1
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Brand JA, Aich U, Yee WKW, Wong BBM, Dowling DK. Sexual Selection Increases Male Behavioral Consistency in Drosophila melanogaster. Am Nat 2024; 203:713-725. [PMID: 38781526 DOI: 10.1086/729600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
AbstractSexual selection has been suggested to influence the expression of male behavioral consistency. However, despite predictions, direct experimental support for this hypothesis has been lacking. Here, we investigated whether sexual selection altered male behavioral consistency in Drosophila melanogaster-a species with both pre- and postcopulatory sexual selection. We took 1,144 measures of locomotor activity (a fitness-related trait in D. melanogaster) from 286 flies derived from replicated populations that have experimentally evolved under either high or low levels of sexual selection for >320 generations. We found that high sexual selection males were more consistent (decreased within-individual variance) in their locomotor activity than male conspecifics from low sexual selection populations. There were no differences in behavioral consistency between females from the high and low sexual selection populations. Furthermore, while females were more behaviorally consistent than males in the low sexual selection populations, there were no sex differences in behavioral consistency in high sexual selection populations. Our results demonstrate that behavioral plasticity is reduced in males from populations exposed to high levels of sexual selection. Disentangling whether these effects represent an evolved response to changes in the intensity of selection or are manifested through nongenetic parental effects represents a challenge for future research.
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2
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Araya-Ajoy YG, Dingemanse NJ, Westneat DF, Wright J. The evolutionary ecology of variation in labile traits: selection on its among- and within-individual components. Evolution 2023; 77:2246-2256. [PMID: 37490354 DOI: 10.1093/evolut/qpad136] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 07/03/2023] [Accepted: 07/21/2023] [Indexed: 07/27/2023]
Abstract
Closer integration between behavioral ecology and quantitative genetics has resulted in a recent increase in studies partitioning sources of variation in labile traits. Repeatable between-individual differences are commonly documented, and their existence is generally explained using adaptive arguments, implying that selection has shaped variation at the among- and within-individual level. However, predicting the expected pattern of non-adaptive phenotypic variation around an optimal phenotypic value is difficult, hampering our ability to provide quantitative assessments of the adaptive nature of observed patterns of phenotypic variation within a population. We argue that estimating the strength of selection on trait variation among and within individuals provides a way to test adaptive theory concerned with phenotypic variation. To achieve this aim, we describe a nonlinear selection analysis that enables the study of the selective pressures on trait means and their among- and within-individual variation. By describing an integrative approach for studying the strength of selection on phenotypic variation at different levels, we hope to stimulate empirical studies investigating the ecological factors that can shape the repeatability, heritability, and coefficients of variation of labile and other repeatedly expressed traits.
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Affiliation(s)
- Yimen G Araya-Ajoy
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Niels J Dingemanse
- Behavioural Ecology, Department of Biology, Ludwig-Maximilians University of Munich, Planegg-Martinsried, Germany
| | - David F Westneat
- Department of Biology, University of Kentucky, Lexington, KY, United States
| | - Jonathan Wright
- Department of Biology, Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim, Norway
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3
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Winter G, Wirsching L, Schielzeth H. Condition dependence of (un)predictability in escape behavior of a grasshopper species. Behav Ecol 2023; 34:741-750. [PMID: 37744172 PMCID: PMC10516674 DOI: 10.1093/beheco/arad047] [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: 03/23/2022] [Revised: 04/03/2023] [Accepted: 05/23/2023] [Indexed: 09/26/2023] Open
Abstract
(Un)predictability has only recently been recognized as an important dimension of animal behavior. Currently, we neither know if (un)predictability encompasses one or multiple traits nor how (un)predictability is dependent on individual conditions. Knowledge about condition dependence, in particular, could inform us about whether predictability or unpredictability is costly in a specific context. Here, we study the condition dependence of (un)predictability in the escape behavior of the steppe grasshopper Chorthippus dorsatus. Predator-prey interactions represent a behavioral context in which we expect unpredictability to be particularly beneficial. By exposing grasshoppers to an immune challenge, we explore if individuals in poor condition become more or less predictable. We quantified three aspects of escape behavior (flight initiation distance, jump distance, and jump angle) in a standardized setup and analyzed the data using a multivariate double-hierarchical generalized linear model. The immune challenge did not affect (un)predictability in flight initiation distance and jump angle, but decreased unpredictability in jump distances, suggesting that unpredictability can be costly. Variance decomposition shows that 3-7% of the total phenotypic variance was explained by individual differences in (un)predictability. Covariation between traits was found both among averages and among unpredictabilities for one of the three trait pairs. The latter might suggest an (un)predictability syndrome, but the lack of (un)predictability correlation in the third trait suggests modularity. Our results indicated condition dependence of (un)predictability in grasshopper escape behavior in one of the traits, and illustrate the value of mean and residual variance decomposition for analyzing animal behavior.
