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Barreto E, Boehm MMA, Ogutcen E, Abrahamczyk S, Kessler M, Bascompte J, Dellinger AS, Bello C, Dehling DM, Duchenne F, Kaehler M, Lagomarsino LP, Lohmann LG, Maglianesi MA, Morlon H, Muchhala N, Ornelas JF, Perret M, Salinas NR, Smith SD, Vamosi JC, Varassin IG, Graham CH. Macroevolution of the plant-hummingbird pollination system. Biol Rev Camb Philos Soc 2024; 99:1831-1847. [PMID: 38705863 DOI: 10.1111/brv.13094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 04/19/2024] [Accepted: 04/26/2024] [Indexed: 05/07/2024]
Abstract
Plant-hummingbird interactions are considered a classic example of coevolution, a process in which mutually dependent species influence each other's evolution. Plants depend on hummingbirds for pollination, whereas hummingbirds rely on nectar for food. As a step towards understanding coevolution, this review focuses on the macroevolutionary consequences of plant-hummingbird interactions, a relatively underexplored area in the current literature. We synthesize prior studies, illustrating the origins and dynamics of hummingbird pollination across different angiosperm clades previously pollinated by insects (mostly bees), bats, and passerine birds. In some cases, the crown age of hummingbirds pre-dates the plants they pollinate. In other cases, plant groups transitioned to hummingbird pollination early in the establishment of this bird group in the Americas, with the build-up of both diversities coinciding temporally, and hence suggesting co-diversification. Determining what triggers shifts to and away from hummingbird pollination remains a major open challenge. The impact of hummingbirds on plant diversification is complex, with many tropical plant lineages experiencing increased diversification after acquiring flowers that attract hummingbirds, and others experiencing no change or even a decrease in diversification rates. This mixed evidence suggests that other extrinsic or intrinsic factors, such as local climate and isolation, are important covariables driving the diversification of plants adapted to hummingbird pollination. To guide future studies, we discuss the mechanisms and contexts under which hummingbirds, as a clade and as individual species (e.g. traits, foraging behaviour, degree of specialization), could influence plant evolution. We conclude by commenting on how macroevolutionary signals of the mutualism could relate to coevolution, highlighting the unbalanced focus on the plant side of the interaction, and advocating for the use of species-level interaction data in macroevolutionary studies.
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Affiliation(s)
- Elisa Barreto
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Mannfred M A Boehm
- Biodiversity Research Centre, University of British Columbia, 2212 Main Mall, Vancouver, BC, Canada
| | - Ezgi Ogutcen
- Department of Environment and Biodiversity, Paris Lodron University of Salzburg, Hellbrunner Straße 34, Salzburg, 5020, Austria
| | - Stefan Abrahamczyk
- Nees Institute for Biodiversity of Plant, University of Bonn, Meckenheimer Allee 170, Bonn, 53115, Germany
- State Museum of Natural History Stuttgart, Botany Department, Rosenstein 1, Stuttgart, 70191, Germany
| | - Michael Kessler
- Systematic and Evolutionary Botany, University of Zurich, Zollikerstrasse 107, Zurich, 8008, Switzerland
| | - Jordi Bascompte
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurestrasse 190, Zurich, 8057, Switzerland
| | - Agnes S Dellinger
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, Vienna, 1030, Austria
| | - Carolina Bello
- Department of Environmental Systems Science, Institute of Integrative Biology, ETH Zurich, Universitätstrasse 16, Zurich, 8092, Switzerland
| | - D Matthias Dehling
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
- Securing Antarctica's Environmental Future, School of Biological Sciences, Monash University, 25 Rainforest Walk, Clayton, 3800, Victoria, Australia
| | - François Duchenne
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
| | - Miriam Kaehler
- Departamento de Botânica, Universidade Federal do Paraná, Avenida Coronel Francisco H. dos Santos 100, Curitiba, 81531-980, Brazil
| | - Laura P Lagomarsino
- Department of Biological Sciences, Shirley C. Tucker Herbarium, Louisiana State University, Life Science Annex Building A257, Baton Rouge, 70803, LA, USA
| | - Lúcia G Lohmann
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, Butantã, São Paulo, 05508-090, Brazil
- Department of Integrative Biology, University and Jepson Herbaria, University of California, Berkeley, 1001 Valley Life Sciences Building, Berkeley, 94720-2465, CA, USA
| | - María A Maglianesi
- Escuela de Ciencias Exactas y Naturales, Universidad Estatal a Distancia, San José, 474-2050, Costa Rica
| | - Hélène Morlon
- Institut de Biologie de l'École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, UMR 8197, 46 rue d'Ulm, Paris, 75005, France
| | - Nathan Muchhala
- Department of Biology, University of Missouri - St. Louis, St. Louis, 63121, MO, USA
| | - Juan Francisco Ornelas
- Departamento de Biología Evolutiva, Instituto de Ecología, A.C. (INECOL), Xalapa, Veracruz, 91073, Mexico
| | - Mathieu Perret
- Department of Plant Sciences, Conservatoire et Jardin Botaniques de Genève, University of Geneva, Chem. de l'Impératrice 1, 1292 Pregny-Chambésy, Geneva, Switzerland
| | - Nelson R Salinas
- Pfizer Plant Research Laboratory, New York Botanical Garden, 2900 Southern Blvd., Bronx, New York City, 10458, NY, USA
| | - Stacey D Smith
- Department of Ecology and Evolutionary Biology, University of Colorado-Boulder, 1900 Pleasant St, Boulder, 80302, CO, USA
| | - Jana C Vamosi
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, T2N1N4, AB, Canada
| | - Isabela G Varassin
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
- Departamento de Botânica, Universidade Federal do Paraná, Avenida Coronel Francisco H. dos Santos 100, Curitiba, 81531-980, Brazil
| | - Catherine H Graham
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, Birmensdorf, 8903, Switzerland
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Harenčár JG, Salazar‐Amoretti D, García‐Robledo C, Kay KM. Growth-defense trade-offs promote habitat isolation between recently-diverged species. Ecol Evol 2024; 14:e11609. [PMID: 38952661 PMCID: PMC11214971 DOI: 10.1002/ece3.11609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 06/04/2024] [Accepted: 06/05/2024] [Indexed: 07/03/2024] Open
Abstract
