1
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Araya-Ajoy YG, Dingemanse NJ, Westneat DF, Wright J. The evolutionary ecology of variation in labile traits: selection on its among- and within-individual components. Evolution 2023; 77:2246-2256. [PMID: 37490354 DOI: 10.1093/evolut/qpad136] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 07/03/2023] [Accepted: 07/21/2023] [Indexed: 07/27/2023]
Abstract
Closer integration between behavioral ecology and quantitative genetics has resulted in a recent increase in studies partitioning sources of variation in labile traits. Repeatable between-individual differences are commonly documented, and their existence is generally explained using adaptive arguments, implying that selection has shaped variation at the among- and within-individual level. However, predicting the expected pattern of non-adaptive phenotypic variation around an optimal phenotypic value is difficult, hampering our ability to provide quantitative assessments of the adaptive nature of observed patterns of phenotypic variation within a population. We argue that estimating the strength of selection on trait variation among and within individuals provides a way to test adaptive theory concerned with phenotypic variation. To achieve this aim, we describe a nonlinear selection analysis that enables the study of the selective pressures on trait means and their among- and within-individual variation. By describing an integrative approach for studying the strength of selection on phenotypic variation at different levels, we hope to stimulate empirical studies investigating the ecological factors that can shape the repeatability, heritability, and coefficients of variation of labile and other repeatedly expressed traits.
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Affiliation(s)
- Yimen G Araya-Ajoy
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Niels J Dingemanse
- Behavioural Ecology, Department of Biology, Ludwig-Maximilians University of Munich, Planegg-Martinsried, Germany
| | - David F Westneat
- Department of Biology, University of Kentucky, Lexington, KY, United States
| | - Jonathan Wright
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim, Norway
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2
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Sanderson S, Bolnick DI, Kinnison MT, O'Dea RE, Gorné LD, Hendry AP, Gotanda KM. Contemporary changes in phenotypic variation, and the potential consequences for eco-evolutionary dynamics. Ecol Lett 2023; 26 Suppl 1:S127-S139. [PMID: 37840026 DOI: 10.1111/ele.14186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 01/30/2023] [Accepted: 02/01/2023] [Indexed: 10/17/2023]
Abstract
Most studies assessing rates of phenotypic change focus on population mean trait values, whereas a largely overlooked additional component is changes in population trait variation. Theoretically, eco-evolutionary dynamics mediated by such changes in trait variation could be as important as those mediated by changes in trait means. To date, however, no study has comprehensively summarised how phenotypic variation is changing in contemporary populations. Here, we explore four questions using a large database: How do changes in trait variances compare to changes in trait means? Do different human disturbances have different effects on trait variance? Do different trait types have different effects on changes in trait variance? Do studies that established a genetic basis for trait change show different patterns from those that did not? We find that changes in variation are typically small; yet we also see some very large changes associated with particular disturbances or trait types. We close by interpreting and discussing the implications of our findings in the context of eco-evolutionary studies.
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Affiliation(s)
- Sarah Sanderson
- Department of Biology and Redpath Museum, McGill University, Montréal, Québec, Canada
| | - Daniel I Bolnick
- Department of Ecology & Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Michael T Kinnison
- School of Biology and Ecology and Maine Center for Genetics in the Environment, University of Maine, Orono, Maine, USA
| | | | - Lucas D Gorné
- Department of Biology and Redpath Museum, McGill University, Montréal, Québec, Canada
- Department of Biological Sciences, Brock University, St. Catharine's, Ontario, Canada
- Département de Biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
- Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Andrew P Hendry
- Department of Biology and Redpath Museum, McGill University, Montréal, Québec, Canada
| | - Kiyoko M Gotanda
- Department of Biological Sciences, Brock University, St. Catharine's, Ontario, Canada
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3
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Mukhopadhyay A, Quader S. Pollination inaccuracy: estimating male fitness in the movement-assisted dichogamous species Clerodendrum infortunatum. Evol Ecol 2022. [DOI: 10.1007/s10682-022-10221-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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4
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Armbruster WS. Floral specialization increases pollination precision: the roles of floral orientation, symmetry, fusion and stamen number. THE NEW PHYTOLOGIST 2022; 235:1307-1309. [PMID: 35621012 DOI: 10.1111/nph.18215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Affiliation(s)
- W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth, PO1 2DY, UK
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
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5
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Stewart AB, Diller C, Dudash MR, Fenster CB. Pollination-precision hypothesis: support from native honey bees and nectar bats. THE NEW PHYTOLOGIST 2022; 235:1629-1640. [PMID: 35194792 DOI: 10.1111/nph.18050] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/09/2022] [Indexed: 05/28/2023]
Abstract
The evolution of floral traits is often considered to reflect selection for increased pollination efficiency. Known as the pollination-precision hypothesis, increased pollination efficiency is achieved by enhancing pollen deposition on precise areas of the pollinator. Most research to date addressing this hypothesis has examined plant species that are a priori predicted to place pollen precisely, but we still lack comparisons with species predicted to have low pollination efficiency. We studied 39 plant species with diverse floral morphologies and measured the precision of pollen placement on two pollinator groups: honey bees (genus Apis) and nectar bats (family Pteropodidae). Pollen was collected from four locations of each pollinator's body (bees: dorsal thorax, ventral thorax, dorsal abdomen, ventral abdomen; bats: crown, face, chest, wing) to calculate pollen placement precision using Pielou's evenness index. We also quantified variation in floral design by scoring floral symmetry, corolla fusion, floral orientation and stamen number. We confirm the importance of four floral character states (bilateral symmetry, fused corollas, horizontal orientation and reduced stamen number) in promoting precise pollen placement on diverse pollinators. Our findings provide phylogenetically corrected, empirical support that the evolution of the four floral characters reflect selection for enhanced precision of pollen placed on pollinators.
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Affiliation(s)
- Alyssa B Stewart
- Department of Plant Science, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Carolina Diller
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, 234 56, Sweden
| | - Michele R Dudash
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, 57007, USA
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
| | - Charles B Fenster
- Oak Lake Field Station, South Dakota State University, Brookings, SD, 57007, USA
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6
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Wright J, Haaland TR, Dingemanse NJ, Westneat DF. A reaction norm framework for the evolution of learning: how cumulative experience shapes phenotypic plasticity. Biol Rev Camb Philos Soc 2022; 97:1999-2021. [PMID: 35790067 PMCID: PMC9543233 DOI: 10.1111/brv.12879] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 05/29/2022] [Accepted: 05/30/2022] [Indexed: 11/30/2022]
Abstract
Learning is a familiar process to most people, but it currently lacks a fully developed theoretical position within evolutionary biology. Learning (memory and forgetting) involves adjustments in behaviour in response to cumulative sequences of prior experiences or exposures to environmental cues. We therefore suggest that all forms of learning (and some similar biological phenomena in development, aging, acquired immunity and acclimation) can usefully be viewed as special cases of phenotypic plasticity, and formally modelled by expanding the concept of reaction norms to include additional environmental dimensions quantifying sequences of cumulative experience (learning) and the time delays between events (forgetting). Memory therefore represents just one of a number of different internal neurological, physiological, hormonal and anatomical ‘states’ that mediate the carry‐over effects of cumulative environmental experiences on phenotypes across different time periods. The mathematical and graphical conceptualisation of learning as plasticity within a reaction norm framework can easily accommodate a range of different ecological scenarios, closely linking statistical estimates with biological processes. Learning and non‐learning plasticity interact whenever cumulative prior experience causes a modification in the reaction norm (a) elevation [mean phenotype], (b) slope [responsiveness], (c) environmental estimate error [informational memory] and/or (d) phenotypic precision [skill acquisition]. Innovation and learning new contingencies in novel (laboratory) environments can also be accommodated within this approach. A common reaction norm approach should thus encourage productive cross‐fertilisation of ideas between traditional studies of learning and phenotypic plasticity. As an example, we model the evolution of plasticity with and without learning under different levels of environmental estimation error to show how learning works as a specific adaptation promoting phenotypic plasticity in temporally autocorrelated environments. Our reaction norm framework for learning and analogous biological processes provides a conceptual and mathematical structure aimed at usefully stimulating future theoretical and empirical investigations into the evolution of plasticity across a wider range of ecological contexts, while providing new interdisciplinary connections regarding learning mechanisms.
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Affiliation(s)
- Jonathan Wright
- Center for Biodiversity Dynamics (CBD), Department of Biology Norwegian University of Science and Technology (NTNU) N‐7491 Trondheim Norway
| | - Thomas R. Haaland
- Center for Biodiversity Dynamics (CBD), Department of Biology Norwegian University of Science and Technology (NTNU) N‐7491 Trondheim Norway
- Department of Evolutionary Biology and Environmental Studies University of Zürich Winterthurerstrasse 190 CH‐8057 Zürich Switzerland
| | - Niels J. Dingemanse
- Behavioural Ecology, Department of Biology Ludwig‐Maximilians University of Munich (LMU) 82152 Planegg‐Martinsried Germany
| | - David F. Westneat
- Department of Biology University of Kentucky 101 Morgan Building Lexington KY 40506‐0225 USA
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7
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O'Dea RE, Noble DWA, Nakagawa S. Unifying individual differences in personality, predictability and plasticity: A practical guide. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Rose E. O'Dea
- Evolution & Ecology Research Centre School of Biological and Environmental Sciences University of New South Wales Sydney NSW Australia
- Diabetes and Metabolism Division Garvan Institute of Medical Research Sydney NSW Australia
| | - Daniel W. A. Noble
- Division of Ecology and Evolution Research School of Biology The Australian National University Canberra ACT Australia
| | - Shinichi Nakagawa
- Evolution & Ecology Research Centre School of Biological and Environmental Sciences University of New South Wales Sydney NSW Australia
- Diabetes and Metabolism Division Garvan Institute of Medical Research Sydney NSW Australia
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8
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Is There More to Within-plant Variation in Seed Size than Developmental Noise? Evol Biol 2021. [DOI: 10.1007/s11692-021-09544-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractWithin-plant variation in seed size may merely reflect developmental instability, or it may be adaptive in facilitating diversifying bet-hedging, that is, production of phenotypically diverse offspring when future environments are unpredictable. To test the latter hypothesis, we analyzed patterns of variation in seed size in 11 populations of the perennial vine Dalechampia scandens grown in a common greenhouse environment. We tested whether population differences in the mean and variation of seed size covaried with environmental predictability at two different timescales. We also tested whether within-plant variation in seed size was correlated with independent measures of floral developmental instability and increased under stressful conditions. Populations differed genetically in the amount of seed-size variation occurring among plants, among infructescences within plants, and among seeds within infructescences. Within-individual variation was not detectably correlated with measures of developmental instability and did not increase under stress, but it increased weakly with short-term environmental unpredictability of precipitation at the source-population site. These results support the hypothesis that greater variation in seed size is adaptive when environmental predictability is low.
