1
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Sinclair BJ, Saruhashi S, Terblanche JS. Integrating water balance mechanisms into predictions of insect responses to climate change. J Exp Biol 2024; 227:jeb247167. [PMID: 38779934 DOI: 10.1242/jeb.247167] [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] [Indexed: 05/25/2024]
Abstract
Efficient water balance is key to insect success. However, the hygric environment is changing with climate change; although there are compelling models of thermal vulnerability, water balance is often neglected in predictions. Insects survive desiccating conditions by reducing water loss, increasing their total amount of water (and replenishing it) and increasing their tolerance of dehydration. The physiology underlying these traits is reasonably well understood, as are the sources of variation and phenotypic plasticity. However, water balance and thermal tolerance intersect at high temperatures, such that mortality is sometimes determined by dehydration, rather than heat (especially during long exposures in dry conditions). Furthermore, water balance and thermal tolerance sometimes interact to determine survival. In this Commentary, we propose identifying a threshold where the cause of mortality shifts between dehydration and temperature, and that it should be possible to predict this threshold from trait measurements (and perhaps eventually a priori from physiological or -omic markers).
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Affiliation(s)
- Brent J Sinclair
- Department of Biology, Western University, London, ON, CanadaN6A 5B7
| | - Stefane Saruhashi
- Department of Biology, Western University, London, ON, CanadaN6A 5B7
| | - John S Terblanche
- Department of Conservation Ecology & Entomology, Faculty of AgriSciences, Stellenbosch University, Matieland 7602, South Africa
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2
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Van Baelen M, Bec A, Sperfeld E, Frizot N, Koussoroplis AM. Food quality shapes gradual phenotypic plasticity in ectotherms facing temperature variability. Ecology 2024; 105:e4263. [PMID: 38385889 DOI: 10.1002/ecy.4263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 11/06/2023] [Accepted: 12/21/2023] [Indexed: 02/23/2024]
Abstract
Organisms exhibit reversible physiological adjustments as a response to rapidly changing environments. Yet such plasticity of the phenotype is gradual and may lag behind environmental fluctuations, thereby affecting long-term average performance of the organisms. By supplying energy and essential compounds for optimal tissue building, food determines the range of possible phenotypic changes and potentially the rate at which they occur. Here, we assess how differences in the dietary supply of essential lipids modulate the phenotypic plasticity of an ectotherm facing thermal fluctuations. We use three phytoplankton strains to create a gradient of polyunsaturated fatty acid and sterol supply for Daphnia magna under constant and fluctuating temperatures. We used three different fluctuation periodicities to unravel the temporal dynamics of gradual plasticity and its long-term consequences for D. magna performance measured as juvenile somatic growth rate. In agreement with gradual plasticity theory, we show that in D. magna, fluctuation periodicity determines the differential between observed growth rates and those expected from constant conditions. Most importantly, we show that diet modulates both the size and the direction of the growth rate differential. Overall, we demonstrate that the nutritional context is essential for predicting ectotherm consumers' performance in fluctuating thermal environments.
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Affiliation(s)
- Marine Van Baelen
- Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome Environnement, Clermont-Ferrand, France
| | - Alexandre Bec
- Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome Environnement, Clermont-Ferrand, France
| | - Erik Sperfeld
- University of Greifswald, Zoological Institute and Museum, Greifswald, Germany
| | - Nathan Frizot
- Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome Environnement, Clermont-Ferrand, France
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3
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Arif S, Massey MDB. Reducing bias in experimental ecology through directed acyclic graphs. Ecol Evol 2023; 13:e9947. [PMID: 37006894 PMCID: PMC10050842 DOI: 10.1002/ece3.9947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/10/2023] [Accepted: 03/12/2023] [Indexed: 03/31/2023] Open
Abstract
Ecologists often rely on randomized control trials (RCTs) to quantify causal relationships in nature. Many of our foundational insights of ecological phenomena can be traced back to well‐designed experiments, and RCTs continue to provide valuable insights today. Although RCTs are often regarded as the “gold standard” for causal inference, it is important to recognize that they too rely on a set of causal assumptions that must be justified and met by the researcher to draw valid causal conclusions. We use key ecological examples to show how biases such as confounding, overcontrol, and collider bias can occur in experimental setups. In tandem, we highlight how such biases can be removed through the application of the structural causal model (SCM) framework. The SCM framework visualizes the causal structure of a system or process under study using directed acyclic graphs (DAGs) and subsequently applies a set of graphical rules to remove bias from both observational and experimental data. We show how DAGs can be applied across ecological experimental studies to ensure proper study design and statistical analysis, leading to more accurate causal estimates drawn from experimental data. Although causal conclusions drawn from RCTs are often taken at face value, ecologists are increasingly becoming aware that experimental approaches must be carefully designed and analyzed to avoid potential biases. By applying DAGs as a visual and conceptual tool, experimental ecologists can increasingly meet the causal assumptions required for valid causal inference.
