollinator shifts in Bornean gingers (Zingiberaceae). These plants have strongly zygomorphic flowers pollinated by spiderhunter birds, bees of the genus Amegilla, and halictid bees. • METHODS We identified pollination systems through field observations and recorded petal color, quantity of floral rewards, and seven measures of flower morphology in 28 ginger species. Phylogenetic trees were constructed from nucleotide sequences of the matK and ITS regions. We examined the correlations between the evolution of pollination systems and floral traits using phylogenetically independent contrasts. • KEY RESULTS Significant association was found between pink color and spiderhunter pollination, orange and Amegilla pollination, and yellow and white and halictid pollination. Sugar production was higher in spiderhunter-pollinated species and lower in halictid-pollinated. Meanwhile, there was a significant association only for a subset of the floral morphological characters measured. Floral tube length, which is often thought to evolve to match the lengths of pollinator probing apparatuses, did not show any correlation. • CONCLUSIONS There is considerable variation in the strength of association among pollination systems and floral traits. Lack of significant correlation in some traits could partly be explained by floral functions other than pollination, such as adaptations to prevent herbivore damage to the ovules. Further studies on these factors may improve understanding of plant-pollinator interactions.
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Affiliation(s)
- Shoko Sakai
- Research Institute for Humanity and Nature, Motoyama 457-4, Kamigamo, Kita-ku, Kyoto 606-8047, Japan.
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Parachnowitsch AL, Raguso RA, Kessler A. Phenotypic selection to increase floral scent emission, but not flower size or colour in bee-pollinated Penstemon digitalis. THE NEW PHYTOLOGIST 2012; 195:667-675. [PMID: 22646058 DOI: 10.1111/j.1469-8137.2012.04188.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Fragrance is a putatively important character in the evolution of flowering plants, but natural selection on scent is rarely studied and thus poorly understood. We characterized floral scent composition and emission in a common garden of Penstemon digitalis from three nearby source populations. We measured phenotypic selection on scent as well as floral traits more frequently examined, such as floral phenology, display size, corolla pigment, and inflorescence height. Scent differed among populations in a common garden, underscoring the potential for scent to be shaped by differential selection pressures. Phenotypic selection on flower number and display size was strong. However, selection favoured scent rather than flower size or colour, suggesting that smelling stronger benefits reproductive success in P. digitalis. Linalool was a direct target of selection and its high frequency in floral-scent bouquets suggests that further studies of both pollinator- and antagonist-mediated selection on this compound would further our understanding of scent evolution. Our results indicate that chemical dimensions of floral display are just as likely as other components to experience selective pressure in a nonspecialized flowering herb. Therefore, studies that integrate visual and chemical floral traits should better reflect the true nature of floral evolutionary ecology.
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Affiliation(s)
- Amy L Parachnowitsch
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Present address: Plant Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala 752 36, Sweden
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
| | - André Kessler
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
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Weber MG, Agrawal AA. Phylogeny, ecology, and the coupling of comparative and experimental approaches. Trends Ecol Evol 2012; 27:394-403. [DOI: 10.1016/j.tree.2012.04.010] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 04/20/2012] [Accepted: 04/23/2012] [Indexed: 11/27/2022]
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Brockmeyer T, Schaefer HM. Do nectar feeders in Andean nature reserves affect flower visitation by hummingbirds? Basic Appl Ecol 2012. [DOI: 10.1016/j.baae.2012.02.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Ortega-Olivencia A, Rodríguez-Riaño T, Pérez-Bote JL, López J, Mayo C, Valtueña FJ, Navarro-Pérez M. Insects, birds and lizards as pollinators of the largest-flowered Scrophularia of Europe and Macaronesia. ANNALS OF BOTANY 2012; 109:153-67. [PMID: 22021816 PMCID: PMC3241579 DOI: 10.1093/aob/mcr255] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS It has traditionally been considered that the flowers of Scrophularia are mainly pollinated by wasps. We studied the pollination system of four species which stand out for their large and showy flowers: S. sambucifolia and S. grandiflora (endemics of the western Mediterranean region), S. trifoliata (an endemic of the Tyrrhenian islands) and S. calliantha (an endemic of the Canary Islands). Our principal aim was to test whether these species were pollinated by birds or showed a mixed pollination system between insects and birds. METHODS Censuses and captures of insects and birds were performed to obtain pollen load transported and deposited on the stigmas. Also, a qualitative and quantitative analysis of the flowers and inflorescences was carried out. KEY RESULTS Flowers were visited by Hymenoptera and by passerine birds. The Canarian species was the most visited by birds, especially by Phylloscopus canariensis, and its flowers were also accessed by juveniles of the lizard Gallotia stehlini. The most important birds in the other three species were Sylvia melanocephala and S. atricapilla. The most important insect-functional groups in the mixed pollination system were: honey-bees and wasps in S. sambucifolia; bumble-bees and wasps in S. grandiflora; wasps in S. trifoliata; and a small bee in S. calliantha. CONCLUSIONS The species studied show a mixed pollination system between insects and passerine birds. In S. calliantha there is, in addition, a third agent (juveniles of Gallotia stehlini). The participation of birds in this mixed pollination system presents varying degrees of importance because, while in S. calliantha they are the main pollinators, in the other species they interact to complement the insects which are the main pollinators. A review of different florae showed that the large showy floral morphotypes of Scrophularia are concentrated in the western and central Mediterranean region, Macaronesia and USA (New Mexico).
