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Eisen KE, Ma R, Raguso RA. Among- and within-population variation in morphology, rewards, and scent in a hawkmoth-pollinated plant. AMERICAN JOURNAL OF BOTANY 2022; 109:1794-1810. [PMID: 35762273 DOI: 10.1002/ajb2.16030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
PREMISE Floral scent is a complex trait that mediates many plant-insect interactions, but our understanding of how floral scent variation evolves, either independently or in concert with other traits, remains limited. Assessing variation in floral scent at multiple levels of biological organization and comparing patterns of variation in scent to variation in other floral traits can contribute to our understanding of how scent variation evolves in nature. METHODS We used a greenhouse common garden experiment to investigate variation in floral scent at three scales-within plants, among plants, and among populations-and to determine whether scent, alone or in combination with morphology and rewards, contributes to population differentiation in Oenothera cespitosa subsp. marginata. Its range spans most of the biomes in the western United States, such that variation in both the abiotic and biotic environment could contribute to trait variation. RESULTS Multiple analytical approaches demonstrated substantial variation among and within populations in compound-specific and total floral scent measures. Overall, populations were differentiated in morphology and reward traits and in scent. Across populations, coupled patterns of variation in linalool, leucine-derived compounds, and hypanthium length are consistent with a long-tongued moth pollination syndrome. CONCLUSIONS The considerable variation in floral scent detected within populations suggests that, similar to other floral traits, variation in floral scent may have a heritable genetic component. Differences in patterns of population differentiation in floral scent and in morphology and rewards indicate that these traits may be shaped by different selective pressures.
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Affiliation(s)
- Katherine E Eisen
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853, USA
- Department of Biology, Lund University, Lund, Sweden
| | - Rong Ma
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
| | - Robert A Raguso
- Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, 14853, USA
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Balbuena MS, Broadhead GT, Dahake A, Barnett E, Vergara M, Skogen KA, Jogesh T, Raguso RA. Mutualism has its limits: consequences of asymmetric interactions between a well-defended plant and its herbivorous pollinator. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210166. [PMID: 35491593 DOI: 10.1098/rstb.2021.0166] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Concern for pollinator health often focuses on social bees and their agricultural importance at the expense of other pollinators and their ecosystem services. When pollinating herbivores use the same plants as nectar sources and larval hosts, ecological conflicts emerge for both parties, as the pollinator's services are mitigated by herbivory and its larvae are harmed by plant defences. We tracked individual-level metrics of pollinator health-growth, survivorship, fecundity-across the life cycle of a pollinating herbivore, the common hawkmoth, Hyles lineata, interacting with a rare plant, Oenothera harringtonii, that is polymorphic for the common floral volatile (R)-(-)-linalool. Linalool had no impact on floral attraction, but its experimental addition suppressed oviposition on plants lacking linalool. Plants showed robust resistance against herbivory from leaf-disc to whole-plant scales, through poor larval growth and survivorship. Higher larval performance on other Oenothera species indicates that constitutive herbivore resistance by O. harringtonii is not a genus-wide trait. Leaf volatiles differed among populations of O. harringtonii but were not induced by larval herbivory. Similarly, elagitannins and other phenolics varied among plant tissues but were not herbivore-induced. Our findings highlight asymmetric plant-pollinator interactions and the importance of third parties, including alternative larval host plants, in maintaining pollinator health. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
- Maria Sol Balbuena
- Department of Neurobiology and Behaviour, Cornell University, Ithaca, NY 14853, USA.,Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET, Universidad de Buenos Aires, C1428EHA, Argentina
| | - Geoffrey T Broadhead
- Department of Neurobiology and Behaviour, Cornell University, Ithaca, NY 14853, USA
| | - Ajinkya Dahake
- Department of Neurobiology and Behaviour, Cornell University, Ithaca, NY 14853, USA
| | - Emily Barnett
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA
| | - Melissa Vergara
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA
| | - Krissa A Skogen
- Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL 60035, USA
| | - Tania Jogesh
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060, USA.,Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL 60035, USA
| | - Robert A Raguso
- Department of Neurobiology and Behaviour, Cornell University, Ithaca, NY 14853, USA
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3
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Cisternas‐Fuentes A, Jogesh T, Broadhead GT, Raguso RA, Skogen KA, Fant JB. Evolution of selfing syndrome and its influence on genetic diversity and inbreeding: A range-wide study in Oenothera primiveris. AMERICAN JOURNAL OF BOTANY 2022; 109:789-805. [PMID: 35596689 PMCID: PMC9320852 DOI: 10.1002/ajb2.1861] [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: 11/04/2021] [Revised: 03/09/2022] [Accepted: 03/11/2022] [Indexed: 06/15/2023]