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Affiliation(s)
- Gabe Winter
- Population Ecology Group, Institute of Ecology and Evolution, Friedrich Schiller University Jena, Dornburger Straße 159, 07743 Jena, Germany
| | - Luis Wirsching
- Population Ecology Group, Institute of Ecology and Evolution, Friedrich Schiller University Jena, Dornburger Straße 159, 07743 Jena, Germany
| | - Holger Schielzeth
- Population Ecology Group, Institute of Ecology and Evolution, Friedrich Schiller University Jena, Dornburger Straße 159, 07743 Jena, Germany
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4
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van Oers K, van den Heuvel K, Sepers B. The Epigenetics of Animal Personality. Neurosci Biobehav Rev 2023; 150:105194. [PMID: 37094740 DOI: 10.1016/j.neubiorev.2023.105194] [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: 10/29/2022] [Revised: 04/12/2023] [Accepted: 04/21/2023] [Indexed: 04/26/2023]
Abstract
Animal personality, consistent individual differences in behaviour, is an important concept for understanding how individuals vary in how they cope with environmental challenges. In order to understand the evolutionary significance of animal personality, it is crucial to understand the underlying regulatory mechanisms. Epigenetic marks such as DNA methylation are hypothesised to play a major role in explaining variation in phenotypic changes in response to environmental alterations. Several characteristics of DNA methylation also align well with the concept of animal personality. In this review paper, we summarise the current literature on the role that molecular epigenetic mechanisms may have in explaining personality variation. We elaborate on the potential for epigenetic mechanisms to explain behavioural variation, behavioural development and temporal consistency in behaviour. We then suggest future routes for this emerging field and point to potential pitfalls that may be encountered. We conclude that a more inclusive approach is needed for studying the epigenetics of animal personality and that epigenetic mechanisms cannot be studied without considering the genetic background.
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Affiliation(s)
- Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands; Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, the Netherlands.
| | - Krista van den Heuvel
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands; Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, the Netherlands
| | - Bernice Sepers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands; Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, the Netherlands
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5
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Montalcini CM, Toscano MJ, Gebhardt-Henrich SG, Petelle MB. Intra-individual variation of hen movements is associated with later keel bone fractures in a quasi-commercial aviary. Sci Rep 2023; 13:2377. [PMID: 36759525 PMCID: PMC9911743 DOI: 10.1038/s41598-023-29587-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
Measuring intra- and inter-individual variation in movement can bring important insights into the fundamental ecology of animals and their welfare. Although previous studies identified consistent differences in movements of laying hens within commercial aviaries, the level of consistency was not quantified, limiting our capacity to understand the importance of individual movements for welfare. We aimed to quantify the scope of intra- and inter-individual differences in movements of commercial laying hens and examined their associations with indicators of welfare at the end of production. We quantified individual differences in one composite daily movement score for 80 hens over 54 days post-transfer to a quasi-commercial aviary. Results showed consistent inter-individual differences in movement averages, explaining 44% of the variation, as well as individual variation in predictability and temporal plasticity (at the population-level, hens increased their movements for 39 days). Hens that were more predictable in their daily movements had more severe keel bone fractures at the end of production while we found no such correlation between daily movement averages (individual intercept) and welfare indicators. Our findings highlight the importance of inter-individual difference in intra-individual variation of movements to improve poultry welfare.