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Affiliation(s)
- Ana Ortega-Olivencia
- Área de Botánica, Facultad de Ciencias, Universidad de Extremadura, Avda. de Elvas s.n., 06006-Badajoz, Spain.
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Tepedino V, Griswold T, Freilich J, Shephard P. Specialist and Generalist Bee Visitors of an Endemic Beardtongue (Penstemon caryi:Plantaginaceae) of the Big Horn Mountains, Wyoming. WEST N AM NATURALIST 2011. [DOI: 10.3398/064.071.0410] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Armbruster WS, Gong YB, Huang SQ. Are Pollination “Syndromes” Predictive? Asian Dalechampia Fit Neotropical Models. Am Nat 2011; 178:135-43. [DOI: 10.1086/660279] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Junker RR, Daehler CC, Dötterl S, Keller A, Blüthgen N. Hawaiian ant–flower networks: nectar-thieving ants prefer undefended native over introduced plants with floral defenses. ECOL MONOGR 2011. [DOI: 10.1890/10-1367.1] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Parachnowitsch A, Kessler A. Pollinator-mediated natural selection in Penstemon digitalis. PLANT SIGNALING & BEHAVIOR 2010; 5:1688-1690. [PMID: 21150291 PMCID: PMC3115138 DOI: 10.4161/psb.5.12.14113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 11/03/2010] [Indexed: 05/30/2023]
Abstract
Measuring the agents of natural selection is important because it allows us to understand not only which traits are expected to evolve but also why they will evolve. Natural selection by pollinators on floral traits is often assumed because in outcrossing animal-pollinated plants flowers are generally thought to function as advertisements of rewards directed at pollinators. We tested the role of bee pollinators in selection on Penstemon digitalis and found that pollinators were driving selection for larger and more flowers. However, what makes our publication unique is the additional information we gained from reviewing the few other studies that also directly tested whether pollinators were agents of selection on floral traits. As we would expect if pollinators are important agents of selection, selection on floral traits was significantly stronger when pollinators were present than when they were experimentally removed. Taken together, these results suggest that pollinators can be important drivers of selection in contemporary populations.
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Affiliation(s)
- Amy Parachnowitsch
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA.
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Parachnowitsch AL, Kessler A. Pollinators exert natural selection on flower size and floral display in Penstemon digitalis. THE NEW PHYTOLOGIST 2010; 188:393-402. [PMID: 20723076 DOI: 10.1111/j.1469-8137.2010.03410.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
• A major gap in our understanding of floral evolution, especially micro-evolutionary processes, is the role of pollinators in generating patterns of natural selection on floral traits. Here we explicitly tested the role of pollinators in selecting floral traits in a herbaceous perennial, Penstemon digitalis. • We manipulated the effect of pollinators on fitness through hand pollinations and compared phenotypic selection in open- and hand-pollinated plants. • Despite the lack of pollen limitation in our population, pollinators mediated selection on floral size and floral display. Hand pollinations removed directional selection for larger flowers and stabilizing selection on flower number, suggesting that pollinators were the agents of selection on both of these traits. • We reviewed studies that measured natural selection on floral traits by biotic agents and generally found stronger signatures of selection imposed by pollinators than by herbivores and co-flowering plant species.
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Affiliation(s)
- Amy L Parachnowitsch
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA.
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Abstract
The development of comparative phylogenetic methods has provided a powerful toolkit for addressing adaptive hypotheses, and researchers have begun to apply these methods to test the role of pollinators in floral evolution and diversification. One approach is to reconstruct the history of both floral traits and pollination systems to determine if floral trait change is spurred by shifts in pollinators. Looking across multiple shifts, it is also possible to test for significant correlations between floral evolution and pollinators using parsimony, likelihood and Bayesian methods for discrete characters or using statistical comparative methods for continuous characters. Evolutionary shifts in pollinators and floral traits may cause changes in diversification rates, and new methods are available for simultaneously studying character evolution and diversification rates. Relatively few studies have yet used formal comparative methods to elucidate how pollinators affect floral evolution across the phylogeny, and fruitful directions for future applications are discussed.
