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Norin T, Rowsey LE, Houslay TM, Reeve C, Speers-Roesch B. Among-individual variation in thermal plasticity of fish metabolic rates causes profound variation in temperature-specific trait repeatability, but does not co-vary with behavioural plasticity. Philos Trans R Soc Lond B Biol Sci 2024; 379:20220488. [PMID: 38186278 PMCID: PMC10772605 DOI: 10.1098/rstb.2022.0488] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/17/2023] [Indexed: 01/09/2024] Open
Abstract
Conspecifics of the same age and size differ consistently in the pace with which they expend energy. This among-individual variation in metabolic rate is thought to influence behavioural variation, since differences in energy requirements should motivate behaviours that facilitate energy acquisition, such as being bold or active in foraging. While there is evidence for links between metabolic rate and behaviour in constant environments, we know little about whether metabolic rate and behaviour change together when the environment changes-that is, if metabolic and behavioural plasticity co-vary. We investigated this using a fish that becomes dormant in winter and strongly reduces its activity when the environment cools, the cunner (Tautogolabrus adspersus). We found strong and predictable among-individual variation in thermal plasticity of metabolic rates, from resting to maximum levels, but no evidence for among-individual variation in thermal plasticity of movement activity, meaning that these key physiological and behavioural traits change independently when the environment changes. The strong among-individual variation in metabolic rate plasticity resulted in much higher repeatability (among-individual consistency) of metabolic rates at warm than cold temperatures, indicating that the potential for metabolic rate to evolve under selection is temperature-dependent, as repeatability can set the upper limit to heritability. This article is part of the theme issue 'The evolutionary significance of variation in metabolic rates'.
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Affiliation(s)
- Tommy Norin
- DTU Aqua: National Institute of Aquatic Resources, Technical University of Denmark, Henrik Dams Allé 202, 2800 Kgs. Lyngby, Denmark
- Department of Biological Sciences, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5
| | - Lauren E. Rowsey
- Department of Biological Sciences, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5
| | - Thomas M. Houslay
- Centre of Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - Connor Reeve
- Department of Biological Sciences, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5
- Department of Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6
| | - Ben Speers-Roesch
- Department of Biological Sciences, University of New Brunswick, Saint John, New Brunswick, Canada E2L 4L5
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2
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Neoh KB, Bong LJ, Silalahi CN, Panthawong A, Chareonviriyaphap T, Ahmad I. Life-history traits of Aedes aegypti (Linnaeus) distributed across a latitudinal range of 23 °N-6 °S. JOURNAL OF MEDICAL ENTOMOLOGY 2024:tjae025. [PMID: 38408179 DOI: 10.1093/jme/tjae025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 01/19/2024] [Accepted: 02/08/2024] [Indexed: 02/28/2024]
Abstract
The growth and associated traits of Aedes aegypti (L.) mosquitoes may adapt and evolve in response to the costs associated with body size in relation to latitudinal variation. We analyzed the life-history traits and energy reserves of field-collected mosquitoes from Taiwan, Thailand, and Indonesia along a latitudinal range spanning from 23°N to 6°S. A U-shaped relationship between body size and latitude was observed. Our study demonstrated the role of latitudinal temperature variations in determining the body size patterns of Ae. aegypti. Notably, the body size of the northern populations (from Taiwan) was significantly larger than those of the tropical populations from Thailand and Indonesia. Models have demonstrated that regional precipitation levels may contribute to body trait variations in certain high-latitude populations in Thailand. However, Indonesian populations have high development rates and large body sizes, indicating the involvement of other physiological traits in determining mosquito body size. The reproductive output of the adult females in this study was positively correlated with body size, but our measure of longevity did not covary significantly with the body size. By contrast, the reproductive output of mosquito-tested populations was in inverse proportion to longevity. Additionally, the mean teneral glycogen levels in the Indonesian and Thai populations were 2.5 times higher than those in the Taiwanese populations. The Indonesian and Thai populations had low mean generation and doubling times, resulting in a high intrinsic rate of increase compared with that of the Taiwanese populations, despite the Taiwanese populations having the highest net reproduction rate.
