1
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Möbius W, Tesser F, Alards KMJ, Benzi R, Nelson DR, Toschi F. The collective effect of finite-sized inhomogeneities on the spatial spread of populations in two dimensions. J R Soc Interface 2021; 18:20210579. [PMID: 34665975 PMCID: PMC8526172 DOI: 10.1098/rsif.2021.0579] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The dynamics of a population expanding into unoccupied habitat has been primarily studied for situations in which growth and dispersal parameters are uniform in space or vary in one dimension. Here, we study the influence of finite-sized individual inhomogeneities and their collective effect on front speed if randomly placed in a two-dimensional habitat. We use an individual-based model to investigate the front dynamics for a region in which dispersal or growth of individuals is reduced to zero (obstacles) or increased above the background (hotspots), respectively. In a regime where front dynamics is determined by a local front speed only, a principle of least time can be employed to predict front speed and shape. The resulting analytical solutions motivate an event-based algorithm illustrating the effects of several obstacles or hotspots. We finally apply the principle of least time to large heterogeneous environments by solving the Eikonal equation numerically. Obstacles lead to a slow-down that is dominated by the number density and width of obstacles, but not by their precise shape. Hotspots result in a speed-up, which we characterize as function of hotspot strength and density. Our findings emphasize the importance of taking the dimensionality of the environment into account.
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Affiliation(s)
- Wolfram Möbius
- Living Systems Institute, University of Exeter, Exeter, UK.,Physics and Astronomy, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK.,Department of Applied Physics, Technische Universiteit Eindhoven, Eindhoven, The Netherlands.,Department of Physics, Harvard University, Cambridge, MA, USA
| | - Francesca Tesser
- Department of Applied Physics, Technische Universiteit Eindhoven, Eindhoven, The Netherlands.,PMMH, ESPCI Paris-PSL, Paris, France
| | - Kim M J Alards
- Department of Applied Physics, Technische Universiteit Eindhoven, Eindhoven, The Netherlands
| | - Roberto Benzi
- Universitá di Roma 'Tor Vergata' and INFN, Rome, Italy
| | - David R Nelson
- Department of Physics, Harvard University, Cambridge, MA, USA.,Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Federico Toschi
- Department of Applied Physics, Technische Universiteit Eindhoven, Eindhoven, The Netherlands.,Istituto per le Applicazioni del Calcolo, Consiglio Nazionale delle Ricerche, Rome, Italy
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2
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Quan J, Latzel V, Tie D, Zhang Y, Münzbergová Z, Chai Y, Liu X, Yue M. Ultraviolet B Radiation Triggers DNA Methylation Change and Affects Foraging Behavior of the Clonal Plant Glechoma longituba. Front Plant Sci 2021; 12:633982. [PMID: 33719308 PMCID: PMC7952652 DOI: 10.3389/fpls.2021.633982] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/19/2021] [Indexed: 06/01/2023]
Abstract
Clonal plants in heterogeneous environments can benefit from their habitat selection behavior, which enables them to utilize patchily distributed resources efficiently. It has been shown that such behavior can be strongly influenced by their memories on past environmental interactions. Epigenetic variation such as DNA methylation was proposed to be one of the mechanisms involved in the memory. Here, we explored whether the experience with Ultraviolet B (UV-B) radiation triggers epigenetic memory and affects clonal plants' foraging behavior in an UV-B heterogeneous environment. Parental ramets of Glechoma longituba were exposed to UV-B radiation for 15 days or not (controls), and their offspring ramets were allowed to choose light environment enriched with UV-B or not (the species is monopodial and can only choose one environment). Sizes and epigenetic profiles (based on methylation-sensitive amplification polymorphism analysis) of parental and offspring plants from different environments were also analyzed. Parental ramets that have been exposed to UV-B radiation were smaller than ramets from control environment and produced less and smaller offspring ramets. Offspring ramets were placed more often into the control light environment (88.46% ramets) than to the UV-B light environment (11.54% ramets) when parental ramets were exposed to UV-B radiation, which is a manifestation of "escape strategy." Offspring of control parental ramets show similar preference to the two light environments. Parental ramets exposed to UV-B had lower levels of overall DNA methylation and had different epigenetic profiles than control parental ramets. The methylation of UV-B-stressed parental ramets was maintained among their offspring ramets, although the epigenetic differentiation was reduced after several asexual generations. The parental experience with the UV-B radiation strongly influenced foraging behavior. The memory on the previous environmental interaction enables clonal plants to better interact with a heterogeneous environment and the memory is at least partly based on heritable epigenetic variation.