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71
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Narbona E, Dirzo R. Experimental defoliation affects male but not female reproductive performance of the tropical monoecious plant Croton suberosus (Euphorbiaceae). ANNALS OF BOTANY 2010; 106:359-69. [PMID: 20519239 PMCID: PMC2908170 DOI: 10.1093/aob/mcq117] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 04/08/2010] [Accepted: 05/10/2010] [Indexed: 05/24/2023]
Abstract
BACKGROUND AND AIMS Monoecious plants have the capacity to allocate resources separately to male and female functions more easily than hermaphrodites. This can be advantageous against environmental stresses such as leaf herbivory. However, studies showing effects of herbivory on male and female functions and on the interaction with the plant's pollinators are limited, particularly in tropical plants. Here, the effects of experimental defoliation were examined in the monoecious shrub Croton suberosus (Euphorbiaceae), a wasp-pollinated species from a Mexican tropical dry forest. METHODS Three defoliation treatments were applied: 0 % (control), 25 % (low) or 75 % (high) of plant leaf area removed. Vegetative (production of new leaves) and reproductive (pistillate and staminate flower production, pollen viability, nectar production, fruit set, and seed set) performance variables, and the abundance and activity of floral visitors were examined. KEY RESULTS Defoliated plants overcompensated for tissue loss by producing more new leaves than control plants. Production of staminate flowers gradually decreased with increasing defoliation and the floral sex ratio (staminate : pistillate flowers) was drastically reduced in high-defoliation plants. In contrast, female reproductive performance (pistillate flower production, fruit set and seed set) and pollinator visitation and abundance were not impacted by defoliation. CONCLUSIONS The asymmetrical effects of defoliation on male and female traits of C. suberosus may be due to the temporal and spatial flexibility in the allocation of resources deployed by monoecious plants. We posit that this helps to maintain the plant's pollination success in the face of leaf herbivory stress.
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Affiliation(s)
- Eduardo Narbona
- Dpto. Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Sevilla, Spain.
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72
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van der Niet T, Zollikofer CPE, León MSPD, Johnson SD, Linder HP. Three-dimensional geometric morphometrics for studying floral shape variation. TRENDS IN PLANT SCIENCE 2010; 15:423-6. [PMID: 20541450 DOI: 10.1016/j.tplants.2010.05.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 04/29/2010] [Accepted: 05/13/2010] [Indexed: 05/20/2023]
Abstract
Variation in floral shape is of major interest to evolutionary and pollination biologists, plant systematists and developmental geneticists. Quantifying this variation has been difficult due to the three-dimensional (3D) complexity of angiosperm flowers. By combining 3D geometric representations of flowers obtained by micro-computed tomography scanning with geometric morphometric methods, well established in zoology and anthropology, floral shape variation can be analyzed quantitatively, allowing for powerful interpretation and visualization of the resulting patterns of variation.
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Affiliation(s)
- Timotheüs van der Niet
- School of Biological and Conservation Sciences, University of KwaZulu Natal, P.Bag X01, Pietermaritzburg 3209, South Africa.
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73
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Hargreaves AL, Harder LD, Johnson SD. Native pollen thieves reduce the reproductive success of a hermaphroditic plant, Aloe maculata. Ecology 2010; 91:1693-703. [PMID: 20583711 DOI: 10.1890/09-0792.1] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Anna L Hargreaves
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N1N4, Canada.
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74
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Alcantara S, Lohmann LG. Evolution of floral morphology and pollination system in Bignonieae (Bignoniaceae). AMERICAN JOURNAL OF BOTANY 2010; 97:782-96. [PMID: 21622444 DOI: 10.3732/ajb.0900182] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The radiation of angiosperms is associated with shifts among pollination modes that are thought to have driven the diversification of floral forms. However, the exact sequence of evolutionary events that led to such great diversity in floral traits is unknown for most plant groups. Here, we characterize the patterns of evolution of individual floral traits and overall floral morphologies in the tribe Bignonieae (Bignoniaceae). We identified 12 discrete traits that are associated with seven floral types previously described for the group and used a penalized likelihood tree of the tribe to reconstruct the ancestral states of those traits at all nodes of the phylogeny of Bignonieae. In addition, evolutionary correlations among traits were conducted using a maximum likelihood approach to test whether the evolution of individual floral traits followed the correlated patterns of evolution expected under the "pollination syndrome" concept. The ancestral Bignonieae flower presented an Anemopaegma-type morphology, which was followed by several parallel shifts in floral morphologies. Those shifts occurred through intermediate stages resulting in mixed floral morphologies as well as directly from the Anemopaegma-type morphology to other floral types. Positive and negative evolutionary correlations among traits fit patterns expected under the pollination syndrome perspective, suggesting that interactions between Bignonieae flowers and pollinators likely played important roles in the diversification of the group as a whole.
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Affiliation(s)
- Suzana Alcantara
- Universidade de São Paulo, IB, Departamento de Botânica, Cidade Universitária, Rua do Matão 277, São Paulo, SP, CEP 05508-090, Brazil
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75
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Narbona E, Dirzo R. A reassessment of the function of floral nectar in Croton suberosus (Euphorbiaceae): A reward for plant defenders and pollinators. AMERICAN JOURNAL OF BOTANY 2010; 97:672-679. [PMID: 21622429 DOI: 10.3732/ajb.0900259] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Typically, plant-pollinator interactions are recognized as mutualistic relationships. Flower visitors, however, can potentially play multiple roles. The floral nectar in Croton suberosus has been proposed to operate as a reward for predators, especially the wasp Polistes instabilis (Vespidae), which kills herbivorous insects, while the plant has been thought to be mainly wind-pollinated. In this study, we reassessed the pollination mode of C. suberosus and the possible role of its flower visitors. Pollinator exclusion experiments demonstrated that C. suberosus should be considered a strictly entomophilous species. Inflorescences of C. suberosus were visited by a diverse entomofauna involving 28 taxa belonging to six orders; however, wasps and bees were the only visitors that carried C. suberosus pollen. The visitation rate of wasps was approximately four times that of bees. This observation, combined with the fact that the small size of bees makes effective contact of their bodies with the stigma difficult, strongly suggests that large wasps are responsible for most of the effective pollination of C. suberosus. Among the wasp visitors, P. instabilis seems to be one of the most important. These findings expose an unusual plant-insect interaction, in which the plant provides nectar and wasps pollinate and defend the plant.