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9
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Olazcuaga L, Foucaud J, Gautier M, Deschamps C, Loiseau A, Leménager N, Facon B, Ravigné V, Hufbauer RA, Estoup A, Rode NO. Adaptation and correlated fitness responses over two time scales in Drosophila suzukii populations evolving in different environments. J Evol Biol 2021; 34:1225-1240. [PMID: 34097795 PMCID: PMC8457093 DOI: 10.1111/jeb.13878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/23/2021] [Accepted: 05/31/2021] [Indexed: 01/09/2023]
Abstract
The process of local adaptation involves differential changes in fitness over time across different environments. Although experimental evolution studies have extensively tested for patterns of local adaptation at a single time point, there is relatively little research that examines fitness more than once during the time course of adaptation. We allowed replicate populations of the fruit pest Drosophila suzukii to evolve in one of eight different fruit media. After five generations, populations with the highest initial levels of maladaptation had mostly gone extinct, whereas experimental populations evolving on cherry, strawberry and cranberry media had survived. We measured the fitness of each surviving population in each of the three fruit media after five and after 26 generations of evolution. After five generations, adaptation to each medium was associated with increased fitness in the two other media. This was also true after 26 generations, except when populations that evolved on cranberry medium developed on cherry medium. These results suggest that, in the theoretical framework of a fitness landscape, the fitness optima of cherry and cranberry media are the furthest apart. Our results show that studying how fitness changes across several environments and across multiple generations provides insights into the dynamics of local adaptation that would not be evident if fitness were analysed at a single point in time. By allowing a qualitative mapping of an experimental fitness landscape, our approach will improve our understanding of the ecological factors that drive the evolution of local adaptation in D. suzukii.
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Affiliation(s)
- Laure Olazcuaga
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université Montpellier, Montpellier, France.,Department of Agricultural Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, USA
| | - Julien Foucaud
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université Montpellier, Montpellier, France
| | - Mathieu Gautier
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université Montpellier, Montpellier, France
| | - Candice Deschamps
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université Montpellier, Montpellier, France
| | - Anne Loiseau
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université Montpellier, Montpellier, France
| | - Nicolas Leménager
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université Montpellier, Montpellier, France
| | - Benoit Facon
- INRAE, UMR Peuplements Végétaux et Bio-agresseurs en Milieu Tropical, La Réunion, France
| | | | - Ruth A Hufbauer
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université Montpellier, Montpellier, France.,Department of Agricultural Biology and Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, USA
| | - Arnaud Estoup
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université Montpellier, Montpellier, France
| | - Nicolas O Rode
- CBGP, INRAE, CIRAD, IRD, Institut Agro, Université Montpellier, Montpellier, France
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10
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Rodgers EM, Franklin CE, Noble DWA. Diving in hot water: a meta-analytic review of how diving vertebrate ectotherms will fare in a warmer world. J Exp Biol 2021; 224:224/Suppl_1/jeb228213. [PMID: 33627460 DOI: 10.1242/jeb.228213] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Diving ectothermic vertebrates are an important component of many aquatic ecosystems, but the threat of climate warming is particularly salient to this group. Dive durations typically decrease as water temperatures rise; yet, we lack an understanding of whether this trend is apparent in all diving ectotherms and how this group will fare under climate warming. We compiled data from 27 studies on 20 ectothermic vertebrate species to quantify the effect of temperature on dive durations. Using meta-analytic approaches, we show that, on average, dive durations decreased by 11% with every 1°C increase in water temperature. Larger increases in temperature (e.g. +3°C versus +8-9°C) exerted stronger effects on dive durations. Although species that respire bimodally are projected to be more resilient to the effects of temperature on dive durations than purely aerial breathers, we found no significant difference between these groups. Body mass had a weak impact on mean dive durations, with smaller divers being impacted by temperature more strongly. Few studies have examined thermal phenotypic plasticity (N=4) in diving ectotherms, and all report limited plasticity. Average water temperatures in marine and freshwater habitats are projected to increase between 1.5 and 4°C in the next century, and our data suggest that this magnitude of warming could translate to substantial decreases in dive durations, by approximately 16-44%. Together, these data shed light on an overlooked threat to diving ectothermic vertebrates and suggest that time available for underwater activities, such as predator avoidance and foraging, may be shortened under future warming.
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Affiliation(s)
- Essie M Rodgers
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
| | - Craig E Franklin
- School of Biological Sciences, The University of Queensland, St Lucia, 4072 Queensland, Australia
| | - Daniel W A Noble
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2600, Australia
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11
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Armbruster WS, Muchhala N. Floral reorientation: the restoration of pollination accuracy after accidents. THE NEW PHYTOLOGIST 2020; 227:232-243. [PMID: 32252125 DOI: 10.1111/nph.16482] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/11/2020] [Indexed: 05/28/2023]
Abstract
Plants sometimes suffer mechanical injury. The nonlethal collapse of a flowering stalk, for example, can greatly reduce plant fitness if it leads to 'incorrect' floral orientation and thus reduced visitation or poor pollination. When floral orientation is important for accurate pollination, as has been suggested for bilaterally symmetrical flowers, we predict that such flowers should have developmental and/or behavioural mechanisms for restoring 'correct' orientation after accidents. We made observations and conducted experiments on 23 native and cultivated flowering plant species in Australia, South America, North America and Europe. We found that flowers with bilateral symmetry usually have the capacity to reorient after accidents, and that this is manifested through rapid bending and/or rotation of pedicels or sexual organs or slower peduncle bending. Floral reorientation restores pollination accuracy and fit with pollinators. However, experimental floral misorientation in eight species with radially symmetrical flowers showed that, with one exception, they had little capacity to reorient their flowers, in line with expectations that the orientation of radially symmetrical flowers does not substantially affect pollination accuracy. Our results suggest that quick corrective reorientation of bilaterally symmetrical flowers is adaptive, highlighting a little-studied aspect of plant-pollinator interactions and plant evolution.
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Affiliation(s)
- W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth, PO1 2DY, UK
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, 99775-7000, USA
| | - Nathan Muchhala
- Department of Biology, University of Missouri-St Louis, St Louis, MO, 63121-4499, USA
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12
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Senior AM, Solon-Biet SM, Cogger VC, Le Couteur DG, Nakagawa S, Raubenheimer D, Simpson SJ. Dietary macronutrient content, age-specific mortality and lifespan. Proc Biol Sci 2020; 286:20190393. [PMID: 31039722 DOI: 10.1098/rspb.2019.0393] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Protein and calorie restrictions extend median lifespan in many organisms. However, studies suggest that among-individual variation in the age at death is also affected. Ultimately, both of these outcomes must be caused by effects of nutrition on underlying patterns of age-specific mortality (ASM). Using model life tables, we tested for effects of dietary macronutrients on ASM in mice ( Mus musculus). High concentrations of protein and fat relative to carbohydrates were associated with low life expectancy and high variation in the age at death, a result caused predominantly by high mortality prior to middle age. A lifelong diet comprising the ratio of macronutrients self-selected by mouse (in early adulthood) was associated with low mortality up until middle age, but higher late-life mortality. This pattern results in reasonably high life expectancy, but very low variation in the age at death. Our analyses also indicate that it may be possible to minimize ASM across life by altering the ratio of dietary protein to carbohydrate in the approach to old age. Mortality in early and middle life was minimized at around one-part protein to two-parts carbohydrate, whereas in later life slightly greater than equal parts protein to carbohydrate reduced mortality.
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Affiliation(s)
- Alistair M Senior
- 1 Charles Perkins Centre, The University of Sydney , Camperdown, New South Wales 2006 , Australia.,2 School of Life and Environmental Sciences, The University of Sydney , Camperdown, New South Wales 2006 , Australia
| | - Samantha M Solon-Biet
- 1 Charles Perkins Centre, The University of Sydney , Camperdown, New South Wales 2006 , Australia.,2 School of Life and Environmental Sciences, The University of Sydney , Camperdown, New South Wales 2006 , Australia
| | - Victoria C Cogger
- 1 Charles Perkins Centre, The University of Sydney , Camperdown, New South Wales 2006 , Australia.,3 School of Medicine, The University of Sydney , Camperdown, New South Wales 2006 , Australia.,4 Ageing and Alzheimers Institute and ANZAC Research Institute, Concord Hospital Concord , New South Wales , Australia
| | - David G Le Couteur
- 1 Charles Perkins Centre, The University of Sydney , Camperdown, New South Wales 2006 , Australia.,3 School of Medicine, The University of Sydney , Camperdown, New South Wales 2006 , Australia.,4 Ageing and Alzheimers Institute and ANZAC Research Institute, Concord Hospital Concord , New South Wales , Australia
| | - Shinichi Nakagawa
- 5 Evolution and Ecology Research Centre and School of Biological, Earth and Environmental Sciences, University of New South Wales , Sydney, New South Wales 2052 , Australia.,6 Diabetes and Metabolism Division, Garvan Institute of Medical Research , Darlinghurst, Sydney, New South Wales 2010 , Australia
| | - David Raubenheimer
- 1 Charles Perkins Centre, The University of Sydney , Camperdown, New South Wales 2006 , Australia.,2 School of Life and Environmental Sciences, The University of Sydney , Camperdown, New South Wales 2006 , Australia
| | - Stephen J Simpson
- 1 Charles Perkins Centre, The University of Sydney , Camperdown, New South Wales 2006 , Australia.,2 School of Life and Environmental Sciences, The University of Sydney , Camperdown, New South Wales 2006 , Australia
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13
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Rivera G, Neely CMD. Patterns of fluctuating asymmetry in the limbs of freshwater turtles: Are more functionally important limbs more symmetrical? Evolution 2020; 74:660-670. [PMID: 31989579 DOI: 10.1111/evo.13933] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 01/09/2020] [Accepted: 01/17/2020] [Indexed: 01/05/2023]
Abstract
Understanding how selective forces influence patterns of symmetry remains an active area of research in evolutionary biology. One hypothesis, which has received relatively little attention, suggests that the functional importance of morphological characters may influence patterns of symmetry. Specifically, it posits that for structures that display bilateral symmetry, those with greater functional importance should display lower levels of asymmetry. The aim of this study was to examine the patterns of fluctuating asymmetry (FA) present in the limb bones of freshwater turtles in the family Emydidae. Aquatic emydid turtles of the subfamily Deirochelyinae employ a hindlimb-dominant swimming style, suggesting that hindlimbs should display lower levels of FA. Consistent with the morpho-functional hypothesis of symmetry, we found a strong, clade-wise pattern of humeral-biased FA in aquatic Deirochelyinae. In contrast, some emydids of the subfamily Emydinae possess more terrestrial tendencies. As terrestrial locomotion places more equal importance on fore- and hindlimbs, we predicted that such behaviors may minimize differences in FA. No clade-wise pattern was detected in the subfamily Emydinae. We also detected a phylogenetic signal in FA within the femur and discovered that FA has evolved at vastly different rates between the fore- and hindlimbs.