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Affiliation(s)
- Suchinta Arif
- Department of BiologyDalhousie University1355 Oxford StreetHalifaxNova ScotiaB3H 4R2Canada
| | - Melanie Duc Bo Massey
- Department of BiologyDalhousie University1355 Oxford StreetHalifaxNova ScotiaB3H 4R2Canada
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4
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Siegel P, Baker KG, Low‐Décarie E, Geider RJ. Phytoplankton competition and resilience under fluctuating temperature. Ecol Evol 2023; 13:e9851. [PMID: 36950368 PMCID: PMC10025077 DOI: 10.1002/ece3.9851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 01/03/2023] [Accepted: 02/02/2023] [Indexed: 03/21/2023] Open
Abstract
Environmental variability is an inherent feature of natural systems which complicates predictions of species interactions. Primarily, the complexity in predicting the response of organisms to environmental fluctuations is in part because species' responses to abiotic factors are non-linear, even in stable conditions. Temperature exerts a major control over phytoplankton growth and physiology, yet the influence of thermal fluctuations on growth and competition dynamics is largely unknown. To investigate the limits of coexistence in variable environments, stable mixed cultures with constant species abundance ratios of the marine diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana, were exposed to different temperature fluctuation regimes (n = 17) under high and low nitrogen (N) conditions. Here we demonstrate that phytoplankton exhibit substantial resilience to temperature variability. The time required to observe a shift in the species abundance ratio decreased with increasing fluctuations, but coexistence of the two model species under high N conditions was disrupted only when amplitudes of temperature fluctuation were high (±8.2°C). N limitation caused the thermal amplitude for disruption of species coexistence to become lower (±5.9°C). Furthermore, once stable conditions were reinstated, the two species differed in their ability to recover from temperature fluctuations. Our findings suggest that despite the expectation of unequal effect of fluctuations on different competitors, cycles in environmental conditions may reduce the rate of species replacement when amplitudes remain below a certain threshold. Beyond these thresholds, competitive exclusion could, however, be accelerated, suggesting that aquatic heatwaves and N availability status are likely to lead to abrupt and unpredictable restructuring of phytoplankton community composition.
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Affiliation(s)
- Philipp Siegel
- School of Life SciencesUniversity of Essex Colchester CampusColchesterUK
| | - Kirralee G. Baker
- School of Life SciencesUniversity of Essex Colchester CampusColchesterUK
- Present address:
Institute for Marine and Antarctic StudiesUniversity of TasmaniaBattery PointTasmaniaAustralia
| | - Etienne Low‐Décarie
- School of Life SciencesUniversity of Essex Colchester CampusColchesterUK
- Present address:
Biological Informatics Center of Expertise, Agriculture and Agrifoods Canada, Government of CanadaMontrealQuebecCanada
| | - Richard J. Geider
- School of Life SciencesUniversity of Essex Colchester CampusColchesterUK
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5
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Rindi L, He J, Benedetti‐Cecchi L. Spatial correlation reverses the compound effect of multiple stressors on rocky shore biofilm. Ecol Evol 2022; 12:e9418. [PMID: 36311394 PMCID: PMC9608791 DOI: 10.1002/ece3.9418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/11/2022] [Accepted: 09/19/2022] [Indexed: 12/01/2022] Open
Abstract
Understanding how multifactorial fluctuating environments affect species and communities remains one of the major challenges in ecology. The spatial configuration of the environment is known to generate complex patterns of correlation among multiple stressors. However, to what extent the spatial correlation between simultaneously fluctuating variables affects ecological assemblages in real‐world conditions remains poorly understood. Here, we use field experiments and simulations to assess the influence of spatial correlation of two relevant climate variables – warming and sediment deposition following heavy precipitation – on the biomass and photosynthetic activity of rocky intertidal biofilm. First, we used a response‐surface design experiment to establish the relation between biofilm, warming, and sediment deposition in the field. Second, we used the response surface to generate predictions of biofilm performance under different scenarios of warming and sediment correlation. Finally, we tested the predicted outcomes by manipulating the degree of correlation between the two climate variables in a second field experiment. Simulations stemming from the experimentally derived response surface showed how the degree and direction (positive or negative) of spatial correlation between warming and sediment deposition ultimately determined the nonlinear response of biofilm biomass (but not photosynthetic activity) to fluctuating levels of the two climate variables. Experimental results corroborated these predictions, probing the buffering effect of negative spatial correlation against extreme levels of warming and sediment deposition. Together, these results indicate that consideration of nonlinear response functions and local‐scale patterns of correlation between climate drivers can improve our understanding and ability to predict ecological responses to multiple processes in heterogeneous environments.
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Affiliation(s)
- Luca Rindi
- Department of BiologyUniversity of Pisa, CoNISMaPisaItaly
| | - Jianyu He
- Department of BiologyUniversity of Pisa, CoNISMaPisaItaly
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6
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Theus ME, Layden TJ, McWilliams N, Crafton‐Tempel S, Kremer CT, Fey SB. Photoperiod influences the shape and scaling of freshwater phytoplankton responses to light and temperature. OIKOS 2022. [DOI: 10.1111/oik.08839] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
| | | | | | | | - Colin T. Kremer
- Dept of Ecology and Evolutionary Biology, Univ. of California Los Angeles Los Angeles CA USA
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7
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Hintz NH, Schulze B, Wacker A, Striebel M. Ecological impacts of photosynthetic light harvesting in changing aquatic environments: A systematic literature map. Ecol Evol 2022; 12:e8753. [PMID: 35356568 PMCID: PMC8939368 DOI: 10.1002/ece3.8753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 01/07/2023] Open
Abstract
Underwater light is spatially as well as temporally variable and directly affects phytoplankton growth and competition. Here we systematically (following the guidelines of PRISMA‐EcoEvo) searched and screened the published literature resulting in 640 individual articles. We mapped the conducted research for the objectives of (1) phytoplankton fundamental responses to light, (2) effects of light on the competition between phytoplankton species, and (3) effects of climate‐change‐induced changes in the light availability in aquatic ecosystems. Among the fundamental responses of phytoplankton to light, the effects of light intensity (quantity, as measure of total photon or energy flux) were investigated in most identified studies. The effects of the light spectrum (quality) that via species‐specific light absorbance result in direct consequences on species competition emerged more recently. Complexity in competition arises due to variability and fluctuations in light which effects are sparsely investigated on community level. Predictions regarding future climate change scenarios included changes in in stratification and mixing, lake and coastal ocean darkening, UV radiation, ice melting as well as light pollution which affect the underwater light‐climate. Generalization of consequences is difficult due to a high variability, interactions of consequences as well as a lack in sustained timeseries and holistic approaches. Nevertheless, our systematic literature map, and the identified articles within, provide a comprehensive overview and shall guide prospective research.
