1
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Reed TE, Visser ME, Waples RS. The opportunity for selection: A slippery concept in ecology and evolution. J Anim Ecol 2023; 92:7-15. [PMID: 36366942 PMCID: PMC10098507 DOI: 10.1111/1365-2656.13841] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 10/18/2022] [Indexed: 11/13/2022]
Abstract
Natural selection can only occur if individuals differ in fitness. For this reason, the variance in relative fitness has been equated with the 'opportunity for selection' ( I ), which has a long, albeit somewhat controversial, history. In this paper we discuss the use/misuse of I and related metrics in evolutionary ecology. The opportunity is only realised if some fraction of I is caused by trait variation. Thus, I > 0 does not imply that selection is occurring, as sometimes erroneously assumed, because all fitness variation could be independent of phenotype. The selection intensity on any given trait cannot exceed I , but this upper limit will never be reached because (a) stochastic factors always affect fitness, and (b) there might be multiple traits under selection. The expected magnitude of the stochastic component of I is negatively correlated with mean fitness. Uncertainty in realised I is also larger when mean fitness or population/sample size are low. Variation in I across time or space thus can be dominated (or solely driven) by variation in the strength of demographic stochasticity. We illustrate these points using simulations and empirical data from a population study on great tits Parus major. Our analysis shows that the scope for fecundity selection in the great tits is substantially higher when using annual number of recruits as the fitness measure, rather than fledglings or eggs, even after adjusting for the dependence of I on mean fitness. This suggests nonrandom survival of juveniles across families between life stages. Indeed, previous work on this population has shown that offspring recruitment is often nonrandom with respect to clutch size and laying date of parents, for example. We conclude that one cannot make direct inferences about selection based on fitness data alone. However, examining variation in ∆ I F (the opportunity for fecundity selection adjusted for mean fitness) across life stages, years or environments can offer clues as to when/where fecundity selection might be strongest, which can be useful for research planning and experimental design.
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Affiliation(s)
- Thomas E Reed
- School of Biological, Earth & Environmental Sciences, University College Cork, Distillery Fields, Cork, Ireland.,Environmental Research Institute, University College Cork, Cork, Ireland
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Robin S Waples
- Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, USA
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2
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Biquet J, Bonamour S, de Villemereuil P, de Franceschi C, Teplitsky C. Phenotypic plasticity drives phenological changes in a Mediterranean blue tit population. J Evol Biol 2021; 35:347-359. [PMID: 34669221 DOI: 10.1111/jeb.13950] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 10/05/2021] [Accepted: 10/08/2021] [Indexed: 01/14/2023]
Abstract
Earlier phenology induced by climate change, such as the passerines' breeding time, is observed in many natural populations. Understanding the nature of such changes is key to predict the responses of wild populations to climate change. Genetic changes have been rarely investigated for laying date, though it has been shown to be heritable and under directional selection, suggesting that the trait could evolve. In a Corsican blue tit population, the birds' laying date has significantly advanced over 40 years, and we here determine whether this response is of plastic or evolutionary origin, by comparing the predictions of the breeder's and the Robertson-Price (STS) equations, to the observed genetic changes. We compare the results obtained for two fitness proxies (fledgling and recruitment success), using models accounting for their zero inflation. Because the trait appears heritable and under directional selection, the breeder's equation predicts that genetic changes could drive a significant part of the phenological change observed. We, however, found that fitness proxies and laying date are not genetically correlated. The STS, therefore, predicts no evolution of the breeding time, predicting correctly the absence of trend in breeding values. Our results also emphasize that when investigating selection on a plastic trait under fluctuating selection, part of the fitness-trait phenotypic covariance can be due to within individual covariance. In the case of repeated measurements, splitting within and between individual covariance can shift our perspective on the actual intensity of selection over multiple selection episodes, shedding light on the potential for the trait to evolve.