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Affiliation(s)
- Jiaxin Quan
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, China
| | - Vít Latzel
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czechia
| | - Dan Tie
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, China
| | - Yuhan Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, China
| | - Zuzana Münzbergová
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czechia
- Department of Botany, Faculty of Science, Charles University, Prague, Czechia
| | - Yongfu Chai
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, China
| | - Xiao Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, China
| | - Ming Yue
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi’an, China
- Xi’an Botanical Garden of Shaanxi Province/Institute of Botany of Shaanxi Province, Xi’an, China
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3
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Cassidy LC, Hannibal DL, Semple S, McCowan B. Improved behavioral indices of welfare in continuous compared to intermittent pair-housing in adult female rhesus macaques (Macaca mulatta). Am J Primatol 2020; 82:e23189. [PMID: 32890432 PMCID: PMC7944647 DOI: 10.1002/ajp.23189] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/29/2020] [Accepted: 08/18/2020] [Indexed: 12/19/2022]
Abstract
Limiting opportunities for captive nonhuman primates (NHPs) to express species-specific social behaviors may disrupt the adaptive drive for social companionship and may lead to increases in coping behaviors and inactivity. While captive NHPs show improved welfare when moving to pair-housing from single-housing, the impact of daily separation of pair-mates, as is implemented in intermittent pair-housing, is not fully understood. We compared behavioral indices of welfare exhibited by adult female rhesus macaques (Macaca mulatta) in two conditions: (1) intermittent pair-housing, involving daily overnight separation of pair-mates, and (2) continuous pair-housing, involving little separation of pair-mates. A within-subjects study design tested two groups of females experiencing both pairing conditions in an alternate order, switching either from continuous to intermittent pair-housing, or from intermittent to continuous pair-housing. Behavioral observations, recording activity state, self-directed, abnormal, and social behaviors, were conducted at midday when all females were paired, and in the afternoon when intermittent pairs were separated. Females exhibited higher levels of inactivity and self-directed behavior when separated due to intermittent pair-housing in comparison to continuous pair-housing. In addition, intermittently paired females showed higher levels of grooming and other types of affiliation when paired, than during the same time frame when they were continuously paired. These results suggest that females in the continuous presence of a social partner experience improved levels of activity and do not need to elevate levels of behavioral coping mechanisms (e.g., self-scratching, increased affiliation) as they receive the benefits associated with social companionship consistently throughout the day. Overall, this study provides the first evidence that continuous pair-housing affords better welfare than intermittent pair-housing in adult female rhesus macaques. Pair-housing options, such as continuous pairing, that reduce reliance on behavioral coping mechanisms and promote adaptive social behavior throughout the entirety of the day should be prioritized over husbandry care scheduled for convenience.