Abstract
PREMISE To avoid inbreeding depression, plants have evolved diverse breeding systems to favor outcrossing, such as self-incompatibility. However, changes in biotic and abiotic conditions can result in selective pressures that lead to a breakdown in self-incompatibility. The shift to increased selfing is commonly associated with reduced floral features, lower attractiveness to pollinators, and increased inbreeding. We tested the hypothesis that the loss of self-incompatibility, a shift to self-fertilization (autogamy), and concomitant evolution of the selfing syndrome (reduction in floral traits associated with cross-fertilization) will lead to increased inbreeding and population differentiation in Oenothera primiveris. Across its range, this species exhibits a shift in its breeding system and floral traits from a self-incompatible population with large flowers to self-compatible populations with smaller flowers. METHODS We conducted a breeding system assessment, evaluated floral traits in the field and under controlled conditions, and measured population genetic parameters using RADseq data. RESULTS Our results reveal a bimodal transition to the selfing syndrome from the west to the east of the range of O. primiveris. This shift includes variation in the breeding system and the mating system, a reduction in floral traits (flower diameter, herkogamy, and scent production), a shift to greater autogamy, reduced genetic diversity, and increased inbreeding. CONCLUSIONS The observed variation highlights the importance of range-wide studies to understand breeding system variation and the evolution of the selfing syndrome within populations and species.
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Affiliation(s)
- Anita Cisternas‐Fuentes
- Negaunee Institute for Plant Conservation Science and ActionChicago Botanic Garden1000 Lake Cook RoadGlencoeIllinois60035USA
- Plant Biology and ConservationNorthwestern University2205 Tech DriveEvanstonIllinois60208USA
- Department of Biological ScienceClemson University132 Long HallClemsonSouth Carolina29631USA
| | - Tania Jogesh
- Negaunee Institute for Plant Conservation Science and ActionChicago Botanic Garden1000 Lake Cook RoadGlencoeIllinois60035USA
| | - Geoffrey T. Broadhead
- Department of Entomology and NematologyUniversity of Florida1881 Natural Area DriveGainesvilleFlorida32611USA
| | - Robert A. Raguso
- Department of Neurobiology and BehaviorCornell UniversityW361 Mudd HallIthacaNew York14853USA
| | - Krissa A. Skogen
- Negaunee Institute for Plant Conservation Science and ActionChicago Botanic Garden1000 Lake Cook RoadGlencoeIllinois60035USA
- Plant Biology and ConservationNorthwestern University2205 Tech DriveEvanstonIllinois60208USA
| | - Jeremie B. Fant
- Negaunee Institute for Plant Conservation Science and ActionChicago Botanic Garden1000 Lake Cook RoadGlencoeIllinois60035USA
- Plant Biology and ConservationNorthwestern University2205 Tech DriveEvanstonIllinois60208USA
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Bechen LL, Johnson MG, Broadhead GT, Levin RA, Overson RP, Jogesh T, Fant JB, Raguso RA, Skogen KA, Wickett NJ. Differential gene expression associated with a floral scent polymorphism in the evening primrose Oenothera harringtonii (Onagraceae). BMC Genomics 2022; 23:124. [PMID: 35151274 PMCID: PMC8840323 DOI: 10.1186/s12864-022-08370-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Accepted: 12/30/2021] [Indexed: 12/13/2022] Open
Abstract
Background Plant volatiles play an important role in both plant-pollinator and plant-herbivore interactions. Intraspecific polymorphisms in volatile production are ubiquitous, but studies that explore underlying differential gene expression are rare. Oenothera harringtonii populations are polymorphic in floral emission of the monoterpene (R)-(−)-linalool; some plants emit (R)-(−)-linalool (linalool+ plants) while others do not (linalool- plants). However, the genes associated with differential production of this floral volatile in Oenothera are unknown. We used RNA-Seq to broadly characterize differential gene expression involved in (R)-(−)-linalool biosynthesis. To identify genes that may be associated with the polymorphism for this trait, we used RNA-Seq to compare gene expression in six different Oenothera harringtonii tissues from each of three linalool+ and linalool- plants. Results Three clusters of differentially expressed genes were enriched for terpene synthase activity: two were characterized by tissue-specific upregulation and one by upregulation only in plants with flowers that produce (R)-(−)-linalool. A molecular phylogeny of all terpene synthases identified two putative (R)-(−)-linalool synthase transcripts in Oenothera harringtonii, a single allele of which is found exclusively in linalool+ plants. Conclusions By using a naturally occurring polymorphism and comparing different tissues, we were able to identify candidate genes putatively involved in the biosynthesis of (R)-(−)-linalool. Expression of these genes in linalool- plants, while low, suggests a regulatory polymorphism, rather than a population-specific loss-of-function allele. Additional terpene biosynthesis-related genes that are up-regulated in plants that emit (R)-(−)-linalool may be associated with herbivore defense, suggesting a potential economy of scale between plant reproduction and defense. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08370-6.