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Affiliation(s)
- Juliette Biquet
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France
| | - Suzanne Bonamour
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France.,Centre d'Ecologie et des Sciences de la Conservation (CESCO, UMR 7204), Muséum national d'histoire naturelle, CNRS, Sorbonne Université, Paris, France
| | - Pierre de Villemereuil
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France.,Institut de Systématique, Évolution, Biodiversité (ISYEB), École Pratique des Hautes Études, PSL, MNHN, CNRS, SU, UA, Paris, France
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3
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Dingemanse NJ, Araya-Ajoy YG, Westneat DF. Most published selection gradients are underestimated: Why this is and how to fix it. Evolution 2021; 75:806-818. [PMID: 33621355 DOI: 10.1111/evo.14198] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 01/29/2021] [Accepted: 02/12/2021] [Indexed: 02/06/2023]
Abstract
Ecologists and evolutionary biologists routinely estimate selection gradients. Most researchers seek to quantify selection on individual phenotypes, regardless of whether fixed or repeatedly expressed traits are studied. Selection gradients estimated to address such questions are attenuated unless analyses account for measurement error and biological sources of within-individual variation. Estimates of standardized selection gradients published in Evolution between 2010 and 2019 were primarily based on traits measured once (59% of 325 estimates). We show that those are attenuated: bias increases with decreasing repeatability but differently for linear versus nonlinear gradients. Others derived individual-mean trait values prior to analyses (41%), typically using few repeats per individual, which does not remove bias. We evaluated three solutions, all requiring repeated measures: (i) correcting gradients derived from classic models using estimates of trait correlations and repeatabilities, (ii) multivariate mixed-effects models, previously used for estimating linear gradients (seven estimates, 2%), which we expand to nonlinear analyses, and (iii) errors-in-variables models that account for within-individual variance, and are rarely used in selection studies. All approaches produced accurate estimates regardless of repeatability and type of gradient, however, errors-in-variables models produced more precise estimates and may thus be preferable.
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Affiliation(s)
- Niels Jeroen Dingemanse
- Department of Biology, Ludwig-Maximilians-Universitat Munchen Department Biologie II, Planegg-Martinsried, Germany
| | - Yimen G Araya-Ajoy
- Center for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, 7012, Norway
| | - David F Westneat
- Department of Biology, University of Kentucky, Lexington, Kentucky
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4
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Henshaw JM, Morrissey MB, Jones AG. Quantifying the causal pathways contributing to natural selection. Evolution 2020; 74:2560-2574. [DOI: 10.1111/evo.14091] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 07/24/2020] [Accepted: 08/07/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Jonathan M. Henshaw
- Institute of Biology I University of Freiburg Freiburg im Breisgau 79104 Germany
- Department of Biological Sciences University of Idaho Moscow Idaho 83844
| | | | - Adam G. Jones
- Department of Biological Sciences University of Idaho Moscow Idaho 83844
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5
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Hajduk GK, Walling CA, Cockburn A, Kruuk LEB. The 'algebra of evolution': the Robertson-Price identity and viability selection for body mass in a wild bird population. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190359. [PMID: 32146880 PMCID: PMC7133512 DOI: 10.1098/rstb.2019.0359] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
By the Robertson–Price identity, the change in a quantitative trait owing to selection, is equal to the trait's covariance with relative fitness. In this study, we applied the identity to long-term data on superb fairy-wrens Malurus cyaneus, to estimate phenotypic and genetic change owing to juvenile viability selection. Mortality in the four-week period between fledging and independence was 40%, and heavier nestlings were more likely to survive, but why? There was additive genetic variance for both nestling mass and survival, and a positive phenotypic covariance between the traits, but no evidence of additive genetic covariance. Comparing standardized gradients, the phenotypic selection gradient was positive, βP = 0.108 (0.036, 0.187 95% CI), whereas the genetic gradient was not different from zero, βA = −0.025 (−0.19, 0.107 95% CI). This suggests that factors other than nestling mass were the cause of variation in survival. In particular, there were temporal correlations between mass and survival both within and between years. We suggest that use of the Price equation to describe cross-generational change in the wild may be challenging, but a more modest aim of estimating its first term, the Robertson–Price identity, to assess within-generation change can provide valuable insights into the processes shaping phenotypic diversity in natural populations. This article is part of the theme issue ‘Fifty years of the Price equation’.