Trade-offs are crucial for species divergence and reproductive isolation. Trade-offs between investment in growth versus defense against herbivores are implicated in tropical forest diversity. Empirically exploring the role of growth-defense trade-offs in closely related species' reproductive isolation can clarify the eco-evolutionary dynamics through which growth-defense trade-offs contribute to diversity. Costus villosissimus and C. allenii are recently diverged, interfertile, and partially sympatric neotropical understory plant species primarily isolated by divergent habitat adaptation. This divergent adaptation involves differences in growth rate, which may constrain investment in defense. Here, we investigate growth-defense trade-offs and how they relate to the divergent habitat adaptation that isolates these species. We characterize leaf toughness and chemistry, evaluate the feeding preferences of primary beetle herbivores in controlled trials and field-based experiments, and investigate natural herbivory patterns. We find clear trade-offs between growth and defense: slower-growing C. allenii has tougher leaves and higher defensive chemical concentrations than faster-growing C. villosissimus. Costus villosissimus has rapid growth-based drought avoidance, enabling growth in drier habitats with few specialist herbivores. Therefore, growth-defense trade-offs mediate synergistic biotic and abiotic selection, causing the divergent habitat adaptation that prevents most interspecific mating between C. villosissimus and C. allenii. Our findings advance understanding of ecological speciation by highlighting the interplay of biotic and abiotic selection that dictates the outcome of trade-offs.
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Affiliation(s)
- Julia G. Harenčár
- Ecology and Evolutionary Biology DepartmentUniversity of CaliforniaSanta CruzCaliforniaUSA
| | | | - Carlos García‐Robledo
- Department of Ecology and Evolutionary BiologyUniversity of ConnecticutStorrsConnecticutUSA
| | - Kathleen M. Kay
- Ecology and Evolutionary Biology DepartmentUniversity of CaliforniaSanta CruzCaliforniaUSA
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3
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Magalhaes ILF, Martins PH, Faleiro BT, Vidigal THDA, Santos FR, Carvalho LS, Santos AJ. Complete phylogeny of Micrathena spiders suggests multiple dispersal events among Neotropical rainforests, islands and landmasses, and indicates that Andean orogeny promotes speciation. Cladistics 2024. [PMID: 38861251 DOI: 10.1111/cla.12593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 04/24/2024] [Accepted: 05/17/2024] [Indexed: 06/12/2024] Open
Abstract
The Neotropical region is the most diverse on the planet, largely owing to its mosaic of tropical rainforests. Multiple tectonic and climatic processes have been hypothesized to contribute to generating this diversity, including Andean orogeny, the closure of the Isthmus of Panama, the GAARlandia land bridge and historical connections among currently isolated forests. Micrathena spiders are diverse and widespread in the region, and thus a complete phylogeny of this genus allows the testing of hypotheses at multiple scales. We estimated a complete, dated phylogeny using morphological data for 117 Micrathena species and molecular data of up to five genes for a subset of 79 species. Employing eventc-based approaches and biogeographic stochastic mapping while considering phylogenetic uncertainty, we estimated ancestral distributions, the timing and direction of dispersal events and diversification rates among areas. The phylogeny is generally robust, with uncertainty in the position of some of the species lacking sequences. Micrathena started diversifying around 25 Ma. Andean cloud forests show the highest in-situ speciation, while the Amazon is the major dispersal source for adjacent areas. The Dry Diagonal generated few species and is a sink of diversity. Species exchange between Central and South America involved approximately 23 dispersal events and started ~20 Ma, which is consistent with a Miocene age for the Isthmus of Panama closure. We inferred four dispersal events from Central America to the Antilles in the last 20 Myr, indicating the spiders did not reach the islands through the GAARlandia land bridge. We identified important species exchange routes among the Amazon, Andean cloud forests and Atlantic forests during the Plio-Pleistocene. Sampling all species of the genus was fundamental to the conclusions above, especially in identifying the Andean forests as the area that generated the majority of species. This highlights the importance of complete taxonomic sampling in biogeographic studies.
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Affiliation(s)
- Ivan L F Magalhaes
- Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Ángel Gallardo 470, C1405DJR, Buenos Aires, Argentina
| | - Pedro H Martins
- Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil
| | - Bárbara T Faleiro
- Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil
| | - Teofânia H D A Vidigal
- Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil
| | - Fabrício R Santos
- Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil
| | - Leonardo S Carvalho
- Universidade Federal do Piauí, Campus Amílcar Ferreira Sobral, BR 343, KM 3.5, Bairro Meladão, s/no. CEP 6, 64808-660, Floriano, Piauí, Brazil
| | - Adalberto J Santos
- Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901, Belo Horizonte, Minas Gerais, Brazil
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4
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Olivares I, Tusso S, José Sanín M, de La Harpe M, Loiseau O, Rolland J, Salamin N, Kessler M, Shimizu KK, Paris M. Hyper-Cryptic radiation of a tropical montane plant lineage. Mol Phylogenet Evol 2024; 190:107954. [PMID: 37898295 DOI: 10.1016/j.ympev.2023.107954] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 10/23/2023] [Accepted: 10/25/2023] [Indexed: 10/30/2023]
Abstract
Species are seen as the fundamental unit of biotic diversity, and thus their delimitation is crucial for defining measures for diversity assessments and studying evolution. Differences between species have traditionally been associated with variation in morphology. And yet, the discovery of cryptic diversity suggests that the evolution of distinct lineages does not necessarily involve morphological differences. Here, we analyze 1,684,987 variant sites and over 4,000 genes for more than 400 samples to show how a tropical montane plant lineage (Geonoma undata species complex) is composed of numerous unrecognized genetic groups that are not morphologically distinct. We find that 11 to 14 clades do not correspond to the three currently recognized species. Most clades are genetically different and geographic distance and topography are the most important factors determining this genetic divergence. The genetic structure of this lineage does not match its morphological variation. Instead, this species complex constitutes the first example of a hyper-cryptic plant radiation in tropical mountains.