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Affiliation(s)
- Gabriel Rivera
- Department of Biology, Creighton University, Omaha, NE, 68178
| | - Cally M Deppen Neely
- Biology Department, Swarthmore College, Swarthmore, PA, 19081.,Present address: , 11604 Piney Lodge Road, Gaithersburg, MD, 20878
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14
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Brady SP, Bolnick DI, Angert AL, Gonzalez A, Barrett RD, Crispo E, Derry AM, Eckert CG, Fraser DJ, Fussmann GF, Guichard F, Lamy T, McAdam AG, Newman AE, Paccard A, Rolshausen G, Simons AM, Hendry AP. Causes of maladaptation. Evol Appl 2019; 12:1229-1242. [PMID: 31417611 PMCID: PMC6691215 DOI: 10.1111/eva.12844] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Evolutionary biologists tend to approach the study of the natural world within a framework of adaptation, inspired perhaps by the power of natural selection to produce fitness advantages that drive population persistence and biological diversity. In contrast, evolution has rarely been studied through the lens of adaptation's complement, maladaptation. This contrast is surprising because maladaptation is a prevalent feature of evolution: population trait values are rarely distributed optimally; local populations often have lower fitness than imported ones; populations decline; and local and global extinctions are common. Yet we lack a general framework for understanding maladaptation; for instance in terms of distribution, severity, and dynamics. Similar uncertainties apply to the causes of maladaptation. We suggest that incorporating maladaptation-based perspectives into evolutionary biology would facilitate better understanding of the natural world. Approaches within a maladaptation framework might be especially profitable in applied evolution contexts - where reductions in fitness are common. Toward advancing a more balanced study of evolution, here we present a conceptual framework describing causes of maladaptation. As the introductory article for a Special Feature on maladaptation, we also summarize the studies in this Issue, highlighting the causes of maladaptation in each study. We hope that our framework and the papers in this Special Issue will help catalyze the study of maladaptation in applied evolution, supporting greater understanding of evolutionary dynamics in our rapidly changing world.
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Affiliation(s)
- Steven P. Brady
- Biology DepartmentSouthern Connecticut State UniversityNew HavenCTUSA
| | - Daniel I. Bolnick
- Department of Ecology and Evolutionary BiologyUniversity of ConnecticutMansfieldCTUSA
| | - Amy L. Angert
- Departments of Botany and ZoologyUniversity of British ColumbiaVancouverBCCanada
| | - Andrew Gonzalez
- Department of BiologyMcGill UniversityMontréalQCCanada
- Quebec Centre for Biodiversity Science, Stewart BiologyMcGill UniversityMontréalQCCanada
| | - Rowan D.H. Barrett
- Department of BiologyMcGill UniversityMontréalQCCanada
- Quebec Centre for Biodiversity Science, Stewart BiologyMcGill UniversityMontréalQCCanada
- Redpath MuseumMcGill UniversityMontréalQCCanada
| | - Erika Crispo
- Department of BiologyPace UniversityNew YorkNYUSA
| | - Alison M. Derry
- Quebec Centre for Biodiversity Science, Stewart BiologyMcGill UniversityMontréalQCCanada
- Département des sciences biologiquesUniversité du Québec à MontréalMontréalQCCanada
| | | | | | - Gregor F. Fussmann
- Department of BiologyMcGill UniversityMontréalQCCanada
- Quebec Centre for Biodiversity Science, Stewart BiologyMcGill UniversityMontréalQCCanada
| | - Frederic Guichard
- Department of BiologyMcGill UniversityMontréalQCCanada
- Quebec Centre for Biodiversity Science, Stewart BiologyMcGill UniversityMontréalQCCanada
| | - Thomas Lamy
- Département de sciences biologiquesUniversité de MontréalMontréalQCCanada
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCAUSA
| | - Andrew G. McAdam
- Department of Integrative BiologyUniversity of GuelphGuelphONCanada
| | - Amy E.M. Newman
- Department of Integrative BiologyUniversity of GuelphGuelphONCanada
| | | | - Gregor Rolshausen
- Senckenberg Biodiversity and Climate Research Centre (SBiK‐F)Frankfurt am MainGermany
| | | | - Andrew P. Hendry
- Department of BiologyMcGill UniversityMontréalQCCanada
- Quebec Centre for Biodiversity Science, Stewart BiologyMcGill UniversityMontréalQCCanada
- Redpath MuseumMcGill UniversityMontréalQCCanada
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15
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Westneat DF, Potts LJ, Sasser KL, Shaffer JD. Causes and Consequences of Phenotypic Plasticity in Complex Environments. Trends Ecol Evol 2019; 34:555-568. [PMID: 30871734 DOI: 10.1016/j.tree.2019.02.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 02/11/2019] [Accepted: 02/18/2019] [Indexed: 10/27/2022]
Abstract
Phenotypic plasticity is a ubiquitous and necessary adaptation of organisms to variable environments, but most environments have multiple dimensions that vary. Many studies have documented plasticity of a trait with respect to variation in multiple environmental factors. Such multidimensional phenotypic plasticity (MDPP) exists at all levels of organismal organization, from the whole organism to within cells. This complexity in plasticity cannot be explained solely by scaling up ideas from models of unidimensional plasticity. MDPP generates new questions about the mechanism and function of plasticity and its role in speciation and population persistence. Here we review empirical and theoretical approaches to plasticity in response to multidimensional environments and we outline new opportunities along with some difficulties facing future research.
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Affiliation(s)
- David F Westneat
- Department of Biology, 101 T.H. Morgan Building, University of Kentucky, Lexington, KY 40506-0225, USA.
| | - Leslie J Potts
- Department of Entomology, S-225 Agricultural Science Center North, University of Kentucky, Lexington, KY 40546-0091, USA
| | - Katherine L Sasser
- Department of Biology, 101 T.H. Morgan Building, University of Kentucky, Lexington, KY 40506-0225, USA
| | - James D Shaffer
- Department of Biology, 101 T.H. Morgan Building, University of Kentucky, Lexington, KY 40506-0225, USA
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16
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Armbruster WS, Wege JA. Detecting canalization and intra-floral modularity in triggerplant (Stylidium) flowers: correlations are only part of the story. ANNALS OF BOTANY 2019; 123:355-372. [PMID: 30383191 PMCID: PMC6344225 DOI: 10.1093/aob/mcy184] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 09/18/2018] [Indexed: 05/25/2023]
Abstract
BACKGROUND AND AIMS The Berg hypothesis proposes that specialized-flower traits experience stronger stabilizing selection than non-floral structures and predicts that variation in specialized-flower traits will be mostly uncorrelated with variation in non-floral traits. Similarly, adaptive-accuracy theory predicts lower variation (as a proportion of the mean) in floral traits than in non-floral ones. Both hypotheses can be extended to comparisons between floral traits, where different parts of the flower can be expected to experience different strengths of stabilizing selection, resulting in contrasting patterns of variation. The present study tests these ideas by analysing variation/covariation in those floral traits influencing the location of pollen placement on, and stigma contact with, pollinators ('pollination-mechanics traits', PMTs) in relation to variation/covariation in non-floral traits and floral traits not directly involved in the mechanics of pollination. The prediction was that PMTs are canalized (buffered against genetic and environmental variation) relative to attraction traits, as manifested in lower variances and modular independence. METHODS Floral and inflorescence structures of ten species of triggerplants (Stylidium, Stylidiaceae) in south-western Australia were measured; the data were analysed using multivariate and bivariate approaches to detect modular structure of floral and non-floral traits and assess evidence for canalization of PMTs. KEY RESULTS Only six of the ten species had PMTs with smaller correlation coefficients than attraction traits, in contrast to the Berg expectation. However, allometric and variance patterns were generally consistent with the predictions of an extended Berg hypothesis and adaptive accuracy. There was modular separation of most floral traits from non-floral traits and clear intra-floral modular structure. PMTs showed lower proportional variation and shallower allometric slopes than pollinator-attraction traits in nine and eight, respectively, of ten species. CONCLUSIONS This study demonstrates the value of allometric and variance analyses (in addition to correlation) in assessing the evolutionary significance of floral-trait stability and plasticity.