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Affiliation(s)
- Kok-Boon Neoh
- Department of Entomology, National Chung Hsing University, 402 Taichung, Taiwan
| | - Lee-Jin Bong
- Department of Entomology, National Chung Hsing University, 402 Taichung, Taiwan
| | | | - Amonrat Panthawong
- Department of Entomology, Faculty of Agriculture, Kasetsart University, Bangkok 10900, Thailand
| | | | - Intan Ahmad
- School of Life Sciences and Technology, Institut Teknologi Bandung, Bandung, West Java 40132, Indonesia
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3
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McCoy JCS, Spicer JI, Rundle SD, Tills O. Comparative phenomics: a new approach to study heterochrony. Front Physiol 2023; 14:1237022. [PMID: 38028775 PMCID: PMC10658192 DOI: 10.3389/fphys.2023.1237022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/02/2023] [Indexed: 12/01/2023] Open
Abstract
Understanding the links between development and evolution is one of the major challenges of biology. 'Heterochronies', evolutionary alterations in the timings of development are posited as a key mechanism of evolutionary change, but their quantification requires gross simplification of organismal development. Consequently, how changes in event timings influence development more broadly is poorly understood. Here, we measure organismal development as spectra of energy in pixel values of video, creating high-dimensional landscapes integrating development of all visible form and function. This approach we termed 'Energy proxy traits' (EPTs) is applied alongside previously identified heterochronies in three freshwater pulmonate molluscs (Lymnaea stagnalis, Radix balthica and Physella acuta). EPTs were calculated from time-lapse video of embryonic development to construct a continuous functional time series. High-dimensional transitions in phenotype aligned with major sequence heterochronies between species. Furthermore, differences in event timings between conspecifics were associated with changes in high-dimensional phenotypic space. We reveal EPTs as a powerful approach to considering the evolutionary importance of alterations to developmental event timings. Reimagining the phenotype as energy spectra enabled continuous quantification of developmental changes in high-dimensional phenotypic space, rather than measurement of timings of discrete events. This approach has the possibility to transform how we study heterochrony and development more generally.
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Abarzúa T, Camus I, Ortiz F, Ñunque A, Cubillos FA, Sabat P, Nespolo RF. Modeling heterothermic fitness landscapes in a marsupial hibernator using changes in body composition. Oecologia 2023; 203:79-93. [PMID: 37798536 PMCID: PMC10615951 DOI: 10.1007/s00442-023-05452-4] [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: 06/14/2023] [Accepted: 09/16/2023] [Indexed: 10/07/2023]
Abstract
Hibernation is an adaptive strategy that allows animals to enter a hypometabolic state, conserving energy and enhancing their fitness by surviving harsh environmental conditions. However, addressing the adaptive value of hibernation, at the individual level and in natural populations, has been challenging. Here, we applied a non-invasive technique, body composition analysis by quantitative magnetic resonance (qMR), to calculate energy savings by hibernation in a population of hibernating marsupials (Dromiciops gliroides). Using outdoor enclosures installed in a temperate rainforest, and measuring qMR periodically, we determined the amount of fat and lean mass consumed during a whole hibernation cycle. With this information, we estimated the daily energy expenditure of hibernation (DEEH) at the individual level and related to previous fat accumulation. Using model selection approaches and phenotypic selection analysis, we calculated linear (directional, β), quadratic (stabilizing or disruptive, γ) and correlational (ρ) coefficients for DEEH and fat accumulation. We found significant, negative directional selection for DEEH (βDEEH = - 0.58 ± 0.09), a positive value for fat accumulation (βFAT = 0.34 ± 0.07), and positive correlational selection between both traits (ρDEEH × FAT = 0.24 ± 0.07). Then, individuals maximizing previous fat accumulation and minimizing DEEH were promoted by selection, which is visualized by a bi-variate selection surface estimated by generalized additive models. At the comparative level, results fall within the isometric allometry known for hibernation metabolic rate in mammals. Thus, by a combination of a non-invasive technique for body composition analysis and semi-natural enclosures, we were characterized the heterothermic fitness landscape in a semi-natural population of hibernators.
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Affiliation(s)
- Tamara Abarzúa
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Isidora Camus
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Felipe Ortiz
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
| | - Abel Ñunque
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile
- Millenium Nucleus of Patagonian Limit of Life (LiLi), Valdivia, Chile
| | - Francisco A Cubillos
- Departamento de Biología y Química, Universidad de Santiago de Chile, Santiago, Chile
- Millenium Nucleus of Patagonian Limit of Life (LiLi), Valdivia, Chile
- Millennium Institute for Integrative Biology (iBio), Santiago, Chile
| | - Pablo Sabat
- Facultad de Ciencias, Universidad de Chile, Santiago, Chile
- Center for Applied Ecology and Sustainability (CAPES), Departamento de Ecología Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Roberto F Nespolo
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, Valdivia, Chile.
