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Freitas O, Campos PRA. The role of epistasis in evolutionary rescue. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2024; 47:49. [PMID: 39066883 DOI: 10.1140/epje/s10189-024-00445-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Accepted: 07/18/2024] [Indexed: 07/30/2024]
Abstract
The process by which adaptive evolution preserves a population threatened with extinction due to environmental changes is known as evolutionary rescue. Several factors determine the fate of those populations, including demography and genetic factors, such as standing genetic variation, gene flow, availability of de novo mutations, and so on. Despite the extensive debate about evolutionary rescue in the current literature, a study about the role of epistasis and the topography of the fitness landscape on the fate of dwindling populations is missing. In the current work, we aim to fill this gap and study the influence of epistasis on the probability of extinction of populations. We present simulation results, and analytical approximations are derived. Counterintuitively, we show that the likelihood of extinction is smaller when the degree of epistasis is higher. The reason underneath is twofold: first, higher epistasis can promote mutations of more significant phenotypic effects, but also, the incongruence between the maps genotype-phenotype and phenotype-fitness turns the fitness landscape at low epistasis more rugged, thus curbing some of its advantages.
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Affiliation(s)
- Osmar Freitas
- Departamento de Física, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil
| | - Paulo R A Campos
- Departamento de Física, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil.
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2
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Hermann RJ, Pantel JH, Réveillon T, Becks L. Range of trait variation in prey determines evolutionary contributions to predator growth rates. J Evol Biol 2024; 37:693-703. [PMID: 38761100 DOI: 10.1093/jeb/voae062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 04/12/2024] [Accepted: 05/15/2024] [Indexed: 05/20/2024]
Abstract
Evolutionary and ecological dynamics can occur on similar timescales and thus influence each other. While it has been shown that the relative contribution of ecological and evolutionary change to population dynamics can vary, it still remains unknown what influences these differences. Here, we test whether prey populations with increased variation in their defence and competitiveness traits will have a stronger impact on evolution for predator growth rates. We controlled trait variation by pairing distinct clonal lineages of the green alga Chlamydomonas reinhardtii with known traits as prey with the rotifer Brachionus calyciforus as predator and compared those results with a mechanistic model matching the empirical system. We measured the impact of evolution (shift in prey clonal frequency) and ecology (shift in prey population density) for predator growth rate and its dependency on trait variation using an approach based on a 2-way ANOVA. Our experimental results indicated that higher trait variation, i.e., a greater distance in trait space, increased the relative contribution of prey evolution to predator growth rate over 3-4 predator generations, which was also observed in model simulations spanning longer time periods. In our model, we also observed clone-specific results, where a more competitive undefended prey resulted in a higher evolutionary contribution, independent of the trait distance. Our results suggest that trait combinations and total prey trait variation combine to influence the contribution of evolution to predator population dynamics, and that trait variation can be used to identify and better predict the role of eco-evolutionary dynamics in predator-prey systems.
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Affiliation(s)
- Ruben J Hermann
- Aquatic Ecology and Evolution, Limnological Institute, University of Konstanz, Konstanz, Germany
| | - Jelena H Pantel
- Ecological Modelling, Faculty of Biology, University Duisburg Essen, Essen, Germany
- Laboratoire Chrono-environnement, UMR 6249 CNRS-UFC, 16 Route de Gray, 25030 Besanc, France
| | - Tom Réveillon
- Aquatic Ecology and Evolution, Limnological Institute, University of Konstanz, Konstanz, Germany
| | - Lutz Becks
- Aquatic Ecology and Evolution, Limnological Institute, University of Konstanz, Konstanz, Germany
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3
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Petkovic N, Colegrave N. The effects of sex on extinction dynamics of Chlamydomonas reinhardtii depend on the rate of environmental change. J Evol Biol 2023; 36:1783-1795. [PMID: 37897099 DOI: 10.1111/jeb.14237] [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] [Received: 11/22/2022] [Revised: 08/18/2023] [Accepted: 09/01/2023] [Indexed: 10/29/2023]
Abstract
The continued existence of sex, despite many the costs it entails, still lacks an adequate explanation, as previous studies demonstrated that the effects of sex are environment-dependent: sex enhances the rate of adaptation in changing environments, but the benefits level off in benign conditions. To the best of our knowledge, the potential impact of different patterns of environmental change on the magnitude of these benefits received less attention in theoretical studies. In this paper, we begin to explore this issue by examining the effect of the rate of environmental deterioration (negatively correlated with population survival rate), on the benefits of sex. To investigate the interplay of sex and the rate of environmental deterioration, we carried out a long-term selection experiment with a unicellular alga (Chlamydomonas reinhardtii), by manipulating mode of reproduction (asexual, facultative or obligate sexual) and the rate of environmental deterioration (an increase of salt concentration). We monitored both the population size and extinction dynamics. The results revealed that the relative advantage of sex increased at the intermediate rate and plateaued at the highest rate of environmental deterioration. Obligate sexual populations had the slowest extinction rate under the intermediate rate of environmental deterioration, while facultative sexuality was favoured under the high rate-treatment. To the best of our knowledge, our study is the first to demonstrate that the interplay of sex and the rate of environmental deterioration affects the probability of survival, which indicates that mode of reproduction may be an important determinant of survival of the anthropogenic-induced environmental change.