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Affiliation(s)
- Camille M Montalcini
- ZTHZ, Division of Animal Welfare, VPH Institute, University of Bern, 3052, Zollikofen, Switzerland.,Graduate School of Cellular and Biomedical Sciences, University of Bern, 3012, Bern, Switzerland
| | - Michael J Toscano
- ZTHZ, Division of Animal Welfare, VPH Institute, University of Bern, 3052, Zollikofen, Switzerland
| | | | - Matthew B Petelle
- ZTHZ, Division of Animal Welfare, VPH Institute, University of Bern, 3052, Zollikofen, Switzerland.
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6
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Cornwell T, Mitchell D, Beckmann C, Joynson A, Biro P. Multilevel repeatability shows selection may act on both personality and predictability, but neither is state dependent. Anim Behav 2023. [DOI: 10.1016/j.anbehav.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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7
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Brand JA, Henry J, Melo GC, Wlodkowic D, Wong BBM, Martin JM. Sex differences in the predictability of risk-taking behavior. Behav Ecol 2022; 34:108-116. [PMID: 36789395 PMCID: PMC9918862 DOI: 10.1093/beheco/arac105] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 10/05/2022] [Accepted: 10/18/2022] [Indexed: 12/15/2022] Open
Abstract
Recent research has found that individuals often vary in how consistently they express their behavior over time (i.e., behavioral predictability) and suggested that these individual differences may be heritable. However, little is known about the intrinsic factors that drive variation in the predictability of behavior. Indeed, whether variation in behavioral predictability is sex-specific is not clear. This is important, as behavioral predictability has been associated with vulnerability to predation, suggesting that the predictability of behavioral traits may have key fitness implications. We investigated whether male and female eastern mosquitofish (Gambusia holbrooki) differed in the predictability of their risk-taking behavior. Specifically, over a total of 954 behavioral trials, we repeatedly measured risk-taking behavior with three commonly used assays-refuge-use, thigmotaxis, and foraging latency. We predicted that there would be consistent sex differences in both mean-level risk-taking behavior and behavioral predictability across the assays. We found that risk-taking behavior was repeatable within each assay, and that some individuals were consistently bolder than others across all three assays. There were also consistent sex differences in mean-level risk-taking behavior, with males being bolder across all three assays compared to females. In contrast, both the magnitude and direction of sex differences in behavioral predictability were assay-specific. Taken together, these results highlight that behavioral predictability may be independent from underlying mean-level behavioral traits and suggest that males and females may differentially adjust the consistency of their risk-taking behavior in response to subtle changes in environmental conditions.