- Millenium Nucleus of Patagonian Limit of Life (LiLi), Valdivia, Chile.
- Center for Applied Ecology and Sustainability (CAPES), Departamento de Ecología Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile.
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Harrison JF, Biewener A, Bernhardt JR, Burger JR, Brown JH, Coto ZN, Duell ME, Lynch M, Moffett ER, Norin T, Pettersen AK, Smith FA, Somjee U, Traniello JFA, Williams TM. White Paper: An Integrated Perspective on the Causes of Hypometric Metabolic Scaling in Animals. Integr Comp Biol 2022; 62:icac136. [PMID: 35933126 PMCID: PMC9724154 DOI: 10.1093/icb/icac136] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 04/16/2022] [Accepted: 05/19/2022] [Indexed: 11/15/2022] Open
Abstract
Larger animals studied during ontogeny, across populations, or across species, usually have lower mass-specific metabolic rates than smaller animals (hypometric scaling). This pattern is usually observed regardless of physiological state (e.g. basal, resting, field, maximally-active). The scaling of metabolism is usually highly correlated with the scaling of many life history traits, behaviors, physiological variables, and cellular/molecular properties, making determination of the causation of this pattern challenging. For across-species comparisons of resting and locomoting animals (but less so for across populations or during ontogeny), the mechanisms at the physiological and cellular level are becoming clear. Lower mass-specific metabolic rates of larger species at rest are due to a) lower contents of expensive tissues (brains, liver, kidneys), and b) slower ion leak across membranes at least partially due to membrane composition, with lower ion pump ATPase activities. Lower mass-specific costs of larger species during locomotion are due to lower costs for lower-frequency muscle activity, with slower myosin and Ca++ ATPase activities, and likely more elastic energy storage. The evolutionary explanation(s) for hypometric scaling remain(s) highly controversial. One subset of evolutionary hypotheses relies on constraints on larger animals due to changes in geometry with size; for example, lower surface-to-volume ratios of exchange surfaces may constrain nutrient or heat exchange, or lower cross-sectional areas of muscles and tendons relative to body mass ratios would make larger animals more fragile without compensation. Another subset of hypotheses suggests that hypometric scaling arises from biotic interactions and correlated selection, with larger animals experiencing less selection for mass-specific growth or neurolocomotor performance. A additional third type of explanation comes from population genetics. Larger animals with their lower effective population sizes and subsequent less effective selection relative to drift may have more deleterious mutations, reducing maximal performance and metabolic rates. Resolving the evolutionary explanation for the hypometric scaling of metabolism and associated variables is a major challenge for organismal and evolutionary biology. To aid progress, we identify some variation in terminology use that has impeded cross-field conversations on scaling. We also suggest that promising directions for the field to move forward include: 1) studies examining the linkages between ontogenetic, population-level, and cross-species allometries, 2) studies linking scaling to ecological or phylogenetic context, 3) studies that consider multiple, possibly interacting hypotheses, and 4) obtaining better field data for metabolic rates and the life history correlates of metabolic rate such as lifespan, growth rate and reproduction.