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Affiliation(s)
- Nikola Petkovic
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Nick Colegrave
- Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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4
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Liu Y, Zhao Y, Qian C, Huang Z, Feng L, Chen L, Yao Z, Xu C, Ye J, Zhou T. Study of Combined Effect of Bacteriophage vB3530 and Chlorhexidine on the Inactivation of Pseudomonas aeruginosa. BMC Microbiol 2023; 23:256. [PMID: 37704976 PMCID: PMC10498570 DOI: 10.1186/s12866-023-02976-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 08/09/2023] [Indexed: 09/15/2023] Open
Abstract
BACKGROUND Chlorhexidine (CHG) is a disinfectant commonly used in hospitals. However, it has been reported that the excessive use of CHG can cause resistance in bacteria to this agent and even to other clinical antibiotics. Therefore, new methods are needed to alleviate the development of CHG tolerance and reduce its dosage. This study aimed to explore the synergistic effects of CHG in combination with bacteriophage against CHG-tolerant Pseudomonas aeruginosa (P. aeruginosa) and provide ideas for optimizing disinfection strategies in clinical environments as well as for the efficient use of disinfectants. METHODS The CHG-tolerant P. aeruginosa strains were isolated from the First Affiliated Hospital of Wenzhou Medical University in China. The bacteriophage vB3530 was isolated from the sewage inlet of the hospital, and its genome was sequenced. Time-killing curve was used to determine the antibacterial effects of vB3530 and chlorohexidine gluconate (CHG). The phage sensitivity to 16 CHG-tolerant P. aeruginosa strains and PAO1 strain was detected using plaque assay. The emergence rate of resistant bacterial strains was detected to determine the development of phage-resistant and CHG-tolerant strains. Finally, the disinfection effects of the disinfectant and phage combination on the surface of the medical devices were preliminarily evaluated. RESULTS The results showed that (1) CHG combined with bacteriophage vB3530 significantly inhibited the growth of CHG-resistant P. aeruginosa and reduced the bacterial colony forming units (CFUs) after 24 h. (2) The combination of CHG and bacteriophage inhibited the emergence of phage-resistant and CHG-tolerant strains. (3) The combination of CHG and bacteriophage significantly reduced the bacterial load on the surface of medical devices. CONCLUSIONS In this study, the combination of bacteriophage vB3530 and CHG presented a combined inactivation effect to CHG-tolerant P. aeruginosa and reduced the emergence of strains resistant to CHG and phage. This study demonstrated the potential of bacteriophage as adjuvants to traditional disinfectants. The use of bacteriophage in combination with commercial disinfectants might be a promising method for controlling the spread of bacteria in hospitals.
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Affiliation(s)
- Yan Liu
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Yining Zhao
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Changrui Qian
- School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, 325000, Zhejiang Province, China
| | - Zeyu Huang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Luozhu Feng
- Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Lijiang Chen
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Zhuocheng Yao
- Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang Province, China
| | - Chunquan Xu
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China
| | - Jianzhong Ye
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
| | - Tieli Zhou
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, China.
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Barton S, Padfield D, Masterson A, Buckling A, Smirnoff N, Yvon-Durocher G. Comparative experimental evolution reveals species-specific idiosyncrasies in marine phytoplankton adaptation to warming. GLOBAL CHANGE BIOLOGY 2023; 29:5261-5275. [PMID: 37395481 DOI: 10.1111/gcb.16827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 05/30/2023] [Indexed: 07/04/2023]
Abstract
A number of experimental studies have demonstrated that phytoplankton can display rapid thermal adaptation in response to warmed environments. While these studies provide insight into the evolutionary responses of single species, they tend to employ different experimental techniques. Consequently, our ability to compare the potential for thermal adaptation across different, ecologically relevant, species remains limited. Here, we address this limitation by conducting simultaneous long-term warming experiments with the same experimental design on clonal isolates of three phylogenetically diverse species of marine phytoplankton; the cyanobacterium Synechococcus sp., the prasinophyte Ostreococcus tauri and the diatom Phaeodoactylum tricornutum. Over the same experimental time period, we observed differing levels of thermal adaptation in response to stressful supra-optimal temperatures. Synechococcus sp. displayed the greatest improvement in fitness (i.e., growth rate) and thermal tolerance (i.e., temperature limits of growth). Ostreococcus tauri was able to improve fitness and thermal tolerance, but to a lesser extent. Finally, Phaeodoactylum tricornutum showed no signs of adaptation. These findings could help us understand how the structure of phytoplankton communities may change in response to warming, and possible biogeochemical implications, as some species show relatively more rapid adaptive shifts in their thermal tolerance.