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Affiliation(s)
- Jack A Brand
- Address correspondence to Jack A. Brand. E-mail:
| | - Jason Henry
- School of Science, RMIT University, Melbourne, Victoria 3083, Australia
| | - Gabriela C Melo
- School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Donald Wlodkowic
- School of Science, RMIT University, Melbourne, Victoria 3083, Australia
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8
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Hutfluss A, Bermúdez-Cuamatzin E, Mouchet A, Briffa M, Slabbekoorn H, Dingemanse NJ. Male song stability shows cross-year repeatability but does not affect reproductive success in a wild passerine bird. J Anim Ecol 2022; 91:1507-1520. [PMID: 35509187 DOI: 10.1111/1365-2656.13736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/18/2022] [Indexed: 12/01/2022]
Abstract
Predictable behaviour (or "behavioural stability") might be favoured in certain ecological contexts, e.g. when representing a quality signal. Costs associated with producing stable phenotypes imply selection should favour plasticity in stability when beneficial. Repeatable among-individual differences in degree of stability are simultaneously expected if individuals differ in ability to pay these costs, or in how they resolve cost-benefit trade-offs. Bird song represents a prime example, where stability may be costly yet beneficial when stable singing is a quality signal favoured by sexual selection. Assuming energetic costs, ecological variation (e.g. in food availability) should result in both within- and among-individual variation in stability. If song stability represents a quality signal, we expect directional selection favouring stable singers. For a three-year period, we monitored 12 nest box plots of great tits Parus major during breeding. We recorded male songs during simulated territory intrusions, twice during their mate's laying stage, and twice during incubation. Each preceding winter, we manipulated food availability. Assuming that stability is costly, we expected food-supplemented males to sing more stable songs. We also expected males to sing more stable songs early in the breeding season (when paternity is not decided), and stable singers to have increased reproductive success. We found strong support for plasticity in stability for two key song characteristics: minimum frequency and phrase length. Males were plastic because they became more stable over the season, contrary to expectations. Food-supplementation did not affect body condition but increased stability in minimum frequency. This treatment effect occurred only in one year, implying that food supplementation affected stability only in interaction with (unknown) year-specific ecological factors. We found no support for directional, correlational, or fluctuating selection on the stability in minimum frequency (i.e., the song trait whose stability exhibited cross-year repeatability): stable singers did not have higher reproductive success. Our findings imply that stability in minimum frequency is not a fitness quality indicator unless males enjoy fitness benefits via pathways not studied here. Future studies should thus address the mechanisms shaping and maintaining individual repeatability of song stability in the wild.
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Affiliation(s)
- Alexander Hutfluss
- Behavioural Ecology, Department of Biology, Ludwig Maximilian University of Munich (LMU), Martinsried, Germany
| | | | - Alexia Mouchet
- Behavioural Ecology, Department of Biology, Ludwig Maximilian University of Munich (LMU), Martinsried, Germany.,Laboratoire Evolution Génomes Comportement et Ecologie (EGCE), UMR Université Paris-Saclay-CNRS-IRD, Gif-sur-Yvette, France
| | - Mark Briffa
- School of Biological and Marine Sciences, Animal Behaviour Research Group, University of Plymouth, Plymouth, Devon, UK
| | - Hans Slabbekoorn
- Behavioural Biology, Institute of Biology, BE, Leiden, The Netherlands
| | - Niels J Dingemanse
- Behavioural Ecology, Department of Biology, Ludwig Maximilian University of Munich (LMU), Martinsried, Germany
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9
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O'Dea RE, Noble DWA, Nakagawa S. Unifying individual differences in personality, predictability and plasticity: A practical guide. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Rose E. O'Dea
- Evolution & Ecology Research Centre School of Biological and Environmental Sciences University of New South Wales Sydney NSW Australia
- Diabetes and Metabolism Division Garvan Institute of Medical Research Sydney NSW Australia
| | - Daniel W. A. Noble
- Division of Ecology and Evolution Research School of Biology The Australian National University Canberra ACT Australia
| | - Shinichi Nakagawa
- Evolution & Ecology Research Centre School of Biological and Environmental Sciences University of New South Wales Sydney NSW Australia
- Diabetes and Metabolism Division Garvan Institute of Medical Research Sydney NSW Australia
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10
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Maskrey DK, Sneddon LU, Arnold KE, Wolfenden DC, Thomson JS. Temperature-driven changes in behavioural unpredictability and personality in the beadlet sea anemone, Actinia equina. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.08.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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11
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Patrick SC, Martin JGA, Ummenhofer CC, Corbeau A, Weimerskirch H. Albatrosses respond adaptively to climate variability by changing variance in a foraging trait. GLOBAL CHANGE BIOLOGY 2021; 27:4564-4574. [PMID: 34089551 DOI: 10.1111/gcb.15735] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 04/07/2021] [Indexed: 06/12/2023]
Abstract
The ability of individuals and populations to adapt to a changing climate is a key determinant of population dynamics. While changes in mean behaviour are well studied, changes in trait variance have been largely ignored, despite being assumed to be crucial for adapting to a changing environment. As the ability to acquire resources is essential to both reproduction and survival, changes in behaviours that maximize resource acquisition should be under selection. Here, using foraging trip duration data collected over 7 years on black-browed albatrosses (Thalassarche melanophris) on the Kerguelen Islands in the southern Indian Ocean, we examined the importance of changes in the mean and variance in foraging behaviour, and the associated effects on fitness, in response to the El Niño Southern Oscillation (ENSO). Using double hierarchical models, we found no evidence that individuals change their mean foraging trip duration in response to a changing environment, but found strong evidence of changes in variance. Younger birds showed greater variability in foraging trip duration in poor conditions as did birds with higher fitness. However, during brooding, birds showed greater variability in foraging behaviour under good conditions, suggesting that optimal conditions allow the alteration between chick provisioning and self-maintenance trips. We found weak correlations between sea surface temperature and the ENSO, but stronger links with sea-level pressure. We suggest that variability in behavioural traits affecting resource acquisition is under selection and offers a mechanism by which individuals can adapt to a changing climate. Studies which look only at effects on mean behaviour may underestimate the effects of climate change and fail to consider variance in traits as a key evolutionary force.