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Affiliation(s)
- Eduardo Narbona
- Área de Botánica, Dpto. Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Ctra. Utrera, km 1, Sevilla 41013 Spain
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Fenster CB, Martén-Rodriguez S, Schemske DW. POLLINATION SYNDROMES AND THE EVOLUTION OF FLORAL DIVERSITY INIOCHROMA(SOLANACEAE). Evolution 2009; 63:2758-62; discussion 2763-7. [DOI: 10.1111/j.1558-5646.2009.00730.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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77
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Li JK, Huang SQ. Effective pollinators of Asian sacred lotus (Nelumbo nucifera): contemporary pollinators may not reflect the historical pollination syndrome. ANNALS OF BOTANY 2009; 104:845-51. [PMID: 19617594 PMCID: PMC2749538 DOI: 10.1093/aob/mcp173] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
BACKGROUND AND AIMS If stabilizing selection by pollinators is a prerequisite for pollinator-mediated floral evolution, spatiotemporal variation in the pollinator assemblage may confuse the plant-pollinator interaction in a given species. Here, effective pollinators in a living fossil plant Nelumbo nucifera (Nelumbonaceae) were examined to test whether beetles are major pollinators as predicted by its pollination syndrome. METHODS Pollinators of N. nucifera were investigated in 11 wild populations and one cultivated population, and pollination experiments were conducted to examine the pollinating role of two major pollinators (bees and beetles) in three populations. KEY RESULTS Lotus flowers are protogynous, bowl shaped and without nectar. The fragrant flowers can be self-heating during anthesis and produce around 1 million pollen grains per flower. It was found that bees and flies were the most frequent flower visitors in wild populations, contributing on average 87.9 and 49.4 % of seed set in Mishan and Lantian, respectively. Beetles were only found in one wild population and in the cultivated population, but the pollinator exclusion experiments showed that beetles were effective pollinators of Asian sacred lotus. CONCLUSIONS This study indicated that in their pollinating role, beetles, probable pollinators for this thermoregulating plant, had been replaced by some generalist insects in the wild. This finding implies that contemporary pollinators may not reflect the pollination syndrome.
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78
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Smith SD, Ané C, Baum DA. MACROEVOLUTIONARY TESTS OF POLLINATION SYNDROMES: A REPLY TO FENSTER ET AL. Evolution 2009. [DOI: 10.1111/j.1558-5646.2009.00732.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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79
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Whitney KD. Comparative evolution of flower and fruit morphology. Proc Biol Sci 2009; 276:2941-7. [PMID: 19474045 PMCID: PMC2817210 DOI: 10.1098/rspb.2009.0483] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Accepted: 04/28/2009] [Indexed: 11/12/2022] Open
Abstract
Angiosperm diversification has resulted in a vast array of plant morphologies. Only recently has it been appreciated that diversification might have proceeded quite differently for the two key diagnostic structures of this clade, flowers and fruits. These structures are hypothesized to have experienced different selective pressures via their interactions with animals in dispersal mutualisms, resulting in a greater amount of morphological diversification in animal-pollinated flowers than in animal-dispersed fruits. I tested this idea using size and colour traits for the flowers and fruits of 472 species occurring in three floras (St John, Hawaii and the Great Plains). Phylogenetically controlled analyses of nearest-neighbour distances in multidimensional trait space matched the predicted pattern: in each of the three floras, flowers were more divergent from one another than were fruits. In addition, the spacing of species clusters differed for flowers versus fruits in the flora of St John, with clusters in flower space more divergent than those in fruit space. The results are consistent with the idea that a major driver of angiosperm diversification has been stronger selection for divergent floral morphology than for divergent fruit morphology, although genetic, physiological and ecological constraints may also play a role.
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Affiliation(s)
- Kenneth D Whitney
- Department of Ecology and Evolutionary Biology, Rice University, 6100 Main Street, Houston, TX 77005, USA.
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80
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Abstract
BACKGROUND AND AIMS The Marantaceae (550 spp.) is the most derived family in the order Zingiberales and exhibits a complex explosive pollination mechanism. To understand the evolutionary significance of this unique process of pollen transfer, comparative morphological and ecological studies were conducted in Gabon. METHODS During a total stay of 11 months, 31 species of Marantaceae were investigated at different sites in Gabon. The study included analyses of floral diversity, observations on the pollinator spectrum as well as ecological measurements (e.g. nectar sugar concentration and volume). KEY RESULTS Analyses reveal five flower types based on flower size and pigmentation, spatial arrangement of the floral tube and presence/absence of nectar guides and conspicuous outer staminodes. Each type is associated with a specific functional pollinator group leading to the description of distinct pollination syndromes. The 'small (horizontal)' flowers are predominantly pollinated by small bees (Thrinchostoma spp., Allodapula ornaticeps), the 'large (horizontal)' and 'medium-sized (horizontal)' flowers by medium-sized bees (Amegilla vivida, Thrinchostoma bicometes), the 'locked (horizontal)' flowers by large bees (Xylocopa nigrita, X. varipes) and the '(large) vertical' flowers by sunbirds. CONCLUSIONS The longevity of Marantaceae individuals and the omnipresence of their pollinators allowed the specialization to a given functional pollinator group. Intermediate ecological values, however, make occasional pollinator overlaps possible, indicating potential pathways of pollinator shifts. Similar radiation tendencies observed on other continents hint at similar selective pressures and evolutionary constraints.