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Affiliation(s)
- Samuel Barton
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
- Department of Earth Sciences, University of Oxford, Oxford, UK
| | - Daniel Padfield
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
| | - Abigail Masterson
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
| | - Angus Buckling
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter, UK
| | - Gabriel Yvon-Durocher
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, UK
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6
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Olazcuaga L, Lincke B, DeLacey S, Durkee LF, Melbourne BA, Hufbauer RA. Population demographic history and evolutionary rescue: Influence of a bottleneck event. Evol Appl 2023; 16:1483-1495. [PMID: 37622091 PMCID: PMC10445088 DOI: 10.1111/eva.13581] [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: 01/12/2023] [Revised: 07/05/2023] [Accepted: 07/05/2023] [Indexed: 08/26/2023] Open
Abstract
Rapid environmental change presents a significant challenge to the persistence of natural populations. Rapid adaptation that increases population growth, enabling populations that declined following severe environmental change to grow and avoid extinction, is called evolutionary rescue. Numerous studies have shown that evolutionary rescue can indeed prevent extinction. Here, we extend those results by considering the demographic history of populations. To evaluate how demographic history influences evolutionary rescue, we created 80 populations of red flour beetle, Tribolium castaneum, with three classes of demographic history: diverse populations that did not experience a bottleneck, and populations that experienced either an intermediate or a strong bottleneck. We subjected these populations to a new and challenging environment for six discrete generations and tracked extinction and population size. Populations that did not experience a bottleneck in their demographic history avoided extinction entirely, while more than 20% of populations that experienced an intermediate or strong bottleneck went extinct. Similarly, among the extant populations at the end of the experiment, adaptation increased the growth rate in the novel environment the most for populations that had not experienced a bottleneck in their history. Taken together, these results highlight the importance of considering the demographic history of populations to make useful and effective conservation decisions and management strategies for populations experiencing environmental change that pushes them toward extinction.
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Affiliation(s)
- Laure Olazcuaga
- Department of Agricultural BiologyColorado State UniversityFort CollinsColoradoUSA
| | - Beatrice Lincke
- Department of Agricultural BiologyColorado State UniversityFort CollinsColoradoUSA
| | - Sarah DeLacey
- Department of Agricultural BiologyColorado State UniversityFort CollinsColoradoUSA
| | - Lily F. Durkee
- Department of Agricultural BiologyColorado State UniversityFort CollinsColoradoUSA
- Graduate Degree Program in EcologyColorado State UniversityFort CollinsColoradoUSA
| | - Brett A. Melbourne
- Department of Ecology & Evolutionary BiologyUniversity of ColoradoBoulderColoradoUSA
| | - Ruth A. Hufbauer
- Department of Agricultural BiologyColorado State UniversityFort CollinsColoradoUSA
- Graduate Degree Program in EcologyColorado State UniversityFort CollinsColoradoUSA
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7
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Del Arco A, Becks L, de Vicente I. Population dynamics hide phenotypic changes driven by subtle chemical exposures: implications for risk assessments. ECOTOXICOLOGY (LONDON, ENGLAND) 2023; 32:281-289. [PMID: 36871096 PMCID: PMC10102127 DOI: 10.1007/s10646-023-02637-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
Ecological risk assessment of chemicals focuses on the response of different taxa in isolation not taking ecological and evolutionary interplay in communities into account. Its consideration would, however, allow for an improved assessment by testing for implications within and across trophic levels and changes in the phenotypic and genotypic diversity within populations. We present a simple experimental system that can be used to evaluate the ecological and evolutionary responses to chemical exposure at microbial community levels. We exposed a microbial model system of the ciliate Tetrahymena thermophila (predator) and the bacterium Pseudomonas fluorescens (prey) to iron released from Magnetic Particles (MP-Fedis), which are Phosphorus (P) adsorbents used in lake restoration. Our results show that while the responses of predator single population size differed across concentrations of MP-Fedis and the responses of prey from communities differed also across concentration of MP-Fedis, the community responses (species ratio) were similar for the different MP-Fedis concentrations. Looking further at an evolutionary change in the bacterial preys' defence, we found that MP-Fedis drove different patterns and dynamics of defence evolution. Overall, our study shows how similar community dynamics mask changes at evolutionary levels that would be overlooked in the design of current risk assessment protocols where evolutionary approaches are not considered.
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Affiliation(s)
- Ana Del Arco
- Community Dynamics Group, Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, 24306, Plön, Germany.
- Limnological Institute, Biology Department, University of Konstanz, 78464, Konstanz/Egg, Germany.
| | - Lutz Becks
- Community Dynamics Group, Department of Evolutionary Ecology, Max Planck Institute for Evolutionary Biology, 24306, Plön, Germany
- Limnological Institute, Biology Department, University of Konstanz, 78464, Konstanz/Egg, Germany
| | - Inmaculada de Vicente
- Departamento de Ecología, Facultad de Ciencias, Universidad de Granada, Granada, 18071, Spain
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8
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Zhou DH, Zhang QG. Fast drug rotation reduces bacterial resistance evolution in a microcosm experiment. J Evol Biol 2023; 36:641-649. [PMID: 36808770 DOI: 10.1111/jeb.14163] [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: 09/18/2022] [Revised: 11/17/2022] [Accepted: 01/16/2023] [Indexed: 02/21/2023]
Abstract
Drug rotation (cycling), in which multiple drugs are administrated alternatively, has the potential for limiting resistance evolution in pathogens. The frequency of drug alternation could be a major factor to determine the effectiveness of drug rotation. Drug rotation practices often have low frequency of drug alternation, with an expectation of resistance reversion. Here we, based on evolutionary rescue and compensatory evolution theories, suggest that fast drug rotation can limit resistance evolution in the first place. This is because fast drug rotation would give little time for the evolutionarily rescued populations to recover in population size and genetic diversity, and thus decrease the chance of future evolutionary rescue under alternate environmental stresses. We experimentally tested this hypothesis using the bacterium Pseudomonas fluorescens and two antibiotics (chloramphenicol and rifampin). Increasing drug rotation frequency reduced the chance of evolutionary rescue, and most of the finally surviving bacterial populations were resistant to both drugs. Drug resistance incurred significant fitness costs, which did not differ among the drug treatment histories. A link between population sizes during the early stages of drug treatment and the end-point fates of populations (extinction vs survival) suggested that population size recovery and compensatory evolution before drug shift increase the chance of population survival. Our results therefore advocate fast drug rotation as a promising approach to reduce bacterial resistance evolution, which in particular could be a substitute for drug combination when the latter has safety risks.