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Affiliation(s)
- W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth, UK
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Juliet A Wege
- Western Australian Herbarium, Biodiversity and Conservation Science, Department of Biodiversity, Conservation and Attractions, Bentley, Western Australia, Australia
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17
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Hendry AP, Schoen DJ, Wolak ME, Reid JM. The Contemporary Evolution of Fitness. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2018. [DOI: 10.1146/annurev-ecolsys-110617-062358] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The rate of evolution of population mean fitness informs how selection acting in contemporary populations can counteract environmental change and genetic degradation (mutation, gene flow, drift, recombination). This rate influences population increases (e.g., range expansion), population stability (e.g., cryptic eco-evolutionary dynamics), and population recovery (i.e., evolutionary rescue). We review approaches for estimating such rates, especially in wild populations. We then review empirical estimates derived from two approaches: mutation accumulation (MA) and additive genetic variance in fitness (IAw). MA studies inform how selection counters genetic degradation arising from deleterious mutations, typically generating estimates of <1% per generation. IAw studies provide an integrated prediction of proportional change per generation, nearly always generating estimates of <20% and, more typically, <10%. Overall, considerable, but not unlimited, evolutionary potential exists in populations facing detrimental environmental or genetic change. However, further studies with diverse methods and species are required for more robust and general insights.
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Affiliation(s)
- Andrew P. Hendry
- Redpath Museum, McGill University, Montréal, Québec H3A 0C4, Canada
- Department of Biology, McGill University, Montréal, Québec H3A 1B1, Canada
| | - Daniel J. Schoen
- Department of Biology, McGill University, Montréal, Québec H3A 1B1, Canada
| | - Matthew E. Wolak
- Department of Biological Sciences, Auburn University, Auburn, Alabama 36849, USA
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom
| | - Jane M. Reid
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, United Kingdom
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18
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Goczal J, Rossa R, Nawrocka A, Sweeney JD, Tofilski A. Developmental Costs of Biological Invasion: The Exotic Wood Borer Tetropium fuscum (Coleoptera: Cerambycidae) is More Asymmetric and Smaller in Invaded Area. ENVIRONMENTAL ENTOMOLOGY 2018; 47:982-989. [PMID: 29684113 DOI: 10.1093/ee/nvy059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Indexed: 06/08/2023]
Abstract
Biological invasions provide a unique opportunity to gain insight into basic biological processes occurring under new circumstances. During the process of establishment, exotic species are exposed to various stressors which may affect their development. Presence of the stressors is often detected by measurements of left-right body asymmetry, which consists of two main components: fluctuating asymmetry and directional asymmetry. Fluctuating asymmetry constitutes random differences between the two body sides, whereas directional asymmetry occurs when a particular trait is bigger on one of the sides. The relation between these two asymmetry components is still not fully understood. Our goal was to investigate the potential differences in asymmetry patterns between native and invasive populations of Tetropium fuscum (Fabr. 1787) (Coleoptera: Cerambycidae), a harmful forest pest native to Europe and introduced to North America. Wing asymmetry assessment was based on the geometric morphometrics of hind wings. We found that specimens from invaded area were markedly smaller and have more asymmetric wings than individuals from native population, suggesting some unfavorable conditions in the invaded area. Moreover, we found significant directional asymmetry in the native but not in the invasive population. On the other hand, differences between left and right hind wings were similar in the native and invasive populations, in terms of direction. This suggests that a high level of fluctuating asymmetry in the invasive population may blur the intrinsic directional asymmetry and hinder its detection. Our data show that fluctuating asymmetry has a potential as an indicator of developmental stress in invasive species.
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Affiliation(s)
- Jakub Goczal
- Institute of Forest Ecosystem Protection, University of Agriculture in Krakow, Krakow, Poland
| | - Robert Rossa
- Institute of Forest Ecosystem Protection, University of Agriculture in Krakow, Krakow, Poland
| | - Anna Nawrocka
- Department of Pomology and Apiculture, University of Agriculture in Krakow, Krakow, Poland
| | - Jon David Sweeney
- Natural Resources Canada, Canadian Forest Service, Fredericton, NB, Canada
| | - Adam Tofilski
- Department of Pomology and Apiculture, University of Agriculture in Krakow, Krakow, Poland
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19
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Webster M. Morphological homeostasis in the fossil record. Semin Cell Dev Biol 2018; 88:91-104. [PMID: 29787861 DOI: 10.1016/j.semcdb.2018.05.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 03/31/2018] [Accepted: 05/15/2018] [Indexed: 12/31/2022]
Abstract
Morphological homeostasis limits the extent to which genetic and/or environmental variation is translated into phenotypic variation, providing generation-to-generation fitness advantage under a stabilizing selection regime. Depending on its lability, morphological homeostasis might also have a longer-term impact on evolution by restricting the variation-and thus the response to directional selection-of a trait. The fossil record offers an inviting opportunity to investigate whether and how morphological homeostasis constrained trait evolution in lineages or clades on long timescales (thousands to millions of years) that are not accessible to neontological studies. Fossils can also reveal insight into the nature of primitive developmental systems that might not be predictable from the study of modern organisms. The ability to study morphological homeostasis in fossils is strongly limited by taphonomic processes that can destroy, blur, or distort the original biological signal: genetic data are unavailable; phenotypic data can be modified by tectonic or compaction-related deformation; time-averaging limits temporal resolution; and environmental variation is hard to study and impossible to control. As a result of these processes, neither allelic sensitivity (and thus genetic canalization) nor macroenvironmental sensitivity (and thus environmental canalization) can be unambiguously assessed in the fossil record. However, homeorhesis-robustness against microenvironmental variation (developmental noise)-can be assessed in ancient developmental systems by measuring the level of fluctuating asymmetry (FA) in a nominally symmetric trait. This requires the analysis of multiple, minimally time-averaged samples of exquisite preservational quality. Studies of FA in fossils stand to make valuable contributions to our understanding of the deep-time significance of homeorhesis. Few empirical studies have been conducted to date, and future paleontological research focusing on how homeorhesis relates to evolutionary rate (including stasis), species survivorship, and purported macroevolutionary trends in evolvability would reap high reward.
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Affiliation(s)
- Mark Webster
- Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL, 60637, USA.
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20
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Kielland ØN, Bech C, Einum S. Is there plasticity in developmental instability? The effect of daily thermal fluctuations in an ectotherm. Ecol Evol 2017; 7:10567-10574. [PMID: 29299238 PMCID: PMC5743494 DOI: 10.1002/ece3.3556] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 01/05/2023] Open
Abstract
Diversified bet-hedging (DBH) by production of within-genotype phenotypic variance may evolve to maximize fitness in stochastic environments. Bet-hedging is generally associated with parental effects, but phenotypic variation may also develop throughout life via developmental instability (DI). This opens for the possibility of a within-generation mechanism creating DBH during the lifetime of individuals. If so, DI could in fact be a plastic trait itself; if a fluctuating environment indicates uncertainty about future conditions, sensing such fluctuations could trigger DI as a DBH response. However, this possibility has received little empirical attention. Here, we test whether fluctuating environments may elicit such a response in the clonally reproducing crustacean Daphnia magna. Specifically, we exposed genetically identical individuals to two environments of different thermal stability (stable vs. pronounced daily realistic temperature fluctuations) and tested for effects on DI in body mass and metabolic rate shortly before maturation. Furthermore, we also estimated the genetic variation in DI. Interestingly, fluctuating temperatures did not affect body mass, but metabolic rate decreased. We found no evidence for plasticity in DI in response to environmental fluctuations. The lack of plasticity was common to all genotypes, and for both traits studied. However, we found considerable evolvability for DI, which implies a general evolutionary potential for DBH under selection for increased phenotypic variance.
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Affiliation(s)
- Øystein Nordeide Kielland
- Department of BiologyCentre for Biodiversity DynamicsNorwegian University of Science and Technology, NTNUTrondheimNorway
| | - Claus Bech
- Department of BiologyNorwegian University of Science and Technology, NTNUTrondheimNorway
| | - Sigurd Einum
- Department of BiologyCentre for Biodiversity DynamicsNorwegian University of Science and Technology, NTNUTrondheimNorway
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21
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Joint evolution of interspecific mutualism and regulation of variation of interaction under directional selection in trait space. THEOR ECOL-NETH 2017. [DOI: 10.1007/s12080-017-0343-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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22
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Armbruster WS, Bolstad GH, Hansen TF, Keller B, Conti E, Pélabon C. The measure and mismeasure of reciprocity in heterostylous flowers. THE NEW PHYTOLOGIST 2017; 215:906-917. [PMID: 28556899 DOI: 10.1111/nph.14604] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 03/31/2017] [Indexed: 06/07/2023]
Abstract
The goal of biological measurement is to capture underlying biological phenomena in numerical form. The reciprocity index applied to heterostylous flowers is meant to measure the degree of correspondence between fertile parts of opposite sex on complementary (inter-compatible) morphs, reflecting the correspondence of locations of pollen placement on, and stigma contact with, pollinators. Pollen of typical heterostylous flowers can achieve unimpeded fertilization only on opposite-morph flowers. Thus, the implicit goal of this measurement is to assess the likelihood of 'legitimate' pollinations between compatible morphs, and hence reproductive fitness. Previous reciprocity metrics fall short of this goal on both empirical and theoretical grounds. We propose a new measure of reciprocity based on theory that relates floral morphology to reproductive fitness. This method establishes a scale based on adaptive inaccuracy, a measure of the fitness cost of the deviation of phenotypes in a population from the optimal phenotype. Inaccuracy allows the estimation of independent contributions of maladaptive bias (mean departure from optimum) and imprecision (within-population variance) to the phenotypic mismatch (inaccuracy) of heterostylous morphs on a common scale. We illustrate this measure using data from three species of Primula (Primulaceae).