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Affiliation(s)
- Ingrid Olivares
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Switzerland.
| | - Sergio Tusso
- Department of Genetics, Faculty of Biology, Ludwig Maximilian Universität München, Germany
| | - María José Sanín
- School of Mathematical and Natural Sciences, Arizona State University. United States; Facultad de Ciencias y Biotecnología, Universidad CES, Colombia
| | - Marylaure de La Harpe
- Office for Nature Conservation and Environment of the Canton of Graubünden, Switzerland
| | - Oriane Loiseau
- School of Geosciences, University of Edinburgh, United Kingdom
| | - Jonathan Rolland
- CNRS, Laboratoire Evolution et Diversité Biologique, Université Toulouse, France
| | - Nicolas Salamin
- Department of Computational Biology, University of Lausanne, Switzerland
| | - Michael Kessler
- Department of Systematic and Evolutionary Botany, University of Zurich, Switzerland
| | - Kentaro K Shimizu
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Switzerland; Kihara Institute of Biological Research, Yokohama City University, Japan
| | - Margot Paris
- Department of Biology. University of Fribourg, Switzerland
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5
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Dellinger AS, Hamilton AM, Wessinger CA, Smith S. Opposing Patterns of Altitude-Driven Pollinator Turnover in the Tropical and Temperate Americas. Am Nat 2023; 202:152-165. [PMID: 37531276 PMCID: PMC7614872 DOI: 10.1086/725017] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
AbstractAbiotic factors (e.g., temperature, precipitation) vary markedly along elevational gradients and differentially affect major groups of pollinators. Ectothermic bees, for example, are impeded in visiting flowers by cold and rainy conditions common at high elevations, while endothermic hummingbirds may continue foraging under such conditions. Despite the possibly far-reaching effects of the abiotic environment on plant-pollinator interactions, we know little about how these factors play out at broad ecogeographic scales. We address this knowledge gap by investigating how pollination systems vary across elevations in 26 plant clades from the Americas. Specifically, we explore Cruden's 1972 hypothesis that the harsh montane environment drives a turnover from insect to vertebrate pollination at higher elevations. We compared the elevational distribution and bioclimatic attributes for a total of 2,232 flowering plants and found that Cruden's hypothesis holds only in the tropics. Above 30°N and below 30°S, plants pollinated by vertebrates (mostly hummingbirds) tend to occur at lower elevations than those pollinated by insects. We hypothesize that this latitudinal transition is due to the distribution of moist, forested habitats favored by vertebrate pollinators, which are common at high elevations in the tropics but not in the temperate Americas.
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6
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Maguiña‐Conde R, Zuñiga‐Rivas D, Kay KM. An elevational gradient in floral traits and pollinator assemblages in the Neotropical species Costus guanaiensis var. tarmicus in Peru. Ecol Evol 2023; 13:e10314. [PMID: 37529588 PMCID: PMC10375365 DOI: 10.1002/ece3.10314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 07/04/2023] [Indexed: 08/03/2023] Open
Abstract
Different populations of plant species can adapt to their local pollinators and diverge in floral traits accordingly. Floral traits are subject to pollinator-driven natural selection to enhance plant reproductive success. Studies on temperate plant systems have shown pollinator-driven selection results in floral trait variation along elevational gradients, but studies in tropical systems are lacking. We analyzed floral traits and pollinator assemblages in the Neotropical bee-pollinated taxon Costus guanaiensis var. tarmicus across four sites along a steep elevational gradient in Peru. We found variations in floral traits of size, color, and reward, and in the pollinator assemblage along the elevational gradient. We examined our results considering two hypotheses, (1) local adaptation to different bee assemblages, and (2) the early stages of an evolutionary shift to a new pollinator functional group (hummingbirds). We found some evidence consistent with the adaptation of C. guanaiensis var. tarmicus to the local bee fauna along the studied elevational gradient. Corolla width across sites was associated with bee thorax width of the local most frequent pollinator. However, we could not rule out the possibility of the beginning of a bee-to-hummingbird pollination shift in the highest-studied site. Our study is one of the few geographic-scale analyses of floral trait and pollinator assemblage variation in tropical plant species. Our results broaden our understanding of plant-pollinator interactions beyond temperate systems by showing substantial intraspecific divergence in both floral traits and pollinator assemblages across geographic space in a tropical plant species.