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Affiliation(s)
- Dong-Hao Zhou
- State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
| | - Quan-Guo Zhang
- State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
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9
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Tsuzuki Y, Takada T, Ohara M. Modeling temporal dynamics of genetic diversity in stage-structured plant populations with reference to demographic genetic structure. Theor Popul Biol 2022; 148:76-85. [PMID: 36402453 DOI: 10.1016/j.tpb.2022.11.001] [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] [Received: 07/25/2022] [Revised: 11/03/2022] [Accepted: 11/04/2022] [Indexed: 11/18/2022]
Abstract
Predicting temporal dynamics of genetic diversity is important for assessing long-term population persistence. In stage-structured populations, especially in perennial plant species, genetic diversity is often compared among life history stages, such as seedlings, juveniles, and flowerings, using neutral genetic markers. The comparison among stages is sometimes referred to as demographic genetic structure, which has been regarded as a proxy of potential genetic changes because individuals in mature stages will die and be replaced by those in more immature stages over the course of time. However, due to the lack of theoretical examination, the basic property of the stage-wise genetic diversity remained unclear. We developed a matrix model which was made up of difference equations of the probability of non-identical-by-descent of each life history stage at a neutral locus to describe the dynamics and the inter-stage differences of genetic diversity in stage-structured plant populations. Based on the model, we formulated demographic genetic structure as well as the annual change rate of the probability of non-identical-by-descent (denoted as η). We checked if theoretical expectations on demographic genetic structure and η obtained from our model agreed with computational results of stochastic simulation using randomly generated 3,000 life histories. We then examined the relationships of demographic genetic structure with effective population size Ne, which is the determinants of diversity loss per generation time. Theoretical expectations on η and demographic genetic structure fitted well to the results of stochastic simulation, supporting the validity of our model. Demographic genetic structure varied independently of Ne and η, while having a strong correlation with stable stage distribution: genetic diversity was lower in stages with fewer individuals. Our results indicate that demographic genetic structure strongly reflects stable stage distribution, rather than temporal genetic dynamics, and that inferring future genetic diversity solely from demographic genetic structure would be misleading. Instead of demographic genetic structure, we propose η as an useful tool to predict genetic diversity at the same time scale as population dynamics (i.e., per year), facilitating evaluation on population viability from a genetic point of view.
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Affiliation(s)
- Yoichi Tsuzuki
- Graduate School of Environmental Science, Hokkaido University, N10W5, Sapporo City, 060-0810, Hokkaido Prefecture, Japan.
| | - Takenori Takada
- Graduate School of Environmental Science, Hokkaido University, N10W5, Sapporo City, 060-0810, Hokkaido Prefecture, Japan
| | - Masashi Ohara
- Graduate School of Environmental Science, Hokkaido University, N10W5, Sapporo City, 060-0810, Hokkaido Prefecture, Japan
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Toll-Riera M, Olombrada M, Castro-Giner F, Wagner A. A limit on the evolutionary rescue of an Antarctic bacterium from rising temperatures. SCIENCE ADVANCES 2022; 8:eabk3511. [PMID: 35857489 PMCID: PMC9286510 DOI: 10.1126/sciadv.abk3511] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
Climate change is gradual, but it can also cause brief extreme heat waves that can exceed the upper thermal limit of any one organism. To study the evolutionary potential of upper thermal tolerance, we evolved the cold-adapted Antarctic bacterium Pseudoalteromonas haloplanktis to survive at 30°C, beyond its ancestral thermal limit. This high-temperature adaptation occurred rapidly and in multiple populations. It involved genomic changes that occurred in a highly parallel fashion and mitigated the effects of protein misfolding. However, it also confronted a physiological limit, because populations failed to grow beyond 30°C. Our experiments aimed to facilitate evolutionary rescue by using a small organism with large populations living at temperatures several degrees below their upper thermal limit. Larger organisms with smaller populations and living at temperatures closer to their upper thermal tolerances are even more likely to go extinct during extreme heat waves.
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Affiliation(s)
- Macarena Toll-Riera
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Miriam Olombrada
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | | | - Andreas Wagner
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- The Santa Fe Institute, Santa Fe, NM, USA
- Stellenbosch Institute for Advanced Study (STIAS), Wallenberg Research Centre at Stellenbosch University, Stellenbosch 7600, South Africa
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11
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Tomasini M, Peischl S. The role of spatial structure in multi-deme models of evolutionary rescue. J Evol Biol 2022; 35:986-1001. [PMID: 35704340 DOI: 10.1111/jeb.14018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 04/07/2022] [Accepted: 04/13/2022] [Indexed: 11/30/2022]
Abstract
Genetic variation and population sizes are critical factors for successful adaptation to novel environmental conditions. Gene flow between sub-populations is a potent mechanism to provide such variation and can hence facilitate adaptation, for instance by increasing genetic variation or via the introduction of beneficial variants. On the other hand, if gene flow between different habitats is too strong, locally beneficial alleles may not be able to establish permanently. In the context of evolutionary rescue, intermediate levels of gene flow are therefore often optimal for maximizing a species chance for survival in metapopulations without spatial structure. To which extent and under which conditions gene flow facilitates or hinders evolutionary rescue in spatially structured populations remains unresolved. We address this question by studying the differences between evolutionary rescue in the island model and in the stepping stone model in a gradually deteriorating habitat. We show that evolutionary rescue is modulated by the rate of gene flow between different habitats, which in turn depends strongly on the spatial structure and the pattern of environmental deterioration. We use these insights to show that in many cases spatially structured models can be translated into a simpler island model using an appropriately scaled effective migration rate.
