1
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Yamamichi M, Gibbs T, Levine JM. Integrating eco-evolutionary dynamics and modern coexistence theory. Ecol Lett 2022; 25:2091-2106. [PMID: 35962483 DOI: 10.1111/ele.14078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 06/13/2022] [Accepted: 06/29/2022] [Indexed: 01/07/2023]
Abstract
Community ecology typically assumes that competitive exclusion and species coexistence are unaffected by evolution on the time scale of ecological dynamics. However, recent studies suggest that rapid evolution operating concurrently with competition may enable species coexistence. Such findings necessitate general theory that incorporates the coexistence contributions of eco-evolutionary processes in parallel with purely ecological mechanisms and provides metrics for quantifying the role of evolution in shaping competitive outcomes in both modelling and empirical contexts. To foster the development of such theory, here we extend the interpretation of the two principal metrics of modern coexistence theory-niche and competitive ability differences-to systems where competitors evolve. We define eco-evolutionary versions of these metrics by considering how invading and resident species adapt to conspecific and heterospecific competitors. We show that the eco-evolutionary niche and competitive ability differences are sums of ecological and evolutionary processes, and that they accurately predict the potential for stable coexistence in previous theoretical studies of eco-evolutionary dynamics. Finally, we show how this theory frames recent empirical assessments of rapid evolution effects on species coexistence, and how empirical work and theory on species coexistence and eco-evolutionary dynamics can be further integrated.
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Affiliation(s)
- Masato Yamamichi
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia.,Department of International Health and Medical Anthropology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan
| | - Theo Gibbs
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, USA
| | - Jonathan M Levine
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
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2
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Kulbaba MW, Shaw RG. Lifetime Fitness through Female and Male Function: Influences of Genetically Effective Population Size and Density. Am Nat 2021; 197:434-447. [PMID: 33755534 DOI: 10.1086/713067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractAn individual's lifetime fitness and patterns of mating between individuals are interdependent features of sexual organisms. Mating systems (outcrossing vs. selfing or mating between close relatives) can affect the distribution of offspring fitness, which generally declines with inbreeding, which in turn is related to a population's genetically effective size (Ne). Fitness and mating patterns are also expected to vary with proximity of mates (i.e., population density). Consequently, density and Ne may influence demographic and genetic changes over generations and interact in their effects. Here, we report an experiment designed to assess the influence of these two population-level properties on mating system and lifetime fitness. In experimental arrays under quasi-natural conditions, we varied the density and Ne of the hermaphroditic annual legume Chamaecrista fasciculata. We recorded components of fitness for each individual and employed microsatellite markers to estimate outcrossing and assign paternity. We used aster analyses to estimate lifetime fitness for genetic families using female (seeds set) and male (seeds sired) reproduction as fitness measures. With estimates from these analyses, we assessed the evidence for a trade-off between fitness attained through female versus male function, but we found none. Lifetime fitness increased with density, especially under high Ne. Outcrossing rates increased with density under high Ne but declined modestly with density under low Ne. Our results show that density and Ne have strong direct effects on fitness and mating systems, with negative fitness effects of low Ne limiting the positive effects of increasing density. These findings highlight the importance of the interactive effects of density and Ne on lifetime fitness.
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3
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Lau JA, terHorst CP. Evolutionary responses to global change in species‐rich communities. Ann N Y Acad Sci 2019; 1476:43-58. [DOI: 10.1111/nyas.14221] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/10/2019] [Accepted: 07/25/2019] [Indexed: 01/06/2023]
Affiliation(s)
- Jennifer A. Lau
- Department of Biology, Environmental Resilience Institute Indiana University Bloomington Indiana
| | - Casey P. terHorst
- Biology Department California State University Northridge California
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4
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Tian X, Ohtsuki H, Urabe J. Evolution of asexual Daphnia pulex in Japan: variations and covariations of the digestive, morphological and life history traits. BMC Evol Biol 2019; 19:122. [PMID: 31195967 PMCID: PMC6567566 DOI: 10.1186/s12862-019-1453-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 06/06/2019] [Indexed: 02/02/2023] Open
Abstract
Background Several genetic lineages of obligate parthenogenetic Daphnia pulex, a common zooplankton species, have invaded Japan from North America. Among these, a lineage named JPN1 is thought to have started colonization as a single genotype several hundred to thousand years ago and subsequently produced many genotypes in Japan. To examine the phenotypic variations due to ecological drivers diverging the genotypes in new habitats, we measured heritability and variation in 17 traits, including life history, morphology and digestive traits, and the genetic distance among the D. pulex JPN1 genotypes in Japan. Results We found that most of the traits measured varied significantly among the genotypes and that heritability was highest in the morphological traits, followed by the digestive and life history traits. In addition, 93% of the variation in these traits was explained by the first three components in the principal component analysis, implying that variation of these heritable traits is not random but rather converged into a few directions. These relations among traits revealed the potential importance of predation pressures and food conditions as factors for diverging and selecting different genotypes. However, the magnitude of the difference in any single trait group did not correlate with the genetic distance. Conclusions Our findings show that the divergent traits evolved within D. pulex JPN1 lineage without genetic recombination, since their ancestral clone invaded Japan. Large variations and covariations of the phenotypic traits, irrespective of the genetic distance among the genotypes, support the view that the invasive success of D. pulex JPN1 was promoted by a genetic architecture that allowed for large phenotypic variations with a limited number of functionally important mutations without recombination. Electronic supplementary material The online version of this article (10.1186/s12862-019-1453-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xiaofei Tian
- Graduate School of Life Sciences, Tohoku University, 6-3 Aramaki aza Aoba, Sendai, 980-8578, Japan.
| | - Hajime Ohtsuki
- Graduate School of Life Sciences, Tohoku University, 6-3 Aramaki aza Aoba, Sendai, 980-8578, Japan
| | - Jotaro Urabe
- Graduate School of Life Sciences, Tohoku University, 6-3 Aramaki aza Aoba, Sendai, 980-8578, Japan
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5
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Hayward AD, Pemberton JM, Berenos C, Wilson AJ, Pilkington JG, Kruuk LEB. Evidence for Selection-by-Environment but Not Genotype-by-Environment Interactions for Fitness-Related Traits in a Wild Mammal Population. Genetics 2018; 208:349-364. [PMID: 29127262 PMCID: PMC5753868 DOI: 10.1534/genetics.117.300498] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 11/07/2017] [Indexed: 11/18/2022] Open
Abstract
How do environmental conditions influence selection and genetic variation in wild populations? There is widespread evidence for selection-by-environment interactions (S*E), but we reviewed studies of natural populations estimating the extent of genotype-by-environment interactions (G*E) in response to natural variation in environmental conditions and found that evidence for G*E appears to be rare within single populations in the wild. Studies estimating the simultaneous impact of environmental variation on both selection and genetic variation are especially scarce. Here, we used 24 years of data collected from a wild Soay sheep population to quantify how an important environmental variable, population density, impacts upon (1) selection through annual contribution to fitness and (2) expression of genetic variation, in six morphological and life history traits: body weight, hind leg length, parasite burden, horn length, horn growth, and testicular circumference. Our results supported the existence of S*E: selection was stronger in years of higher population density for all traits apart from horn growth, with directional selection being stronger under more adverse conditions. Quantitative genetic models revealed significant additive genetic variance for body weight, leg length, parasite burden, horn length, and testes size, but not for horn growth or our measure of annual fitness. However, random regression models found variation between individuals in their responses to the environment in only three traits, and did not support the presence of G*E for any trait. Our analyses of St Kilda Soay sheep data thus concurs with our cross-study review that, while natural environmental variation within a population can profoundly alter the strength of selection on phenotypic traits, there is less evidence for its effect on the expression of genetic variance in the wild.