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Affiliation(s)
- Rossana Maguiña‐Conde
- Ecology and Evolutionary Biology DepartmentUniversity of California Santa CruzSanta CruzCaliforniaUSA
| | - Dorali Zuñiga‐Rivas
- Laboratorio de EntomologíaUniversidad Nacional San Antonio Abad del CuscoCuscoPeru
| | - Kathleen M. Kay
- Ecology and Evolutionary Biology DepartmentUniversity of California Santa CruzSanta CruzCaliforniaUSA
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7
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Vargas OM, Madriñán S, Simpson B. Allopatric speciation is more prevalent than parapatric ecological divergence in a recent high-Andean diversification ( Linochilus: Asteraceae). PeerJ 2023; 11:e15479. [PMID: 37312875 PMCID: PMC10259450 DOI: 10.7717/peerj.15479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 05/08/2023] [Indexed: 06/15/2023] Open
Abstract
Elucidating how species accumulate in diversity hotspots is an ongoing debate in evolutionary biology. The páramo, in the Northern Andes, has remarkably high indices of plant diversity, endemicity, and diversification rates. A hypothesis for explaining such indices is that allopatric speciation is high in the páramo given its island-like distribution. An alternative hypothesis is that the altitudinal gradient of the Andean topography provides a variety of niches that drive vertical parapatric ecological speciation. A formal test for evaluating the relative roles of allopatric and parapatric ecological speciation is lacking. The main aim of our study is to test which kind of speciation is more common in an endemic páramo genus. We developed a framework incorporating phylogenetics, species' distributions, and a morpho-ecological trait (leaf area) to compare sister species and infer whether allopatric or parapatric ecological divergence caused their speciation. We applied our framework to the species-rich genus Linochilus (63 spp.) and found that the majority of recent speciation events in it (12 events, 80%) have been driven by allopatric speciation, while a smaller fraction (one event, 6.7%) is attributed to parapatric ecological speciation; two pairs of sister species produced inconclusive results (13.3%). We conclude that páramo autochthonous (in-situ) diversification has been primarily driven by allopatric speciation.
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Affiliation(s)
- Oscar M. Vargas
- Department of Biological Sciences, California State Polytechnic University, Humboldt, Arcata, CA, United States
- Department of Integrative Biology and Billie Turner Plant Resources Center, The University of Texas at Austin, Austin, TX, USA
| | - Santiago Madriñán
- Department of Biological Sciences, University of the Andes, Bogotá, DC, Colombia
- Jardín Botánico de Cartagena, Turbaco, Bolívar, Colombia
| | - Beryl Simpson
- Department of Integrative Biology and Billie Turner Plant Resources Center, The University of Texas at Austin, Austin, TX, USA
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Harenčár J, Vargas OM, Escalona M, Schemske DW, Kay KM. Genome assemblies and comparison of two Neotropical spiral gingers: Costus pulverulentus and C. lasius. J Hered 2023; 114:286-293. [PMID: 36928286 PMCID: PMC10212132 DOI: 10.1093/jhered/esad018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 03/15/2023] [Indexed: 03/18/2023] Open
Abstract
The spiral gingers (Costus L.) are a pantropical genus of herbaceous perennial monocots; the Neotropical clade of Costus radiated rapidly in the past few million years into over 60 species. The Neotropical spiral gingers have a rich history of evolutionary and ecological research that can motivate and inform modern genetic investigations. Here, we present the first 2 chromosome-level genome assemblies in the genus, for C. pulverulentus and C. lasius, and briefly compare their synteny. We assembled the C. pulverulentus genome from a combination of short-read data, Chicago and Dovetail Hi-C chromatin-proximity sequencing, and alignment with a linkage map. We annotated the genome by mapping a C. pulverulentus transcriptome and querying mapped transcripts against a protein database. We assembled the C. lasius genome with Pacific Biosciences HiFi long reads and alignment to the C. pulverulentus genome. These 2 assemblies are the first published genomes for non-cultivated tropical plants. These genomes solidify the spiral gingers as a model system and will facilitate research on the poorly understood genetic basis of tropical plant diversification.
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Affiliation(s)
- Julia Harenčár
- Ecology and Evolutionary Biology Department, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Oscar M Vargas
- Department of Biological Sciences, California State Polytechnic University, Humboldt, Arcata, CA, United States
| | - Merly Escalona
- Department of Biomolecular Engineering, University of California, Santa Cruz, Santa Cruz, CA, United States
| | - Douglas W Schemske
- Department of Plant Biology, Michigan State University, East Lansing, MI, United States
| | - Kathleen M Kay
- Ecology and Evolutionary Biology Department, University of California, Santa Cruz, Santa Cruz, CA, United States
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9
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Maas PJM, Maas-van de Kamer H, André T, Skinner D, Valderrama E, Specht CD. Eighteen new species of Neotropical Costaceae (Zingiberales). PHYTOKEYS 2023; 222:75-127. [PMID: 37252638 PMCID: PMC10210046 DOI: 10.3897/phytokeys.222.87779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 01/19/2023] [Indexed: 05/31/2023]
Abstract
In preparation for a full taxonomic revision of the Neotropical genera of Costaceae (i.e., Chamaecostus, Costus, Dimerocostus, and Monocostus), we present the description of 17 new species of Neotropical Costus and one new species of the Neotropic endemic genus Chamaecostus with notes on their distribution and ecology, vernacular names (when known), and diagnostic characters for identification. Distribution maps are included for all species, and each description is accompanied by photographic plates illustrating diagnostic characters.