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Affiliation(s)
- Matteo Tomasini
- Interfaculty Bioinformatics Unit, University of Bern, Bern, Switzerland.,Computational and Molecular Population Genetics Laboratory, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland.,Swiss Institute for Bioinformatics, Lausanne, Switzerland
| | - Stephan Peischl
- Interfaculty Bioinformatics Unit, University of Bern, Bern, Switzerland.,Swiss Institute for Bioinformatics, Lausanne, Switzerland
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12
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Loria A, Cristescu ME, Gonzalez A. Genotype diversity promotes the persistence of Daphnia populations exposed to severe copper stress. J Evol Biol 2022; 35:265-277. [PMID: 35000231 DOI: 10.1111/jeb.13979] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 12/15/2021] [Accepted: 12/20/2021] [Indexed: 11/29/2022]
Abstract
When environmental stressors of high intensity are sustained for long periods of time, populations face high probabilities of being extirpated. However, depending on the intensity of the stressor, large populations with sufficient genetic diversity may persist. We report the results of an experiment that tracked the persistence of Daphnia populations exposed to copper contamination. We assessed whether genotypic diversity reduced the risk of extinction. We created monoclonal and multiclonal populations and monitored their population sizes during a 32-week experiment. Cu was applied at a sub-lethal concentration and then increased every week until the population sizes dropped to about 10% of the carrying capacity (Cu at 180 μg/L). The concentration was then increased up to 186 μg/L and held stable until the end of the experiment. A survival analysis showed that clonal diversity extended the persistence of Daphnia populations, but copper contamination caused a substantial genetic erosion followed by population extirpation. However, some Cu-treated populations, mostly multiclonal, showed U-shaped patterns of growth consistent with evolutionary rescue but these did not lead to lasting population recovery. These results highlight the importance of genetic variation for population persistence, but they also show how quickly it can be lost in contaminated environments.
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Affiliation(s)
| | | | - Andrew Gonzalez
- Department of Biology, McGill University, Montreal, QC, Canada
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13
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Abstract
AbstractThe transformation of ecosystems proceeds at unprecedented rates. Recent studies suggest that high rates of environmental change can cause rate-induced tipping. In ecological models, the associated rate-induced critical transition manifests during transient dynamics in which populations drop to dangerously low densities. In this work, we study how indirect evolutionary rescue—due to the rapid evolution of a predator’s trait—can save a prey population from the rate-induced collapse. Therefore, we explicitly include the time-dependent dynamics of environmental change and evolutionary adaptation in an eco-evolutionary system. We then examine how fast the evolutionary adaptation needs to be to counteract the response to environmental degradation and express this relationship by means of a critical rate. Based on this critical rate, we conclude that indirect evolutionary rescue is more probable if the predator population possesses a high genetic variation and, simultaneously, the environmental change is slow. Hence, our results strongly emphasize that the maintenance of biodiversity requires a deceleration of the anthropogenic degradation of natural habitats.
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14
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Greenspoon PB, Spencer HG. Avoiding extinction under nonlinear environmental change: models of evolutionary rescue with plasticity. Biol Lett 2021; 17:20210459. [PMID: 34875181 PMCID: PMC8651410 DOI: 10.1098/rsbl.2021.0459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 11/15/2021] [Indexed: 12/21/2022] Open
Abstract
Rapid environmental changes are putting numerous species at risk of extinction. For migration-limited species, persistence depends on either phenotypic plasticity or evolutionary adaptation (evolutionary rescue). Current theory on evolutionary rescue typically assumes linear environmental change. Yet accelerating environmental change may pose a bigger threat. Here, we present a model of a species encountering an environment with accelerating or decelerating change, to which it can adapt through evolution or phenotypic plasticity (within-generational or transgenerational). We show that unless either form of plasticity is sufficiently strong or adaptive genetic variation is sufficiently plentiful, accelerating or decelerating environmental change increases extinction risk compared to linear environmental change for the same mean rate of environmental change.
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Affiliation(s)
| | - Hamish G. Spencer
- Department of Zoology, University of Otago, Dunedin 9016, New Zealand
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15
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Azevedo RBR, Olofsson P. A branching process model of evolutionary rescue. Math Biosci 2021; 341:108708. [PMID: 34560091 DOI: 10.1016/j.mbs.2021.108708] [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: 04/29/2021] [Revised: 09/05/2021] [Accepted: 09/13/2021] [Indexed: 12/01/2022]
Abstract
Evolutionary rescue is the process whereby a declining population may start growing again, thus avoiding extinction, via an increase in the frequency of fitter genotypes. These genotypes may either already be present in the population in small numbers, or arise by mutation as the population declines. We present a simple two-type discrete-time branching process model and use it to obtain results such as the probability of rescue, the shape of the population growth curve of a rescued population, and the time until the first rescuing mutation occurs. Comparisons are made to existing results in the literature in cases where both the mutation rate and the selective advantage of the beneficial mutations are small.