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Affiliation(s)
- Lauren C. Cassidy
- Welfare and Cognition Group, Cognitive Neuroscience Laboratory, German Primate Center–Leibniz Institute for Primate Research, Goettingen, Germany
- Leibniz-ScienceCampus Primate Cognition, German Primate Center & University of Goettingen, Goettingen, Germany
| | - Darcy L. Hannibal
- California National Primate Research Center, University of California Davis, Davis, California
- Department of Population Health & Reproduction, University of California Davis, Davis, California
| | - Stuart Semple
- Centre for Research in Evolutionary, Social and Interdisciplinary Anthropology, University of Roehampton, London, United Kingdom
| | - Brenda McCowan
- California National Primate Research Center, University of California Davis, Davis, California
- Department of Population Health & Reproduction, University of California Davis, Davis, California
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4
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da Silva LAZ, Vidal VF, Honório LM, Dantas MAR, Pinto MF, Capretz M. A Heterogeneous Edge-Fog Environment Supporting Digital Twins for Remote Inspections. Sensors (Basel) 2020; 20:s20185296. [PMID: 32947907 PMCID: PMC7570532 DOI: 10.3390/s20185296] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 09/07/2020] [Accepted: 09/08/2020] [Indexed: 11/16/2022]
Abstract
The increase in the development of digital twins brings several advantages to inspection and maintenance, but also new challenges. Digital models capable of representing real equipment for full remote inspection demand the synchronization, integration, and fusion of several sensors and methodologies such as stereo vision, monocular Simultaneous Localization and Mapping (SLAM), laser and RGB-D camera readings, texture analysis, filters, thermal, and multi-spectral images. This multidimensional information makes it possible to have a full understanding of given equipment, enabling remote diagnosis. To solve this problem, the present work uses an edge-fog-cloud architecture running over a publisher-subscriber communication framework to optimize the computational costs and throughput. In this approach, each process is embedded in an edge node responsible for prepossessing a given amount of data that optimizes the trade-off of processing capabilities and throughput delays. All information is integrated with different levels of fog nodes and a cloud server to maximize performance. To demonstrate this proposal, a real-time 3D reconstruction problem using moving cameras is shown. In this scenario, a stereo and RDB-D cameras run over edge nodes, filtering, and prepossessing the initial data. Furthermore, the point cloud and image registration, odometry, and filtering run over fog clusters. A cloud server is responsible for texturing and processing the final results. This approach enables us to optimize the time lag between data acquisition and operator visualization, and it is easily scalable if new sensors and algorithms must be added. The experimental results will demonstrate precision by comparing the results with ground-truth data, scalability by adding further readings and performance.
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Affiliation(s)
- Luiz A. Z. da Silva
- Department of Electrical Engineering, Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil; (L.A.Z.d.S.); (V.F.V.)
| | - Vinicius F. Vidal
- Department of Electrical Engineering, Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil; (L.A.Z.d.S.); (V.F.V.)
| | - Leonardo M. Honório
- Department of Electrical Engineering, Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil; (L.A.Z.d.S.); (V.F.V.)
- Correspondence:
| | - Mário A. R. Dantas
- Department of Computer Science, Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil;
| | - Milena Faria Pinto
- Department of Electronics Engineering, Federal Center for Technological Education of Rio de Janeiro, Rio de Janeiro 20271-110, Brazil;
| | - Miriam Capretz
- Department of Electrical and Computer Engineering, Faculty of Engineering, Western University, London, ON N6G 1G8, Canada;
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5
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Blanquart F, Lehtinen S, Lipsitch M, Fraser C. The evolution of antibiotic resistance in a structured host population. J R Soc Interface 2019; 15:rsif.2018.0040. [PMID: 29925579 PMCID: PMC6030642 DOI: 10.1098/rsif.2018.0040] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 05/29/2018] [Indexed: 11/12/2022] Open
Abstract
The evolution of antibiotic resistance in opportunistic pathogens such as Streptococcus pneumoniae, Escherichia coli or Staphylococcus aureus is a major public health problem, as infection with resistant strains leads to prolonged hospital stay and increased risk of death. Here, we develop a new model of the evolution of antibiotic resistance in a commensal bacterial population adapting to a heterogeneous host population composed of untreated and treated hosts, and structured in different host classes with different antibiotic use. Examples of host classes include age groups and geographic locations. Explicitly modelling the antibiotic treatment reveals that the emergence of a resistant strain is favoured by more frequent but shorter antibiotic courses, and by higher transmission rates. In addition, in a structured host population, localized transmission in host classes promotes both local adaptation of the bacterial population and the global maintenance of coexistence between sensitive and resistant strains. When transmission rates are heterogeneous across host classes, resistant strains evolve more readily in core groups of transmission. These findings have implications for the better management of antibiotic resistance: reducing the rate at which individuals receive antibiotics is more effective to reduce resistance than reducing the duration of treatment. Reducing the rate of treatment in a targeted class of the host population allows greater reduction in resistance, but determining which class to target is difficult in practice.