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Skogen KA, Jogesh T, Hilpman ET, Todd SL, Rhodes MK, Still SM, Fant JB. Land-use change has no detectable effect on reproduction of a disturbance-adapted, hawkmoth-pollinated plant species. AMERICAN JOURNAL OF BOTANY 2016; 103:1950-1963. [PMID: 27803000 DOI: 10.3732/ajb.1600302] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 09/22/2016] [Indexed: 06/06/2023]
Abstract
PREMISE OF THE STUDY Land-use change is cited as a primary driver of global biodiversity loss, with myriad consequences for species, populations, and ecosystems. However, few studies have examined its impact on species interactions, particularly pollination. Furthermore, when the effects of land-use change on pollination have been studied, the focus has largely been on species pollinated by diurnal pollinators, namely, bees and butterflies. Here, we focus on Oenothera harringtonii, a night-flowering, disturbance-adapted species that has experienced a range-wide gradient of land-use change. We tested the hypothesis that the negative impacts of land-use change are mitigated by long-distance pollination. METHODS Our study included both temporal (4 yr) and spatial (19 populations range-wide, and 1, 2, and 5 km from the population center) data, providing a comprehensive understanding of the role of land-use change on pollination biology and reproduction. KEY RESULTS We first confirmed that O. harringtonii is self-incompatible and reliant on pollinators for reproduction. We then showed that hawkmoths (primarily Hyles lineata) are highly reliable and effective pollinators in both space and time. Unlike other studies, we did not detect an effect of population size, increased isolation, or a reduction in suitable habitat in areas with evidence of land-use change on pollination (visitation, pollen removal and deposition). Furthermore, the proportion of suitable habitat and other fragmentation metrics examined were not associated with population size or density in this plant species. CONCLUSIONS We conclude that nocturnal pollination of Oenothera harringtonii via hawkmoths is robust to the negative impacts of land-use change.