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Affiliation(s)
- W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth, PO1 2DY, UK
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA
| | - Geir H Bolstad
- Norwegian Institute for Nature Research (NINA), Trondheim, NO-7485, Norway
| | - Thomas F Hansen
- Department of Biology, CEES & Evogene, University of Oslo, PB1016, Oslo, 0316, Norway
| | - Barbara Keller
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, Zürich, 8008, Switzerland
| | - Elena Conti
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, Zürich, 8008, Switzerland
| | - Christophe Pélabon
- Institute of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway
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23
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The evolvability of herkogamy: Quantifying the evolutionary potential of a composite trait. Evolution 2017; 71:1572-1586. [DOI: 10.1111/evo.13258] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/21/2017] [Indexed: 12/18/2022]
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24
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Mimura M, Yahara T, Faith DP, Vázquez‐Domínguez E, Colautti RI, Araki H, Javadi F, Núñez‐Farfán J, Mori AS, Zhou S, Hollingsworth PM, Neaves LE, Fukano Y, Smith GF, Sato Y, Tachida H, Hendry AP. Understanding and monitoring the consequences of human impacts on intraspecific variation. Evol Appl 2017; 10:121-139. [PMID: 28127389 PMCID: PMC5253428 DOI: 10.1111/eva.12436] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 09/20/2016] [Indexed: 12/15/2022] Open
Abstract
Intraspecific variation is a major component of biodiversity, yet it has received relatively little attention from governmental and nongovernmental organizations, especially with regard to conservation plans and the management of wild species. This omission is ill-advised because phenotypic and genetic variations within and among populations can have dramatic effects on ecological and evolutionary processes, including responses to environmental change, the maintenance of species diversity, and ecological stability and resilience. At the same time, environmental changes associated with many human activities, such as land use and climate change, have dramatic and often negative impacts on intraspecific variation. We argue for the need for local, regional, and global programs to monitor intraspecific genetic variation. We suggest that such monitoring should include two main strategies: (i) intensive monitoring of multiple types of genetic variation in selected species and (ii) broad-brush modeling for representative species for predicting changes in variation as a function of changes in population size and range extent. Overall, we call for collaborative efforts to initiate the urgently needed monitoring of intraspecific variation.
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Affiliation(s)
- Makiko Mimura
- Department of Bioenvironmental SystemsTamagawa UniversityTokyoJapan
| | - Tetsukazu Yahara
- Department of Biology and Institute of Decision Science for a Sustainable SocietyKyushu UniversityFukuokaJapan
| | - Daniel P. Faith
- The Australian Museum Research InstituteThe Australian MuseumSydneyNSWAustralia
| | | | | | - Hitoshi Araki
- Research Faculty of AgricultureHokkaido UniversitySapporoHokkaidoJapan
| | - Firouzeh Javadi
- Department of Biology and Institute of Decision Science for a Sustainable SocietyKyushu UniversityFukuokaJapan
| | - Juan Núñez‐Farfán
- Instituto de EcologíaUniversidad Nacional Autónoma de MéxicoMéxicoMéxico
| | - Akira S. Mori
- Graduate School of Environment and Information SciencesYokohama National UniversityYokohamaJapan
| | - Shiliang Zhou
- State Key Laboratory of Systematic and Evolutionary BotanyInstitute of BotanyChinese Academy of SciencesBeijingChina
| | | | - Linda E. Neaves
- Royal Botanic Garden EdinburghEdinburghUK
- Australian Centre for Wildlife Genomics, Australian Museum Research InstituteAustralian MuseumSydneyNSWAustralia
| | - Yuya Fukano
- Department of Biology and Institute of Decision Science for a Sustainable SocietyKyushu UniversityFukuokaJapan
| | - Gideon F. Smith
- Department of BotanyNelson Mandela Metropolitan UniversityPort ElizabethSouth Africa
- Departamento de Ciências da VidaCentre for Functional EcologyUniversidade de CoimbraCoimbraPortugal
| | | | - Hidenori Tachida
- Department of Biology and Institute of Decision Science for a Sustainable SocietyKyushu UniversityFukuokaJapan
| | - Andrew P. Hendry
- Redpath Museum and Department of BiologyMcGill UniversityMontrealQuebecCanada
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25
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Tocts AMS, Johnson DW, Carter AJR. Strong nonlinear selection against fluctuating asymmetry in wild populations of a marine fish. Evolution 2016; 70:2899-2908. [PMID: 27757960 DOI: 10.1111/evo.13092] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 08/27/2016] [Accepted: 09/26/2016] [Indexed: 01/10/2023]
Abstract
Theoretical links between fluctuating asymmetry (FA) and fitness have led many to use FA as a proxy for average fitness. However, studies examining whether asymmetry actually correlates with individual fitness in wild populations are relatively rare and often use simple measures of association (e.g., correlation coefficients). Consequently, the pattern of selection on asymmetry in the wild is seldom clear. We examined selection on FA of pectoral fin morphology in two wild populations of a marine fish (the kelp perch; Brachyistius frenatus). As expected, variance in signed FA in each initial sample was significantly greater than that found in the surviving population, indicating selection against FA. Our estimate of the fitness surface confirmed perfect symmetry as the phenotypic optimum and indicated strong, nonlinear selection against asymmetry. No difference in the form of selection was detected between populations. However, the level of FA in the initial samples varied among populations, leading to an overall difference in the level of selective mortality. Our results suggest that selection on asymmetry in wild populations may be strongly nonlinear, and indicate that the demographic costs of asymmetry may play a substantial role in the dynamics of populations.
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Affiliation(s)
- Ashley M S Tocts
- Department of Biological Sciences, California State University, Long Beach, CA, 90840, USA
| | - Darren W Johnson
- Department of Biological Sciences, California State University, Long Beach, CA, 90840, USA
| | - Ashley J R Carter
- Department of Biological Sciences, California State University, Long Beach, CA, 90840, USA
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26
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Gonzalez PN, Pavlicev M, Mitteroecker P, Pardo-Manuel de Villena F, Spritz RA, Marcucio RS, Hallgrímsson B. Genetic structure of phenotypic robustness in the collaborative cross mouse diallel panel. J Evol Biol 2016; 29:1737-51. [PMID: 27234063 DOI: 10.1111/jeb.12906] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 05/11/2016] [Accepted: 05/22/2016] [Indexed: 12/19/2022]
Abstract
Developmental stability and canalization describe the ability of developmental systems to minimize phenotypic variation in the face of stochastic micro-environmental effects, genetic variation and environmental influences. Canalization is the ability to minimize the effects of genetic or environmental effects, whereas developmental stability is the ability to minimize the effects of micro-environmental effects within individuals. Despite much attention, the mechanisms that underlie these two components of phenotypic robustness remain unknown. We investigated the genetic structure of phenotypic robustness in the collaborative cross (CC) mouse reference population. We analysed the magnitude of fluctuating asymmetry (FA) and among-individual variation of cranial shape in reciprocal crosses among the eight parental strains, using geometric morphometrics and a diallel analysis based on a Bayesian approach. Significant differences among genotypes were found for both measures, although they were poorly correlated at the level of individuals. An overall positive effect of inbreeding was found for both components of variation. The strain CAST/EiJ exerted a positive additive effect on FA and, to a lesser extent, among-individual variance. Sex- and other strain-specific effects were not significant. Neither FA nor among-individual variation was associated with phenotypic extremeness. Our results support the existence of genetic variation for both developmental stability and canalization. This finding is important because robustness is a key feature of developmental systems. Our finding that robustness is not related to phenotypic extremeness is consistent with theoretical work that suggests that its relationship to stabilizing selection is not straightforward.
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Affiliation(s)
- P N Gonzalez
- Instituto de Genética Veterinaria, CCT-CONICET, La Plata, Argentina
| | - M Pavlicev
- Department of Pediatrics, Cincinnati Children's Hospital Medical Centre, Cincinnati, OH, USA
| | - P Mitteroecker
- Department of Theoretical Biology, University of Vienna, Wien, Austria
| | | | - R A Spritz
- Human Medical Genetics and Genomics Program, University of Colorado School of Medicine, Aurora, CO, USA
| | - R S Marcucio
- Department of Orthopaedic Surgery, Orthopaedic Trauma Institute, San Francisco General Hospital, University of California San Francisco, San Francisco, CA, USA
| | - B Hallgrímsson
- Department of Cell Biology and Anatomy, McCaig Institute for Bone and Joint Health, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada.
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27
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Gómez JM, Torices R, Lorite J, Klingenberg CP, Perfectti F. The role of pollinators in the evolution of corolla shape variation, disparity and integration in a highly diversified plant family with a conserved floral bauplan. ANNALS OF BOTANY 2016; 117:889-904. [PMID: 26884512 PMCID: PMC4845802 DOI: 10.1093/aob/mcv194] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 09/17/2015] [Accepted: 10/14/2015] [Indexed: 05/25/2023]
Abstract
BACKGROUND AND AIMS Brassicaceae is one of the most diversified families in the angiosperms. However, most species from this family exhibit a very similar floral bauplan. In this study, we explore the Brassicaceae floral morphospace, examining how corolla shape variation (an estimation of developmental robustness), integration and disparity vary among phylogenetically related species. Our aim is to check whether these floral attributes have evolved in this family despite its apparent morphological conservation, and to test the role of pollinators in driving this evolution. METHODS Using geometric morphometric tools, we calculated the phenotypic variation, disparity and integration of the corolla shape of 111 Brassicaceae taxa. We subsequently inferred the phylogenetic relationships of these taxa and explored the evolutionary lability of corolla shape. Finally, we sampled the pollinator assemblages of every taxon included in this study, and determined their pollination niches using a modularity algorithm. We explore the relationship between pollination niche and the attributes of corolla shape. KEY RESULTS Phylogenetic signal was weak for all corolla shape attributes. All taxa had generalized pollination systems. Nevertheless, they belong to different pollination niches. There were significant differences in corolla shape among pollination niches even after controlling for the phylogenetic relationship of the plant taxa. Corolla shape variation and disparity was significantly higher in those taxa visited mostly by nocturnal moths, indicating that this pollination niche is associated with a lack of developmental robustness. Corolla integration was higher in those taxa visited mostly by hovering long-tongued flies and long-tongued large bees. CONCLUSIONS Corolla variation, integration and disparity were evolutionarily labile and evolved very recently in the evolutionary history of the Brassicaceae. These floral attributes were strongly related to the pollination niche. Even in a plant clade having a very generalized pollination system and exhibiting a conserved floral bauplan, pollinators can drive the evolution of important developmental attributes of corolla shape.