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Affiliation(s)
- François Blanquart
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS, INSERM, PSL Research University, Paris, France .,IAME, UMR 1137, INSERM, Université Paris Diderot, Site Xavier Bichat, Paris, France.,Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Sonja Lehtinen
- Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Marc Lipsitch
- Center for Communicable Disease Dynamics, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA.,Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, MA, USA
| | - Christophe Fraser
- Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK.,Department of Infectious Disease Epidemiology, Imperial College London, London, UK
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6
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Firman RC, Ottewell KM, Fisher DO, Tedeschi JN. Range-wide genetic structure of a cooperative mouse in a semi-arid zone: Evidence for panmixia. J Evol Biol 2019; 32:1014-1026. [PMID: 31211909 DOI: 10.1111/jeb.13498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 06/05/2019] [Accepted: 06/12/2019] [Indexed: 12/20/2022]
Abstract
Landscape topography and the mobility of individuals will have fundamental impacts on a species' population structure, for example by enhancing or reducing gene flow and therefore influencing the effective size and genetic diversity of the population. However, social organization will also influence population genetic structure. For example, species that live and breed in cooperative groups may experience high levels of inbreeding and strong genetic drift. The western pebble-mound mouse (Pseudomys chapmani), which occupies a highly heterogeneous, semi-arid landscape in Australia, is an enigmatic social mammal that has the intriguing behaviour of working cooperatively in groups to build permanent pebble mounds above a subterranean burrow system. Here, we used both nuclear (microsatellite) and mitochondrial (mtDNA) markers to analyse the range-wide population structure of western pebble-mound mice sourced from multiple social groups. We observed high levels of genetic diversity at the broad scale, very weak genetic differentiation at a finer scale and low levels of inbreeding. Our genetic analyses suggest that the western pebble-mound mouse population is both panmictic and highly viable. We conclude that high genetic connectivity across the complex landscape is a consequence of the species' ability to permeate their environment, which may be enhanced by "boom-bust" population dynamics driven by the semi-arid climate. More broadly, our results highlight the importance of sampling strategies to infer social structure and demonstrate that sociality is an important component of population genetic structure.
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Affiliation(s)
- Renée C Firman
- Centre for Evolutionary Biology, University of Western Australia, Crawley, Western Australia, Australia
| | - Kym M Ottewell
- Science and Conservation, Department of Biodiversity, Conservation and Attractions, Bentley Delivery Centre, Kensington, Western Australia, Australia
| | - Diana O Fisher
- School of Biological Sciences, University of Queensland, Brisbane, Queensland, Australia
| | - Jamie N Tedeschi
- Centre for Evolutionary Biology, University of Western Australia, Crawley, Western Australia, Australia
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7
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Liu YF, Sun GW, Wang L, Guo ZM. Establishing Wolbachia in the wild mosquito population: The effects of wind and critical patch size. Math Biosci Eng 2019; 16:4399-4414. [PMID: 31499668 DOI: 10.3934/mbe.2019219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Releasing mosquitoes with Wolbachia into the wild mosquito population is becoming the very promising strategy to control mosquito-borne infections. To investigate the effects of wind and critical patch size on the Wolbachia establishment in the wild mosquito population, in this paper, we propose a diffusion-reaction-advection system in a heterogeneous environment. By studying the related eigenvalue problems, we derive various conditions under which Wolbachia can fully establish in the entire wild mosquito population. Our findings may provide some useful insights on designing practical releasing strategies to control the mosquito population.