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Affiliation(s)
- Paul J. M. Maas
- Naturalis Biodiversity Centre, Botany, P.O. Box 9517, 2300 RA Leiden, NetherlandsNaturalis Biodiversity CentreLeidenNetherlands
| | - Hiltje Maas-van de Kamer
- Naturalis Biodiversity Centre, Botany, P.O. Box 9517, 2300 RA Leiden, NetherlandsNaturalis Biodiversity CentreLeidenNetherlands
| | - Thiago André
- Universidade de Brasília, Departamento de Botânica, Campus Universitário Darcy Ribeiro, Asa Norte, Brasília (DF), BrazilUniversidade de BrasíliaBrasíliaBrazil
| | - David Skinner
- Le Jardin Ombragé, Tallahassee, (Private botanical garden, Botanic Gardens Conservation International – BGCI – registration ID 50148), Florida, USALe Jardin OmbragéTallahasseeUnited States of America
| | - Eugenio Valderrama
- Cornell University, Section of Plant Biology and the L.H.Bailey Hortorium, School of Integrative Plant Science, Ithaca, NY, USACornell UniversityIthacaUnited States of America
| | - Chelsea D. Specht
- Cornell University, Section of Plant Biology and the L.H.Bailey Hortorium, School of Integrative Plant Science, Ithaca, NY, USACornell UniversityIthacaUnited States of America
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10
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Kay KM, Grossenbacher DL. Evolutionary convergence on hummingbird pollination in Neotropical Costus provides insight into the causes of pollinator shifts. THE NEW PHYTOLOGIST 2022; 236:1572-1583. [PMID: 36068995 PMCID: PMC9826479 DOI: 10.1111/nph.18464] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 08/10/2022] [Indexed: 06/15/2023]
Abstract
The evolution of hummingbird pollination is common across angiosperms throughout the Americas, presenting an opportunity to examine convergence in both traits and environments to better understand how complex phenotypes arise. Here we examine independent shifts from bee to hummingbird pollination in the Neotropical spiral gingers (Costus) and address common explanations for the prevalence of transitions from bee to hummingbird pollination. We use floral traits of species with observed pollinators to predict pollinators of unobserved species and reconstruct ancestral pollination states on a well-resolved phylogeny. We examine whether independent transitions evolve towards the same phenotypic optimum and whether shifts to hummingbird pollination correlate with elevation or climate. Traits predicting hummingbird pollination include small flower size, brightly colored floral bracts and the absence of nectar guides. We find many shifts to hummingbird pollination and no reversals, a single shared phenotypic optimum across hummingbird flowers, and no association between pollination and elevation or climate. Evolutionary shifts to hummingbird pollination in Costus are highly convergent and directional, involve a surprising set of traits when compared with other plants with analogous transitions and refute the generality of several common explanations for the prevalence of transitions from bee to hummingbird pollination.
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Affiliation(s)
- Kathleen M. Kay
- Department of Ecology and Evolutionary BiologyUniversity of California, Santa CruzSanta CruzCA95060USA
| | - Dena L. Grossenbacher
- Department of BiologyCalifornia Polytechnic State UniversitySan Luis ObispoCA93401USA
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Valderrama E, Landis JB, Skinner D, Maas PJM, Maas-van de Kramer H, André T, Grunder N, Sass C, Pinilla-Vargas M, Guan CJ, Phillips HR, de Almeida AMR, Specht CD. The genetic mechanisms underlying the convergent evolution of pollination syndromes in the Neotropical radiation of Costus L. FRONTIERS IN PLANT SCIENCE 2022; 13:874322. [PMID: 36161003 PMCID: PMC9493542 DOI: 10.3389/fpls.2022.874322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 06/27/2022] [Indexed: 06/16/2023]
Abstract
Selection together with variation in floral traits can act to mold floral form, often driven by a plant's predominant or most effective pollinators. To investigate the evolution of traits associated with pollination, we developed a phylogenetic framework for evaluating tempo and mode of pollination shifts across the genus Costus L., known for its evolutionary toggle between traits related to bee and bird pollination. Using a target enrichment approach, we obtained 957 loci for 171 accessions to expand the phylogenetic sampling of Neotropical Costus. In addition, we performed whole genome resequencing for a subset of 20 closely related species with contrasting pollination syndromes. For each of these 20 genomes, a high-quality assembled transcriptome was used as reference for consensus calling of candidate loci hypothesized to be associated with pollination-related traits of interest. To test for the role these candidate genes may play in evolutionary shifts in pollinators, signatures of selection were estimated as dN/dS across the identified candidate loci. We obtained a well-resolved phylogeny for Neotropical Costus despite conflict among gene trees that provide evidence of incomplete lineage sorting and/or reticulation. The overall topology and the network of genome-wide single nucleotide polymorphisms (SNPs) indicate that multiple shifts in pollination strategy have occurred across Costus, while also suggesting the presence of previously undetected signatures of hybridization between distantly related taxa. Traits related to pollination syndromes are strongly correlated and have been gained and lost in concert several times throughout the evolution of the genus. The presence of bract appendages is correlated with two traits associated with defenses against herbivory. Although labellum shape is strongly correlated with overall pollination syndrome, we found no significant impact of labellum shape on diversification rates. Evidence suggests an interplay of pollination success with other selective pressures shaping the evolution of the Costus inflorescence. Although most of the loci used for phylogenetic inference appear to be under purifying selection, many candidate genes associated with functional traits show evidence of being under positive selection. Together these results indicate an interplay of phylogenetic history with adaptive evolution leading to the diversification of pollination-associated traits in Neotropical Costus.