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Affiliation(s)
- Samantha C Patrick
- School of Environmental Sciences, University of Liverpool, Liverpool, UK
| | | | - Caroline C Ummenhofer
- Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Alexandre Corbeau
- Centre d'Etudes Biologiques de Chizé, UMR 7372, CNRS - La Rochelle Université, Villiers-en-Bois, France
| | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé, UMR 7372, CNRS - La Rochelle Université, Villiers-en-Bois, France
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12
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Mitchell DJ, Beckmann C, Biro PA. Understanding the unexplained: The magnitude and correlates of individual differences in residual variance. Ecol Evol 2021; 11:7201-7210. [PMID: 34188806 PMCID: PMC8216950 DOI: 10.1002/ece3.7603] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/24/2021] [Accepted: 04/01/2021] [Indexed: 01/11/2023] Open
Abstract
Behavioral and physiological ecologists have long been interested in explaining the causes and consequences of trait variation, with a focus on individual differences in mean values. However, the majority of phenotypic variation typically occurs within individuals, rather than among individuals (as indicated by average repeatability being less than 0.5). Recent studies have further shown that individuals can also differ in the magnitude of variation that is unexplained by individual variation or environmental factors (i.e., residual variation). The significance of residual variation, or why individuals differ, is largely unexplained, but is important from evolutionary, methodological, and statistical perspectives. Here, we broadly reviewed literature on individual variation in behavior and physiology, and located 39 datasets with sufficient repeated measures to evaluate individual differences in residual variance. We then analyzed these datasets using methods that permit direct comparisons of parameters across studies. This revealed substantial and widespread individual differences in residual variance. The magnitude of individual variation appeared larger in behavioral traits than in physiological traits, and heterogeneity was greater in more controlled situations. We discuss potential ecological and evolutionary implications of individual differences in residual variance and suggest productive future research directions.