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Affiliation(s)
- Adam D Hayward
- Department of Biological and Environmental Sciences, School of Natural Sciences, University of Stirling, FK9 4LA, UK
| | - Josephine M Pemberton
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL, UK
| | - Camillo Berenos
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL, UK
| | - Alastair J Wilson
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall TR10 9FE, UK
| | - Jill G Pilkington
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL, UK
| | - Loeske E B Kruuk
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, EH9 3FL, UK
- Research School of Biology, The Australian National University, Acton, Australian Capital Territory 2601, Australia
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6
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Capuana M, Colzi I, Buccianti A, Coppi A, Palm E, Del Bubba M, Gonnelli C. Paradoxical effects of density on measurement of copper tolerance in Silene paradoxa L. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:1331-1339. [PMID: 29086177 DOI: 10.1007/s11356-017-0593-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 10/24/2017] [Indexed: 06/07/2023]
Abstract
This work investigated if the assessment of tolerance to trace metals can depend on plant density in the experimental design. A non-metallicolous and a metallicolous populations of Silene paradoxa were hydroponically cultivated at increasing density and in both the absence (-Cu conditions) and excess of copper (+Cu conditions). In -Cu conditions, the metallicolous population showed a lower susceptibility to plant density in comparison to the non-metallicolous one, explained by a higher capacity of the metallicolous population to exploit resources. In +Cu conditions, an alleviating effect of increasing density was found in roots. Such effect was present to a greater extent in the non-metallicolous population, thus making the populations equally copper-tolerant at the highest density used. In shoots, an additive effect of increasing plant density to copper toxicity was reported. Its higher intensity in the metallicolous population reverted the copper tolerance relationship at the highest plant densities used. In both populations, a density-induced decrease in root copper accumulation was observed, thus concurring to the reported mitigation in +Cu conditions. Our work revealed the importance of density studies on the optimization of eco-toxicological bioassays and of metal tolerance assessment and it can be considered the first example of an alleviating effect of increasing plant number on copper stress in a metallophyte.
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Affiliation(s)
- Maurizio Capuana
- Institute of Bioscience and Bioresources-Consiglio Nazionale delle Ricerche, Polo Scientifico, Via Madonna del Piano 10, Sesto Fiorentino, Florence, Italy
| | - Ilaria Colzi
- Department of Biology, Università di Firenze, via Micheli 1, 50121, Florence, Italy
| | - Antonella Buccianti
- Department of Earth Science, Università di Firenze, via La Pira 4, 50121, Florence, Italy
| | - Andrea Coppi
- Department of Biology, Università di Firenze, via Micheli 1, 50121, Florence, Italy
| | - Emily Palm
- Department of Agri-Food and Environmental Science, Università di Firenze, via delle Idee 30, Sesto Fiorentino, 50019, Florence, Italy
| | - Massimo Del Bubba
- Department of Chemistry, University of Florence, Via della Lastruccia 3, Sesto Fiorentino, 50019, Florence, Italy
| | - Cristina Gonnelli
- Department of Biology, Università di Firenze, via Micheli 1, 50121, Florence, Italy.
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7
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Fry JD, Heinsohn SL, Mackay TFC. THE CONTRIBUTION OF NEW MUTATIONS TO GENOTYPE‐ENVIRONMENT INTERACTION FOR FITNESS IN
DROSOPHILA MELANOGASTER. Evolution 2017; 50:2316-2327. [DOI: 10.1111/j.1558-5646.1996.tb03619.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/1995] [Accepted: 05/14/1996] [Indexed: 11/29/2022]
Affiliation(s)
- James D. Fry
- Department of Genetics, Box 7614 North Carolina State University Raleigh North Carolina 27695
| | - Stefanie L. Heinsohn
- Department of Genetics, Box 7614 North Carolina State University Raleigh North Carolina 27695
| | - Trudy F. C. Mackay
- Department of Genetics, Box 7614 North Carolina State University Raleigh North Carolina 27695
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8
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Roche BM, Fritz RS. GENETICS OF RESISTANCE OF
SALIX SERICEA
TO A DIVERSE COMMUNITY OF HERBIVORES. Evolution 2017; 51:1490-1498. [DOI: 10.1111/j.1558-5646.1997.tb01472.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/1996] [Accepted: 05/21/1997] [Indexed: 11/28/2022]
Affiliation(s)
| | - Robert S. Fritz
- Department of Biology Vassar College Poughkeepsie New York 12604
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9
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Byers DL, Platenkamp GAJ, Shaw RG. VARIATION IN SEED CHARACTERS IN NEMOPHILA MENZIESII: EVIDENCE OF A GENETIC BASIS FOR MATERNAL EFFECT. Evolution 2017; 51:1445-1456. [PMID: 28568617 DOI: 10.1111/j.1558-5646.1997.tb01468.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/1996] [Accepted: 06/23/1997] [Indexed: 11/30/2022]
Abstract
A growing body of evidence indicates that phenotypic selection on juvenile traits of both plants and animals may be considerable. Because juvenile traits are typically subject to maternal effects and often have low heritabilities, adaptive responses to natural selection on these traits may seem unlikely. To determine the potential for evolutionary response to selection on juvenile traits of Nemophila menziesii (Hydrophyllaceae), we conducted two quantitative genetic studies. A reciprocal factorial cross, involving 16 parents and 1960 progeny, demonstrated a significant maternal component of variance in seed mass and additive genetic component of variance in germination time. This experiment also suggested that interaction between parents, though small, provides highly significant contributions to the variance of both traits. Such a parental interaction could arise by diverse mechanisms, including dependence of nuclear gene expression on cytoplasmic genotype, but the design of this experiment could not distinguish this from other possible causes, such as effects on progeny phenotype of interaction between the environmental conditions of both parents. The second experiment, spanning three generations with over 11,000 observations, was designed for investigation of the additive genetic variance in maternal effect, assessment of paternal effects, as well as further partitioning of the parental interaction identified in the reciprocal factorial experiment. It yielded no consistent evidence of paternal effects on seed mass, nor of parental interactions. Our inference of such interaction effects from the first experiment was evidently an artifact of failing to account for the substantial variance among fruits within crosses. The maternal effect was found to have a large additive genetic component, accounting for at least 20% of the variation in individual seed mass. This result suggests that there is appreciable potential for response to selection on seed mass through evolution of the maternal effect. We discuss aspects that may nevertheless limit response to individual selection on seed mass, including trade-offs between the size of individual seeds and germination time and between the number of seeds a maternal plant can mature and their mean size.