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Affiliation(s)
- Nils Hendrik Hintz
- Institute for Chemistry and Biology of the Marine Environment (ICBM) Carl von Ossietzky University of Oldenburg Wilhelmshaven Germany
| | - Brian Schulze
- Zoological Institute and Museum University of Greifswald Greifswald Germany
| | - Alexander Wacker
- Zoological Institute and Museum University of Greifswald Greifswald Germany
| | - Maren Striebel
- Institute for Chemistry and Biology of the Marine Environment (ICBM) Carl von Ossietzky University of Oldenburg Wilhelmshaven Germany
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8
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Denny MW, Dowd WW. Physiological Consequences of Oceanic Environmental Variation: Life from a Pelagic Organism's Perspective. ANNUAL REVIEW OF MARINE SCIENCE 2022; 14:25-48. [PMID: 34314598 DOI: 10.1146/annurev-marine-040221-115454] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
To better understand life in the sea, marine scientists must first quantify how individual organisms experience their environment, and then describe how organismal performance depends on that experience. In this review, we first explore marine environmental variation from the perspective of pelagic organisms, the most abundant life forms in the ocean. Generation time, the ability to move relative to the surrounding water (even slowly), and the presence of environmental gradients at all spatial scales play dominant roles in determining the variation experienced by individuals, but this variation remains difficult to quantify. We then use this insight to critically examine current understanding of the environmental physiology of pelagic marine organisms. Physiologists have begun to grapple with the complexity presented by environmental variation, and promising frameworks exist for predicting and/or interpreting the consequences for physiological performance. However, new technology needs to be developed and much difficult empirical work remains, especially in quantifying response times to environmental variation and the interactions among multiple covarying factors. We call on the field of global-change biology to undertake these important challenges.
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Affiliation(s)
- Mark W Denny
- Hopkins Marine Station, Stanford University, Pacific Grove, California 93950, USA;
| | - W Wesley Dowd
- School of Biological Sciences, Washington State University, Pullman, Washington 99164, USA;
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9
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Wacker A, Harzsch S. Crustaceans in a changing world. ZOOLOGY 2021; 146:125921. [PMID: 33773397 DOI: 10.1016/j.zool.2021.125921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 03/08/2021] [Indexed: 02/08/2023]
Affiliation(s)
- Alexander Wacker
- University of Greifswald, Zoological Institute and Museum, Department of Animal Ecology, D-17489, Greifswald, Germany.
| | - Steffen Harzsch
- Department of Cytology and Evolutionary Biology, D-17489, Greifswald, Germany.
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10
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Ma CS, Ma G, Pincebourde S. Survive a Warming Climate: Insect Responses to Extreme High Temperatures. ANNUAL REVIEW OF ENTOMOLOGY 2021; 66:163-184. [PMID: 32870704 DOI: 10.1146/annurev-ento-041520-074454] [Citation(s) in RCA: 117] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Global change includes a substantial increase in the frequency and intensity of extreme high temperatures (EHTs), which influence insects at almost all levels. The number of studies showing the ecological importance of EHTs has risen in recent years, but the knowledge is rather dispersed in the contemporary literature. In this article, we review the biological and ecological effects of EHTs actually experienced in the field, i.e., when coupled to fluctuating thermal regimes. First, we characterize EHTs in the field. Then, we summarize the impacts of EHTs on insects at various levels and the processes allowing insects to buffer EHTs. Finally, we argue that the mechanisms leading to positive or negative impacts of EHTs on insects can only be resolved from integrative approaches considering natural thermal regimes. Thermal extremes, perhaps more than the gradual increase in mean temperature, drive insect responses to climate change, with crucial impacts on pest management and biodiversity conservation.