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Affiliation(s)
- Eugenio Valderrama
- School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Cornell University, Ithaca, NY, United States
| | - Jacob B. Landis
- School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Cornell University, Ithaca, NY, United States
- BTI Computational Biology Center, Boyce Thompson Institute, Ithaca, NY, United States
| | - Dave Skinner
- Le Jardin Ombragé, Tallahassee, FL, United States
| | - Paul J. M. Maas
- Section Botany, Naturalis Biodiversity Center, Leiden, Netherlands
| | | | - Thiago André
- Departamento de Botânica, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF, Brazil
| | - Nikolaus Grunder
- Department of Biological Sciences, California State University, East Bay, Hayward, CA, United States
| | - Chodon Sass
- University and Jepson Herbaria, University of California, Berkeley, Berkeley, CA, United States
| | - Maria Pinilla-Vargas
- School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Cornell University, Ithaca, NY, United States
| | - Clarice J. Guan
- School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Cornell University, Ithaca, NY, United States
| | - Heather R. Phillips
- School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Cornell University, Ithaca, NY, United States
| | | | - Chelsea D. Specht
- School of Integrative Plant Science, Section of Plant Biology and the L.H. Bailey Hortorium, Cornell University, Ithaca, NY, United States
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12
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Harenčár JG, Ávila‐Lovera E, Goldsmith GR, Chen GF, Kay KM. Flexible drought deciduousness in a neotropical understory herb. AMERICAN JOURNAL OF BOTANY 2022; 109:1262-1272. [PMID: 35862815 PMCID: PMC9545341 DOI: 10.1002/ajb2.16037] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 06/21/2022] [Accepted: 06/24/2022] [Indexed: 06/15/2023]
Abstract
PREMISE Adaptive divergence across environmental gradients is a key driver of speciation. Precipitation seasonality gradients are common in the tropics, yet drought adaptation is nearly unexplored in neotropical understory herbs. Here, we examined two recently diverged neotropical spiral gingers, one adapted to seasonal drought and one reliant on perennial water, to uncover the basis of drought adaptation. METHODS We combined ecophysiological trait measurements in the field and greenhouse with experimental and observational assessments of real-time drought response to determine how Costus villosissimus (Costaceae) differs from C. allenii to achieve drought adaptation. RESULTS We found that drought-adapted C. villosissimus has several characteristics indicating flexible dehydration avoidance via semi-drought-deciduousness and a fast economic strategy. Although the two species do not differ in water-use efficiency, C. villosissimus has a more rapid growth rate, lower leaf mass per area, lower stem density, higher leaf nitrogen, and a strong trend of greater light-saturated photosynthetic rates. These fast economic strategy traits align with both field-based observations and experimental dry-down results. During drought, C. villosissimus displays facultative drought-deciduousness, losing lower leaves during the dry season and rapidly growing new leaves in the wet season. CONCLUSIONS We revealed a drought adaptation strategy that has not, to our knowledge, previously been documented in tropical herbs. This divergent drought adaptation evolved recently and is an important component of reproductive isolation between C. villosissimus and C. allenii, indicating that adaptive shifts to survive seasonal drought may be an underappreciated axis of neotropical understory plant diversification.
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Affiliation(s)
- Julia G. Harenčár
- Ecology and Evolutionary Biology DepartmentUniversity of California, Santa CruzSanta CruzCA95060USA
| | - Eleinis Ávila‐Lovera
- Smithsonian Tropical Research InstituteApartado Postal 0843‐03092Panamá, República de Panamá
- Schmid College of Science and TechnologyChapman UniversityOrangeCA92866USA
| | | | - Grace F. Chen
- Department of BiologyEast Carolina UniversityGreenvilleNC27858USA
| | - Kathleen M. Kay
- Ecology and Evolutionary Biology DepartmentUniversity of California, Santa CruzSanta CruzCA95060USA
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13
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Wessinger CA. Small genetic steps lead to mechanical isolation in hummingbird-pollinated gingers. Mol Ecol 2022; 31:4205-4207. [PMID: 35796626 DOI: 10.1111/mec.16605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/04/2022] [Indexed: 11/28/2022]
Abstract
Interactions with pollinators are a potent source of natural selection driving the spectacular array of flowering plant diversity on Earth (Kay & Sargent, 2009; Van der Niet et al., 2014). Floral traits play a central role in this process: reliable and effective pollination by animal pollinators depends on complex floral features, including traits that determine pollinator attraction and reward, as well as the mechanics of pollen transfer. Pollinators specify mating events between individuals, and thus differences in flowers have the potential to generate reproductive isolating barriers (floral isolation). A compelling case of floral isolation comes from spiral gingers (Costus), where hummingbird-adapted species have evolved distinct pollen placement strategies (on the bills vs. foreheads of pollinators) due to differences in flower shape and the arrangements of flower parts. This difference in pollen placement causes a mechanical barrier to cross-pollination. In this issue of Molecular Ecology, Kay and Surget-Groba (2022) dissect the genetic basis of these floral differences using a quantitative trait locus (QTL) mapping approach. They find small-effect QTLs that influence multiple correlated traits and allelic effects that suggest a history of directional selection. Their results indicate mechanical isolation reflects adaptive divergence that has built up piecemeal over time.
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14
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Sanín MJ, Borchsenius F, Paris M, Carvalho-Madrigal S, Gómez Hoyos AC, Cardona A, Arcila Marín N, Ospina Y, Hoyos-Gómez SE, Manrique HF, Bernal R. The Tracking of Moist Habitats Allowed Aiphanes (Arecaceae) to Cover the Elevation Gradient of the Northern Andes. FRONTIERS IN PLANT SCIENCE 2022; 13:881879. [PMID: 35832227 PMCID: PMC9272002 DOI: 10.3389/fpls.2022.881879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 05/20/2022] [Indexed: 06/15/2023]
Abstract
The topographic gradients of the Tropical Andes may have triggered species divergence by different mechanisms. Topography separates species' geographical ranges and offers climatic heterogeneity, which could potentially foster local adaptation to specific climatic conditions and result in narrowly distributed endemic species. Such a pattern is found in the Andean centered palm genus Aiphanes. To test the extent to which geographic barriers and climatic heterogeneity can explain distribution patterns in Aiphanes, we sampled 34 out of 36 currently recognized species in that genus and sequenced them by Sanger sequencing and/or sequence target capture sequencing. We generated Bayesian, likelihood, and species-tree phylogenies, with which we explored climatic trait evolution from current climatic occupation. We also estimated species distribution models to test the relative roles of geographical and climatic divergence in their evolution. We found that Aiphanes originated in the Miocene in Andean environments and possibly in mid-elevation habitats. Diversification is related to the occupation of the adjacent high and low elevation habitats tracking high annual precipitation and low precipitation seasonality (moist habitats). Different species in different clades repeatedly occupy all the different temperatures offered by the elevation gradient from 0 to 3,000 m in different geographically isolated areas. A pattern of conserved adaptation to moist environments is consistent among the clades. Our results stress the evolutionary roles of niche truncation of wide thermal tolerance by physical range fragmentation, coupled with water-related niche conservatism, to colonize the topographic gradient.