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Affiliation(s)
- Diane L Byers
- Department of Ecology, Evolution, Behavior, University of Minnesota, Saint Paul, Minnesota, 55108
| | - Gerrit A J Platenkamp
- Department of Botany and Plant Sciences, University of California, Riverside, California, 92521
| | - Ruth G Shaw
- Department of Ecology, Evolution, Behavior, University of Minnesota, Saint Paul, Minnesota, 55108.,Department of Botany and Plant Sciences, University of California, Riverside, California, 92521
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10
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Putnam RC, Reich PB. Climate and competition affect growth and survival of transplanted sugar maple seedlings along a 1700-km gradient. ECOL MONOGR 2017. [DOI: 10.1002/ecm.1237] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Rachel C. Putnam
- Department of Ecology, Evolution, and Behavior; University of Minnesota; 1987 Upper Buford Circle St. Paul Minnesota 55108 USA
| | - Peter B. Reich
- Department of Forest Resources; University of Minnesota; 1530 Cleveland Avenue North St. Paul Minnesota 55108 USA
- Hawkesbury Institute for the Environment; Western Sydney University; Penrith New South Wales 2753 Australia
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11
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Bassar RD, Simon T, Roberts W, Travis J, Reznick DN. The evolution of coexistence: Reciprocal adaptation promotes the assembly of a simple community. Evolution 2016; 71:373-385. [DOI: 10.1111/evo.13086] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 09/26/2016] [Accepted: 09/30/2016] [Indexed: 11/30/2022]
Affiliation(s)
- Ronald D. Bassar
- Department of Zoology University of Oxford Oxford United Kingdom
| | - Troy Simon
- Odum School of Ecology University of Georgia Athens Georgia
- Warnell School of Forestry and Natural Resources University of Georgia Athens Georgia
| | - William Roberts
- Department of Biology University of California Riverside California
| | - Joseph Travis
- Department of Biological Science Florida State University Tallahassee Florida
| | - David N. Reznick
- Department of Biology University of California Riverside California
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12
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Salmela MJ, Ewers BE, Weinig C. Natural quantitative genetic variance in plant growth differs in response to ecologically relevant temperature heterogeneity. Ecol Evol 2016; 6:7574-7585. [PMID: 30128112 PMCID: PMC6093144 DOI: 10.1002/ece3.2482] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 07/22/2016] [Accepted: 08/28/2016] [Indexed: 01/06/2023] Open
Abstract
Adaptation to large‐scale spatial heterogeneity in the environment accounts for a major proportion of genetic diversity within species. Theory predicts the erosion of adaptive genetic variation on a within‐population level, but considerable genetic diversity is often found locally. Genetic diversity could be expected to be maintained within populations in temporally or spatially variable conditions if genotypic rank orders vary across contrasting microenvironmental settings. Taking advantage of fine‐resolution environmental data, we tested the hypothesis that temperature heterogeneity among years could be one factor maintaining quantitative genetic diversity within a natural and genetically diverse plant population. We sampled maternal families of Boechera stricta, an Arabidopsis thaliana relative, at one location in the central Rocky Mountains and grew them in three treatments that, based on records from an adjacent weather station, simulated hourly temperature changes at the native site during three summers with differing mean temperatures. Treatment had a significant effect on all traits, with 2–3‐fold increase in above‐ and belowground biomass and the highest allocation to roots observed in the treatment simulating the warmest summer on record at the site. Treatment affected bivariate associations between traits, with the weakest correlation between above‐ and belowground biomass in the warmest treatment. The magnitude of quantitative genetic variation for all traits differed across treatments: Genetic variance of biomass was 0 in the warmest treatment, while highly significant diversity was found in average conditions, resulting in broad‐sense heritability of 0.31. Significant genotype × environment interactions across all treatments were found only in root‐to‐shoot ratio. Therefore, temperature variation among summers appears unlikely to account for the observed levels of local genetic variation in size in this perennial species, but may influence family rank order in growth allocation. Our results indicate that natural environmental fluctuations can have a large impact on the magnitude of within‐population quantitative genetic variance.
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Affiliation(s)
- Matti J Salmela
- Department of Botany University of Wyoming Laramie WY USA.,Present address: Natural Resources Institute Finland Vantaa Finland
| | - Brent E Ewers
- Department of Botany University of Wyoming Laramie WY USA.,Program in Ecology University of Wyoming Laramie WY USA
| | - Cynthia Weinig
- Department of Botany University of Wyoming Laramie WY USA.,Program in Ecology University of Wyoming Laramie WY USA.,Department of Molecular Biology University of Wyoming Laramie WY USA
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13
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Adler LS, Leege LM, Irwin RE. Geographic variation in resistance to nectar robbing and consequences for pollination. AMERICAN JOURNAL OF BOTANY 2016; 103:1819-1828. [PMID: 27765776 DOI: 10.3732/ajb.1600114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 09/01/2016] [Indexed: 06/06/2023]
Abstract
PREMISE OF THE STUDY Floral evolution is frequently ascribed to selection by pollinators, but may also be shaped by antagonists. However, remarkably few studies have examined geographic mosaics in resistance to floral antagonists or the consequences for other floral interactions. METHODS Gelsemium sempervirens experiences frequent nectar robbing in northern Georgia, but rarely in southern Georgia. We conducted common-garden experiments in both locations using genotypes from each region and measured robbing, pollinator attraction, floral attractive and defensive traits, and plant reproduction. KEY RESULTS Nectar robbing was more than four times higher in the north vs. south, and pollinator visits did not differ between gardens. Across both gardens, northern genotypes were half as likely to be nectar-robbed but received half as many pollinator visits as southern genotypes, suggesting evolution of resistance to robbing at a cost of reduced pollinator attraction. Plant-level traits, such as height and number of flowers, were more closely associated with resistance to robbing than floral size, shape, or chemistry. Northern genotypes had lower female and estimated male reproduction compared to southern genotypes at both locations, which could be due to costs of resistance to nectar robbing, or costs of adaptations to other biotic or abiotic differences between regions. CONCLUSIONS Our study indicates that geographic variation can play a strong role structuring interactions with floral antagonists and mutualists and provides evidence consistent with the hypothesis that local resistance to nectar robbing imposes costs in terms of decreased pollinator attraction and reproduction.
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Affiliation(s)
- Lynn S Adler
- Department of Biology, 221 Morrill Science Center South, 611 N. Pleasant St., University of Massachusetts, Amherst, Massachusetts 01003 USA
| | - Lissa M Leege
- Department of Biology, Georgia Southern University, PO Box 8042-1, Statesboro, Georgia 30460 USA
| | - Rebecca E Irwin
- Department of Biological Sciences, Life Science Center, 78 College Street, Dartmouth College, Hanover, New Hampshire 03755 USA
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14
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Stotz GC, Gianoli E, Cahill JF. Spatial pattern of invasion and the evolutionary responses of native plant species. Evol Appl 2016; 9:939-51. [PMID: 27606003 PMCID: PMC4999525 DOI: 10.1111/eva.12398] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 05/22/2016] [Indexed: 01/02/2023] Open
Abstract
Invasive plant species can have a strong negative impact on the resident native species, likely imposing new selective pressures on them. Altered selective pressures may result in evolutionary changes in some native species, reducing competitive exclusion and allowing for coexistence with the invader. Native genotypes that are able to coexist with strong invaders may represent a valuable resource for management efforts. A better understanding of the conditions under which native species are more, or less, likely to adapt to an invader is necessary to incorporate these eco-evolutionary dynamics into management strategies. We propose that the spatial structure of invasion, in particular the size and isolation of invaded patches, is one factor which can influence the evolutionary responses of native species through modifying gene flow and the strength of selection. We present a conceptual model in which large, dense, and well-connected patches result in a greater likelihood of native species adaptation. We also identify characteristics of the interacting species that may influence the evolutionary response of native species to invasion and outline potential management implications. Identifying areas of rapid evolutionary change may offer one additional tool to managers in their effort to conserve biodiversity in the face of invasion.