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Affiliation(s)
- Yun Feng Liu
- School of Mathematics and Information Sciences, Guangzhou University, Guangzhou, 510006, China
| | - Guo Wei Sun
- School of Mathematics and Information Technology, Yuncheng University, Yuncheng, Shanxi, 044000, China
| | - Lin Wang
- Department of Mathematics and Statistics, University of New Brunswick, Fredericton, NB, E3B 5A3, Canada
| | - Zhi Ming Guo
- School of Mathematics and Information Sciences, Guangzhou University, Guangzhou, 510006, China
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8
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Romeo-Aznar V, Paul R, Telle O, Pascual M. Mosquito-borne transmission in urban landscapes: the missing link between vector abundance and human density. Proc Biol Sci 2018; 285:rspb.2018.0826. [PMID: 30111594 PMCID: PMC6111166 DOI: 10.1098/rspb.2018.0826] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 07/17/2018] [Indexed: 12/25/2022] Open
Abstract
With escalating urbanization, the environmental, demographic, and socio-economic heterogeneity of urban landscapes poses a challenge to mathematical models for the transmission of vector-borne infections. Classical coupled vector–human models typically assume that mosquito abundance is either independent from, or proportional to, human population density, implying a decreasing force of infection, or per capita infection rate with host number. We question these assumptions by introducing an explicit dependence between host and vector densities through different recruitment functions, whose dynamical consequences we examine in a modified model formulation. Contrasting patterns in the force of infection are demonstrated, including in particular increasing trends when recruitment grows sufficiently fast with human density. Interaction of these patterns with seasonality in temperature can give rise to pronounced differences in timing, relative peak sizes, and duration of epidemics. These proposed dependencies explain empirical dengue risk patterns observed in the city of Delhi where socio-economic status has an impact on both human and mosquito densities. These observed risk trends with host density are inconsistent with current standard models. A better understanding of the connection between vector recruitment and host density is needed to address the population dynamics of mosquito-transmitted infections in urban landscapes.
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Affiliation(s)
- Victoria Romeo-Aznar
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA
| | - Richard Paul
- Institut Pasteur, Functional Genetics of Infectious Diseases Unit, 75724 Paris Cedex 15, France.,Centre National de la Recherche Scientifique (CNRS), Génomique évolutive, modélisation et santé UMR 2000, 75724 Paris Cedex 15, France
| | - Olivier Telle
- Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Humaines (CSH), Delhi, India.,Center for Policy Research (CPR), Delhi, India
| | - Mercedes Pascual
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA .,Santa Fe Institute, Santa Fe, NM, 87501, USA
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9
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Wood CW, Wice EW, Del Sol J, Paul S, Sanderson BJ, Brodie ED. Constraints Imposed by a Natural Landscape Override Offspring Fitness Effects to Shape Oviposition Decisions in Wild Forked Fungus Beetles. Am Nat 2018; 191:524-538. [PMID: 29570398 DOI: 10.1086/696218] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Oviposition site decisions often maximize offspring fitness, but costs constraining choice can cause females to oviposit in poor developmental environments. It is unclear whether these constraints cumulatively outweigh offspring fitness to determine oviposition decisions in wild populations. Understanding how constraints shape oviposition in natural landscapes is a critical step toward revealing how maternal behavior influences fundamental phenomena like the evolution of specialization and the use of sink environments. Here, we used a genetic capture-recapture technique to reconstruct the oviposition decisions of individual females in a natural metapopulation of a beetle (Bolitotherus cornutus) that oviposits on three fungus species. We measured larval fitness-related traits (mass, development time, survival) on each fungus and compared the oviposition preferences of females in laboratory versus field tests. Larval fitness differed substantially among fungi, and females preferred a high-quality (high larval fitness) fungus in laboratory trials. However, females frequently laid eggs on the lowest-quality fungus in the wild. They preferred high-quality fungi when moving between oviposition sites, but this preference disappeared as the distance between sites increased and was inconsistent between study plots. Our results suggest that constraints on oviposition preferences in natural landscapes are sufficiently large to drive oviposition in poor developmental environments even when offspring fitness consequences are severe.