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Affiliation(s)
- Ricardo B R Azevedo
- Department of Biology and Biochemistry, University of Houston, Houston, TX, USA
| | - Peter Olofsson
- Department of Mathematics, Physics and Chemical Engineering, Jönköping University, Sweden.
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16
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Golas BD, Goodell B, Webb CT. Host adaptation to novel pathogen introduction: Predicting conditions that promote evolutionary rescue. Ecol Lett 2021; 24:2238-2255. [PMID: 34310798 DOI: 10.1111/ele.13845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/04/2021] [Accepted: 06/09/2021] [Indexed: 02/02/2023]
Abstract
Novel pathogen introduction can have drastic consequences for naive host populations, and outcomes can be difficult to predict. Evolutionary rescue (ER) provides a foundation for understanding whether hosts are driven to extinction or survive via adaptation. Currently, patterns of host population dynamics alongside evidence of adaptation are used to infer ER. However, the gap between established ER theory and complexity inherent in natural systems makes interpreting empirical patterns difficult because they can be confounded with ecological drivers of survival under current theory. To bridge this gap, we expand ER theory to include biological selective agents, such as pathogens. We find birth processes to be more important than previously theorised in determining ER potential. We employ a novel framework evaluating ER potential within natural systems and gain ability to identify system characteristics that make ER possible. Identifying these characteristics allows a shift from retrospective observation to a predictive mindset, and our findings suggest that ER occurrence may be more limited than previously thought. We use the plague system of Yersinia pestis infecting Cynomys ludovicianus (black-tailed prairie dogs) and Spermophilus beecheyi (California ground squirrels) as a case study.
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17
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Abstract
Rising antimicrobial resistance severely limits efforts to treat infections and is a cause for critical concern. Renewed interest in bacteriophage therapy has advanced understanding of the breadth of species capable of targeting bacterial antimicrobial resistance mechanisms, but many questions concerning ideal application remain unanswered. The following minireview examines bacterial resistance mechanisms, the current state of bacteriophage therapy, and how bacteriophage therapy can augment strategies to combat resistance with a focus on the clinically relevant bacterium Pseudomonas aeruginosa, as well as the role of efflux pumps in antimicrobial resistance. Methods to prevent antimicrobial efflux using efflux pump inhibitors and phage steering, a type of bacteriophage therapy, are also covered. The evolutionary context underlying antimicrobial resistance and the need to include theory in the ongoing development of bacteriophage therapy are also discussed.
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18
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Tsuzuki Y, Sato MP, Matsuo A, Suyama Y, Ohara M. Genetic consequences of habitat fragmentation in a perennial plant
Trillium camschatcense
are subjected to its slow‐paced life history. POPUL ECOL 2021. [DOI: 10.1002/1438-390x.12093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yoichi Tsuzuki
- Graduate School of Environmental Science Hokkaido University Sapporo Hokkaido Japan
| | - Mitsuhiko P. Sato
- Kawatabi Field Science Center Graduate School of Agricultural Science, Tohoku University Osaki Miyagi Japan
| | - Ayumi Matsuo
- Kawatabi Field Science Center Graduate School of Agricultural Science, Tohoku University Osaki Miyagi Japan
| | - Yoshihisa Suyama
- Kawatabi Field Science Center Graduate School of Agricultural Science, Tohoku University Osaki Miyagi Japan
| | - Masashi Ohara
- Graduate School of Environmental Science Hokkaido University Sapporo Hokkaido Japan
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19
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Zhou D, Zhang Q. Compensatory adaptation and diversification subsequent to evolutionary rescue in a model adaptive radiation. Ecol Evol 2021; 11:9689-9696. [PMID: 34306654 PMCID: PMC8293784 DOI: 10.1002/ece3.7792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 05/27/2021] [Indexed: 11/23/2022] Open
Abstract
Biological populations may survive lethal environmental stress through evolutionary rescue. The rescued populations typically suffer a reduction in growth performance and harbor very low genetic diversity compared with their parental populations. The present study addresses how population size and within-population diversity may recover through compensatory evolution, using the experimental adaptive radiation of bacterium Pseudomonas fluorescens. We exposed bacterial populations to an antibiotic treatment and then imposed a one-individual-size population bottleneck on those surviving the antibiotic stress. During the subsequent compensatory evolution, population size increased and leveled off very rapidly. The increase of diversity was of slower paces and persisted longer. In the very early stage of compensatory evolution, populations of large sizes had a greater chance to diversify; however, this productivity-diversification relationship was not observed in later stages. Population size and diversity from the end of the compensatory evolution was not contingent on initial population growth performance. We discussed the possibility that our results be explained by the emergence of a "holey" fitness landscape under the antibiotic stress.
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Affiliation(s)
- Dong‐Hao Zhou
- State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life SciencesBeijing Normal UniversityBeijingChina
| | - Quan‐Guo Zhang
- State Key Laboratory of Earth Surface Processes and Resource Ecology and MOE Key Laboratory for Biodiversity Science and Ecological Engineering, College of Life SciencesBeijing Normal UniversityBeijingChina
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20
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Searle CL, Christie MR. Evolutionary rescue in host-pathogen systems. Evolution 2021; 75:2948-2958. [PMID: 34018610 DOI: 10.1111/evo.14269] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 05/07/2021] [Accepted: 05/12/2021] [Indexed: 11/28/2022]
Abstract
Natural populations encounter a variety of threats that can increase their risk of extinction. Populations can avoid extinction through evolutionary rescue (ER), which occurs when an adaptive, genetic response to selection allows a population to recover from an environmental change that would otherwise cause extinction. While the traditional framework for ER was developed with abiotic risk factors in mind, ER may also occur in response to a biotic source of demographic change, such as the introduction of a novel pathogen. We first describe how ER in response to a pathogen differs from the traditional ER framework; density-dependent transmission, pathogen evolution, and pathogen extinction can change the strength of selection imposed by a pathogen and make host population persistence more likely. We also discuss several variables that affect traditional ER (abundance, genetic diversity, population connectivity, and community composition) that also directly affect disease risk resulting in diverse outcomes for ER in host-pathogen systems. Thus, generalizations developed in studies of traditional ER may not be relevant for ER in response to the introduction of a pathogen. Incorporating pathogens into the framework of ER will lead to a better understanding of how and when populations can avoid extinction in response to novel pathogens.