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Affiliation(s)
- G K Hajduk
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - C A Walling
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - A Cockburn
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
| | - L E B Kruuk
- Research School of Biology, Australian National University, Canberra, ACT 2601, Australia
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6
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O'Sullivan RJ, Aykanat T, Johnston SE, Kane A, Poole R, Rogan G, Prodöhl PA, Primmer CR, McGinnity P, Reed TE. Evolutionary stasis of a heritable morphological trait in a wild fish population despite apparent directional selection. Ecol Evol 2019; 9:7096-7111. [PMID: 31312431 PMCID: PMC6617767 DOI: 10.1002/ece3.5274] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/03/2019] [Accepted: 05/04/2019] [Indexed: 12/14/2022] Open
Abstract
Comparing observed versus theoretically expected evolutionary responses is important for our understanding of the evolutionary process, and for assessing how species may cope with anthropogenic change. Here, we document directional selection for larger female size in Atlantic salmon, using pedigree-derived estimates of lifetime reproductive success as a fitness measure. We show the trait is heritable and, thus, capable of responding to selection. The Breeder's Equation, which predicts microevolution as the product of phenotypic selection and heritability, predicted evolution of larger size. This was at odds, however, with the observed lack of either phenotypic or genetic temporal trends in body size, a so-called "paradox of stasis." To investigate this paradox, we estimated the additive genetic covariance between trait and fitness, which provides a prediction of evolutionary change according to Robertson's secondary theorem of selection (STS) that is unbiased by missing variables. The STS prediction was consistent with the observed stasis. Decomposition of phenotypic selection gradients into genetic and environmental components revealed a potential upward bias, implying unmeasured factors that covary with trait and fitness. These results showcase the power of pedigreed, wild population studies-which have largely been limited to birds and mammals-to study evolutionary processes on contemporary timescales.
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Affiliation(s)
- Ronan James O'Sullivan
- School of Biological, Earth & Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Tutku Aykanat
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
| | - Susan E. Johnston
- Institute of Evolutionary Biology, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Adam Kane
- School of Biology and Environmental Science and Earth InstituteUniversity College DublinDublinIreland
| | | | - Ger Rogan
- Marine Institute, FurnaceNewportMayoIreland
| | - Paulo A. Prodöhl
- Institute for Global Food Security, School of Biological Sciences, Medical Biology CentreQueen's University BelfastBelfastUK
| | - Craig R. Primmer
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
| | - Philip McGinnity
- School of Biological, Earth & Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Thomas Eric Reed
- School of Biological, Earth & Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
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7
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Ramakers JJC, Gienapp P, Visser ME. Phenological mismatch drives selection on elevation, but not on slope, of breeding time plasticity in a wild songbird. Evolution 2019; 73:175-187. [PMID: 30556587 PMCID: PMC6519030 DOI: 10.1111/evo.13660] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/16/2018] [Indexed: 12/18/2022]
Abstract
Phenotypic plasticity is an important mechanism for populations to respond to fluctuating environments, yet may be insufficient to adapt to a directionally changing environment. To study whether plasticity can evolve under current climate change, we quantified selection and genetic variation in both the elevation (RNE ) and slope (RNS ) of the breeding time reaction norm in a long-term (1973-2016) study population of great tits (Parus major). The optimal RNE (the caterpillar biomass peak date regressed against the temperature used as cue by great tits) changed over time, whereas the optimal RNS did not. Concordantly, we found strong directional selection on RNE , but not RNS , of egg-laying date in the second third of the study period; this selection subsequently waned, potentially due to increased between-year variability in optimal laying dates. We found individual and additive genetic variation in RNE but, contrary to previous studies on our population, not in RNS . The predicted and observed evolutionary change in RNE was, however, marginal, due to low heritability and the sex limitation of laying date. We conclude that adaptation to climate change can only occur via micro-evolution of RNE, but this will necessarily be slow and potentially hampered by increased variability in phenotypic optima.