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Affiliation(s)
- Gisela C Stotz
- Department of Biological Sciences University of Alberta Edmonton AB Canada
| | - Ernesto Gianoli
- Departamento de Biología Universidad de la Serena La Serena Chile; Departmento de Botánica Universidad de Concepción Concepción Chile
| | - James F Cahill
- Department of Biological Sciences University of Alberta Edmonton AB Canada
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15
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Intraspecific competitive ability declines towards the edge of the expanding range of the invasive vine Mikania micrantha. Oecologia 2016; 181:115-23. [DOI: 10.1007/s00442-015-3526-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 12/05/2015] [Indexed: 10/22/2022]
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16
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Culumber ZW, Tobler M. Spatiotemporal environmental heterogeneity and the maintenance of the tailspot polymorphism in the variable platyfish (Xiphophorus variatus). Evolution 2016; 70:408-19. [PMID: 26748941 DOI: 10.1111/evo.12852] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 10/29/2015] [Accepted: 12/08/2015] [Indexed: 11/28/2022]
Abstract
Genetic variation is critical for adaptive evolution. Despite its importance, there is still limited evidence in support of some prominent theoretical models explaining the maintenance of genetic polymorphism within populations. We examined 84 populations of Xiphophorus variatus, a livebearing fish with a genetic polymorphism associated with physiological performance, to test: (1) whether niche differentiation explains broad-scale maintenance of polymorphism, (2) whether polymorphism is maintained among populations by local adaptation and migration, or (3) whether heterogeneity in explicit environmental variables could be linked to levels of polymorphism within populations. We found no evidence of climatic niche differentiation that could generate or maintain broad geographic variation in polymorphism. Subsequently, hierarchical partitioning of genetic richness and partial mantel tests revealed that 76% of the observed genetic richness was partitioned within populations with no effect of geographic distance on polymorphism. These results strongly suggest a lack of migration-selection balance in the maintenance of polymorphism, and model selection confirmed a significant relationship between environmental heterogeneity and genetic richness within populations. Few studies have demonstrated such effects at this scale, and additional studies in other taxa should examine the generality of gene-by-environment interactions across populations to better understand the dynamics and scale of balancing selection.
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Affiliation(s)
| | - Michael Tobler
- Division of Biology, Kansas State University, Manhattan, Kansas, 66506
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17
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Culumber ZW, Schumer M, Monks S, Tobler M. Environmental heterogeneity generates opposite gene-by-environment interactions for two fitness-related traits within a population. Evolution 2015; 69:541-50. [PMID: 25496554 DOI: 10.1111/evo.12574] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 10/27/2014] [Indexed: 12/17/2022]
Abstract
Theory predicts that environmental heterogeneity offers a potential solution to the maintenance of genetic variation within populations, but empirical evidence remains sparse. The live-bearing fish Xiphophorus variatus exhibits polymorphism at a single locus, with different alleles resulting in up to five distinct melanistic "tailspot" patterns within populations. We investigated the effects of heterogeneity in two ubiquitous environmental variables (temperature and food availability) on two fitness-related traits (upper thermal limits and body condition) in two different tailspot types (wild-type and upper cut crescent). We found gene-by-environment (G × E) interactions between tailspot type and food level affecting upper thermal limits (UTL), as well as between tailspot type and thermal environment affecting body condition. Exploring mechanistic bases underlying these G × E patterns, we found no differences between tailspot types in hsp70 gene expression despite significant overall increases in expression under both thermal and food stress. Similarly, there was no difference in routine metabolic rates between the tailspot types. The reversal of relative performance of the two tailspot types under different environmental conditions revealed a mechanism by which environmental heterogeneity can balance polymorphism within populations through selection on different fitness-related traits.
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Affiliation(s)
- Zachary W Culumber
- Centro de Investigaciones Cientificas de las Huastecas "Aguazarca", 392 Colonia Aguazarca, Calnali, Hidalgo, 43230, Mexico; Division of Biology, Kansas State University, Manhattan, Kansas, 66506.
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Lankau RA, Strauss SY. Newly rare or newly common: evolutionary feedbacks through changes in population density and relative species abundance, and their management implications. Evol Appl 2015; 4:338-53. [PMID: 25567977 PMCID: PMC3352561 DOI: 10.1111/j.1752-4571.2010.00173.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2010] [Accepted: 11/18/2010] [Indexed: 11/26/2022] Open
Abstract
Environmental management typically seeks to increase or maintain the population sizes of desirable species and to decrease population sizes of undesirable pests, pathogens, or invaders. With changes in population size come long-recognized changes in ecological processes that act in a density-dependent fashion. While the ecological effects of density dependence have been well studied, the evolutionary effects of changes in population size, via changes in ecological interactions with community members, are underappreciated. Here, we provide examples of changing selective pressures on, or evolution in, species as a result of changes in either density of conspecifics or changes in the frequency of heterospecific versus conspecific interactions. We also discuss the management implications of such evolutionary responses in species that have experienced rapid increases or decreases in density caused by human actions.
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Affiliation(s)
- Richard A Lankau
- Illinois Natural History Survey, University of Illinois Urbana-Champaign, IL, USA ; Department of Evolution and Ecology UC Davis, Davis, CA, USA
| | - Sharon Y Strauss
- Illinois Natural History Survey, University of Illinois Urbana-Champaign, IL, USA ; Department of Evolution and Ecology UC Davis, Davis, CA, USA
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19
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Latimer CAL, McGuigan K, Wilson RS, Blows MW, Chenoweth SF. The contribution of spontaneous mutations to thermal sensitivity curve variation in Drosophila serrata. Evolution 2014; 68:1824-37. [PMID: 24576006 DOI: 10.1111/evo.12392] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 01/27/2014] [Indexed: 10/25/2022]
Abstract
Many traits studied in ecology and evolutionary biology change their expression in response to a continuously varying environmental factor. One well-studied example are thermal performance curves (TPCs); continuous reaction norms that describe the relationship between organismal performance and temperature and are useful for understanding the trade-offs involved in thermal adaptation. We characterized curves describing the thermal sensitivity of voluntary locomotor activity in a set of 66 spontaneous mutation accumulation lines in the fly Drosophila serrata. Factor-analytic modeling of the mutational variance-covariance matrix, M, revealed support for three axes of mutational variation in males and two in females. These independent axes of mutational variance corresponded well to the major axes of TPC variation required for different types of thermal adaptation; "faster-slower" representing changes in performance largely independent of temperature, and the "hotter-colder" and "generalist-specialist" axes, representing trade-offs. In contrast to its near-absence from standing variance in this species, a "faster-slower" axis, accounted for most mutational variance (75% in males and 66% in females) suggesting selection may easily fix or remove these types of mutations in outbred populations. Axes resembling the "hotter-colder" and "generalist-specialist" modes of variation contributed less mutational variance but nonetheless point to an appreciable input of new mutations that may contribute to thermal adaptation.