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10
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Johannesson K, Tatarenkov A. ALLOZYME VARIATION IN A SNAIL (LITTORINA SAXATILIS)-DECONFOUNDING THE EFFECTS OF MICROHABITAT AND GENE FLOW. Evolution 2017; 51:402-409. [PMID: 28565362 DOI: 10.1111/j.1558-5646.1997.tb02427.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/1996] [Accepted: 11/01/1996] [Indexed: 11/28/2022]
Abstract
It is commonly observed that a restricted gene flow among populations of a species generates genetic differentiation in, for example, allozyme markers. However, recent studies suggest that microhabitat-specific variation may contribute to the total differentiation. To appreciate the relative contributions of geographic variation and habitat-specific variation, we sampled 42 subpopulations of the intertidal snail Littorina saxatilis from three different microhabitats (boulders, low and high rocky intertidal) on five small islands within a distance of 15 km. We used a modified orthogonal version of Nei's gene diversity analysis with a modified analysis of variance (ANOVA) that estimated the significance of habitat and geographic separation and the interaction between them. Between subpopulation differentiation (GST ) was usually in the range of 5% to 10% but was exceptionally high in one locus (Aat; 53%). Genetic differentiation attributable to different habitats accounted for 10% to 81% (mean 35%) of the between subpopulation variation and was significant (P < 0.05) in six loci. Differentiation due to geographic separation accounted for 11% to 61% (mean 36%) and was significant (P < 0.05) in seven loci. Furthermore, three loci showed interactions between habitat and island, suggesting varying effects of habitat in different islands. Microhabitat-specific variation, probably through spatially varying fitness, seems particularly likely in Aat and Pgm-2. Moderate levels of habitat associated variation added to the observed differentiation due to gene flow in Pgi, Pnp, and Pgm-1, whereas in the remaining three loci either the habitat effect was confused by strong habitat-island interaction (Ark) or was virtually absent (Pep and Mpi).
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Affiliation(s)
| | - Andrey Tatarenkov
- Tjärnö Marine Biological Laboratory, S-452 96, Strömstad, Sweden.,Institute of Marine Biology, Vladivostok, 690041, Russia
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11
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Hannibal DL, Bliss-Moreau E, Vandeleest J, McCowan B, Capitanio J. Laboratory rhesus macaque social housing and social changes: Implications for research. Am J Primatol 2017; 79:1-14. [PMID: 26848542 PMCID: PMC5436575 DOI: 10.1002/ajp.22528] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 11/30/2015] [Accepted: 01/04/2016] [Indexed: 12/21/2022]
Abstract
Macaque species, specifically rhesus (Macaca mulatta), are the most common nonhuman primates (NHPs) used in biomedical research due to their suitability as a model of high priority diseases (e.g., HIV, obesity, cognitive aging), cost effective breeding and housing compared to most other NHPs, and close evolutionary relationship to humans. With this close evolutionary relationship, however, is a shared adaptation for a socially stimulating environment, without which both their welfare and suitability as a research model are compromised. While outdoor social group housing provides the best approximation of a social environment that matches the macaque behavioral biology in the wild, this is not always possible at all facilities, where animals may be housed indoors in small groups, in pairs, or alone. Further, animals may experience many housing changes in their lifetime depending on project needs, changes in social status, management needs, or health concerns. Here, we review the evidence for the physiological and health effects of social housing changes and the potential impacts on research outcomes for studies using macaques, particularly rhesus. We situate our review in the context of increasing regulatory pressure for research facilities to both house NHPs socially and mitigate trauma from social aggression. To meet these regulatory requirements and further refine the macaque model for research, significant advances must be made in our understanding and management of rhesus macaque social housing, particularly pair-housing since it is the most common social housing configuration for macaques while on research projects. Because most NHPs are adapted for sociality, a social context is likely important for improving repeatability, reproducibility, and external validity of primate biomedical research. Am. J. Primatol. 79:e22528, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Darcy L Hannibal