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Affiliation(s)
- Alexandra C Ley
- Institut für Spezielle Botanik und Botanischer Garten, Johannes Gutenberg-Universität Mainz, Germany.
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81
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Schlumpberger BO, Cocucci AA, Moré M, Sérsic AN, Raguso RA. Extreme variation in floral characters and its consequences for pollinator attraction among populations of an Andean cactus. ANNALS OF BOTANY 2009; 103:1489-500. [PMID: 19342397 PMCID: PMC2701769 DOI: 10.1093/aob/mcp075] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS A South American cactus species, Echinopsis ancistrophora (Cactaceae), with dramatic among-population variation in floral traits is presented. METHODS Eleven populations of E. ancistrophora were studied in their habitats in northern Argentina, and comparisons were made of relevant floral traits such as depth, stigma position, nectar volume and sugar concentration, and anthesis time. Diurnal and nocturnal pollinator assemblages were evaluated for populations with different floral trait combinations. KEY RESULTS Remarkable geographical variations in floral traits were recorded among the 11 populations throughout the distribution range of E. ancistrophora, with flower lengths ranging from 4.5 to 24.1 cm. Other floral traits associated with pollinator attraction also varied in a population-specific manner, in concert with floral depth. Populations with the shortest flowers showed morning anthesis and those with the longest flowers opened at dusk, whereas those with flowers of intermediate length opened at unusual times (2300-0600 h). Nectar production varied non-linearly with floral length; it was absent to low (population means up to 15 microL) in short- to intermediate-length flowers, but was high (population means up to 170 microL) in the longest tubed flowers. Evidence from light-trapping of moths, pollen carriage on their bodies and moth scale deposition on stigmas suggests that sphingid pollination is prevalent only in the four populations with the longest flowers, in which floral morphological traits and nectar volumes match the classic expectations for the hawkmoth pollination syndrome. All other populations, with flowers 4.5-15 cm long, were pollinated exclusively by solitary bees. CONCLUSIONS The results suggest incipient differentiation at the population level and local adaptation to either bee or hawkmoth (potentially plus bee) pollination.
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82
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Mitchell RJ, Irwin RE, Flanagan RJ, Karron JD. Ecology and evolution of plant-pollinator interactions. ANNALS OF BOTANY 2009; 103:1355-63. [PMID: 19482881 PMCID: PMC2701755 DOI: 10.1093/aob/mcp122] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 04/27/2009] [Accepted: 05/01/2009] [Indexed: 05/08/2023]
Abstract
BACKGROUND Some of the most exciting advances in pollination biology have resulted from interdisciplinary research combining ecological and evolutionary perspectives. For example, these two approaches have been essential for understanding the functional ecology of floral traits, the dynamics of pollen transport, competition for pollinator services, and patterns of specialization and generalization in plant-pollinator interactions. However, as research in these and other areas has progressed, many pollination biologists have become more specialized in their research interests, focusing their attention on either evolutionary or ecological questions. We believe that the continuing vigour of a synthetic and interdisciplinary field like pollination biology depends on renewed connections between ecological and evolutionary approaches. SCOPE In this Viewpoint paper we highlight the application of ecological and evolutionary approaches to two themes in pollination biology: (1) links between pollinator behaviour and plant mating systems, and (2) generalization and specialization in pollination systems. We also describe how mathematical models and synthetic analyses have broadened our understanding of pollination biology, especially in human-modified landscapes. We conclude with several suggestions that we hope will stimulate future research. This Viewpoint also serves as the introduction to this Special Issue on the Ecology and Evolution of Plant-Pollinator Interactions. These papers provide inspiring examples of the synergy between evolutionary and ecological approaches, and offer glimpses of great accomplishments yet to come.