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Affiliation(s)
- Jip J. C. Ramakers
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)6700AB WageningenThe Netherlands
| | - Phillip Gienapp
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)6700AB WageningenThe Netherlands
| | - Marcel E. Visser
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)6700AB WageningenThe Netherlands
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8
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Henshaw JM, Jennions MD, Kruuk LEB. How to quantify (the response to) sexual selection on traits. Evolution 2018; 72:1904-1917. [PMID: 30004126 DOI: 10.1111/evo.13554] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 06/16/2018] [Accepted: 07/07/2018] [Indexed: 01/01/2023]
Abstract
Natural selection operates via fitness components like mating success, fecundity, and longevity, which can be understood as intermediaries in the causal process linking traits to fitness. In particular, sexual selection occurs when traits influence mating or fertilization success, which, in turn, influences fitness. We show how to quantify both these steps in a single path analysis, leading to better estimates of the strength of sexual selection. Our model controls for confounding variables, such as body size or condition, when estimating the relationship between mating and reproductive success. Correspondingly, we define the Bateman gradient and the Jones index using partial rather than simple regressions, which better captures how they are commonly interpreted. The model can be applied both to purely phenotypic data and to quantitative genetic parameters estimated using information on relatedness. The phenotypic approach breaks down selection differentials into a sexually selected and a "remainder" component. The quantitative genetic approach decomposes the estimated evolutionary response to selection analogously. We apply our method to analyze sexual selection in male dusky pipefish, Syngnathus floridae, and in two simulated datasets. We highlight conceptual and statistical limitations of previous path-based approaches, which can lead to substantial misestimation of sexual selection.
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Affiliation(s)
- Jonathan M Henshaw
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Acton, ACT 2601, Canberra, Australia.,Institute of Zoology, University of Graz, Universitätsplatz 2, Graz, 8010, Austria
| | - Michael D Jennions
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Acton, ACT 2601, Canberra, Australia
| | - Loeske E B Kruuk
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Acton, ACT 2601, Canberra, Australia
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9
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Ramakers JJC, Culina A, Visser ME, Gienapp P. Environmental coupling of heritability and selection is rare and of minor evolutionary significance in wild populations. Nat Ecol Evol 2018; 2:1093-1103. [PMID: 29915341 PMCID: PMC6027994 DOI: 10.1038/s41559-018-0577-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 05/15/2018] [Indexed: 01/01/2023]
Abstract
Predicting the rate of adaptation to environmental change in wild populations is important for understanding evolutionary change. However, predictions may be unreliable if the two key variables affecting the rate of evolutionary change-heritability and selection-are both affected by the same environmental variable. To determine how general such an environmentally induced coupling of heritability and selection is, and how this may influence the rate of adaptation, we made use of freely accessible, open data on pedigreed wild populations to answer this question at the broadest possible scale. Using 16 populations from 10 vertebrate species, which provided data on 50 traits (relating to body mass, morphology, physiology, behaviour and life history), we found evidence for an environmentally induced relationship between heritability and selection in only 6 cases, with weak evidence that this resulted in an increase or decrease in the expected selection response. We conclude that such a coupling of heritability and selection is unlikely to strongly affect evolutionary change, even though both heritability and selection are commonly postulated to be dependent on the environment.