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Affiliation(s)
- Chun-Sen Ma
- Climate Change Biology Research Group, State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; ,
| | - Gang Ma
- Climate Change Biology Research Group, State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; ,
| | - Sylvain Pincebourde
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS, Université de Tours, 37200 Tours, France;
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11
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Lear KO, Morgan DL, Whitty JM, Beatty SJ, Gleiss AC. Wet season flood magnitude drives resilience to dry season drought of a euryhaline elasmobranch in a dry-land river. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 750:142234. [PMID: 33182167 DOI: 10.1016/j.scitotenv.2020.142234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 06/11/2023]
Abstract
The increase in severity and occurrence of drought from environmental change poses a significant threat to freshwater ecosystems. However, many of the mechanisms by which periodic drought affects aquatic animals are poorly understood. Here we integrated physical, physiological, and behavioural measurements made in the field over a twelve-year period to provide a comprehensive understanding of the factors affecting the loss of body condition of fish in arid rivers, using the Critically Endangered freshwater sawfish (Pristis pristis) in the dryland Fitzroy River, Western Australia, as a model species. Sawfish lost condition throughout the long dry season in all years and had significantly poorer body condition throughout years characterized by low volumes of wet season flooding and little occurrence of overbank flooding. A mechanistic examination of factors leading to this loss of condition using measurements of body temperature, field energetics, and habitat use from telemetry techniques showed that the loss of condition throughout the season was likely due to substantial habitat compression and low productivity in drier years, while high rates of competition were more likely to drive this pattern in wetter years. This information can be used to forecast how climate change and water abstraction will affect aquatic fauna experiencing intermittent drought and can inform management decisions to help mitigate these threats.
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Affiliation(s)
- Karissa O Lear
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia; Environmental and Conservation Sciences, College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia.
| | - David L Morgan
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia
| | - Jeff M Whitty
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia
| | - Stephen J Beatty
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia
| | - Adrian C Gleiss
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia; Environmental and Conservation Sciences, College of Science, Health, Engineering and Education, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia
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12
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Cavieres G, Rezende EL, Clavijo‐Baquet S, Alruiz JM, Rivera‐Rebella C, Boher F, Bozinovic F. Rapid within- and transgenerational changes in thermal tolerance and fitness in variable thermal landscapes. Ecol Evol 2020; 10:8105-8113. [PMID: 32788964 PMCID: PMC7417229 DOI: 10.1002/ece3.6496] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 05/30/2020] [Accepted: 06/02/2020] [Indexed: 12/20/2022] Open
Abstract
Phenotypic plasticity may increase the performance and fitness and allow organisms to cope with variable environmental conditions. We studied within-generation plasticity and transgenerational effects of thermal conditions on temperature tolerance and demographic parameters in Drosophila melanogaster. We employed a fully factorial design, in which both parental (P) and offspring generations (F1) were reared in a constant or a variable thermal environment. Thermal variability during ontogeny increased heat tolerance in P, but with demographic cost as this treatment resulted in substantially lower survival, fecundity, and net reproductive rate. The adverse effects of thermal variability (V) on demographic parameters were less drastic in flies from the F1, which exhibited higher net reproductive rates than their parents. These compensatory responses could not totally overcome the challenges of the thermally variable regime, contrasting with the offspring of flies raised in a constant temperature (C) that showed no reduction in fitness with thermal variation. Thus, the parental thermal environment had effects on thermal tolerance and demographic parameters in fruit fly. These results demonstrate how transgenerational effects of environmental conditions on heat tolerance, as well as their potential costs on other fitness components, can have a major impact on populations' resilience to warming temperatures and more frequent thermal extremes.
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Affiliation(s)
- Grisel Cavieres
- Departamento de EcologíaCenter of Applied Ecology and Sustainability (CAPES)Pontificia Universidad Católica de ChileSantiagoChile
| | - Enrico L. Rezende
- Departamento de EcologíaCenter of Applied Ecology and Sustainability (CAPES)Pontificia Universidad Católica de ChileSantiagoChile
| | | | - José M. Alruiz
- Departamento de EcologíaCenter of Applied Ecology and Sustainability (CAPES)Pontificia Universidad Católica de ChileSantiagoChile
| | - Carla Rivera‐Rebella
- Departamento de EcologíaCenter of Applied Ecology and Sustainability (CAPES)Pontificia Universidad Católica de ChileSantiagoChile
| | - Francisca Boher
- Departamento de EcologíaCenter of Applied Ecology and Sustainability (CAPES)Pontificia Universidad Católica de ChileSantiagoChile
| | - Francisco Bozinovic
- Departamento de EcologíaCenter of Applied Ecology and Sustainability (CAPES)Pontificia Universidad Católica de ChileSantiagoChile
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13
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Dillon ME, Lozier JD. Adaptation to the abiotic environment in insects: the influence of variability on ecophysiology and evolutionary genomics. CURRENT OPINION IN INSECT SCIENCE 2019; 36:131-139. [PMID: 31698151 DOI: 10.1016/j.cois.2019.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/10/2019] [Accepted: 09/10/2019] [Indexed: 06/10/2023]
Abstract
Advances in tools to gather environmental, phenotypic, and molecular data have accelerated our ability to detect abiotic drivers of variation across the genome-to-phenome spectrum in model and non-model insects. However, differences in the spatial and temporal resolution of these data sets may create gaps in our understanding of linkages between environment, genotype, and phenotype that yield missed or misleading results about adaptive variation. In this review we highlight sources of variability that might impact studies of phenotypic and 'omic environmental adaptation, challenges to collecting data at relevant scales, and possible solutions that link intensive fine-scale reductionist studies of mechanisms to large-scale biogeographic patterns.