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Affiliation(s)
- Camille A L Latimer
- School of Biological Sciences, University of Queensland, St. Lucia, Queensland, 4072, Australia
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20
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Beans CM. The case for character displacement in plants. Ecol Evol 2014; 4:852-65. [PMID: 24683467 PMCID: PMC3967910 DOI: 10.1002/ece3.978] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/28/2013] [Accepted: 01/10/2014] [Indexed: 01/31/2023] Open
Abstract
The evidence for character displacement as a widespread response to competition is now building. This progress is largely the result of the establishment of rigorous criteria for demonstrating character displacement in the animal literature. There are, however, relatively few well-supported examples of character displacement in plants. This review explores the potential for character displacement in plants by addressing the following questions: (1) Why aren't examples of character displacement in plants more common? (2) What are the requirements for character displacement to occur and how do plant populations meet those requirements? (3) What are the criteria for testing the pattern and process of character displacement and what methods can and have been used to address these criteria in the plant literature? (4) What are some additional approaches for studying character displacement in plants? While more research is needed, the few plant systems in which character displacement hypotheses have been rigorously tested suggest that character displacement may play a role in shaping plant communities. Plants are especially amenable to character displacement studies because of the experimental ease with which they can be used in common gardens, selection analyses, and breeding designs. A deeper investigation of character displacement in plants is critical for a more complete understanding of the ecological and evolutionary processes that permit the coexistence of plant species.
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Affiliation(s)
- Carolyn M Beans
- Department of Biology, University of VirginiaCharlottesville, Virginia
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21
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Lau JA, Shaw RG, Reich PB, Tiffin P. Indirect effects drive evolutionary responses to global change. THE NEW PHYTOLOGIST 2014; 201:335-343. [PMID: 24102351 DOI: 10.1111/nph.12490] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 07/30/2013] [Indexed: 06/02/2023]
Abstract
Anthropogenic environmental changes pose significant threats to plant and animal populations. These changes also may affect the evolution of natural populations either directly or indirectly by altering the outcome of species interactions that are important drivers of evolution. This latter indirect pathway may be especially important for evolutionary responses to elevated atmospheric CO2 concentrations (eCO2), which appear to have minimal direct effects on plant evolution but have large effects on interspecific interactions, such as competition. We manipulated competitive and CO2 environments of experimental Arabidopsis thaliana populations to test whether eCO2 alters evolutionary trajectories indirectly by altering selection imposed by competitors. We found that interspecific competition increased selection on growth traits, reduced heritabilities, and altered genetic covariances between traits and that the magnitude of these effects depended upon the CO2 environment. Although eCO2 had minimal direct effects on evolutionary processes, eCO2 typically reduced the strength of selection imposed by competitors and, therefore, relaxed selection on plant traits when competitors were present. Our results indicate that global changes may affect plant evolution indirectly by altering competitive interactions and underscore the importance of conducting research in natural communities when attempting to predict population responses to global change.
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Affiliation(s)
- Jennifer A Lau
- Department of Plant Biology, University of Minnesota, St Paul, MN, 55108, USA
- Kellogg Biological Station and Department of Plant Biology, Michigan State University, 3700 E Gull Lake Dr., Hickory Corners, MI, 49060, USA
| | - Ruth G Shaw
- Department of Ecology, Evolution and Behavior, University of Minnesota, St Paul, MN, 55108, USA
| | - Peter B Reich
- Department of Forestry, University of Minnesota, St Paul, MN, 55108, USA
- Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, NSW, 2751, Australia
| | - Peter Tiffin
- Department of Plant Biology, University of Minnesota, St Paul, MN, 55108, USA
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22
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Stinchcombe JR, Simonsen AK, Blows MW. ESTIMATING UNCERTAINTY IN MULTIVARIATE RESPONSES TO SELECTION. Evolution 2013; 68:1188-96. [DOI: 10.1111/evo.12321] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 11/06/2013] [Indexed: 01/26/2023]
Affiliation(s)
- John R. Stinchcombe
- Department of Ecology and Evolutionary Biology; University of Toronto; Toronto Ontario M5S3B2 Canada
- Centre for Genome Evolution and Function; University of Toronto; Toronto Ontario M5S3B2 Canada
| | - Anna K. Simonsen
- Department of Ecology and Evolutionary Biology; University of Toronto; Toronto Ontario M5S3B2 Canada
| | - Mark. W. Blows
- School of Biological Sciences; University of Queensland; Brisbane Queensland 4072 Australia
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23
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Griffith T, Sultan SE. Field-based insights to the evolution of specialization: plasticity and fitness across habitats in a specialist/generalist species pair. Ecol Evol 2012; 2:778-91. [PMID: 22837826 PMCID: PMC3399200 DOI: 10.1002/ece3.202] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 11/22/2011] [Indexed: 11/17/2022] Open
Abstract
Factors promoting the evolution of specialists versus generalists have been little studied in ecological context. In a large-scale comparative field experiment, we studied genotypes from naturally evolved populations of a closely related generalist/specialist species pair (Polygonum persicaria and P. hydropiper), reciprocally transplanting replicates of multiple lines into open and partially shaded sites where the species naturally co-occur. We measured relative fitness, individual plasticity, herbivory, and genetic variance expressed in the contrasting light habitats at both low and high densities. Fitness data confirmed that the putative specialist out-performed the generalist in only one environment, the favorable full sun/low-density environment to which it is largely restricted in nature, while the generalist had higher lifetime reproduction in both canopy and dense neighbor shade. The generalist, P. persicaria, also expressed greater adaptive plasticity for biomass allocation and leaf size in shaded conditions than the specialist. We found no evidence that the ecological specialization of P. hydropiper reflects either genetically based fitness trade-offs or maintenance costs of plasticity, two types of genetic constraint often invoked to prevent the evolution of broadly adaptive genotypes. However, the patterns of fitness variance and herbivore damage revealed how release from herbivory in a new range can cause an introduced species to evolve as a specialist in that range, a surprising finding with important implications for invasion biology. Patterns of fitness variance between and within sites are also consistent with a possible role for the process of mutation accumulation (in this case, mutations affecting shade-expressed phenotypes) in the evolution and/or maintenance of specialization in P. hydropiper.