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Affiliation(s)
- Jip J C Ramakers
- Department of Animal Ecology, Netherlands Institute of Ecology, Wageningen, the Netherlands.
| | - Antica Culina
- Department of Animal Ecology, Netherlands Institute of Ecology, Wageningen, the Netherlands
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology, Wageningen, the Netherlands
| | - Phillip Gienapp
- Department of Animal Ecology, Netherlands Institute of Ecology, Wageningen, the Netherlands
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10
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Williams CM, Ragland GJ, Betini G, Buckley LB, Cheviron ZA, Donohue K, Hereford J, Humphries MM, Lisovski S, Marshall KE, Schmidt PS, Sheldon KS, Varpe Ø, Visser ME. Understanding Evolutionary Impacts of Seasonality: An Introduction to the Symposium. Integr Comp Biol 2018; 57:921-933. [PMID: 29045649 DOI: 10.1093/icb/icx122] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Seasonality is a critically important aspect of environmental variability, and strongly shapes all aspects of life for organisms living in highly seasonal environments. Seasonality has played a key role in generating biodiversity, and has driven the evolution of extreme physiological adaptations and behaviors such as migration and hibernation. Fluctuating selection pressures on survival and fecundity between summer and winter provide a complex selective landscape, which can be met by a combination of three outcomes of adaptive evolution: genetic polymorphism, phenotypic plasticity, and bet-hedging. Here, we have identified four important research questions with the goal of advancing our understanding of evolutionary impacts of seasonality. First, we ask how characteristics of environments and species will determine which adaptive response occurs. Relevant characteristics include costs and limits of plasticity, predictability, and reliability of cues, and grain of environmental variation relative to generation time. A second important question is how phenological shifts will amplify or ameliorate selection on physiological hardiness. Shifts in phenology can preserve the thermal niche despite shifts in climate, but may fail to completely conserve the niche or may even expose life stages to conditions that cause mortality. Considering distinct environmental sensitivities of life history stages will be key to refining models that forecast susceptibility to climate change. Third, we must identify critical physiological phenotypes that underlie seasonal adaptation and work toward understanding the genetic architectures of these responses. These architectures are key for predicting evolutionary responses. Pleiotropic genes that regulate multiple responses to changing seasons may facilitate coordination among functionally related traits, or conversely may constrain the expression of optimal phenotypes. Finally, we must advance our understanding of how changes in seasonal fluctuations are impacting ecological interaction networks. We should move beyond simple dyadic interactions, such as predator prey dynamics, and understand how these interactions scale up to affect ecological interaction networks. As global climate change alters many aspects of seasonal variability, including extreme events and changes in mean conditions, organisms must respond appropriately or go extinct. The outcome of adaptation to seasonality will determine responses to climate change.
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Affiliation(s)
- Caroline M Williams
- Department of Integrative Biology, University of California, 3040 Valley Life Sciences Building, Berkeley, CA 94705, USA
| | - Gregory J Ragland
- Department of Integrative Biology, University of Colorado, Denver, CO, USA
| | - Gustavo Betini
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Lauren B Buckley
- Department of Biology, University of Washington, Seattle, WA, USA
| | - Zachary A Cheviron
- Division of Biological Sciences, University of Montana, Missoula, MT, USA
| | | | - Joe Hereford
- Department of Ecology and Evolution, University of California, Davis, CA, USA
| | - Murray M Humphries
- Department of Natural Resource Sciences, McGill University, Quebec, Canada
| | - Simeon Lisovski
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, CA, USA
| | | | - Paul S Schmidt
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Kimberly S Sheldon
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA
| | - Øystein Varpe
- Department of Arctic Biology, The University Centre in Svalbard, Longyearbyen, Norway.,Akvaplan-niva, Fram Centre, Tromsø, Norway
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
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11
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Bonnet T, Postma E. Fluctuating selection and its (elusive) evolutionary consequences in a wild rodent population. J Evol Biol 2018; 31:572-586. [PMID: 29380455 DOI: 10.1111/jeb.13246] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/16/2018] [Accepted: 01/18/2018] [Indexed: 01/19/2023]
Abstract
Temporal fluctuations in the strength and direction of selection are often proposed as a mechanism that slows down evolution, both over geological and contemporary timescales. Both the prevalence of fluctuating selection and its relevance for evolutionary dynamics remain poorly understood however, especially on contemporary timescales: unbiased empirical estimates of variation in selection are scarce, and the question of how much of the variation in selection translates into variation in genetic change has largely been ignored. Using long-term individual-based data for a wild rodent population, we quantify the magnitude of fluctuating selection on body size. Subsequently, we estimate the evolutionary dynamics of size and test for a link between fluctuating selection and evolution. We show that, over the past 11 years, phenotypic selection on body size has fluctuated significantly. However, the strength and direction of genetic change have remained largely constant over the study period; that is, the rate of genetic change was similar in years where selection favoured heavier vs. lighter individuals. This result suggests that over shorter timescales, fluctuating selection does not necessarily translate into fluctuating evolution. Importantly however, individual-based simulations show that the correlation between fluctuating selection and fluctuating evolution can be obscured by the effect of drift, and that substantially more data are required for a precise and accurate estimate of this correlation. We identify new challenges in measuring the coupling between selection and evolution, and provide methods and guidelines to overcome them.