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Affiliation(s)
- María José Sanín
- Facultad de Ciencias y Biotecnología, Universidad CES, Medellín, Colombia
- School of Mathematical and Natural Sciences, Arizona State University, Tempe, AZ, United States
- Departamento de Procesos y Energía, Universidad Nacional de Colombia, Medellín, Colombia
| | - Finn Borchsenius
- Faculty of Technical Sciences, Aarhus University, Aarhus, Denmark
| | - Margot Paris
- Unit of Ecology and Evolution, Department of Biology, University of Fribourg, Fribourg, Switzerland
| | | | | | - Agustín Cardona
- Departamento de Procesos y Energía, Universidad Nacional de Colombia, Medellín, Colombia
| | | | - Yerson Ospina
- Facultad de Ciencias y Biotecnología, Universidad CES, Medellín, Colombia
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15
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Ávila-Lovera E, Goldsmith GR, Kay KM, Funk JL. Above- and below-ground functional trait coordination in the Neotropical understory genus Costus. AOB PLANTS 2022; 14:plab073. [PMID: 35035869 PMCID: PMC8757582 DOI: 10.1093/aobpla/plab073] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 11/30/2021] [Indexed: 06/14/2023]
Abstract
The study of plant functional traits and variation among and within species can help illuminate functional coordination and trade-offs in key processes that allow plants to grow, reproduce and survive. We studied 20 leaf, above-ground stem, below-ground stem and fine-root traits of 17 Costus species from forests in Costa Rica and Panama to answer the following questions: (i) Do congeneric species show above-ground and below-ground trait coordination and trade-offs consistent with theory of resource acquisition and conservation? (ii) Is there correlated evolution among traits? (iii) Given the diversity of habitats over which Costus occurs, what is the relative contribution of site and species to trait variation? We performed a principal components analysis (PCA) to assess for the existence of a spectrum of trait variation and found that the first two PCs accounted for 21.4 % and 17.8 % of the total trait variation, respectively, with the first axis of variation being consistent with a continuum of resource-acquisitive and resource-conservative traits in water acquisition and use, and the second axis of variation being related to the leaf economics spectrum. Stomatal conductance was negatively related to both above-ground stem and rhizome specific density, and these relationships became stronger after accounting for evolutionary relatedness, indicating correlated evolution. Despite elevation and climatic differences among sites, high trait variation was ascribed to individuals rather than to sites. We conclude that Costus species present trait coordination and trade-offs that allow species to be categorized as having a resource-acquisitive or resource-conservative functional strategy, consistent with a whole-plant functional strategy with evident coordination and trade-offs between above-ground and below-ground function. Our results also show that herbaceous species and species with rhizomes tend to agree with trade-offs found in more species-rich comparisons.
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Affiliation(s)
- Eleinis Ávila-Lovera
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
| | - Gregory R Goldsmith
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
| | - Kathleen M Kay
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA
| | - Jennifer L Funk
- Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA
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16
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Larson DA, Vargas OM, Vicentini A, Dick CW. Admixture may be extensive among hyperdominant Amazon rainforest tree species. THE NEW PHYTOLOGIST 2021; 232:2520-2534. [PMID: 34389989 PMCID: PMC9292926 DOI: 10.1111/nph.17675] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 08/04/2021] [Indexed: 05/25/2023]
Abstract
Admixture is a mechanism by which species of long-lived plants may acquire novel alleles. However, the potential role of admixture in the origin and maintenance of tropical plant diversity is unclear. We ask whether admixture occurs in an ecologically important clade of Eschweilera (Parvifolia clade, Lecythidaceae), which includes some of the most widespread and abundant tree species in Amazonian forests. Using target capture sequencing, we conducted a detailed phylogenomic investigation of 33 species in the Parvifolia clade and investigated specific hypotheses of admixture within a robust phylogenetic framework. We found strong evidence of admixture among three ecologically dominant species, E. coriacea, E. wachenheimii and E. parviflora, but a lack of evidence for admixture among other lineages. Accepted species were largely distinguishable from one another, as was geographic structure within species. We show that hybridization may play a role in the evolution of the most widespread and ecologically variable Amazonian tree species. While admixture occurs among some species of Eschweilera, it has not led to widespread erosion of most species' genetic or morphological identities. Therefore, current morphological based species circumscriptions appear to provide a useful characterization of the clade's lineage diversity.