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Affiliation(s)
- Krissa A Skogen
- Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA
| | - Tania Jogesh
- Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA
| | - Evan T Hilpman
- Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA
- Washingtion State University, School of Biological Sciences, P.O. Box 644236, Pullman, Washington 99164 USA
| | - Sadie L Todd
- Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA
- Iowa Department of Agriculture and Land Stewardship, 2230 S. Ankeny Boulevard, Ankeny, Iowa 50023 USA
| | - Matthew K Rhodes
- Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA
- Department of Ecology and Evolutionary Biology, University of Arizona, P.O. Box 210088, Tucson, Arizona 85721 USA
| | - Shannon M Still
- Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA
- University of California Davis Arboretum and Public Garden, One Shields Avenue, Davis, California 95616 USA
| | - Jeremie B Fant
- Chicago Botanic Garden 1000 Lake Cook Road, Glencoe, Illinois 60022 USA
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Dudley LS, Hove AA, Emms SK, Verhoeven AS, Mazer SJ. Seasonal changes in physiological performance in wild Clarkia xantiana populations: Implications for the evolution of a compressed life cycle and self-fertilization. AMERICAN JOURNAL OF BOTANY 2015; 102:962-972. [PMID: 26101420 DOI: 10.3732/ajb.1400557] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 05/05/2015] [Indexed: 06/04/2023]
Abstract
PREMISE OF THE STUDY One explanation for the evolution of selfing, the drought escape hypothesis, proposes that self-fertilization may evolve under conditions of intensifying seasonal drought as part of a suite of traits that enable plants to accelerate the completion of their life cycle, thereby escaping late-season drought. Here, we test two fundamental assumptions of this hypothesis in Clarkia xantiana: (1) that a seasonal decline in precipitation causes an increase in drought stress and (2) that this results in changes in physiological performance, reflecting these deteriorating conditions. METHODS We examined seasonal and interannual variation in abiotic environmental conditions (estimated by ambient temperature, relative humidity, predawn leaf water potentials, and carbon isotope ratios) and physiological traits (photosynthesis, conductance, transpiration, instantaneous water-use efficiency, ascorbate peroxidase and glutathione reductase activities, quantum yield of photosystem II, PSII potential efficiency) in field populations of C. xantiana in 2009 and 2010. KEY RESULTS In both years, plants experienced intensifying drought across the growing season. Gas exchange rates decreased over the growing season and were lower in 2009 (a relatively dry year) than in 2010, suggesting that the temporal changes from early to late spring were directly linked to the deteriorating environmental conditions. CONCLUSIONS Seasonal declines in transpiration rate may have increased survival by protecting plants from desiccation. Concomitant declines in photosynthetic rate likely reduced the availability of resources for seed production late in the season. Thus, the physiological patterns observed are consistent with the conditions required for the drought escape hypothesis.
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Affiliation(s)
- Leah S Dudley
- Warren Wilson College, P.O. Box 9000, Asheville, North Carolina 28815 USA
| | - Alisa A Hove
- Warren Wilson College, P.O. Box 9000, Asheville, North Carolina 28815 USA
| | - Simon K Emms
- University of St. Thomas, 2115 Summit Ave., St. Paul, Minnesota, USA 5105
| | - Amy S Verhoeven
- University of St. Thomas, 2115 Summit Ave., St. Paul, Minnesota, USA 5105
| | - Susan J Mazer
- University of California, Santa Barbara, Santa Barbara, California 93106 USA
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Martínez-Peralta C, Márquez-Guzmán J, Mandujano MC. How common is self-incompatibility across species of the herkogamous genus Ariocarpus? AMERICAN JOURNAL OF BOTANY 2014; 101:530-538. [PMID: 24607514 DOI: 10.3732/ajb.1400022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
PREMISE OF THE STUDY Self-incompatibility (SI), the most effective mechanism to prevent selfing, may limit the number of compatible mates in populations. The seven species of Ariocarpus are endangered and predominantly outcrossers but fruit set may reach 1-20% after selfing. We aimed to determine whether SI is the underlying mechanism influencing mating in Ariocarpus species. METHODS We characterized the presence/absence of SI using pollination treatments (self-pollination, cross-pollination, natural pollination) in one population per species. We assessed SI using epifluorescence and generalized linear models (GLMs) to compare the presence of pollen tubes in the stigma, stylar transmitting tissue, and ovary among self- and cross-pollinated pistils 48 h after pollination. Following the same treatments, production of fruit set was noted and related to pollen tube growth. KEY RESULTS Pollen tubes were found more frequently in the ovaries of natural and cross-pollinated flowers than in ovaries of self-pollinated. Stylar rejection of self-pollen indicated gametophytic SI, although pollen tubes reached the ovaries in six species (4-33% of pistils). Fruit set was lower after hand-pollinations than expected from pollen tube observations. CONCLUSIONS The low percentages of self-compatibility in all species in pollen tube growth and pollination experiments indicated that no species had complete self-sterility, suggesting the presence of partial SI. Reduced fruit set relative to pollen tube production could result from a threshold of insufficient pollination, early-acting inbreeding depression, or resource limitation. The origin of partial SI in Ariocarpus could respond to pressures such as pollen limitation and population size.