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Affiliation(s)
- David J. Mitchell
- Centre for Integrative EcologySchool of Life & Environmental SciencesDeakin UniversityGeelongVICAustralia
- Department of Zoology/EthologyStockholm UniversityStockholmSweden
| | - Christa Beckmann
- Centre for Integrative EcologySchool of Life & Environmental SciencesDeakin UniversityGeelongVICAustralia
- School of Science and HealthWestern Sydney UniversityParramattaNSWAustralia
- Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSWAustralia
| | - Peter A. Biro
- Centre for Integrative EcologySchool of Life & Environmental SciencesDeakin UniversityGeelongVICAustralia
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13
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Henriksen R, Höglund A, Fogelholm J, Abbey-Lee R, Johnsson M, Dingemanse NJ, Wright D. Intra-Individual Behavioural Variability: A Trait under Genetic Control. Int J Mol Sci 2020; 21:ijms21218069. [PMID: 33138119 PMCID: PMC7663371 DOI: 10.3390/ijms21218069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 10/15/2020] [Accepted: 10/19/2020] [Indexed: 11/30/2022] Open
Abstract
When individuals are measured more than once in the same context they do not behave in exactly the same way each time. The degree of predictability differs between individuals, with some individuals showing low levels of variation around their behavioural mean while others show high levels of variation. This intra-individual variability in behaviour has received much less attention than between-individual variability in behaviour, and very little is known about the underlying mechanisms that affect this potentially large but understudied component of behavioural variation. In this study, we combine standardized behavioural tests in a chicken intercross to estimate intra-individual behavioural variability with a large-scale genomics analysis to identify genes affecting intra-individual behavioural variability in an avian population. We used a variety of different anxiety-related behavioural phenotypes for this purpose. Our study shows that intra-individual variability in behaviour has a direct genetic basis that is largely unique compared to the genetic architecture for the standard behavioural measures they are based on (at least in the detected quantitative trait locus). We identify six suggestive candidate genes that may underpin differences in intra-individual behavioural variability, with several of these candidates having previously been linked to behaviour and mental health. These findings demonstrate that intra-individual variability in behaviour appears to be a heritable trait in and of itself on which evolution can act.
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Affiliation(s)
- Rie Henriksen
- AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, 58183 Linköping, Sweden; (A.H.); (R.A.-L.); (M.J.)
- Correspondence: (R.H.); (D.W.)
| | - Andrey Höglund
- AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, 58183 Linköping, Sweden; (A.H.); (R.A.-L.); (M.J.)
| | - Jesper Fogelholm
- AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, 58183 Linköping, Sweden; (A.H.); (R.A.-L.); (M.J.)
| | - Robin Abbey-Lee
- AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, 58183 Linköping, Sweden; (A.H.); (R.A.-L.); (M.J.)
| | - Martin Johnsson
- AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, 58183 Linköping, Sweden; (A.H.); (R.A.-L.); (M.J.)
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Edinburgh EH25 9RG, UK
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden
| | - Niels J. Dingemanse
- Ludwig Maximilians University of Munich (LMU), 82152 Munich, Planegg-Martinsried, Germany;
| | - Dominic Wright
- AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, 58183 Linköping, Sweden; (A.H.); (R.A.-L.); (M.J.)
- Correspondence: (R.H.); (D.W.)
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14
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Prentice PM, Houslay TM, Martin JGA, Wilson AJ. Genetic variance for behavioural 'predictability' of stress response. J Evol Biol 2020; 33:642-652. [PMID: 32022966 DOI: 10.1111/jeb.13601] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/07/2020] [Accepted: 01/30/2020] [Indexed: 02/02/2023]
Abstract
Genetic factors underpinning phenotypic variation are required if natural selection is to result in adaptive evolution. However, evolutionary and behavioural ecologists typically focus on variation among individuals in their average trait values and seek to characterize genetic contributions to this. As a result, less attention has been paid to if and how genes could contribute towards within-individual variance or trait 'predictability'. In fact, phenotypic 'predictability' can vary among individuals, and emerging evidence from livestock genetics suggests this can be due to genetic factors. Here, we test this empirically using repeated measures of a behavioural stress response trait in a pedigreed population of wild-type guppies. We ask (a) whether individuals differ in behavioural predictability and (b) whether this variation is heritable and so evolvable under selection. Using statistical methodology from the field of quantitative genetics, we find support for both hypotheses and also show evidence of a genetic correlation structure between the behavioural trait mean and individual predictability. We show that investigating sources of variability in trait predictability is statistically tractable and can yield useful biological interpretation. We conclude that, if widespread, genetic variance for 'predictability' will have major implications for the evolutionary causes and consequences of phenotypic variation.