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Affiliation(s)
- Jon F Harrison
- School of Life Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Andrew Biewener
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Joanna R Bernhardt
- Department of Zoology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
- Yale Institute for Biospheric Studies, New Haven, CT 06520, USA
| | - Joseph R Burger
- Department of Biology, University of Kentucky, Lexington, KY 40506, USA
| | - James H Brown
- Center for Evolutionary and Theoretical Immunology, The University of New Mexico, Albuquerque, NM 87131, USA
| | - Zach N Coto
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Meghan E Duell
- Department of Biology, The University of Western Ontario, London, ON N6A 3K7, Canada
| | - Michael Lynch
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ 85281, USA
| | - Emma R Moffett
- Department of Ecology and Evolution, University of California, Irvine, CA 92697, USA
| | - Tommy Norin
- DTU Aqua | National Institute of Aquatic Resources, Technical University of Denmark, Anker Engelunds Vej 1 Bygning 101A, 2800 Kgs. Lyngby, Denmark
| | - Amanda K Pettersen
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Felisa A Smith
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Ummat Somjee
- Smithsonian Tropical Research Institute, Panama City, Panama
| | | | - Terrie M Williams
- Division of Physical and Biological Sciences, University of California, Santa Cruz, CA 95064, USA
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6
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Pettersen AK, Schuster L, Metcalfe NB. The Evolution of Offspring Size: a Metabolic Scaling Perspective. Integr Comp Biol 2022; 62:icac076. [PMID: 35657724 PMCID: PMC9724151 DOI: 10.1093/icb/icac076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/17/2022] [Accepted: 05/30/2022] [Indexed: 11/13/2022] Open
Abstract
Size at the start of life reflects the initial per offspring parental investment - including both the embryo and the nutrients supplied to it. Initial offspring size can vary substantially both within and among species. Within species, increasing offspring size can enhance growth, reproduction, competitive ability, and reduce susceptibility to predation and starvation later in life, that can ultimately increase fitness. Previous work has suggested that the fitness benefits of larger offspring size may be driven by energy expenditure during development - or how offspring metabolic rate scales with offspring size. Despite the importance of early life energy expenditure in shaping later life fitness trajectories, consideration of among-species scaling of metabolic rate at the time of birth as a potential source of general metabolic scaling patterns has been overlooked by theory. Here we review the patterns and processes of energy expenditure at the start of life when mortality is often greatest. We compile existing data on metabolic rate and offspring size for 191 ectotherm species spanning eight phyla and use phylogenetically-controlled methods to quantify among-species scaling patterns. Across a 109-fold mass range, we find that offspring metabolic rate scales hypometrically with size, with an overall scaling exponent of 0.66. This exponent varies across ontogenetic stage and feeding activity, but is consistently hypometric, including across environmental temperatures. Despite differences in parental investment, life history and habitat, large-offspring species use relatively less energy as a proportion of size, compared with small-offspring species. Greater residual energy can be used to fuel the next stages of life, particularly in low resource environments. Based on available evidence, we conclude that, while large knowledge gaps remain, the evolution of offspring size is likely shaped by context-dependent selection acting on correlated traits, including metabolic rates maintaining hypometric scaling, that operates within broader physical constraints.
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Affiliation(s)
- Amanda K Pettersen
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW 2006, Australia
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G20 0TH, UK
| | - Lukas Schuster
- School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia
| | - Neil B Metcalfe
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G20 0TH, UK
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7
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Bech C, Christiansen MT, Kvernland P, Nygård RM, Rypdal E, Sneltorp SK, Trondrud LM, Tvedten ØG. The standard metabolic rate of a land snail (Cepaea hortensis) is a repeatable trait and influences winter survival. Comp Biochem Physiol A Mol Integr Physiol 2020; 249:110773. [PMID: 32711162 DOI: 10.1016/j.cbpa.2020.110773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 07/19/2020] [Accepted: 07/19/2020] [Indexed: 10/23/2022]
Abstract
Phenotypic selection on physiological parameters is an underrepresented topic in studies of evolutionary biology. There is especially a lack of studies involving invertebrate organisms. We studied the repeatability of the standard metabolic rate (SMR) and the effect of individual variation in SMR on the subsequent winter survival in a terrestrial shell-bearing mollusc, the white-lipped snail (Cepaea hortensis) in mid-Norway. SMR was measured twice during the autumn and - after an experimental overwintering at controlled conditions - twice during the following spring. We found a significant repeatability of SMR over all three time periods tested, with a clear effect of time, with a high repeatability of 0.56 over 4 days during spring, 0.44 over 12 days in the autumn and 0.17 over 194 days from autumn to spring. That SMR is a repeatable physiological trait across the winter period during which a possible selection might occur, suggests that SMR could be a potential target of natural selection. We indeed found that the autumn SMR significantly influenced the probability of survival during the winter period, with a combination of a positive linear (P = .011) and a quadratic stabilizing (P = .001) effect on SMR. Our results hence support the view that metabolic rate is an important physiological component influencing the fitness of an organism.