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Affiliation(s)
- Michael E Dillon
- Department of Zoology & Physiology and Program in Ecology, The University of Wyoming, Laramie, Wyoming 82071, USA.
| | - Jeffrey D Lozier
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, Alabama 35487, USA
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14
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Denny M. Performance in a variable world: using Jensen's inequality to scale up from individuals to populations. CONSERVATION PHYSIOLOGY 2019; 7:coz053. [PMID: 31528348 PMCID: PMC6736373 DOI: 10.1093/conphys/coz053] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 06/07/2019] [Accepted: 07/05/2019] [Indexed: 05/06/2023]
Abstract
Body temperature affects plants' and animals' performance, but these effects are complicated by thermal variation through time within an individual and variation through space among individuals in a population. This review and synthesis describes how the effects of thermal variation-in both time and space-can be estimated by applying a simple, nonlinear averaging scheme. The method is first applied to the temporal variation experienced by an individual, providing an estimate of the individual's average performance. The method is then applied to the scale-dependent thermal variation among individuals, which is modelled as a 1/f-noise phenomenon. For an individual, thermal variation reduces average performance, lowers the temperature of maximum performance (Topt ) and contracts the range of viable temperatures. Thermal variation among individuals similarly reduces performance and lowers Topt , but increases the viable range of average temperatures. These results must be viewed with caution, however, because they do not take into account the time-dependent interaction between body temperature and physiological plasticity. Quantifying these interactions is perhaps the largest challenge for ecological and conservation physiologists as they attempt to predict the effects of climate change.
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Affiliation(s)
- Mark Denny
- Hopkins Marine Station of Stanford University, 120 Ocean View Blvd., Pacific Grove, California, 93950 USA
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15
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Rozen‐Rechels D, Dupoué A, Lourdais O, Chamaillé‐Jammes S, Meylan S, Clobert J, Le Galliard J. When water interacts with temperature: Ecological and evolutionary implications of thermo-hydroregulation in terrestrial ectotherms. Ecol Evol 2019; 9:10029-10043. [PMID: 31534711 PMCID: PMC6745666 DOI: 10.1002/ece3.5440] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 06/17/2019] [Indexed: 02/06/2023] Open
Abstract
The regulation of body temperature (thermoregulation) and of water balance (defined here as hydroregulation) are key processes underlying ecological and evolutionary responses to climate fluctuations in wild animal populations. In terrestrial (or semiterrestrial) ectotherms, thermoregulation and hydroregulation closely interact and combined temperature and water constraints should directly influence individual performances. Although comparative physiologists traditionally investigate jointly water and temperature regulation, the ecological and evolutionary implications of these coupled processes have so far mostly been studied independently. Here, we revisit the concept of thermo-hydroregulation to address the functional integration of body temperature and water balance regulation in terrestrial ectotherms. We demonstrate how thermo-hydroregulation provides a framework to investigate functional adaptations to joint environmental variation in temperature and water availability, and potential physiological and/or behavioral conflicts between thermoregulation and hydroregulation. We extend the classical cost-benefit model of thermoregulation in ectotherms to highlight the adaptive evolution of optimal thermo-hydroregulation strategies. Critical gaps in the parameterization of this conceptual optimality model and guidelines for future empirical research are discussed. We show that studies of thermo-hydroregulation refine our mechanistic understanding of physiological and behavioral plasticity, and of the fundamental niche of the species. This is illustrated with relevant and recent examples of space use and dispersal, resource-based trade-offs, and life-history tactics in insects, amphibians, and nonavian reptiles.
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Affiliation(s)
- David Rozen‐Rechels
- Sorbonne Université, UPEC, CNRS, IRD INRAInstitut d'Écologie et des Sciences de l'Environnement, IEESParisFrance
| | - Andréaz Dupoué
- UMR 5321 CNRS-Université Toulouse III Paul SabatierStation d'Écologie Théorique et ExpérimentaleMoulisFrance
| | - Olivier Lourdais
- UMR 7372 CNRS-ULRCentre d'Études Biologiques de ChizéVilliers en BoisFrance
- School of Life SciencesArizona State UniversityTempeAZUSA
| | - Simon Chamaillé‐Jammes
- CNRS, Univ Montpellier, EPHE, IRD, Univ Paul Valéry Montpellier 3Centre d'Écologie Fonctionnelle et ÉvolutiveMontpellierFrance
| | - Sandrine Meylan
- Sorbonne Université, UPEC, CNRS, IRD INRAInstitut d'Écologie et des Sciences de l'Environnement, IEESParisFrance
- Sorbonne UniversitéESPE de ParisParisFrance
| | - Jean Clobert
- UMR 5321 CNRS-Université Toulouse III Paul SabatierStation d'Écologie Théorique et ExpérimentaleMoulisFrance
| | - Jean‐François Le Galliard
- Sorbonne Université, UPEC, CNRS, IRD INRAInstitut d'Écologie et des Sciences de l'Environnement, IEESParisFrance
- École normale supérieure, CNRS, UMS 3194Centre de recherche en écologie expérimentale et prédictive (CEREEP‐Ecotron IleDeFrance), Département de biologiePSL Research UniversitySaint‐Pierre‐lès‐NemoursFrance
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16
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Gerhard M, Koussoroplis AM, Hillebrand H, Striebel M. Phytoplankton community responses to temperature fluctuations under different nutrient concentrations and stoichiometry. Ecology 2019; 100:e02834. [DOI: 10.1002/ecy.2834] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 06/25/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Miriam Gerhard