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Affiliation(s)
- Pamela M Prentice
- Centre for Ecology and Conservation, University of Exeter, Cornwall, UK
| | | | | | - Alastair J Wilson
- Centre for Ecology and Conservation, University of Exeter, Cornwall, UK
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15
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Bruijning M, Metcalf CJE, Jongejans E, Ayroles JF. The Evolution of Variance Control. Trends Ecol Evol 2020; 35:22-33. [PMID: 31519463 PMCID: PMC7482585 DOI: 10.1016/j.tree.2019.08.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 08/08/2019] [Accepted: 08/12/2019] [Indexed: 12/12/2022]
Abstract
Genetically identical individuals can be phenotypically variable, even in constant environmental conditions. The ubiquity of this phenomenon, known as 'intra-genotypic variability', is increasingly evident and the relevant mechanistic underpinnings are beginning to be understood. In parallel, theory has delineated a number of formal expectations for contexts in which such a feature would be adaptive. Here, we review empirical evidence across biological systems and theoretical expectations, including nonlinear averaging and bet hedging. We synthesize existing results to illustrate the dependence of selection outcomes both on trait characteristics, features of environmental variability, and species' demographic context. We conclude by discussing ways to bridge the gap between empirical evidence of intra-genotypic variability, studies demonstrating its genetic component, and evidence that it is adaptive.
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Affiliation(s)
- Marjolein Bruijning
- Department of Animal Ecology and Physiology, Radboud University, 6500, GL, Nijmegen, The Netherlands; Department of Ecology and Evolutionary Biology, Princeton University, 08540 Princeton, NJ, USA
| | - C Jessica E Metcalf
- Department of Ecology and Evolutionary Biology, Princeton University, 08540 Princeton, NJ, USA
| | - Eelke Jongejans
- Department of Animal Ecology and Physiology, Radboud University, 6500, GL, Nijmegen, The Netherlands
| | - Julien F Ayroles
- Department of Ecology and Evolutionary Biology, Princeton University, 08540 Princeton, NJ, USA.
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Sonnweber R, Araya-Ajoy YG, Behringer V, Deschner T, Tkaczynski P, Fedurek P, Preis A, Samuni L, Zommers Z, Gomes C, Zuberbühler K, Wittig RM, Crockford C. Circadian Rhythms of Urinary Cortisol Levels Vary Between Individuals in Wild Male Chimpanzees: A Reaction Norm Approach. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00085] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Goold C, Newberry RC. Modelling personality, plasticity and predictability in shelter dogs. ROYAL SOCIETY OPEN SCIENCE 2017; 4:170618. [PMID: 28989764 PMCID: PMC5627104 DOI: 10.1098/rsos.170618] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 08/12/2017] [Indexed: 06/07/2023]
Abstract
Behavioural assessments of shelter dogs (Canis lupus familiaris) typically comprise standardized test batteries conducted at one time point, but test batteries have shown inconsistent predictive validity. Longitudinal behavioural assessments offer an alternative. We modelled longitudinal observational data on shelter dog behaviour using the framework of behavioural reaction norms, partitioning variance into personality (i.e. inter-individual differences in behaviour), plasticity (i.e. inter-individual differences in average behaviour) and predictability (i.e. individual differences in residual intra-individual variation). We analysed data on interactions of 3263 dogs (n = 19 281) with unfamiliar people during their first month after arrival at the shelter. Accounting for personality, plasticity (linear and quadratic trends) and predictability improved the predictive accuracy of the analyses compared to models quantifying personality and/or plasticity only. While dogs were, on average, highly sociable with unfamiliar people and sociability increased over days since arrival, group averages were unrepresentative of all dogs and predictions made at the individual level entailed considerable uncertainty. Effects of demographic variables (e.g. age) on personality, plasticity and predictability were observed. Behavioural repeatability was higher one week after arrival compared to arrival day. Our results highlight the value of longitudinal assessments on shelter dogs and identify measures that could improve the predictive validity of behavioural assessments in shelters.
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Affiliation(s)
- Conor Goold
- Author for correspondence: Conor Goold e-mail:
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St-Hilaire É, Réale D, Garant D. Determinants, selection and heritability of docility in wild eastern chipmunks (Tamias striatus). Behav Ecol Sociobiol 2017. [DOI: 10.1007/s00265-017-2320-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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