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Affiliation(s)
- Concepción Martínez-Peralta
- Departamento de Ecología de la Biodiversidad, Laboratorio de Genética y Ecología, Instituto de Ecología, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, México, D. F., México
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Greiner S, Köhl K. Growing evening primroses (Oenothera). FRONTIERS IN PLANT SCIENCE 2014; 5:38. [PMID: 24592268 PMCID: PMC3923160 DOI: 10.3389/fpls.2014.00038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 01/27/2014] [Indexed: 05/10/2023]
Abstract
The model plant Oenothera has contributed significantly to the biological sciences and it dominated the early development of plant genetics, cytogenetics, and evolutionary biology. The great advantage of using Oenothera as a model system is a large body of genetic, cytological, morphological, and ecological information collected over more than a century. The Oenothera system offers a well-studied taxonomy, population structure, and ecology. Cytogenetics and formal genetics at the population level are extensively developed, providing an excellent basis to study evolutionary questions. Further, Oenothera is grown as an oil seed crop for the production of essential fatty acids (gamma-linoleic acid) and is considered to be a medicinal plant due to its many pharmaceutically active secondary metabolites, such as ellagitannins. Although Oenothera has been cultivated as a laboratory organism since the end of the 19th century, there is a substantial lack of literature dealing with modern greenhouse techniques for the genus. This review compiles an overview about the growth requirements for the genus Oenothera, with a special focus on its genetically best-studied subsections Oenothera and Munzia. Requirements for greenhouse, field, and agronomic cultures are presented, together with information on substrate types, pest control, as well as vegetative and seed propagation, cross pollination, harvest, and seed storage. Particular aspects like germination, bolting, and flowering induction in taxonomically diverse material are reviewed. Methods recommended are supported by ecological and experimental data. An overview of the possibilities for wide hybridization and polyploidy induction in the genus is given. Germplasm resources are referenced. In summary, a comprehensive guideline for successful laboratory cultivation of Oenothera species is provided.
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Affiliation(s)
- Stephan Greiner
- Max Planck Institute of Molecular Plant PhysiologyPotsdam, Germany
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Evans MEK, Hearn DJ, Theiss KE, Cranston K, Holsinger KE, Donoghue MJ. Extreme environments select for reproductive assurance: evidence from evening primroses (Oenothera). THE NEW PHYTOLOGIST 2011; 191:555-563. [PMID: 21449951 DOI: 10.1111/j.1469-8137.2011.03697.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Competing evolutionary forces shape plant breeding systems (e.g. inbreeding depression, reproductive assurance). Which of these forces prevails in a given population or species is predicted to depend upon such factors as life history, ecological conditions, and geographical context. Here, we examined two such predictions: that self-compatibility should be associated with the annual life history or extreme climatic conditions. We analyzed data from a clade of plants remarkable for variation in breeding system, life history and climatic conditions (Oenothera, sections Anogra and Kleinia, Onagraceae). We used a phylogenetic comparative approach and Bayesian or hybrid Bayesian tests to account for phylogenetic uncertainty. Geographic information system (GIS)-based climate data and ecological niche modeling allowed us to quantify climatic conditions. Breeding system and reproductive life span are not correlated in Anogra and Kleinia. Instead, self-compatibility is associated with the extremes of temperature in the coldest part of the year and precipitation in the driest part of the year. In the 60 yr since this pattern was anticipated, this is the first demonstration of a relationship between the evolution of self-compatibility and climatic extremes. We discuss possible explanations for this pattern and possible implications with respect to anthropogenic climate change.
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Affiliation(s)
- Margaret E K Evans
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06511, USA
- Present address: Origin, Structure, and Evolution of Biodiversity, UMR 7205, Museum National d'Histoire Naturelle, 16 rue Buffon, 75231 Paris, Cedex 05, France
| | - David J Hearn
- Department of Biological Sciences, Towson University, 8000 York Road, Towson, MD 21252, USA
| | - Kathryn E Theiss
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Road, U-3043, Storrs, CT 06269, USA
| | - Karen Cranston
- National Evolutionary Synthesis Center, 2024 W. Main Street, A200, Durham, NC 27705, USA
| | - Kent E Holsinger
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 N. Eagleville Road, U-3043, Storrs, CT 06269, USA
| | - Michael J Donoghue
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06511, USA
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