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Affiliation(s)
- Claus Bech
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
| | | | - Pernille Kvernland
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Randi Marie Nygård
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Eline Rypdal
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Sara Kjeldsø Sneltorp
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Liv Monica Trondrud
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
| | - Øyvind Gjønnes Tvedten
- Department of Biology, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
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8
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Schweizer M, Triebskorn R, Köhler H. Snails in the sun: Strategies of terrestrial gastropods to cope with hot and dry conditions. Ecol Evol 2019; 9:12940-12960. [PMID: 31788227 PMCID: PMC6875674 DOI: 10.1002/ece3.5607] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/15/2019] [Accepted: 08/05/2019] [Indexed: 11/08/2022] Open
Abstract
Terrestrial gastropods do not only inhabit humid and cool environments but also habitat in which hot and dry conditions prevail. Snail species that are able to cope with such climatic conditions are thus expected to having developed multifaceted strategies and mechanisms to ensure their survival and reproduction under heat and desiccation stress. This review paper aims to provide an integrative overview of the numerous adaptation strategies terrestrial snails have evolved to persist in hot and dry environments as well as their mutual interconnections and feedbacks, but also to outline research gaps and questions that remained unanswered. We extracted relevant information from more than 140 publications in order to show how biochemical, cellular, physiological, morphological, ecological, thermodynamic, and evolutionary parameters contribute to provide an overall picture of this classical example in stress ecology. These mechanisms range from behavioral and metabolic adaptations, including estivation, to the induction of chaperones and antioxidant enzymes, mucocyte and digestive gland cell responses and the modification and frequency of morphological features, particularly shell pigmentation. In this context, thermodynamic constraints call for processes of complex adaptation at varying levels of biological organization that are mutually interwoven. We were able to assemble extensive, mostly narrowly focused information from the literature into a web of network parameters, showing that future work on this subject requires multicausal thinking to account for the complexity of relationships involved in snails' adaptation to insolation, heat, and drought.
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Affiliation(s)
- Mona Schweizer
- Animal Physiological EcologyInstitute of Evolution and EcologyUniversity of TübingenTübingenGermany
| | - Rita Triebskorn
- Animal Physiological EcologyInstitute of Evolution and EcologyUniversity of TübingenTübingenGermany
- Steinbeis Transfer Center for Ecotoxicology and EcophysiologyRottenburgGermany
| | - Heinz‐R. Köhler
- Animal Physiological EcologyInstitute of Evolution and EcologyUniversity of TübingenTübingenGermany
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9
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Pettersen AK, Marshall DJ, White CR. Understanding variation in metabolic rate. J Exp Biol 2018; 221:221/1/jeb166876. [DOI: 10.1242/jeb.166876] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
ABSTRACT
Metabolic rate reflects an organism's capacity for growth, maintenance and reproduction, and is likely to be a target of selection. Physiologists have long sought to understand the causes and consequences of within-individual to among-species variation in metabolic rates – how metabolic rates relate to performance and how they should evolve. Traditionally, this has been viewed from a mechanistic perspective, relying primarily on hypothesis-driven approaches. A more agnostic, but ultimately more powerful tool for understanding the dynamics of phenotypic variation is through use of the breeder's equation, because variation in metabolic rate is likely to be a consequence of underlying microevolutionary processes. Here we show that metabolic rates are often significantly heritable, and are therefore free to evolve under selection. We note, however, that ‘metabolic rate’ is not a single trait: in addition to the obvious differences between metabolic levels (e.g. basal, resting, free-living, maximal), metabolic rate changes through ontogeny and in response to a range of extrinsic factors, and is therefore subject to multivariate constraint and selection. We emphasize three key advantages of studying metabolic rate within a quantitative genetics framework: its formalism, and its predictive and comparative power. We make several recommendations when applying a quantitative genetics framework: (i) measuring selection based on actual fitness, rather than proxies for fitness; (ii) considering the genetic covariances between metabolic rates throughout ontogeny; and (iii) estimating genetic covariances between metabolic rates and other traits. A quantitative genetics framework provides the means for quantifying the evolutionary potential of metabolic rate and why variance in metabolic rates within populations might be maintained.