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Affiliation(s)
- Randall J. Mitchell
- Department of Biology, Program in Integrated Biosciences, University of Akron, Akron, OH 44325, USA
| | - Rebecca E. Irwin
- Department of Biology, Dartmouth College, Hanover, New Hampshire 03755, USA
| | - Rebecca J. Flanagan
- Department of Biological Sciences, P.O. Box 413, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
| | - Jeffrey D. Karron
- Department of Biological Sciences, P.O. Box 413, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA
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83
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Ollerton J, Masinde S, Meve U, Picker M, Whittington A. Fly pollination in Ceropegia (Apocynaceae: Asclepiadoideae): biogeographic and phylogenetic perspectives. ANNALS OF BOTANY 2009; 103:1501-14. [PMID: 19339298 PMCID: PMC2701756 DOI: 10.1093/aob/mcp072] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Revised: 01/05/2009] [Accepted: 02/12/2009] [Indexed: 05/21/2023]
Abstract
BACKGROUND AND AIMS Ceropegia (Apocynaceae subfamily Asclepiadoideae) is a large, Old World genus of >180 species, all of which possess distinctive flask-shaped flowers that temporarily trap pollinators. The taxonomic diversity of pollinators, biogeographic and phylogenetic patterns of pollinator exploitation, and the level of specificity of interactions were assessed in order to begin to understand the role of pollinators in promoting diversification within the genus. METHODS Flower visitor and pollinator data for approx. 60 Ceropegia taxa were analysed with reference to the main centres of diversity of the genus and to a cpDNA-nrDNA molecular phylogeny of the genus. KEY RESULTS Ceropegia spp. interact with flower-visiting Diptera from at least 26 genera in 20 families, of which 11 genera and 11 families are pollinators. Size range of flies was 0.5-4.0 mm and approx. 94 % were females. Ceropegia from particular regions do not use specific fly genera or families, though Arabian Peninsula species are pollinated by a wider range of Diptera families than those in other regions. The basal-most clade interacts with the highest diversity of Diptera families and genera, largely due to one hyper-generalist taxon, C. aristolochioides subsp. deflersiana. Species in the more-derived clades interact with a smaller diversity of Diptera. Approximately 60 % of taxa are so far recorded as interacting with only a single genus of pollinators, the remaining 40 % being less conservative in their interactions. Ceropegia spp. can therefore be ecological specialists or generalists. CONCLUSIONS The genus Ceropegia has largely radiated without evolutionary shifts in pollinator functional specialization, maintaining its interactions with small Diptera. Intriguing biogeographic and phylogenetic patterns may reflect processes of regional dispersal, diversification and subsequent specialization onto a narrower range of pollinators, though some of the findings may be caused by inconsistent sampling. Comparisons are made with other plant genera in the Aristolochiaceae and Araceae that have evolved flask-shaped flowers that trap female flies seeking oviposition sites.
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Ollerton J, Alarcón R, Waser NM, Price MV, Watts S, Cranmer L, Hingston A, Peter CI, Rotenberry J. A global test of the pollination syndrome hypothesis. ANNALS OF BOTANY 2009; 103:1471-80. [PMID: 19218577 PMCID: PMC2701765 DOI: 10.1093/aob/mcp031] [Citation(s) in RCA: 198] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 11/20/2008] [Accepted: 01/07/2009] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS 'Pollination syndromes' are suites of phenotypic traits hypothesized to reflect convergent adaptations of flowers for pollination by specific types of animals. They were first developed in the 1870s and honed during the mid 20th Century. In spite of this long history and their central role in organizing research on plant-pollinator interactions, the pollination syndromes have rarely been subjected to test. The syndromes were tested here by asking whether they successfully capture patterns of covariance of floral traits and predict the most common pollinators of flowers. METHODS Flowers in six communities from three continents were scored for expression of floral traits used in published descriptions of the pollination syndromes, and simultaneously the pollinators of as many species as possible were characterized. KEY RESULTS Ordination of flowers in a multivariate 'phenotype space' defined by the syndromes showed that almost no plant species fall within the discrete syndrome clusters. Furthermore, in approximately two-thirds of plant species, the most common pollinator could not be successfully predicted by assuming that each plant species belongs to the syndrome closest to it in phenotype space. CONCLUSIONS The pollination syndrome hypothesis as usually articulated does not successfully describe the diversity of floral phenotypes or predict the pollinators of most plant species. Caution is suggested when using pollination syndromes for organizing floral diversity, or for inferring agents of floral adaptation. A fresh look at how traits of flowers and pollinators relate to visitation and pollen transfer is recommended, in order to determine whether axes can be identified that describe floral functional diversity more successfully than the traditional syndromes.
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85
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Campbell DR. Using phenotypic manipulations to study multivariate selection of floral trait associations. ANNALS OF BOTANY 2009; 103:1557-66. [PMID: 19218579 PMCID: PMC2701750 DOI: 10.1093/aob/mcp032] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
BACKGROUND A basic theme in the study of plant-pollinator interactions is that pollinators select not just for single floral traits, but for associations of traits. Responses of pollinators to sets of traits are inherent in the idea of pollinator syndromes. In its most extreme form, selection on a suite of traits can take the form of correlational selection, in which a response to one trait depends on the value of another, thereby favouring floral integration. Despite the importance of selection for combinations of traits in the evolution of flowers, evidence is relatively sparse and relies mostly on observational approaches. SCOPE Here, methods for measuring selection on multivariate suites of floral traits are presented, and the studies to date are reviewed. It is argued that phenotypic manipulations present a powerful, but rarely used, approach to teasing apart the separate and combined effects of particular traits. The approach is illustrated with data from studies of alpine plants in Colorado and New Zealand, and recommendations are made about several features of the design of such experiments. CONCLUSIONS Phenotypic manipulations of two or more traits in combination provide a direct way of testing for selection of floral trait associations. Such experiments will be particularly valuable if rooted in hypotheses about differences between types of pollinators and tied to a proposed evolutionary history.
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Affiliation(s)
- Diane R Campbell
- Department of Ecology & Evolutionary Biology, University of California, Irvine, 92697, USA.