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Affiliation(s)
- Drew A. Larson
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMI48109USA
| | - Oscar M. Vargas
- Department of Biological SciencesHumboldt State UniversityArcataCA95521USA
| | - Alberto Vicentini
- Instituto Nacional de Pesquisas da Amazônia (INPA)ManausAMCEP 69067‐375Brazil
| | - Christopher W. Dick
- Department of Ecology & Evolutionary BiologyUniversity of MichiganAnn ArborMI48109USA
- Smithsonian Tropical Research InstitutePanama CityRepublic of Panama
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17
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Goff KA, Martinez Del Rio C, Kay KM. A greenhouse experiment partially supports inferences of ecogeographic isolation from niche models of Clarkia sister species. AMERICAN JOURNAL OF BOTANY 2021; 108:2002-2014. [PMID: 34661904 PMCID: PMC9298282 DOI: 10.1002/ajb2.1756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/10/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
PREMISE Ecogeographic isolation, or geographic isolation caused by ecological divergence, is thought to be of primary importance in speciation, yet is difficult to demonstrate and quantify. To determine whether distributions are limited by divergent adaptation or historical contingency, the gold standard is to reciprocally transplant species between their geographic ranges. Alternatively, ecogeographic isolation is inferred from species distribution models and niche divergence tests using widely available environmental and occurrence data. METHODS We tested for ecogeographic isolation between two sister species of California annual wildflowers, Clarkia concinna and C. breweri, with a hybrid approach. We used niche models to predict water availability as the major axis of ecological divergence and then tested that with a greenhouse experiment. Specifically, we manipulated water availability in field soils for two populations of each species and predicted higher fitness in conditions representing home habitats to those representing the environment of each's sister species. RESULTS Water availability and soil representing C. concinna generally increased both species' fitness. Thus, water and soil may indeed limit C. concinna from colonizing the range of C. breweri, but not vice versa. We suggest that the competitive environment and pollinator availability, which are not directly captured with either approach, may be key biotic factors correlated with climate that contribute to unexplained ecogeographic isolation for C. breweri. CONCLUSIONS Ours is a valuable approach to assessing ecogeographic isolation, in that it balances feasibility with model validation, and our results have implications for species distribution modeling efforts geared toward predicting climate change responses.
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Affiliation(s)
- Kaleb A. Goff
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaSanta CruzCA95060USA
- Present address:
Kaleb A. Goff, Department of Plant and Microbial BiologyNorth Carolina State UniversityRaleighNC 27695USA
| | | | - Kathleen M. Kay
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaSanta CruzCA95060USA
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18
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Kay KM, Surget-Groba Y. The genetic basis of floral mechanical isolation between two hummingbird-pollinated Neotropical understorey herbs. Mol Ecol 2021; 31:4351-4363. [PMID: 34487383 DOI: 10.1111/mec.16165] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/29/2021] [Accepted: 08/31/2021] [Indexed: 12/29/2022]
Abstract
Floral divergence can contribute to reproductive isolation among plant lineages, and thus provides an opportunity to study the genetics of speciation, including the number, effect size, mode of action and interactions of quantitative trait loci (QTL). Moreover, flowers represent suites of functionally interrelated traits, but it is unclear to what extent the phenotypic integration of the flower is underlain by a shared genetic architecture, which could facilitate or constrain correlated evolution of floral traits. Here, we examine the genetic architecture of floral morphological traits involved in an evolutionary switch from bill to forehead pollen placement between two species of hummingbird-pollinated Neotropical understorey herbs that are reproductively isolated by these floral differences. For the majority of traits, we find multiple QTL of relatively small effect spread throughout the genome. We also find substantial colocalization and alignment of effects of QTL underlying different floral traits that function together to promote outcrossing and reduce heterospecific pollen transfer. Our results are consistent with adaptive pleiotropy or linkage of many co-adapted genes, either of which could have facilitated a response to correlated selection and helped to stabilize divergent phenotypes in the face of low levels of hybridization. Moreover, our results indicate that floral mechanical isolation can be consistent with an infinitesimal model of adaptation.
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Affiliation(s)
- Kathleen M Kay
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - Yann Surget-Groba
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA, USA.,Département de Biologie, Université du Québec en Outaouais, Ripon, QC, Canada
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19
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Dellinger AS, Pérez-Barrales R, Michelangeli FA, Penneys DS, Fernández-Fernández DM, Schönenberger J. Low bee visitation rates explain pollinator shifts to vertebrates in tropical mountains. THE NEW PHYTOLOGIST 2021; 231:864-877. [PMID: 33864287 DOI: 10.1111/nph.17390] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/26/2021] [Indexed: 06/12/2023]
Abstract
Evolutionary shifts from bee to vertebrate pollination are common in tropical mountains. Reduction in bee pollination efficiency under adverse montane weather conditions was proposed to drive these shifts. Although pollinator shifts are central to the evolution and diversification of angiosperms, we lack experimental evidence of the ecological processes underlying such shifts. Here, we combine phylogenetic and distributional data for 138 species of the Neotropical plant tribe Merianieae (Melastomataceae) with pollinator observations of 11 and field pollination experiments of six species to test whether the mountain environment may indeed drive such shifts. We demonstrate that shifts from bee to vertebrate pollination coincided with occurrence at high elevations. We show that vertebrates were highly efficient pollinators even under the harsh environmental conditions of tropical mountains, whereas bee pollination efficiency was lowered significantly through reductions in flower visitation rates. Furthermore, we show that pollinator shifts in Merianieae coincided with the final phases of the Andean uplift and were contingent on adaptive floral trait changes to alternative rewards and mechanisms facilitating pollen dispersal. Our results provide evidence that abiotic environmental conditions (i.e. mountain climate) may indeed reduce the efficiency of a plant clade's ancestral pollinator group and correlate with shifts to more efficient new pollinators.
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Affiliation(s)
- Agnes S Dellinger
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, Vienna, 1030, Austria
| | - Rocio Pérez-Barrales
- School of Biological Sciences, University of Portsmouth, King Henry 1st Street, Portsmouth, PO1 2DY, UK
| | - Fabián A Michelangeli
- Institute of Systematic Botany, The New York Botanical Garden, 2900 Southern Blvd, Bronx, NY, 10458-5125, USA
| | - Darin S Penneys
- Biology & Marine Biology, University of North Carolina Wilmington, 601 South College Road, Wilmington, NC, 28403-5915, USA
| | | | - Jürg Schönenberger
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, Vienna, 1030, Austria
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