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Affiliation(s)
- Catherine L Searle
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, 47907
| | - Mark R Christie
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, 47907.,Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana, 47907
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21
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Lagator M, Uecker H, Neve P. Adaptation at different points along antibiotic concentration gradients. Biol Lett 2021; 17:20200913. [PMID: 33975485 PMCID: PMC8113895 DOI: 10.1098/rsbl.2020.0913] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Antibiotic concentrations vary dramatically in the body and the environment. Hence, understanding the dynamics of resistance evolution along antibiotic concentration gradients is critical for predicting and slowing the emergence and spread of resistance. While it has been shown that increasing the concentration of an antibiotic slows resistance evolution, how adaptation to one antibiotic concentration correlates with fitness at other points along the gradient has not received much attention. Here, we selected populations of Escherichia coli at several points along a concentration gradient for three different antibiotics, asking how rapidly resistance evolved and whether populations became specialized to the antibiotic concentration they were selected on. Populations selected at higher concentrations evolved resistance more slowly but exhibited equal or higher fitness across the whole gradient. Populations selected at lower concentrations evolved resistance rapidly, but overall fitness in the presence of antibiotics was lower. However, these populations readily adapted to higher concentrations upon subsequent selection. Our results indicate that resistance management strategies must account not only for the rates of resistance evolution but also for the fitness of evolved strains.
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Affiliation(s)
- Mato Lagator
- IST Austria, Am Campus 1, 3400 Klosterneuburg, Austria.,School of Biological Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Hildegard Uecker
- IST Austria, Am Campus 1, 3400 Klosterneuburg, Austria.,Institute of Integrative Biology, ETH Zurich, 8092 Zurich, Switzerland.,Research group Stochastic Evolutionary Dynamics, Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany
| | - Paul Neve
- Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.,Department of Plant and Environmental Sciences, University of Copenhagen, Højbakkegård 9, Tåstrup 2630, Denmark
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22
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Czuppon P, Blanquart F, Uecker H, Débarre F. The Effect of Habitat Choice on Evolutionary Rescue in Subdivided Populations. Am Nat 2021; 197:625-643. [PMID: 33989144 DOI: 10.1086/714034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractEvolutionary rescue is the process by which a population, in response to an environmental change, successfully avoids extinction through adaptation. In spatially structured environments, dispersal can affect the probability of rescue. Here, we model an environment consisting of patches that degrade one after another, and we investigate the probability of rescue by a mutant adapted to the degraded habitat. We focus on the effects of dispersal and of immigration biases. We identify up to three regions delimiting the effect of dispersal on the probability of evolutionary rescue: (i) starting from low dispersal rates, the probability of rescue increases with dispersal; (ii) at intermediate dispersal rates, it decreases; and (iii) at large dispersal rates, it increases again with dispersal, except if mutants are too counterselected in not-yet-degraded patches. The probability of rescue is generally highest when mutant and wild-type individuals preferentially immigrate into patches that have already undergone environmental change. Additionally, we find that mutants that will eventually rescue the population most likely first appear in nondegraded patches. Overall, our results show that habitat choice, compared with the often-studied unbiased immigration scheme, can substantially alter the dynamics of population survival and adaptation to new environments.
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23
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Peniston JH, Barfield M, Holt RD, Orive ME. Environmental fluctuations dampen the effects of clonal reproduction on evolutionary rescue. J Evol Biol 2021; 34:710-722. [PMID: 33682225 DOI: 10.1111/jeb.13778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/19/2021] [Accepted: 02/22/2021] [Indexed: 12/27/2022]
Abstract
Evolutionary rescue occurs when genetic change allows a population to persist in response to an environmental change that would otherwise have led to extinction. Most studies of evolutionary rescue assume that species have either fully clonal or fully sexual reproduction; however, many species have partially clonal reproductive strategies in which they reproduce both clonally and sexually. Furthermore, the few evolutionary rescue studies that have evaluated partially clonal reproduction did not consider fluctuations in the environment, which are nearly ubiquitous in nature. Here, we use individual-based simulations to investigate how environmental fluctuations (either uncorrelated or positively autocorrelated) influence the effect of clonality on evolutionary rescue. We show that, for moderate magnitudes of environmental fluctuations, as was found in the absence of fluctuations, increasing the degree of clonality increases the probability of population persistence in response to an abrupt environmental change, but decreases persistence in response to a continuous, directional environmental change. However, with large magnitudes of fluctuations, both the benefits of clonality following a step change and the detrimental effects of clonality following a continuous, directional change are generally reduced; in fact, in the latter scenario, increasing clonality can even become beneficial if environmental fluctuations are autocorrelated. We also show that increased generational overlap dampens the effects of environmental fluctuations. Overall, we demonstrate that understanding the evolutionary rescue of partially clonal organisms requires not only knowledge of the species life history and the type of environmental change, but also an understanding of the magnitude and autocorrelation of environmental fluctuations.