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Affiliation(s)
- José M Gómez
- Department of Functional and Evolutionary Ecology, Estación Experimental de Zonas Áridas (EEZA-CSIC), Almería, Spain, Department of Ecology,
| | - Ruben Torices
- Department of Functional and Evolutionary Ecology, Estación Experimental de Zonas Áridas (EEZA-CSIC), Almería, Spain, Centre for Functional Ecology, Department of Life Science, University of Coimbra, Coimbra, Portugal and
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28
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Westneat DF, Wright J, Dingemanse NJ. The biology hidden inside residual within-individual phenotypic variation. Biol Rev Camb Philos Soc 2014; 90:729-43. [PMID: 25080034 DOI: 10.1111/brv.12131] [Citation(s) in RCA: 166] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 06/23/2014] [Accepted: 06/24/2014] [Indexed: 11/29/2022]
Abstract
Phenotypes vary hierarchically among taxa and populations, among genotypes within populations, among individuals within genotypes, and also within individuals for repeatedly expressed, labile phenotypic traits. This hierarchy produces some fundamental challenges to clearly defining biological phenomena and constructing a consistent explanatory framework. We use a heuristic statistical model to explore two consequences of this hierarchy. First, although the variation existing among individuals within populations has long been of interest to evolutionary biologists, within-individual variation has been much less emphasized. Within-individual variance occurs when labile phenotypes (behaviour, physiology, and sometimes morphology) exhibit phenotypic plasticity or deviate from a norm-of-reaction within the same individual. A statistical partitioning of phenotypic variance leads us to explore an array of ideas about residual within-individual variation. We use this approach to draw attention to additional processes that may influence within-individual phenotypic variance, including interactions among environmental factors, ecological effects on the fitness consequences of plasticity, and various types of adaptive variance. Second, our framework for investigating variation in phenotypic variance reveals that interactions between levels of the hierarchy form the preconditions for the evolution of all types of plasticity, and we extend this idea to the residual level within individuals, where both adaptive plasticity in residuals and canalization-like processes (stability) can evolve. With the statistical tools now available to examine heterogeneous residual variance, an array of novel questions linking phenotype to environment can be usefully addressed.
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Affiliation(s)
- David F Westneat
- Department of Biology, Center for Ecology, Evolution, and Behavior, University of Kentucky, 101 Morgan Building, Lexington, KY 40506-0225, U.S.A
| | - Jonathan Wright
- Department of Biology, Center for Biodiversity Dynamics, Norwegian University of Science and Technology (NTNU), N-7491, Trondheim, Norway
| | - Niels J Dingemanse
- Behavioural Ecology, Department of Biology, Ludwig-Maximilians University of Munich, Planegg-Martinsried, Germany.,Evolutionary Ecology of Variation Research Group, Max Planck Institute for Ornithology, Seewiesen, Germany
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Armbruster WS. Floral specialization and angiosperm diversity: phenotypic divergence, fitness trade-offs and realized pollination accuracy. AOB PLANTS 2014; 6:plu003. [PMID: 24790124 PMCID: PMC4038416 DOI: 10.1093/aobpla/plu003] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 01/05/2014] [Indexed: 05/08/2023]
Abstract
Plant reproduction by means of flowers has long been thought to promote the success and diversification of angiosperms. It remains unclear, however, how this success has come about. Do flowers, and their capacity to have specialized functions, increase speciation rates or decrease extinction rates? Is floral specialization fundamental or incidental to the diversification? Some studies suggest that the conclusions we draw about the role of flowers in the diversification and increased phenotypic disparity (phenotypic diversity) of angiosperms depends on the system. For orchids, for example, specialized pollination may have increased speciation rates, in part because in most orchids pollen is packed in discrete units so that pollination is precise enough to contribute to reproductive isolation. In most plants, however, granular pollen results in low realized pollination precision, and thus key innovations involving flowers more likely reflect reduced extinction rates combined with opportunities for evolution of greater phenotypic disparity (phenotypic diversity) and occupation of new niches. Understanding the causes and consequences of the evolution of specialized flowers requires knowledge of both the selective regimes and the potential fitness trade-offs in using more than one pollinator functional group. The study of floral function and flowering-plant diversification remains a vibrant evolutionary field. Application of new methods, from measuring natural selection to estimating speciation rates, holds much promise for improving our understanding of the relationship between floral specialization and evolutionary success.
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Affiliation(s)
- W. Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775-7000, USA
- Department of Biology, Norwegian University of Science & Technology, Trondheim N-7491, Norway
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Armbruster WS, Shi XQ, Huang SQ. Do specialized flowers promote reproductive isolation? Realized pollination accuracy of three sympatric Pedicularis species. ANNALS OF BOTANY 2014; 113:331-40. [PMID: 24047714 PMCID: PMC3890382 DOI: 10.1093/aob/mct187] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
BACKGROUND AND AIMS Interest in pollinator-mediated evolutionary divergence of flower phenotype and speciation in plants has been at the core of plant evolutionary studies since Darwin. Specialized pollination is predicted to lead to reproductive isolation and promote speciation among sympatric species by promoting partitioning of (1) the species of pollinators used, (2) when pollinators are used, or (3) the sites of pollen placement. Here this last mechanism is investigated by observing the pollination accuracy of sympatric Pedicularis species (Orobanchacae). METHODS Pollinator behaviour was observed on three species of Pedicularis (P. densispica, P. tricolor and P. dichotoma) in the Hengduan Mountains, south-west China. Using fluorescent powder and dyed pollen, the accuracy was assessed of stigma contact with, and pollen deposition on, pollinating bumble-bees, respectively. KEY RESULTS All three species of Pedicularis were pollinated by bumble-bees. It was found that the adaptive accuracy of female function was much higher than that of male function in all three flower species. Although peak pollen deposition corresponded to the optimal location on the pollinator (i.e. the site of stigma contact) for each species, substantial amounts of pollen were scattered over much of the bees' bodies. CONCLUSIONS The Pedicularis species studied in the eastern Himalayan region did not conform with Grant's 'Pedicularis Model' of mechanical reproductive isolation. The specialized flowers of this diverse group of plants seem unlikely to have increased the potential for reproductive isolation or influenced rates of speciation. It is suggested instead that the extreme species richness of the Pedicularis clade was generated in other ways and that specialized flowers and substantial pollination accuracy evolved as a response to selection generated by the diversity of co-occurring congeners.
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Affiliation(s)
- W. Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK
- Department of Biology, NTNU, NO-7491 Trondheim, Norway
- Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775, USA
- For correspondence. E-mail
| | - Xiao-Qing Shi
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Shuang-Quan Huang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
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31
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Armbruster WS, Corbet SA, Vey AJM, Liu SJ, Huang SQ. In the right place at the right time: Parnassia resolves the herkogamy dilemma by accurate repositioning of stamens and stigmas. ANNALS OF BOTANY 2014; 113:97-103. [PMID: 24265349 PMCID: PMC3864732 DOI: 10.1093/aob/mct261] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Spatial (herkogamy) and temporal (dichogamy) separation of pollen presentation and stigma receptivity have been interpreted as reducing interference between male and female functions in hermaphroditic flowers. However, spatial separation leads to a potential conflict: reduced pollination accuracy, where pollen may be placed in a location on the pollinator different from the point of stigma contact. METHODS To understand better how herkogamous flowers resolve this conflict, a study was made of a subalpine herb, Parnassia epunctulata, the nectariferous flowers of which exhibit sequential anther dehiscence (staggered pollen presentation) and stamen movements; usually one newly dehisced anther is positioned each day over the central gynoecium, while the older stamens bend away from the central position. KEY RESULTS The open flowers were visited by a variety of pollinators, most of which were flies. Seed set was pollinator-dependent (bagged flowers set almost no seeds) and pollen-limited (manual pollination increased seed set over open pollination). Analyses of adaptive accuracy showed that coordinated stamen movements and style elongation (movement herkogamy) dramatically increased pollination accuracy. Specifically, dehiscing anthers and receptive stigmas were positioned accurately in the vertical and horizontal planes in relation to the opposite sexual structure and pollinator position. By contrast, the spatial correspondence between anthers and stigma was dramatically lower before the anthers dehisced and after stamens bent outwards, as well as before and after the period of stigmatic receptivity. CONCLUSIONS It is shown for the first time that a combination of movement herkogamy and dichogamy can maintain high pollination accuracy in flowers with generalized pollination. Staggered pollen and stigma presentation with spatial correspondence can both reduce sexual interference and improve pollination accuracy.
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Affiliation(s)
- W. Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK
- Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775-7000, USA
- Department of Biology, NTNU, N-7491 Trondheim, Norway
| | - Sarah A. Corbet
- 1 St Loy Cottages, St Buryan, Penzance, Cornwall TR19 6DH, UK
| | - Aidan J. M. Vey
- School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK
| | - Shu-Juan Liu
- College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Shuang-Quan Huang
- College of Life Sciences, Central China Normal University, Wuhan 430079, China
- For correspondence. E-mail
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32
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Breno M, Bots J, Van Dongen S. Heritabilities of directional asymmetry in the fore- and hindlimbs of rabbit fetuses. PLoS One 2013; 8:e76358. [PMID: 24130770 PMCID: PMC3794934 DOI: 10.1371/journal.pone.0076358] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 08/26/2013] [Indexed: 11/19/2022] Open
Abstract
Directional asymmetry (DA), where at the population level symmetry differs from zero, has been reported in a wide range of traits and taxa, even for traits in which symmetry is expected to be the target of selection such as limbs or wings. In invertebrates, DA has been suggested to be non-adaptive. In vertebrates, there has been a wealth of research linking morphological asymmetry to behavioural lateralisation. On the other hand, the prenatal expression of DA and evidences for quantitative genetic variation for asymmetry may suggest it is not solely induced by differences in mechanic loading between sides. We estimate quantitative genetic variation of fetal limb asymmetry in a large dataset of rabbits. Our results showed a low but highly significant level of DA that is partially under genetic control for all traits, with forelimbs displaying higher levels of asymmetry. Genetic correlations were positive within limbs, but negative across bones of fore and hind limbs. Environmental correlations were positive for all, but smaller across fore and hind limbs. We discuss our results in light of the existence and maintenance of DA in locomotory traits.