- Institute for Chemistry and Biology of the Marine Environment (ICBM) University of Oldenburg, Schleusenstrsse 1, 26382 Wilhelmshaven Germany
| | - Apostolos Manuel Koussoroplis
- Laboratoire Microorganismes Génome et Environnement (LMGE) UMR CNRS 6023 Université Clermont Auvergne, 1 ImpasseAmélie Murat, F‐63178 Aubière cedex France
- Theoretical Aquatic Ecology and Ecophysiology Group Institute of Biochemistry and Biology University of Potsdam, Am Neuen Palais 10, Maulbeerallee 2, D‐14469 Potsdam Germany
| | - Helmut Hillebrand
- Institute for Chemistry and Biology of the Marine Environment (ICBM) University of Oldenburg, Schleusenstrsse 1, 26382 Wilhelmshaven Germany
- Helmholtz Institute for Functional Marine Biodiversity (HIFMB) University of Oldenburg, Ammerländer Heerstraße 231, 26129 Oldenburg Germany
| | - Maren Striebel
- Institute for Chemistry and Biology of the Marine Environment (ICBM) University of Oldenburg, Schleusenstrsse 1, 26382 Wilhelmshaven Germany
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17
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Zeis B, Buchen I, Wacker A, Martin-Creuzburg D. Temperature-induced changes in body lipid composition affect vulnerability to oxidative stress in Daphnia magna. Comp Biochem Physiol B Biochem Mol Biol 2019; 232:101-107. [DOI: 10.1016/j.cbpb.2019.03.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 03/11/2019] [Accepted: 03/15/2019] [Indexed: 10/27/2022]
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18
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Koussoroplis AM, Schälicke S, Raatz M, Bach M, Wacker A. Feeding in the frequency domain: coarser-grained environments increase consumer sensitivity to resource variability, covariance and phase. Ecol Lett 2019; 22:1104-1114. [PMID: 31016844 DOI: 10.1111/ele.13267] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/10/2019] [Accepted: 03/19/2019] [Indexed: 11/28/2022]
Abstract
Theory predicts that resource variability hinders consumer performance. How this effect depends on the temporal structure of resource fluctuations encountered by individuals remains poorly understood. Combining modelling and growth experiments with Daphnia magna, we decompose the complexity of resource fluctuations and test the effect of resource variance, supply peak timing (i.e. phase) and co-limiting resource covariance along a gradient from high to low frequencies reflecting fine- to coarse-grained environments. Our results show that resource storage can buffer growth at high frequencies, but yields a sensitivity of growth to resource peak timing at lower ones. When two resources covary, negative covariance causes stronger growth depression at low frequencies. However, negative covariance might be beneficial at intermediate frequencies, an effect that can be explained by digestive acclimation. Our study provides a mechanistic basis for understanding how alterations of the environmental grain size affect consumers experiencing variable nutritional quality in nature.
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Affiliation(s)
- Apostolos-Manuel Koussoroplis
- Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Aquatic Food Web Interactions group (I.R.T.A), Microorganisms Genome and Environment Lab (L.M.G.E.), UMR CNRS 6023, Université Clermont Auvergne, Aubière, France
| | - Svenja Schälicke
- Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Michael Raatz
- Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Moritz Bach
- Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany
| | - Alexander Wacker
- Theoretical Aquatic Ecology and Ecophysiology group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Animal Ecology group, Zoological Institute and Museum, University of Greifswald, Greifswald, Germany
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19
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Cavieres G, Alruiz JM, Medina NR, Bogdanovich JM, Bozinovic F. Transgenerational and within-generation plasticity shape thermal performance curves. Ecol Evol 2019; 9:2072-2082. [PMID: 30847093 PMCID: PMC6392392 DOI: 10.1002/ece3.4900] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 12/16/2018] [Accepted: 12/20/2018] [Indexed: 01/03/2023] Open
Abstract
Thermal performance curves (TPCs) compute the effects of temperature on the performance of ectotherms and are frequently used to predict the effect of environmental conditions and currently, climate change, on organismal vulnerability and sensitivity. Using Drosophila melanogaster as an animal model, we examined how different thermal environments affected the shape of the performance curve and their parameters. We measured the climbing speed as a measure of locomotor performance in adult flies and tested the ontogenetic and transgenerational effects of thermal environment on TPC shape. Parents and offspring were reared at 28 ± 0ºC (28C), 28 ± 4ºC (28V), and 30 ± 0ºC (30C). We found that both, environmental thermal variability (28V) and high temperature (30C) experienced during early ontogeny shaped the fruit fly TPC sensitivity. Flies reared at variable thermal environments shifted the TPC to the right and increased heat tolerance. Flies held at high and constant temperature exhibited lower maximum performance than flies reared at the variable thermal environment. Furthermore, these effects were extended to the next generation. The parental thermal environment had a significative effect on TPC and its parameters. Indeed, flies reared at 28V whose parents were held at a high and constant temperature (30C) had a lower heat tolerance than F1 of flies reared at 28C or 28V. Also, offspring of flies reared at variable thermal environment (28V) reached the maximum performance at a higher temperature than offspring of flies reared at 28C or 30C. Consequently, since TPC parameters are not fixed, we suggest cautiousness when using TPCs to predict the impact of climate change on natural populations.