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86
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Gómez JM, Perfectti F, Bosch J, Camacho JPM. A geographic selection mosaic in a generalized plant–pollinator–herbivore system. ECOL MONOGR 2009. [DOI: 10.1890/08-0511.1] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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87
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Plant–hummingbird interactions in the West Indies: floral specialisation gradients associated with environment and hummingbird size. Oecologia 2009; 159:757-66. [DOI: 10.1007/s00442-008-1255-z] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2008] [Accepted: 12/03/2008] [Indexed: 11/30/2022]
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Anderson B, Johnson SD. Geographical covariation and local convergence of flower depth in a guild of fly-pollinated plants. THE NEW PHYTOLOGIST 2009; 182:533-540. [PMID: 19210717 DOI: 10.1111/j.1469-8137.2009.02764.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Plant adaptations to pollinators are usually studied at the species level, but are expected to occur at the local population level and be reflected in fine-scale patterns of floral variation. Here, we examined whether a guild of c. 20 South African plant species pollinated by the long proboscid fly Prosoeca ganglbaueri (Nemestrinidae) exhibits fine-scale patterns of geographical covariation and convergent evolution at a local scale. Fly proboscis length is highly variable among sites (20-50 mm). Plant adaptation results in floral depths of plants within the guild being closely matched with the proboscis length of their fly pollinator across numerous sites. This results in patterns of divergence among allopatric populations and convergence among species within a site. The most likely evolutionary processes driving these patterns include coevolution between the fly and plants with consistent and abundant rewards, as well as one-sided evolution in rare and nonrewarding species that do not influence the coevolutionary process. Pollinator-mediated selection on spur length was confirmed for a nonrewarding orchid species in the guild by a reciprocal translocation experiment. Thus, rarer and nonrewarding species in the guild are forced to keep pace with the coevolutionary race between common rewarding flowers and flies.
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Affiliation(s)
- Bruce Anderson
- School of Biological and Conservation Sciences, University of KwaZulu-Natal, P. Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
- Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland, 7602, South Africa
| | - Steven D Johnson
- School of Biological and Conservation Sciences, University of KwaZulu-Natal, P. Bag X01, Scottsville, Pietermaritzburg 3209, South Africa
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Bloch D, Erhardt A. Selection toward shorter flowers by butterflies whose probosces are shorter than floral tubes. Ecology 2008; 89:2453-60. [PMID: 18831167 DOI: 10.1890/06-2023.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Darwin's meticulous observations on the function of floral shape led to his famous prediction of a long-tongued pollinator, which he believed to be the evolutionary trigger for the long-spurred flowers of the Madagascar star orchid. Although tubular flowers are common, long tubes or spurs are an exception, suggesting that selection maintaining short flowers is widespread. Using the butterfly-pollinated carnation Dianthus carthusianorum and two butterfly species differing in proboscis length (Melanargia galathea and Inachis io) as model organisms, we experimentally demonstrate a reduction in pollinator efficiency with an increasing difference between proboscis length and floral tube length. Such a relationship is a prerequisite for the evolution of floral shape in response to pollinator morphology.
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Affiliation(s)
- Daniel Bloch
- Department of Environmental Sciences, Section Conservation Biology (NLU), University of Basel, St. Johanns-Vorstadt 10, CH-4056 Basel, Switzerland
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90
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Tripp EA, Manos PS. IS FLORAL SPECIALIZATION AN EVOLUTIONARY DEAD-END POLLINATION SYSTEM TRANSITIONS INRUELLIA(ACANTHACEAE). Evolution 2008; 62:1712-1737. [DOI: 10.1111/j.1558-5646.2008.00398.x] [Citation(s) in RCA: 148] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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91
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Schlumpberger BO, Raguso RA. Geographic variation in floral scent of Echinopsis ancistrophora
(Cactaceae); evidence for constraints on hawkmoth attraction. OIKOS 2008. [DOI: 10.1111/j.0030-1299.2008.16211.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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92
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Kimball S. Links between floral morphology and floral visitors along an elevational gradient in aPenstemonhybrid zone. OIKOS 2008. [DOI: 10.1111/j.0030-1299.2008.16573.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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93
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Smith SD, Ané C, Baum DA. THE ROLE OF POLLINATOR SHIFTS IN THE FLORAL DIVERSIFICATION OFIOCHROMA(SOLANACEAE). Evolution 2008; 62:793-806. [DOI: 10.1111/j.1558-5646.2008.00327.x] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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94
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Rausher M. Evolutionary Transitions in Floral Color. INTERNATIONAL JOURNAL OF PLANT SCIENCES 2008; 169:7-21. [PMID: 0 DOI: 10.1086/523358] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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95
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Ornelas JF, Ordano M, De-Nova AJ, Quintero ME, Garland T. Phylogenetic analysis of interspecific variation in nectar of hummingbird-visited plants. J Evol Biol 2007; 20:1904-17. [PMID: 17714307 DOI: 10.1111/j.1420-9101.2007.01374.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We tested whether phylogeny, flower size and/or altitude were significant predictors of interspecific variation in nectar production of hummingbird-visited plants in an assembled database (289 species, in 22 orders, 56 families and 131 genera). Although the study is focused on hummingbird-pollinated plants (241 plant species), plants with different pollinator syndromes (48 species) are also included in the analyses. Nectar volume secreted in a given time period (usually 24 h) by a given flower, its sugar concentration and corolla length were compiled mainly from the literature. Altitude was also obtained from the original references. Sugar production was computed basically as the product of nectar secretion and sugar concentration, and expressed on a per 24-h basis. All nectar traits and corolla length (all log transformed), as well as altitude, showed statistically significant phylogenetic signal. Both nonphylogenetic and phylogenetically informed (independent contrasts) analyses indicated a highly significant positive correlation between corolla length and both nectar volume and sugar production. In addition, altitude (which is partially a surrogate for temperature) was significantly negatively correlated with both sugar concentration and production. Possible reasons for coadaptation of nectar production and sugar production with corolla length are discussed.