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Affiliation(s)
- Amanda K. Pettersen
- School of Biological Sciences/Centre for Geometric Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Dustin J. Marshall
- School of Biological Sciences/Centre for Geometric Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Craig R. White
- School of Biological Sciences/Centre for Geometric Biology, Monash University, Melbourne, VIC 3800, Australia
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10
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Morozov S, Leinonen T, Merilä J, McCairns RJS. Selection on the morphology-physiology-performance nexus: Lessons from freshwater stickleback morphs. Ecol Evol 2018; 8:1286-1299. [PMID: 29375798 PMCID: PMC5773335 DOI: 10.1002/ece3.3644] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 10/25/2017] [Accepted: 10/27/2017] [Indexed: 12/17/2022] Open
Abstract
Conspecifics inhabiting divergent environments frequently differ in morphology, physiology, and performance, but the interrelationships amongst traits and with Darwinian fitness remains poorly understood. We investigated population differentiation in morphology, metabolic rate, and swimming performance in three-spined sticklebacks (Gasterosteus aculeatus L.), contrasting a marine/ancestral population with two distinct freshwater morphotypes derived from it: the "typical" low-plated morph, and a unique "small-plated" morph. We test the hypothesis that similar to plate loss in other freshwater populations, reduction in lateral plate size also evolved in response to selection. Additionally, we test how morphology, physiology, and performance have evolved in concert as a response to differences in selection between marine and freshwater environments. We raised pure-bred second-generation fish originating from three populations and quantified their lateral plate coverage, burst- and critical swimming speeds, as well as standard and active metabolic rates. Using a multivariate QST-FST framework, we detected signals of directional selection on metabolic physiology and lateral plate coverage, notably demonstrating that selection is responsible for the reduction in lateral plate coverage in a small-plated stickleback population. We also uncovered signals of multivariate selection amongst all bivariate trait combinations except the two metrics of swimming performance. Divergence between the freshwater and marine populations exceeded neutral expectation in morphology and in most physiological and performance traits, indicating that adaptation to freshwater habitats has occurred, but through different combinations of traits in different populations. These results highlight both the complex interplay between morphology, physiology and performance in local adaptation, and a framework for their investigation.
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Affiliation(s)
- Sergey Morozov
- Ecological Genetics Research UnitUniversity of HelsinkiHelsinkiFinland
| | - Tuomas Leinonen
- Ecological Genetics Research UnitUniversity of HelsinkiHelsinkiFinland
- Department of BiosciencesUniversity of HelsinkiHelsinkiFinland
| | - Juha Merilä
- Ecological Genetics Research UnitUniversity of HelsinkiHelsinkiFinland
| | - R. J. Scott McCairns
- Ecological Genetics Research UnitUniversity of HelsinkiHelsinkiFinland
- ESE, Ecology and Ecosystem HealthINRARennesFrance
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11
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Maldonado K, Sabat P, Piriz G, Bogdanovich JM, Nespolo RF, Bozinovic F. Is Maximum Food Intake in Endotherms Constrained by Net or Factorial Aerobic Scope? Lessons from the Leaf-Eared Mouse. Front Physiol 2016; 7:649. [PMID: 28082915 PMCID: PMC5186761 DOI: 10.3389/fphys.2016.00649] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 12/09/2016] [Indexed: 12/28/2022] Open
Abstract
Food availability varies substantially throughout animals' lifespans, thus the ability to profit from high food levels may directly influence animal fitness. Studies exploring the link between basal metabolic rate (BMR), growth, reproduction, and other fitness traits have shown varying relationships in terms of both magnitude and direction. The diversity of results has led to the hypothesis that these relationships are modulated by environmental conditions (e.g., food availability), suggesting that the fitness consequences of a given BMR may be context-dependent. In turn, there is indirect evidence that individuals with an increased capacity for aerobic work also have a high capacity for acquiring energy from food. Surprisingly, very few studies have explored the correlation between maximum rates of energy acquisition and BMR in endotherms, and to the best of our knowledge, none have attempted to elucidate relationships between the former and aerobic capacity [e.g., maximum metabolic rate (MMR), aerobic scope (Factorial aerobic scope, FAS; Net aerobic scope, NAS)]. In this study, we measured BMR, MMR, maximum food intake (recorded under low ambient temperature and ad libitum food conditions; MFI), and estimated aerobic scope in the leaf-eared mouse (Phyllotis darwini). We, then, examined correlations among these variables to determine whether metabolic rates and aerobic scope are functionally correlated, and whether an increased aerobic capacity is related to a higher MFI. We found that aerobic capacity measured as NAS is positively correlated with MFI in endotherms, but with neither FAS nor BMR. Therefore, it appears plausible that the capacity for assimilating energy under conditions of abundant resources is determined adaptively by NAS, as animals with higher NAS would be promoted by selection. In theory, FAS is an invariant measurement of the extreme capacity for energy turnover in relation to resting expenditure, whereas NAS represents the maximum capacity for simultaneous aerobic processes above maintenance levels. Accordingly, in our study, FAS and NAS represent different biological variables; FAS, in contrast to NAS, may not constrain food intake. The explanations for these differences are discussed in biological and mathematical terms; further, we encourage the use of NAS rather than FAS when analyzing the aerobic capacity of animals.