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Affiliation(s)
- Grisel Cavieres
- Center of Applied Ecology and Sustainability (CAPES), Departamento de Ecologia, Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
- CCT-Mendoza CONICET, Grupo de Investigaciones de la Biodiversidad, CONICET Instituto Argentino de Investigaciones de Zonas Áridas Mendoza Argentina
| | - José M Alruiz
- Center of Applied Ecology and Sustainability (CAPES), Departamento de Ecologia, Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
| | - Nadia R Medina
- Center of Applied Ecology and Sustainability (CAPES), Departamento de Ecologia, Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
| | - José M Bogdanovich
- Center of Applied Ecology and Sustainability (CAPES), Departamento de Ecologia, Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
| | - Francisco Bozinovic
- Center of Applied Ecology and Sustainability (CAPES), Departamento de Ecologia, Facultad de Ciencias Biológicas Pontificia Universidad Católica de Chile Santiago Chile
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20
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Lachmann SC, Mettler‐Altmann T, Wacker A, Spijkerman E. Nitrate or ammonium: Influences of nitrogen source on the physiology of a green alga. Ecol Evol 2019; 9:1070-1082. [PMID: 30805141 PMCID: PMC6374670 DOI: 10.1002/ece3.4790] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 10/19/2018] [Accepted: 10/30/2018] [Indexed: 11/25/2022] Open
Abstract
In freshwaters, algal species are exposed to different inorganic nitrogen (Ni) sources whose incorporation varies in biochemical energy demand. We hypothesized that due to the lesser energy requirement of ammonium ( NH 4 + )-use, in contrast to nitrate ( NO 3 - )-use, more energy remains for other metabolic processes, especially under CO2- and phosphorus (Pi) limiting conditions. Therefore, we tested differences in cell characteristics of the green alga Chlamydomonas acidophila grown on NH 4 + or NO 3 - under covariation of CO2 and Pi-supply in order to determine limitations, in a full-factorial design. As expected, results revealed higher carbon fixation rates for NH 4 + -grown cells compared to growth with NO 3 - under low CO2 conditions. NO 3 - -grown cells accumulated more of the nine analyzed amino acids, especially under Pi-limited conditions, compared to cells provided with NH 4 + . This is probably due to a slower protein synthesis in cells provided with NO 3 - . In contrast to our expectations, compared to NH 4 + -grown cells NO 3 - -grown cells had higher photosynthetic efficiency under Pi-limitation. In conclusion, growth on the Ni-source NH 4 + did not result in a clearly enhanced Ci-assimilation, as it was highly dependent on Pi and CO2 conditions (replete or limited). Results are potentially connected to the fact that C. acidophila is able to use only CO2 as its inorganic carbon (Ci) source.
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Affiliation(s)
| | - Tabea Mettler‐Altmann
- Cluster of Excellence on Plant Sciences and Institute of Plant BiochemistryHeinrich‐Heine UniversityDüsseldorfGermany
| | - Alexander Wacker
- Heisenberg‐Group: Theoretical Aquatic Ecology and Ecophysiology, Institute of Biochemistry and BiologyUniversity of PotsdamPotsdamGermany
| | - Elly Spijkerman
- Institute of Biochemistry and BiologyUniversity of PotsdamPotsdamGermany
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21
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Judge R, Choi F, Helmuth B. Recent Advances in Data Logging for Intertidal Ecology. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00213] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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22
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Guislain A, Beisner BE, Köhler J. Variation in species light acquisition traits under fluctuating light regimes: implications for non‐equilibrium coexistence. OIKOS 2018. [DOI: 10.1111/oik.05297] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Alexis Guislain
- Dept of Ecosystem Research, Leibniz‐Inst. of Freshwater Ecology and Inland Fisheries Berlin Germany
- Dept of Ecology and Ecosystem Modeling, Univ. of Potsdam Potsdam Germany
| | - Beatrix E. Beisner
- Dept of Ecosystem Research, Leibniz‐Inst. of Freshwater Ecology and Inland Fisheries Berlin Germany
- Groupe de Recherche Interuniversitaire en Limnologie et en Environnement Aquatique (GRIL), and Dept of Biological Sciences, Univ. of Québec at Montréal, Montréal Québec Canada
| | - Jan Köhler
- Dept of Ecosystem Research, Leibniz‐Inst. of Freshwater Ecology and Inland Fisheries Berlin Germany
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23
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Morash AJ, Neufeld C, MacCormack TJ, Currie S. The importance of incorporating natural thermal variation when evaluating physiological performance in wild species. ACTA ACUST UNITED AC 2018; 221:221/14/jeb164673. [PMID: 30037965 DOI: 10.1242/jeb.164673] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Environmental variability in aquatic ecosystems makes the study of ectotherms complex and challenging. Physiologists have historically overcome this hurdle in the laboratory by using 'average' conditions, representative of the natural environment for any given animal. Temperature, in particular, has widespread impact on the physiology of animals, and it is becoming increasingly important to understand these effects as we face future climate challenges. The majority of research to date has focused on the expected global average increase in temperature; however, increases in climate variability are predicted to affect animals as much or more than climate warming. Physiological responses associated with the acclimation to a new stable temperature are distinct from those in thermally variable environments. Our goal is to highlight these physiological differences as they relate to both thermal acclimation and the 'fallacy of the average' or Jensen's inequality using theoretical models and novel empirical data. We encourage the use of more realistic thermal environments in experimental design to advance our understanding of these physiological responses such that we can better predict how aquatic animals will respond to future changes in our climate.