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Affiliation(s)
- Matteo Breno
- Evolutionary Biology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Jessica Bots
- Evolutionary Biology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
| | - Stefan Van Dongen
- Evolutionary Biology Group, Department of Biology, University of Antwerp, Antwerp, Belgium
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Hendry AP, Kaeuffer R, Crispo E, Peichel CL, Bolnick DI. Evolutionary inferences from the analysis of exchangeability. Evolution 2013; 67:3429-41. [PMID: 24299398 PMCID: PMC3852416 DOI: 10.1111/evo.12160] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Accepted: 04/15/2013] [Indexed: 01/11/2023]
Abstract
Evolutionary inferences are usually based on statistical models that compare mean genotypes or phenotypes (or their frequencies) among populations. An alternative is to use the full distribution of genotypes and phenotypes to infer the "exchangeability" of individuals among populations. We illustrate this approach by using discriminant functions on principal components to classify individuals among paired lake and stream populations of threespine stickleback in each of six independent watersheds. Classification based on neutral and nonneutral microsatellite markers was highest to the population of origin and next highest to populations in the same watershed. These patterns are consistent with the influence of historical contingency (separate colonization of each watershed) and subsequent gene flow (within but not between watersheds). In comparison to this low genetic exchangeability, ecological (diet) and morphological (trophic and armor traits) exchangeability was relatively high-particularly among populations from similar habitats. These patterns reflect the role of natural selection in driving parallel adaptive changes when independent populations colonize similar habitats. Importantly, however, substantial nonparallelism was also evident. Our results show that analyses based on exchangeability can confirm inferences based on statistical analyses of means or frequencies, while also refining insights into the drivers of-and constraints on-evolutionary diversification.
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Affiliation(s)
- Andrew P Hendry
- Redpath Museum and Department of Biology, McGill University, 859 Sherbrooke St. W., Montreal, Quebec, Canada, H3A 0C4.
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Breno M, Bots J, Van Dongen S. Relationship between canalization and developmental stability of foetal rabbit limbs in two reproductive toxicological experiments. Biol J Linn Soc Lond 2013. [DOI: 10.1111/bij.12058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Matteo Breno
- Evolutionary Ecology Group; Department of Biology; University of Antwerp; Groenenborgerlaan 171 B-2020 Antwerp Belgium
| | - Jessica Bots
- Evolutionary Ecology Group; Department of Biology; University of Antwerp; Groenenborgerlaan 171 B-2020 Antwerp Belgium
| | - Stefan Van Dongen
- Evolutionary Ecology Group; Department of Biology; University of Antwerp; Groenenborgerlaan 171 B-2020 Antwerp Belgium
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35
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Breno M, Bots J, Van Dongen S. Between-family variation and quantitative genetics of developmental instability of long bones in rabbit foetuses. Biol J Linn Soc Lond 2013. [DOI: 10.1111/bij.12051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Matteo Breno
- Evolutionary Ecology Group; Department of Biology; University of Antwerp; Groenenborgerlaan 171; B-2020; Antwerp; Belgium
| | - Jessica Bots
- Evolutionary Ecology Group; Department of Biology; University of Antwerp; Groenenborgerlaan 171; B-2020; Antwerp; Belgium
| | - Stefan Van Dongen
- Evolutionary Ecology Group; Department of Biology; University of Antwerp; Groenenborgerlaan 171; B-2020; Antwerp; Belgium
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36
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Vercken E, Wellenreuther M, Svensson EI, Mauroy B. Don'T fall off the adaptation cliff: when asymmetrical fitness selects for suboptimal traits. PLoS One 2012; 7:e34889. [PMID: 22509364 PMCID: PMC3324540 DOI: 10.1371/journal.pone.0034889] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 03/07/2012] [Indexed: 11/19/2022] Open
Abstract
The cliff-edge hypothesis introduces the counterintuitive idea that the trait value associated with the maximum of an asymmetrical fitness function is not necessarily the value that is selected for if the trait shows variability in its phenotypic expression. We develop a model of population dynamics to show that, in such a system, the evolutionary stable strategy depends on both the shape of the fitness function around its maximum and the amount of phenotypic variance. The model provides quantitative predictions of the expected trait value distribution and provides an alternative quantity that should be maximized ("genotype fitness") instead of the classical fitness function ("phenotype fitness"). We test the model's predictions on three examples: (1) litter size in guinea pigs, (2) sexual selection in damselflies, and (3) the geometry of the human lung. In all three cases, the model's predictions give a closer match to empirical data than traditional optimization theory models. Our model can be extended to most ecological situations, and the evolutionary conditions for its application are expected to be common in nature.
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Affiliation(s)
- Elodie Vercken
- Institut Sophia Agrobiotech, UMR 1355 ISA, Institut National de la Recherche Agronomique, Sophia-Antipolis, France.
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Dalziel AC, Ou M, Schulte PM. Mechanisms underlying parallel reductions in aerobic capacity in non-migratory threespine stickleback (Gasterosteus aculeatus) populations. J Exp Biol 2012; 215:746-59. [DOI: 10.1242/jeb.065425] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
SUMMARY
Non-migratory, stream-resident populations of threespine stickleback, Gasterosteus aculeatus, have a lower maximum oxygen consumption (ṀO2,max) than ancestral migratory marine populations. Here, we examined laboratory-bred stream-resident and marine crosses from two locations (West and Bonsall Creeks) to determine which steps in the oxygen transport and utilization cascade evolved in conjunction with, and thus have the potential to contribute to, these differences in ṀO2,max. We found that West Creek stream-resident fish have larger muscle fibres (not measured in Bonsall fish), Bonsall Creek stream-resident fish have smaller ventricles, and both stream-resident populations have evolved smaller pectoral adductor and abductor muscles. However, many steps of the oxygen cascade did not evolve in stream-resident populations (gill surface area, hematocrit, mean cellular hemoglobin content and the activities of mitochondrial enzymes per gram ventricle and pectoral muscle), arguing against symmorphosis. We also studied F1 hybrids to determine which traits in the oxygen cascade have a genetic architecture similar to that of ṀO2,max. In West Creek, ṀO2,max, abductor and adductor size all showed dominance of marine alleles, whereas in Bonsall Creek, ṀO2,max and ventricle mass showed dominance of stream-resident alleles. We also found genetically based differences among marine populations in hematocrit, ventricle mass, pectoral muscle mass and pectoral muscle pyruvate kinase activity. Overall, reductions in pectoral muscle mass evolved in conjunction with reductions in ṀO2,max in both stream-resident populations, but the specific steps in the oxygen cascade that have a genetic basis similar to that of ṀO2,max, and are thus predicted to have the largest impact on ṀO2,max, differ among populations.
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Affiliation(s)
- Anne C. Dalziel
- Biodiversity Research Center and Department of Zoology, 6270 University Blvd, University of British Columbia, Vancouver, BC, CanadaV6T 1Z4
| | - Michelle Ou
- Biodiversity Research Center and Department of Zoology, 6270 University Blvd, University of British Columbia, Vancouver, BC, CanadaV6T 1Z4
| | - Patricia M. Schulte
- Biodiversity Research Center and Department of Zoology, 6270 University Blvd, University of British Columbia, Vancouver, BC, CanadaV6T 1Z4
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38
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Armbruster WS, Gong YB, Huang SQ. Are Pollination “Syndromes” Predictive? Asian Dalechampia Fit Neotropical Models. Am Nat 2011; 178:135-43. [DOI: 10.1086/660279] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Malcom JW. Gene networks and metacommunities: dispersal differences can override adaptive advantage. PLoS One 2011; 6:e21541. [PMID: 21738698 PMCID: PMC3125243 DOI: 10.1371/journal.pone.0021541] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Accepted: 06/03/2011] [Indexed: 11/18/2022] Open
Abstract
Dispersal is an important mechanism contributing to both ecological and evolutionary dynamics. In metapopulation and metacommunity ecology, dispersal enables new patches to be colonized; in evolution, dispersal counter-acts local selection, leading to regional homogenization. Here, I consider a three-patch metacommunity in which two species, each with a limiting quantitative trait underlain by gene networks of 16 to 256 genes, compete with one another and disperse among patches. Incorporating dispersal among heterogeneous patches introduces a tradeoff not observed in single-patch simulations: if the difference between gene network size of the two species is greater than the difference in dispersal ability (e.g., if the ratio of network sizes is larger than the ratio of dispersal abilities), then genetic architecture drives community outcome. However, if the difference in dispersal abilities is greater than gene network differences, then any adaptive advantages afforded by genetic architecture are over-ridden by dispersal. Thus, in addition to the selective pressures imposed by competition that shape the genetic architecture of quantitative traits, dispersal among patches creates an escape that may further alter the effects of different genetic architectures. These results provide a theoretical expectation for what we may observe as the field of ecological genomics develops.
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Affiliation(s)
- Jacob W Malcom
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, United States of America.
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40
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Malcom JW. Evolution of competitive ability: an adaptation speed vs. accuracy tradeoff rooted in gene network size. PLoS One 2011; 6:e14799. [PMID: 21541014 PMCID: PMC3081808 DOI: 10.1371/journal.pone.0014799] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Accepted: 03/11/2011] [Indexed: 11/19/2022] Open
Abstract
Ecologists have increasingly come to understand that evolutionary change on short time-scales can alter ecological dynamics (and vice-versa), and this idea is being incorporated into community ecology research programs. Previous research has suggested that the size and topology of the gene network underlying a quantitative trait should constrain or facilitate adaptation and thereby alter population dynamics. Here, I consider a scenario in which two species with different genetic architectures compete and evolve in fluctuating environments. An important trade-off emerges between adaptive accuracy and adaptive speed, driven by the size of the gene network underlying the ecologically-critical trait and the rate of environmental change. Smaller, scale-free networks confer a competitive advantage in rapidly-changing environments, but larger networks permit increased adaptive accuracy when environmental change is sufficiently slow to allow a species time to adapt. As the differences in network characteristics increase, the time-to-resolution of competition decreases. These results augment and refine previous conclusions about the ecological implications of the genetic architecture of quantitative traits, emphasizing a role of adaptive accuracy. Along with previous work, in particular that considering the role of gene network connectivity, these results provide a set of expectations for what we may observe as the field of ecological genomics develops.
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Affiliation(s)
- Jacob W Malcom
- Integrative Biology, University of Texas at Austin, Austin, Texas, United States of America.