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Affiliation(s)
- Karin Maldonado
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de ChileSantiago, Chile
| | - Pablo Sabat
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de ChileSantiago, Chile
- Center of Applied Ecology and Sustainability, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Gabriela Piriz
- Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de ChileSantiago, Chile
| | - José M. Bogdanovich
- Center of Applied Ecology and Sustainability, Pontificia Universidad Católica de ChileSantiago, Chile
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
| | - Roberto F. Nespolo
- Center of Applied Ecology and Sustainability, Pontificia Universidad Católica de ChileSantiago, Chile
- Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Campus Isla TejaValdivia, Chile
| | - Francisco Bozinovic
- Center of Applied Ecology and Sustainability, Pontificia Universidad Católica de ChileSantiago, Chile
- Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de ChileSantiago, Chile
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Boratyński JS, Jefimow M, Wojciechowski MS. Individual Differences in the Phenotypic Flexibility of Basal Metabolic Rate in Siberian Hamsters Are Consistent on Short- and Long-Term Timescales. Physiol Biochem Zool 2016; 90:139-152. [PMID: 28277958 DOI: 10.1086/689870] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Basal metabolic rate (BMR) correlates with the cost of life in endothermic animals. It usually differs consistently among individuals in a population, but it may be adjusted in response to predictable or unpredictable changes in the environment. The phenotypic flexibility of BMR is considered an adaptation to living in a stochastic environment; however, whether it is also repeatable it is still unexplored. Assuming that variations in phenotypic flexibility are evolutionarily important, we hypothesized that they are consistently different among individuals. We predicted that not only BMR but also its flexibility in response to changes in ambient temperature (Ta) are repeatable on short- and long-term timescales. To examine this, we acclimated Siberian hamsters (Phodopus sungorus) for 100 d to winterlike and then to summerlike conditions, and after each acclimation we exposed them interchangeably to 10° and 28°C for 14 d. The difference in BMR measured after each exposure defined an individual's phenotypic flexibility (ΔBMR). BMR was repeatable within and among seasons. It was also flexible in both seasons, but in winter this flexibility was lower in individuals responding to seasonal changes than in nonresponding ones. When we accounted for individual responsiveness, the repeatability of ΔBMR was significant in winter (τ = 0.48, P = 0.01) and in summer (τ = 0.55, P = 0.005). Finally, the flexibility of BMR in response to changes in Ta was also repeatable on a long-term timescale, that is, among seasons (τ = 0.31, P = 0.008). Our results indicate the evolutionary importance of the phenotypic flexibility of energy metabolism and suggest that it may be subject to selection.
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Auer SK, Bassar RD, Salin K, Metcalfe NB. Repeatability of metabolic rate is lower for animals living under field versus laboratory conditions. J Exp Biol 2016; 219:631-4. [DOI: 10.1242/jeb.133678] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 12/22/2015] [Indexed: 12/14/2022]
Abstract
Metabolic rate has been linked to multiple components of fitness and is both heritable and repeatable to a certain extent. However, its repeatability can differ among studies, even after controlling for the time interval between measurements. Some of this variation in repeatability may be due to the relative stability of the environmental conditions in which the animals are living between measurements. We compared published repeatability estimates for basal, resting, and maximum metabolic rate from studies of endotherms living in the laboratory versus those living in the wild during the interval between measurements. We found that repeatability declines over time, as demonstrated previously, but show for the first time that estimates from free-living animals are also considerably lower than those from animals living under more stable laboratory conditions.
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Affiliation(s)
- Sonya K. Auer
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ United Kingdom
| | - Ronald D. Bassar
- Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK
| | - Karine Salin
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ United Kingdom
| | - Neil B. Metcalfe
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ United Kingdom
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