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Affiliation(s)
- Andrea J Morash
- Department of Biology, Mount Allison University, Sackville, NB, Canada, E4L 1G7
| | - Claire Neufeld
- Department of Biology, Mount Allison University, Sackville, NB, Canada, E4L 1G7
| | - Tyson J MacCormack
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada, E4L 1G8
| | - Suzanne Currie
- Department of Biology, Mount Allison University, Sackville, NB, Canada, E4L 1G7.,Acadia University, Wolfville, NS, Canada, B4P 2R6
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24
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Cavieres G, Bogdanovich JM, Toledo P, Bozinovic F. Fluctuating thermal environments and time-dependent effects on fruit fly egg-hatching performance. Ecol Evol 2018; 8:7014-7021. [PMID: 30073063 PMCID: PMC6065328 DOI: 10.1002/ece3.4220] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 05/09/2018] [Accepted: 05/10/2018] [Indexed: 12/24/2022] Open
Abstract
Organismal performance in a changing environment is dependent on temporal patterns and duration of exposure to thermal variability. We experimentally assessed the time-dependent effects of thermal variability (i.e., patterns of thermal exposure) on the hatching performance of Drosophila melanogaster. Flies were collected in central Chile and maintained for four generations in laboratory conditions. Fourth generation eggs were acclimated to different thermal fluctuation cycles until hatching occurred. Our results show that the frequency of extreme thermal events has a significant effect on hatching success. Eggs exposed to 24 hr cycles of thermal fluctuation had a higher proportion of eggs that hatched than those acclimated to shorter (6 and 12 hr) and longer cycles (48 hr). Furthermore, eggs subjected to frequent thermal fluctuations hatched earlier than those acclimated to less frequent thermal fluctuations. Overall, we show that, egg-to-adult viability is dependent on the pattern of thermal fluctuations experienced during ontogeny; thus, the pattern of thermal fluctuation experienced by flies has a significant and until now unappreciated impact on fitness.
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Affiliation(s)
- Grisel Cavieres
- Departamento de EcologíaCenter of Applied Ecology and Sustainability (CAPES‐UC) Facultad de Ciencias BiológicasPontificia Universidad Católica de ChileSantiagoChile
- CCT‐Mendoza CONICETGrupo de Investigaciones de la BiodiversidadCONICETInstituto Argentino de Investigaciones de Zonas ÁridasMendozaArgentina
| | - José M. Bogdanovich
- Departamento de EcologíaCenter of Applied Ecology and Sustainability (CAPES‐UC) Facultad de Ciencias BiológicasPontificia Universidad Católica de ChileSantiagoChile
- Centro de Investigación e Innovación para el Cambio ClimáticoUniversidad Santo TomásSantiagoChile
| | - Paloma Toledo
- Departamento de EcologíaCenter of Applied Ecology and Sustainability (CAPES‐UC) Facultad de Ciencias BiológicasPontificia Universidad Católica de ChileSantiagoChile
| | - Francisco Bozinovic
- Departamento de EcologíaCenter of Applied Ecology and Sustainability (CAPES‐UC) Facultad de Ciencias BiológicasPontificia Universidad Católica de ChileSantiagoChile
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25
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Pearse IS, Paul R, Ode PJ. Variation in Plant Defense Suppresses Herbivore Performance. Curr Biol 2018; 28:1981-1986.e2. [DOI: 10.1016/j.cub.2018.04.070] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/12/2018] [Accepted: 04/19/2018] [Indexed: 10/14/2022]
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26
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Abstract
Arthropods at the surface of plants live in particular microclimatic conditions that can differ from atmospheric conditions. The temperature of plant leaves can deviate from air temperature, and leaf temperature influences the eco-physiology of small insects. The activity of insects feeding on leaf tissues, may, however, induce changes in leaf surface temperatures, but this effect was only rarely demonstrated. Using thermography analysis of leaf surfaces under controlled environmental conditions, we quantified the impact of presence of apple green aphids on the temperature distribution of apple leaves during early infestation. Aphids induced a slight change in leaf surface temperature patterns after only three days of infestation, mostly due to the effect of aphids on the maximal temperature that can be found at the leaf surface. Aphids may induce stomatal closure, leading to a lower transpiration rate. This effect was local since aphids modified the configuration of the temperature distribution over leaf surfaces. Aphids were positioned at temperatures near the maximal leaf surface temperatures, thus potentially experiencing the thermal changes. The feedback effect of feeding activity by insects on their host plant can be important and should be quantified to better predict the response of phytophagous insects to environmental changes.
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27
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Denny M. The fallacy of the average: on the ubiquity, utility and continuing novelty of Jensen's inequality. ACTA ACUST UNITED AC 2017; 220:139-146. [PMID: 28100801 DOI: 10.1242/jeb.140368] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Biologists often cope with variation in physiological, environmental and ecological processes by measuring how living systems perform under average conditions. However, performance at average conditions is seldom equal to average performance across a range of conditions. This basic property of nonlinear averaging - known as 'Jensen's inequality' or 'the fallacy of the average' - has important implications for all of biology. For instance, a burgeoning awareness of Jensen's inequality has improved our ability to predict how plants and animals will respond to a warmer and more variable future climate. But for many biologists, the fallacy of the average is still a novel concept. Here, I highlight the importance of Jensen's inequality, provide a simple graphical approach to understanding its effects, and explore its consequences at atomic, molecular, organismal and ecological levels.
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Affiliation(s)
- Mark Denny
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
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