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24
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Lankau RA. Rapid Evolutionary Change and the Coexistence of Species. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2011. [DOI: 10.1146/annurev-ecolsys-102710-145100] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Richard A. Lankau
- Department of Plant Biology, University of Georgia, Athens, Georgia 30606;
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25
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Whitlock R, Bilton MC, Grime JP, Burke T. Fine-scale community and genetic structure are tightly linked in species-rich grasslands. Philos Trans R Soc Lond B Biol Sci 2011; 366:1346-57. [PMID: 21444309 DOI: 10.1098/rstb.2010.0329] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent evidence indicates that grassland community structure and species diversity are influenced by genetic variation within species. We review what is known regarding the impact of intraspecific diversity on grassland community structure, using an ancient limestone pasture as a focal example. Two genotype-dependent effects appear to modify community structure in this system. First, the abundance of individual constituent species can depend upon the combined influence of direct genetic effects stemming from individuals within the population. Second, the outcome of localized interspecific interactions occurring within the community can depend on the genotypes of participating individuals (indicating indirect genetic effects). Only genotypic interactions are thought to be capable of allowing the long-term coexistence of both genotypes and species. We discuss the implications of these effects for the maintenance of diversity in grasslands. Next, we present new observations indicating that losses of genotypic diversity from each of two species can be predicted by the abundance of other coexisting species within experimental grassland communities. These results suggest genotype-specific responses to abundance in other coexisting species. We conclude that both direct and indirect genetic effects are likely to shape community structure and species coexistence in grasslands, implying tight linkage between fine-scale genetic and community structure.
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Affiliation(s)
- Raj Whitlock
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
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26
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Adams RI, Vellend M. Species diversity of grasses promotes genotypic diversity of clover populations in simulated communities. OIKOS 2011. [DOI: 10.1111/j.1600-0706.2011.19107.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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27
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Emery NC, Rice KJ, Stanton ML. Fitness variation and local distribution limits in an annual plant population. Evolution 2010; 65:1011-20. [PMID: 21062275 DOI: 10.1111/j.1558-5646.2010.01183.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Understanding how genetic variation shapes species' distributions involves examining how variation is distributed across a species' range as well as how it responds to underlying environmental heterogeneity. We examined patterns of fitness variation across the local distribution of an annual composite (Lasthenia fremontii) spanning a small-scale inundation gradient in a California vernal pool wetland. Using seeds collected from the center and edge of a population, paternal half-sib families were generated and transplanted back to the center and edge of the original population. All transplants were adapted to the conditions at the center of the population. The effect of the environment on the opportunity for selection depended on the model of selection assumed. Under a model of hard selection, variance in absolute fitness was lower among transplants at the edge of the population than at the center. Under a model of soft selection, the variance in relative fitness was similar between center and edge microhabitats. Given that this population is likely well-mixed, differences in habitat quality between center and edge microhabitats will likely cause selection at the center of the population to dominate the evolutionary trajectory of this population.
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Affiliation(s)
- Nancy C Emery
- Center for Population Biology and Department of Evolution and Ecology, University of California, One Shields Avenue, Davis, California 95616, USA.
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28
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29
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Cost of trichome production and resistance to a specialist insect herbivore in Arabidopsis lyrata. Evol Ecol 2010. [DOI: 10.1007/s10682-010-9381-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Johnson MTJ, Agrawal AA, Maron JL, Salminen JP. Heritability, covariation and natural selection on 24 traits of common evening primrose (Oenothera biennis) from a field experiment. J Evol Biol 2009; 22:1295-307. [PMID: 19490388 DOI: 10.1111/j.1420-9101.2009.01747.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This study explored genetic variation and co-variation in multiple functional plant traits. Our goal was to characterize selection, heritabilities and genetic correlations among different types of traits to gain insight into the evolutionary ecology of plant populations and their interactions with insect herbivores. In a field experiment, we detected significant heritable variation for each of 24 traits of Oenothera biennis and extensive genetic covariance among traits. Traits with diverse functions formed several distinct groups that exhibited positive genetic covariation with each other. Genetic variation in life-history traits and secondary chemistry together explained a large proportion of variation in herbivory (r(2) = 0.73). At the same time, selection acted on lifetime biomass, life-history traits and two secondary compounds of O. biennis, explaining over 95% of the variation in relative fitness among genotypes. The combination of genetic covariances and directional selection acting on multiple traits suggests that adaptive evolution of particular traits is constrained, and that correlated evolution of groups of traits will occur, which is expected to drive the evolution of increased herbivore susceptibility. As a whole, our study indicates that an examination of genetic variation and covariation among many different types of traits can provide greater insight into the evolutionary ecology of plant populations and plant-herbivore interactions.
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Affiliation(s)
- M T J Johnson
- Department of Plant Biology, North Carolina State University, Raleigh, NC 27695, USA.
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31
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Agosta SJ, Klemens JA. Resource specialization in a phytophagous insect: no evidence for genetically based performance trade-offs across hosts in the field or laboratory. J Evol Biol 2009; 22:907-12. [PMID: 19220649 DOI: 10.1111/j.1420-9101.2009.01694.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a field test of the genetically based performance trade-off hypothesis for resource specialization in a population of the moth Rothschildia lebeau whose larvae primarily feed on three host plant species. Pairwise correlations between growth vs. growth, survival vs. survival and growth vs. survival across the different hosts were calculated, using families (sibships) as the units of analysis. Of 15 pairwise correlations, 14 were positive, 5 significantly so and none were negative. The same pattern was found using complementary growth and survival data from the laboratory. Overall, we found no evidence of negative genetic correlations in cross-host performance that would be indicative of performance trade-offs in this population. Rather, variation among families in performance appears to reflect 'general vigour' whereby families that perform well on one host perform well across multiple hosts. We discuss the implications of positive genetic correlations in cross-host performance in terms of the ecology and evolution of host range. We argue that this genetic architecture facilitates colonization of novel hosts and recolonization of historical hosts, therefore contributing to host shifts, host range expansions, biological invasions and introductions, and host ranges that are regionally broad but locally narrow.
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Affiliation(s)
- S J Agosta
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA.
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32
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Franks S, Pratt P, Dray F, Simms E. Selection on Herbivory Resistance and Growth Rate in an Invasive Plant. Am Nat 2008; 171:678-91. [DOI: 10.1086/587078] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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33
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Bossart JL. Genetic architecture of host use in a widely distributed, polyphagous butterfly (Lepidoptera: Papilionidae): adaptive inferences based on comparison of spatio-temporal populations. Biol J Linn Soc Lond 2008. [DOI: 10.1111/j.1095-8312.1998.tb01143.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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34
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Pigliucci M, Byrd N. Genetics and evolution of phenotypic plasticity to nutrient stress in Arabidopsis: drift, constraints or selection? Biol J Linn Soc Lond 2008. [DOI: 10.1111/j.1095-8312.1998.tb01531.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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35
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Abstract
While there is some information on genetic variation in response to competition in plants, we know nothing about intraspecific variation in facilitation. Previous studies suggest that facilitation should increase fitness in stressful environments. However, whether a plant experiences an environment as stressful may depend on prior adaptive responses to stressors at a site. Local adaptation to stress at a site may reduce the likelihood of facilitation. Seeds of Plantago erecta from stressful (serpentine soil) and non-stressful (non-serpentine soil) edaphic environments were reciprocally planted into these two soil types. Although competition did not differ significantly among seed sources, there was evidence for a local adaptation effect on facilitation. Non-serpentine seeds planted into serpentine soil exhibited greater individual plant biomass at higher densities. The interaction between population source and growth environment indicates a role for evolutionary processes such as local adaptation in the expression of facilitation in plants.
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Affiliation(s)
- E K Espeland
- Ecology Graduate Group, Department of Plant Sciences, Mail Stop 1, University of California, Davis, California 95616, USA.