- California National Primate Research Center, University of California, Davis, California
- Department of Population Health and Reproduction, University of California, Davis, California
| | - Eliza Bliss-Moreau
- California National Primate Research Center, University of California, Davis, California
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, California
| | - Jessica Vandeleest
- California National Primate Research Center, University of California, Davis, California
| | - Brenda McCowan
- California National Primate Research Center, University of California, Davis, California
- Department of Population Health and Reproduction, University of California, Davis, California
| | - John Capitanio
- California National Primate Research Center, University of California, Davis, California
- Department of Psychology, University of California, Davis, California
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12
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Abstract
Why do species not adapt to ever-wider ranges of conditions, gradually expanding their ecological niche and geographic range? Gene flow across environments has two conflicting effects: although it increases genetic variation, which is a prerequisite for adaptation, gene flow may swamp adaptation to local conditions. In 1956, Haldane proposed that, when the environment varies across space, "swamping" by gene flow creates a positive feedback between low population size and maladaptation, leading to a sharp range margin. However, current deterministic theory shows that, when variance can evolve, there is no such limit. Using simple analytical tools and simulations, we show that genetic drift can generate a sharp margin to a species' range, by reducing genetic variance below the level needed for adaptation to spatially variable conditions. Aided by separation of ecological and evolutionary timescales, the identified effective dimensionless parameters reveal a simple threshold that predicts when adaptation at the range margin fails. Two observable parameters determine the threshold: (i) the effective environmental gradient, which can be measured by the loss of fitness due to dispersal to a different environment; and (ii) the efficacy of selection relative to genetic drift. The theory predicts sharp range margins even in the absence of abrupt changes in the environment. Furthermore, it implies that gradual worsening of conditions across a species' habitat may lead to a sudden range fragmentation, when adaptation to a wide span of conditions within a single species becomes impossible.
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Gomez-Mestre I, Jovani R. A heuristic model on the role of plasticity in adaptive evolution: plasticity increases adaptation, population viability and genetic variation. Proc Biol Sci 2013; 280:20131869. [PMID: 24068357 DOI: 10.1098/rspb.2013.1869] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
An ongoing new synthesis in evolutionary theory is expanding our view of the sources of heritable variation beyond point mutations of fixed phenotypic effects to include environmentally sensitive changes in gene regulation. This expansion of the paradigm is necessary given ample evidence for a heritable ability to alter gene expression in response to environmental cues. In consequence, single genotypes are often capable of adaptively expressing different phenotypes in different environments, i.e. are adaptively plastic. We present an individual-based heuristic model to compare the adaptive dynamics of populations composed of plastic or non-plastic genotypes under a wide range of scenarios where we modify environmental variation, mutation rate and costs of plasticity. The model shows that adaptive plasticity contributes to the maintenance of genetic variation within populations, reduces bottlenecks when facing rapid environmental changes and confers an overall faster rate of adaptation. In fluctuating environments, plasticity is favoured by selection and maintained in the population. However, if the environment stabilizes and costs of plasticity are high, plasticity is reduced by selection, leading to genetic assimilation, which could result in species diversification. More broadly, our model shows that adaptive plasticity is a common consequence of selection under environmental heterogeneity, and hence a potentially common phenomenon in nature. Thus, taking adaptive plasticity into account substantially extends our view of adaptive evolution.
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Affiliation(s)
- Ivan Gomez-Mestre
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas, , Avenida de Americo Vespucio s/n, Isla de la Cartuja, Seville 41092, Spain
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