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Affiliation(s)
- J F Ornelas
- Departamento de Biología Evolutiva, Instituto de Ecología, A.C., Xalapa, Veracruz, México.
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96
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Rezende EL, Jordano P, Bascompte J. Effects of phenotypic complementarity and phylogeny on the nested structure of mutualistic networks. OIKOS 2007. [DOI: 10.1111/j.0030-1299.2007.16029.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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97
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Howell AD, Alarcón R. Osmia bees (Hymenoptera: Megachilidae) can detect nectar-rewarding flowers using olfactory cues. Anim Behav 2007. [DOI: 10.1016/j.anbehav.2006.11.012] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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98
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Streisfeld MA, Kohn JR. Environment and pollinator-mediated selection on parapatric floral races of Mimulus aurantiacus. J Evol Biol 2007; 20:122-32. [PMID: 17210005 DOI: 10.1111/j.1420-9101.2006.01216.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We tested whether selection by pollinators could explain the parapatric distribution of coastal red- and inland yellow-flowered races of Mimulus aurantiacus (Phrymaceae) by examining visitation to natural and experimental populations. As a first step in evaluating whether indirect selection might explain floral divergence, we also tested for local adaptation in early life stages using a reciprocal transplant experiment. Hummingbirds visited flowers of each race at similar rates in natural populations but showed strong (>95%) preference for red flowers in all habitats in experimental arrays. Hawkmoths demonstrated nearly exclusive (>99% of visits) preference for yellow flowers and only visited in inland regions. Strong preferences for alternative floral forms support a direct role for pollinators in floral divergence. Despite these preferences, measures of plant performance across environments showed that red-flowered plants consistently survived better, grew larger and received more overall pollinator visits than yellow-flowered plants. Unmeasured components of fitness may favour the yellow race in inland habitats. Alternatively, we document a marked recent increase in inland hummingbird density that may have caused a change in the selective environment, favouring the eastward advance of red-flowered plants.
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Affiliation(s)
- M A Streisfeld
- Section of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California San Diego, La Jolla, CA , USA.
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99
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Perret M, Chautems A, Spichiger R, Barraclough TG, Savolainen V. THE GEOGRAPHICAL PATTERN OF SPECIATION AND FLORAL DIVERSIFICATION IN THE NEOTROPICS: THE TRIBE SINNINGIEAE (GESNERIACEAE) AS A CASE STUDY. Evolution 2007; 61:1641-60. [PMID: 17598746 DOI: 10.1111/j.1558-5646.2007.00136.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The geographical pattern of speciation and the relationship between floral variation and species ranges were investigated in the tribe Sinningieae (Gesneriaceae), which is found mainly in the Atlantic forests of Brazil. Geographical distribution data recorded on a grid system of 0.5 x 0.5 degree intervals and a near-complete species-level phylogenetic tree of Sinningieae inferred from a simultaneous analysis of seven DNA regions were used to address the role of geographical isolation in speciation. Geographical range overlaps between sister lineages were measured across all nodes in the phylogenetic tree and analyzed in relation to relative ages estimated from branch lengths. Although there are several cases of species sympatry in Sinningieae, patterns of sympatry between sister taxa support the predominance of allopatric speciation. The pattern of sympatry between sister taxa is consistent with range shifts following allopatric speciation, except in one clade, in which the overlapping distribution of recent sister species indicates speciation within a restricted geographical area and involving changes in pollinators and habitats. The relationship between floral divergence and regional sympatry was also examined by analyzing floral contrasts, phenological overlap, and the degree of sympatry between sister clades. Morphological contrast between flowers is not increased in sympatry and phenological divergence is more apparent between allopatric clades than between sympatric clades. Therefore, our results failed to indicate a tendency for sympatric taxa to minimize morphological and phenological overlap (geographic exclusion and/or character displacement hypotheses). Instead, they point toward adaptation in phenology to local conditions and buildup of sympatries at random with respect to flower morphology. Additional studies at a lower geographical scale are needed to identify truely coexisting species and the components of their reproductive isolation.
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Affiliation(s)
- Mathieu Perret
- Conservatoire and Jardin botaniques, CH-1292 Geneva, Switzerland.
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100
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Lewinsohn JS, Tepedino VJ. BREEDING BIOLOGY AND FLOWER VISITORS OF THE RARE WHITE RIVER PENSTEMON, PENSTEMON SCARIOSUS VAR. ALBIFLUVIS (SCROPHULARIACEAE). WEST N AM NATURALIST 2007. [DOI: 10.3398/1527-0904(2007)67[232:bbafvo]2.0.co;2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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