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36
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Miller CW, Moore AJ. A potential resolution to the lek paradox through indirect genetic effects. Proc Biol Sci 2007; 274:1279-86. [PMID: 17341455 PMCID: PMC2176171 DOI: 10.1098/rspb.2006.0413] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Females often prefer males with elaborate traits, even when they receive no direct benefits from their choice. In such situations, mate discrimination presumably has genetic advantages; selective females will produce offspring of higher genetic quality. Over time, persistent female preferences for elaborate secondary-sexual traits in males should erode genetic variance in these traits, eventually eliminating any benefit to the preferences. Yet, strong female preferences persist in many taxa. This puzzle is called the lek paradox and raises two primary questions: do females obtain genetic benefits for offspring by selecting males with elaborate secondary-sexual characteristics and, if so, how is the genetic variation in these male traits maintained? We suggest that indirect genetic effects may help to resolve the lek paradox. Maternal phenotypes, such as habitat selection behaviours and offspring provisioning, often influence the condition and the expression of secondary-sexual traits in sons. These maternal influences are commonly genetic based (i.e. they are indirect genetic effects). Females choosing mates with elaborate traits may receive 'good genes' for daughters in the form of effective maternal characteristics. Recognizing the significance of indirect genetic effects may be important to our understanding of the process and consequences of sexual selection.
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Affiliation(s)
- Christine W Miller
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA.
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37
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Leips J, Gilligan P, Mackay TFC. Quantitative trait loci with age-specific effects on fecundity in Drosophila melanogaster. Genetics 2005; 172:1595-605. [PMID: 16272414 PMCID: PMC1456283 DOI: 10.1534/genetics.105.048520] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Life-history theory and evolutionary theories of aging assume the existence of alleles with age-specific effects on fitness. While various studies have documented age-related changes in the genetic contribution to variation in fitness components, we know very little about the underlying genetic architecture of such changes. We used a set of recombinant inbred lines to map and characterize the effects of quantitative trait loci (QTL) affecting fecundity of Drosophila melanogaster females at 1 and 4 weeks of age. We identified one QTL on the second chromosome and one or two QTL affecting fecundity on the third chromosome, but these QTL affected fecundity only at 1 week of age. There was more genetic variation for fecundity at 4 weeks of age than at 1 week of age and there was no genetic correlation between early and late-age fecundity. These results suggest that different loci contribute to the variation in fecundity as the organism ages. Our data provide support for the mutation accumulation theory of aging as applied to reproductive senescence. Comparing the results from this study with our previous work on life-span QTL, we also find evidence that antagonistic pleiotropy may contribute to the genetic basis of senescence in these lines as well.
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Affiliation(s)
- Jeff Leips
- Department of Biological Sciences, University of Maryland Baltimore County, Baltimore 21250, USA.
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38
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Byers DL. Evolution in heterogeneous environments and the potential of maintenance of genetic variation in traits of adaptive significance. Genetica 2005; 123:107-24. [PMID: 15881684 DOI: 10.1007/s10709-003-2721-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The maintenance of genetic variation in traits of adaptive significance has been a major dilemma of evolutionary biology. Considering the pattern of increased genetic variation associated with environmental clines and heterogeneous environments, selection in heterogeneous environments has been proposed to facilitate the maintenance of genetic variation. Some models examining whether genetic variation can be maintained, in heterogeneous environments are reviewed. Genetic mechanisms that constrain evolution in quantitative genetic traits indicate that genetic variation can be maintained but when is not clear. Furthermore, no comprehensive models have been developed, likely due to the genetic and environmental complexity of this issue. Therefore, I have suggested two empirical approaches to provide insight for future theoretical and empirical research. Traditional path analysis has been a very powerful approach for understanding phenotypic selection. However, it requires substantial information on the biology of the study system to construct a causal model and alternatives. Exploratory path analysis is a data driven approach that uses the statistical relationships in the data to construct a set of models. For example, it can be used for understanding phenotypic selection in different environments, where there is no prior information to develop path models in the different environments. Data from Brassica rapa grown in different nutrients indicated that selection changed in the different environments. Experimental evolutionary studies will provide direct tests as to when genetic variation is maintained.
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Affiliation(s)
- Diane L Byers
- Behavior, Ecology, Evolution, and Systematics Section, Department of Biological Sciences, Illinois State University, Campus Box 4120, Normal, IL 61790-4120, USA.
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39
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Stanton ML, Thiede DA. Statistical convenience vs biological insight: consequences of data transformation for the analysis of fitness variation in heterogeneous environments. THE NEW PHYTOLOGIST 2005; 166:319-337. [PMID: 15760373 DOI: 10.1111/j.1469-8137.2004.01311.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In plants, more favourable environmental conditions can lead to dramatic increases in both mean fitness and variance in fitness. This results in data that violate the equality-of-variance assumption of anova, a problem that most empiricists would address by log-transforming fitness values. Using heuristic data sets and simple simulations, we show that anova on log-transformed fitness consistently fails to match the outcome of selection in a heterogeneous environment or its sensitivity to environmental frequency. Only anova based on relative fitness within environments accurately predicts the sensitivity of genotype selection to the frequency of alternative environments. Parallel analyses of variance based on absolute fitness and relative fitness can bracket the expected success of alternative genotypes under hard and soft selection, respectively. For example, for Sinapis arvensis growing in full sun and partial shade treatments, families achieving high fitness in the best environment are favoured under hard selection, whereas soft selection favours different families that achieve consistently good performance across environments. Based on these findings, we recommend that log-transformation of fitness should no longer be standard practice in ecological genetics studies. Weighted anova is a preferable method for dealing with unequal variances, and investigators should also make greater use of techniques such as quantile regression or resampling to describe and evaluate fitness variation across heterogeneous environments.
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Affiliation(s)
- Maureen L Stanton
- Section of Evolution and Ecology and The Center for Population Biology, University of California, Davis, CA 95616, USA.
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40
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Johnson MTJ, Agrawal AA. PLANT GENOTYPE AND ENVIRONMENT INTERACT TO SHAPE A DIVERSE ARTHROPOD COMMUNITY ON EVENING PRIMROSE (OENOTHERA BIENNIS). Ecology 2005. [DOI: 10.1890/04-1068] [Citation(s) in RCA: 272] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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41
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42
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Stanton M, Thiede D, Roy B. Consequences of Intraspecific Competition and Environmental Variation for Selection in the MustardSinapsis arvensis: Contrasting Ecological and Evolutionary Perspectives. Am Nat 2004; 164:736-752. [DOI: 10.1086/425331] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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43
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Turelli M, Barton NH. Polygenic variation maintained by balancing selection: pleiotropy, sex-dependent allelic effects and G x E interactions. Genetics 2004; 166:1053-79. [PMID: 15020487 PMCID: PMC1470722 DOI: 10.1534/genetics.166.2.1053] [Citation(s) in RCA: 193] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We investigate three alternative selection-based scenarios proposed to maintain polygenic variation: pleiotropic balancing selection, G x E interactions (with spatial or temporal variation in allelic effects), and sex-dependent allelic effects. Each analysis assumes an additive polygenic trait with n diallelic loci under stabilizing selection. We allow loci to have different effects and consider equilibria at which the population mean departs from the stabilizing-selection optimum. Under weak selection, each model produces essentially identical, approximate allele-frequency dynamics. Variation is maintained under pleiotropic balancing selection only at loci for which the strength of balancing selection exceeds the effective strength of stabilizing selection. In addition, for all models, polymorphism requires that the population mean be close enough to the optimum that directional selection does not overwhelm balancing selection. This balance allows many simultaneously stable equilibria, and we explore their properties numerically. Both spatial and temporal G x E can maintain variation at loci for which the coefficient of variation (across environments) of the effect of a substitution exceeds a critical value greater than one. The critical value depends on the correlation between substitution effects at different loci. For large positive correlations (e.g., rho(ij)2>3/4), even extreme fluctuations in allelic effects cannot maintain variation. Surprisingly, this constraint on correlations implies that sex-dependent allelic effects cannot maintain polygenic variation. We present numerical results that support our analytical approximations and discuss our results in connection to relevant data and alternative variance-maintaining mechanisms.