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41
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Simons AM. Modes of response to environmental change and the elusive empirical evidence for bet hedging. Proc Biol Sci 2011; 278:1601-9. [PMID: 21411456 DOI: 10.1098/rspb.2011.0176] [Citation(s) in RCA: 253] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Uncertainty is a problem not only in human decision-making, but is a prevalent quality of natural environments and thus requires evolutionary response. Unpredictable natural selection is expected to result in the evolution of bet-hedging strategies, which are adaptations to long-term fluctuating selection. Despite a recent surge of interest in bet hedging, its study remains mired in conceptual and practical difficulties, compounded by confusion over what constitutes evidence for its existence. Here, I attempt to resolve misunderstandings about bet hedging and its relationship with other modes of response to environmental change, identify the challenges inherent to its study and assess the state of existing empirical evidence. The variety and distribution of plausible bet-hedging traits found across 16 phyla in over 100 studies suggest their ubiquity. Thus, bet hedging should be considered a specific mode of response to environmental change. However, the distribution of bet-hedging studies across evidence categories-defined according to potential strength-is heavily skewed towards weaker categories, underscoring the need for direct appraisals of the adaptive significance of putative bet-hedging traits in nature.
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Affiliation(s)
- Andrew M Simons
- Department of Biology, Carleton University, Ottawa, Ontario, Canada
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42
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LABRA ANTONIETA, VOJE KJETILL, SELIGMANN HERVÉ, HANSEN THOMASF. Evolution of the third eye: a phylogenetic comparative study of parietal-eye size as an ecophysiological adaptation in Liolaemus lizards. Biol J Linn Soc Lond 2010. [DOI: 10.1111/j.1095-8312.2010.01541.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abbott JK, Bedhomme S, Chippindale AK. Sexual conflict in wing size and shape in Drosophila melanogaster. J Evol Biol 2010; 23:1989-97. [PMID: 20695965 DOI: 10.1111/j.1420-9101.2010.02064.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Intralocus sexual conflict occurs when opposing selection pressures operate on loci expressed in both sexes, constraining the evolution of sexual dimorphism and displacing one or both sexes from their optimum. We eliminated intralocus conflict in Drosophila melanogaster by limiting transmission of all major chromosomes to males, thereby allowing them to win the intersexual tug-of-war. Here, we show that this male-limited (ML) evolution treatment led to the evolution (in both sexes) of masculinized wing morphology, body size, growth rate, wing loading, and allometry. In addition to more male-like size and shape, ML evolution resulted in an increase in developmental stability for males. However, females expressing ML chromosomes were less developmentally stable, suggesting that being ontogenetically more male-like was disruptive to development. We suggest that sexual selection over size and shape of the imago may therefore explain the persistence of substantial genetic variation in these characters and the ontogenetic processes underlying them.
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Affiliation(s)
- J K Abbott
- Department of Biology, Queen's University, Kingston, Ontario, Canada
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Abstract
Local adaptation is considered to be the result of fitness trade-offs for particular phenotypes across different habitats. However, it is unclear whether such phenotypic trade-offs exist at the level of individual genetic loci. Local adaptation could arise from trade-offs of alternative alleles at individual loci or by complementary sets of loci with different fitness effects of alleles in one habitat but selective neutrality in the alternative habitat. To evaluate the genome-wide basis of local adaptation, we performed a field-based quantitative trait locus (QTL) mapping experiment on recombinant inbred lines (RILs) created from coastal perennial and inland annual races of the yellow monkeyflower (Mimulus guttatus) grown reciprocally in native parental habitats. Overall, we detected 19 QTLs affecting one or more of 16 traits measured in two environments, most of small effect. We identified 15 additional QTL effects at two previously identified candidate QTLs [DIVERGENCE (DIV)]. Significant QTL by environment interactions were detected at the DIV loci, which was largely attributable to genotypic differences at a single field site. We found no detectable evidence for trade-offs for any one component of fitness, although DIV2 showed a trade-off involving different fitness traits between sites, suggesting that local adaptation is largely controlled by non-overlapping loci. This is surprising for an outcrosser, implying that reduced gene flow prevents the evolution of individuals adapted to multiple environments. We also determined that native genotypes were not uniformly adaptive, possibly reflecting fixed mutational load in one of the populations.
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Affiliation(s)
- M C Hall
- Department of Molecular and Cell Biology, Energy Biosciences Institute, 545 Life Sciences Addition, University of California-Berkeley, Berkeley, CA 94720-3200, USA.
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Peiman KS, Robinson BW. Ecology and Evolution of Resource-Related Heterospecific Aggression. QUARTERLY REVIEW OF BIOLOGY 2010; 85:133-58. [PMID: 20565037 DOI: 10.1086/652374] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Kathryn S Peiman
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California 90095-1606, USA.
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Pélabon C, Hansen TF, Carter AJR, Houle D. Evolution of variation and variability under fluctuating, stabilizing, and disruptive selection. Evolution 2010; 64:1912-25. [PMID: 20199560 DOI: 10.1111/j.1558-5646.2010.00979.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
How variation and variability (the capacity to vary) may respond to selection remain open questions. Indeed, effects of different selection regimes on variational properties, such as canalization and developmental stability are under debate. We analyzed the patterns of among- and within-individual variation in two wing-shape characters in populations of Drosophila melanogaster maintained under fluctuating, disruptive, and stabilizing selection for more than 20 generations. Patterns of variation in wing size, which was not a direct target of selection, were also analyzed. Disruptive selection dramatically increased phenotypic variation in the two shape characters, but left phenotypic variation in wing size unaltered. Fluctuating and stabilizing selection consistently decreased phenotypic variation in all traits. In contrast, within-individual variation, measured by the level of fluctuating asymmetry, increased for all traits under all selection regimes. These results suggest that canalization and developmental stability are evolvable and presumably controlled by different underlying genetic mechanisms, but the evolutionary responses are not consistent with an adaptive response to selection on variation. Selection also affected patterns of directional asymmetry, although inconsistently across traits and treatments.
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Affiliation(s)
- Christophe Pélabon
- Department of Biology, Center for Conservation Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
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48
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Fierst JL, Hansen TF. Genetic architecture and postzygotic reproductive isolation: evolution of Bateson-Dobzhansky-Muller incompatibilities in a polygenic model. Evolution 2009; 64:675-93. [PMID: 19817852 DOI: 10.1111/j.1558-5646.2009.00861.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The Bateson-Dobzhansky-Muller model predicts that postzygotic isolation evolves due to the accumulation of incompatible epistatic interactions, but few studies have quantified the relationship between genetic architecture and patterns of reproductive divergence. We examined how the direction and magnitude of epistatic interactions in a polygenic trait under stabilizing selection influenced the evolution of hybrid incompatibilities. We found that populations evolving independently under stabilizing selection experienced suites of compensatory allelic changes that resulted in genetic divergence between populations despite the maintenance of a stable, high-fitness phenotype. A small number of loci were then incompatible with multiple alleles in the genetic background of the hybrid and the identity of these incompatibility loci changed over the evolution of the populations. For F(1) hybrids, reduced fitness evolved in a window of intermediate strengths of epistatic interactions, but F(2) and backcross hybrids evolved reduced fitness across weak and moderate strengths of epistasis due to segregation variance. Strong epistatic interactions constrained the allelic divergence of parental populations and prevented the development of reproductive isolation. Because many traits with varying genetic architectures must be under stabilizing selection, our results indicate that polygenetic drift is a plausible hypothesis for the evolution of postzygotic reproductive isolation.
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Affiliation(s)
- Janna L Fierst
- Center for Ecological and Evolutionary Synthesis, Department of Biology, University of Oslo, 0316 Oslo, Norway.
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Armbruster WS, Pélabon C, Hansen TF, Bolstad GH. Macroevolutionary patterns of pollination accuracy: a comparison of three genera. THE NEW PHYTOLOGIST 2009; 183:600-617. [PMID: 19594697 DOI: 10.1111/j.1469-8137.2009.02930.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We hypothesize that pollination efficiency selects for equal distances between the pollinator reward and the anthers, and the stigmas, creating an adaptive ridge. We predict that this fitness surface governs the divergence of many plant species. We use the theory of adaptive accuracy, precision and mean optimality to assess how close populations lie to the hypothesized adaptive ridge and which factors contribute to departure from the optimum. Patterns of accuracy of pollen placement and receipt were compared across species in three study systems, Dalechampia (Euphorbiaceae), Collinsieae (Plantaginaceae) and Stylidium (Stylidiaceae), in order to assess the roles of stamen/stigma imprecision and population mean departure from the optimum in the generation of floral inaccuracy. We found that population mean departure from the optimum was the most important factor in Dalechampia, female imprecision and departure from the optimum were about equally important factors in Collinsieae, and stamen and stigma imprecision were equally important in Stylidium, with virtually no departure from the optimum. Possible reasons for imprecision and departure from the optimum were assessed using phylogenetically informed methods, indicating important roles of limited floral integration in the generation of imprecision, and conflicting selective pressures, associated with outcrossing, in the generation of departure from the optimum.
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Affiliation(s)
- W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, Portsmouth PO1 2DY, UK
- Department of Biology, NTNU, N-7491, Trondheim, Norway
- Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775, USA
| | - Christophe Pélabon
- Centre for Conservation Biology, Department of Biology, NTNU, N-7491, Trondheim, Norway
| | - Thomas F Hansen
- Centre for Ecological and Evolutionary Synthesis, Department of Biology, University of Oslo, PO Box 1066, N-0316 Oslo, Norway
| | - Geir H Bolstad
- Centre for Conservation Biology, Department of Biology, NTNU, N-7491, Trondheim, Norway
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Fenster CB, Armbruster WS, Dudash MR. Specialization of flowers: is floral orientation an overlooked first step? THE NEW PHYTOLOGIST 2009; 183:502-506. [PMID: 19422542 DOI: 10.1111/j.1469-8137.2009.02852.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Affiliation(s)
- Charles B Fenster
- Mountain Lake Biological Station, University of Virginia, Pembroke, VA, 24136, USA
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
| | - W Scott Armbruster
- School of Biological Sciences, University of Portsmouth, King Henry Building, Portsmouth, PO1 2DY, UK
- Institute of Arctic Biology, University of Alaska, Fairbanks, AK 99775, USA
- Department of Biology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | - Michele R Dudash
- Mountain Lake Biological Station, University of Virginia, Pembroke, VA, 24136, USA
- Department of Biology, University of Maryland, College Park, MD, 20742, USA
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