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Affiliation(s)
- T Bonnet
- Research School of Biology, ANU College of Science, The Australian National University, Acton, ACT, Australia.,Department of Evolutionary Biology and Environmental Studies (IEU), University of Zurich, Zurich, Switzerland
| | - E Postma
- Department of Evolutionary Biology and Environmental Studies (IEU), University of Zurich, Zurich, Switzerland.,Centre for Ecology and Conservation, University of Exeter, College of Life and Environmental Sciences, Penryn, Cornwall, UK
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12
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Dobson FS, Becker PH, Arnaud CM, Bouwhuis S, Charmantier A. Plasticity results in delayed breeding in a long-distant migrant seabird. Ecol Evol 2017; 7:3100-3109. [PMID: 28480009 PMCID: PMC5415518 DOI: 10.1002/ece3.2777] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/22/2016] [Accepted: 01/03/2017] [Indexed: 01/16/2023] Open
Abstract
A major question for conservationists and evolutionary biologists is whether natural populations can adapt to rapid environmental change through micro-evolution or phenotypic plasticity. Making use of 17 years of data from a colony of a long-distant migratory seabird, the common tern (Sterna hirundo), we examined phenotypic plasticity and the evolutionary potential of breeding phenology, a key reproductive trait. We found that laying date was strongly heritable (0.27 ± 0.09) and under significant fecundity selection for earlier laying. Paradoxically, and in contrast to patterns observed in most songbird populations, laying date became delayed over the study period, by about 5 days. The discrepancy between the observed changes and those predicted from selection on laying date was explained by substantial phenotypic plasticity. The plastic response in laying date did not vary significantly among individuals. Exploration of climatic factors showed individual responses to the mean sea surface temperature in Senegal in December prior to breeding: Common terns laid later following warmer winters in Senegal. For each 1°C of warming of the sea surface in Senegal, common terns delayed their laying date in northern Germany by 6.7 days. This suggests that warmer waters provide poorer wintering resources. We therefore found that substantial plastic response to wintering conditions can oppose natural selection, perhaps constraining adaptation.
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Affiliation(s)
- F. Stephen Dobson
- Centre d'Ecologie Fonctionnelle et EvolutiveUMR 5175 Campus CNRSMontpellier Cedex 5France
- Department of Biological SciencesAuburn UniversityAuburnALUSA
| | - Peter H. Becker
- Institute of Avian Research “Vogelwarte Helgoland”WilhelmshavenGermany
| | - Coline M. Arnaud
- Centre d'Ecologie Fonctionnelle et EvolutiveUMR 5175 Campus CNRSMontpellier Cedex 5France
| | - Sandra Bouwhuis
- Institute of Avian Research “Vogelwarte Helgoland”WilhelmshavenGermany
| | - Anne Charmantier
- Centre d'Ecologie Fonctionnelle et EvolutiveUMR 5175 Campus CNRSMontpellier Cedex 5France
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