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Affiliation(s)
- Michael Turelli
- Section of Evolution and Ecology and Center for Population Biology, University of California, Davis 95616, USA.
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Adler LS, Kittelson PM. Variation in Lupinus arboreus alkaloid profiles and relationships with multiple herbivores. BIOCHEM SYST ECOL 2004. [DOI: 10.1016/j.bse.2003.11.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Turelli M, Barton NH. Polygenic Variation Maintained by Balancing Selection: Pleiotropy, Sex-Dependent Allelic Effects and G × E Interactions. Genetics 2004. [DOI: 10.1093/genetics/166.2.1053] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
We investigate three alternative selection-based scenarios proposed to maintain polygenic variation: pleiotropic balancing selection, G × E interactions (with spatial or temporal variation in allelic effects), and sex-dependent allelic effects. Each analysis assumes an additive polygenic trait with n diallelic loci under stabilizing selection. We allow loci to have different effects and consider equilibria at which the population mean departs from the stabilizing-selection optimum. Under weak selection, each model produces essentially identical, approximate allele-frequency dynamics. Variation is maintained under pleiotropic balancing selection only at loci for which the strength of balancing selection exceeds the effective strength of stabilizing selection. In addition, for all models, polymorphism requires that the population mean be close enough to the optimum that directional selection does not overwhelm balancing selection. This balance allows many simultaneously stable equilibria, and we explore their properties numerically. Both spatial and temporal G × E can maintain variation at loci for which the coefficient of variation (across environments) of the effect of a substitution exceeds a critical value greater than one. The critical value depends on the correlation between substitution effects at different loci. For large positive correlations (e.g., ρij2>3∕4), even extreme fluctuations in allelic effects cannot maintain variation. Surprisingly, this constraint on correlations implies that sex-dependent allelic effects cannot maintain polygenic variation. We present numerical results that support our analytical approximations and discuss our results in connection to relevant data and alternative variance-maintaining mechanisms.
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Affiliation(s)
- Michael Turelli
- Section of Evolution and Ecology and Center for Population Biology, University of California, Davis, California 95616
| | - N H Barton
- Institute of Cell, Animal and Population Biology, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom
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Etterson JR. EVOLUTIONARY POTENTIAL OF CHAMAECRISTA FASCICULATA IN RELATION TO CLIMATE CHANGE. II. GENETIC ARCHITECTURE OF THREE POPULATIONS RECIPROCALLY PLANTED ALONG AN ENVIRONMENTAL GRADIENT IN THE GREAT PLAINS. Evolution 2004. [DOI: 10.1554/03-375] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Chang SM, Shaw RG. The contribution of spontaneous mutation to variation in environmental response in Arabidopsis thaliana: responses to nutrients. Evolution 2003; 57:984-94. [PMID: 12836817 DOI: 10.1111/j.0014-3820.2003.tb00310.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Although the evolutionary importance of spontaneous mutation is evident, its contribution to the evolution of ecological specificity remains unclear, because the environmental sensitivity of effects of new mutations has received little empirical attention. To address this issue, we report a greenhouse in which we grew plants from 20 mutation-accumulation (MA) lines, advanced by selfing and single-seed descent from a single common founder to generation 17, as well as plants from five lines representing the founder, in high and low nutrient conditions. We examined 11 traits throughout life history, including germination, survivorship, bolting date, flowering date, leaf number, leaf size, early and late height, mean fruit size, total seed weight, and reproductive biomass. Comparison of trait means between the two generations did not support the commonly held view that new mutations affecting fitness in these MA lines are strongly biased toward deleterious effects. We detected significant variance among MA lines for one fitness component, mean fruit size, but we did not detect a significant contribution of mutations accumulated in these MA lines to genotype by environment interaction (GEI). These results suggest that other evolutionary mechanisms play a more important role than spontaneous mutation alone in establishing the GEI found for wild collections and lab accessions of Arabidopsis thaliana in previous studies.
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Affiliation(s)
- Shu-Mei Chang
- Department of Plant Biology, University of Georgia, Athens, Georgia 30602-7271, USA.
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Conner JK, Franks R, Stewart C. Expression of additive genetic variances and covariances for wild radish floral traits: comparison between field and greenhouse environments. Evolution 2003; 57:487-95. [PMID: 12703938 DOI: 10.1111/j.0014-3820.2003.tb01540.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Measurements of the genetic variation and covariation underlying quantitative traits are crucial to our understanding of current evolutionary change and the mechanisms causing this evolution. This fact has spurred a large number of studies estimating heritabilities and genetic correlations in a variety of organisms. Most of these studies have been done in laboratory or greenhouse settings, but it is not well known how accurately these measurements estimate genetic variance and covariance expressed in the field. We conducted a quantitative genetic half-sibling analysis on six floral traits in wild radish. Plants were grown from seed in the field and were exposed to natural environmental variation throughout their lives, including herbivory and intra- and interspecific competition. The estimates of heritabilities and the additive genetic variance-covariance matrix (G) obtained from this analysis were then compared to previous greenhouse estimates of the same floral traits from the same natural population. Heritabilities were much lower in the field for all traits, and this was due to both large increases in environmental variance and decreases in additive genetic variance. Additive genetic covariance expressed was also much lower in the field. These differences resulted in highly significant differences in the G matrix between the greenhouse and field environments using two complementary testing methods. Although the G matrices shared some principal components in common, they were not simply proportional to each other. Therefore, the greenhouse results did not accurately depict how the floral traits would respond to natural selection in the field.
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Affiliation(s)
- Jeffrey K Conner
- W. K. Kellogg Biological Station and Department of Plant Biology, Michigan State University, Hickory Corners, Michigan 49060, USA.
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Chang SM, Shaw RG. THE CONTRIBUTION OF SPONTANEOUS MUTATION TO VARIATION IN ENVIRONMENTAL RESPONSE IN ARABIDOPSIS THALIANA: RESPONSES TO NUTRIENTS. Evolution 2003. [DOI: 10.1554/0014-3820(2003)057[0984:tcosmt]2.0.co;2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Conner JK, Franks R, Stewart C. EXPRESSION OF ADDITIVE GENETIC VARIANCES AND COVARIANCES FOR WILD RADISH FLORAL TRAITS: COMPARISON BETWEEN FIELD AND GREENHOUSE ENVIRONMENTS. Evolution 2003. [DOI: 10.1554/0014-3820(2003)057[0487:eoagva]2.0.co;2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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