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Affiliation(s)
- James H Peniston
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Michael Barfield
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Robert D Holt
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Maria E Orive
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS, USA
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24
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García-Ulloa MI, Escalante AE, Moreno-Letelier A, Eguiarte LE, Souza V. Evolutionary Rescue of an Environmental Pseudomonas otitidis in Response to Anthropogenic Perturbation. Front Microbiol 2021; 11:563885. [PMID: 33552002 PMCID: PMC7856823 DOI: 10.3389/fmicb.2020.563885] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 12/15/2020] [Indexed: 11/13/2022] Open
Abstract
Anthropogenic perturbations introduce novel selective pressures to natural environments, impacting the genomic variability of organisms and thus altering the evolutionary trajectory of populations. Water overexploitation for agricultural purposes and defective policies in Cuatro Cienegas, Coahuila, Mexico, have strongly impacted its water reservoir, pushing entire hydrological systems to the brink of extinction along with their native populations. Here, we studied the effects of continuous water overexploitation on an environmental aquatic lineage of Pseudomonas otitidis over a 13-year period which encompasses three desiccation events. By comparing the genomes of a population sample from 2003 (original state) and 2015 (perturbed state), we analyzed the demographic history and evolutionary response to perturbation of this lineage. Through coalescent simulations, we obtained a demographic model of contraction-expansion-contraction which points to the occurrence of an evolutionary rescue event. Loss of genomic and nucleotide variation alongside an increment in mean and variance of Tajima’s D, characteristic of sudden population expansions, support this observation. In addition, a significant increase in recombination rate (R/θ) was observed, pointing to horizontal gene transfer playing a role in population recovery. Furthermore, the gain of phosphorylation, DNA recombination, small-molecule metabolism and transport and loss of biosynthetic and regulatory genes suggest a functional shift in response to the environmental perturbation. Despite subsequent sampling events in the studied site, no pseudomonad was found until the lagoon completely dried in 2017. We speculate about the causes of P. otitidis final decline or possible extinction. Overall our results are evidence of adaptive responses at the genomic level of bacterial populations in a heavily exploited aquifer.
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Affiliation(s)
- Manuel Ii García-Ulloa
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
| | - Ana Elena Escalante
- Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
| | - Alejandra Moreno-Letelier
- Jardín Botánico, Instituto de Biología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
| | - Luis E Eguiarte
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
| | - Valeria Souza
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, Mexico
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25
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Burmeister AR, Hansen E, Cunningham JJ, Rego EH, Turner PE, Weitz JS, Hochberg ME. Fighting microbial pathogens by integrating host ecosystem interactions and evolution. Bioessays 2020; 43:e2000272. [PMID: 33377530 DOI: 10.1002/bies.202000272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/22/2020] [Accepted: 11/30/2020] [Indexed: 12/19/2022]
Abstract
Successful therapies to combat microbial diseases and cancers require incorporating ecological and evolutionary principles. Drawing upon the fields of ecology and evolutionary biology, we present a systems-based approach in which host and disease-causing factors are considered as part of a complex network of interactions, analogous to studies of "classical" ecosystems. Centering this approach around empirical examples of disease treatment, we present evidence that successful therapies invariably engage multiple interactions with other components of the host ecosystem. Many of these factors interact nonlinearly to yield synergistic benefits and curative outcomes. We argue that these synergies and nonlinear feedbacks must be leveraged to improve the study of pathogenesis in situ and to develop more effective therapies. An eco-evolutionary systems perspective has surprising and important consequences, and we use it to articulate areas of high research priority for improving treatment strategies.
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Affiliation(s)
- Alita R Burmeister
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA.,BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, USA
| | - Elsa Hansen
- Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Jessica J Cunningham
- Department of Integrated Mathematical Oncology, Moffitt Cancer Center & Research Institute, Tampa, Florida, USA
| | - E Hesper Rego
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Paul E Turner
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA.,BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, USA.,Program in Microbiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Joshua S Weitz
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA.,School of Physics, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Michael E Hochberg
- Institute of Evolutionary Sciences, University of Montpellier, Montpellier, France.,Santa Fe Institute, Santa Fe, New Mexico, USA
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26
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O'Connor LMJ, Fugère V, Gonzalez A. Evolutionary Rescue Is Mediated by the History of Selection and Dispersal in Diversifying Metacommunities. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.517434] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Rapid evolution can sometimes prevent population extirpation in stressful environments, but the conditions leading to “evolutionary rescue” in metacommunities are unclear. Here we studied the eco-evolutionary response of microbial metacommunities adapting to selection by the antibiotic streptomycin. Our experiment tested how the history of antibiotic selection and contrasting modes of dispersal influenced diversification and subsequent evolutionary rescue in microbial metacommunities undergoing adaptive radiation. We first tracked the change in diversity and density of Pseudomonas fluorescens morphotypes selected on a gradient of antibiotic stress. We then examined the recovery of these metacommunities following abrupt application of a high concentration of streptomycin lethal to the ancestral organisms. We show that dispersal increases diversity within the stressed metacommunities, that exposure to stress alters diversification dynamics, and that community composition, dispersal, and past exposure to stress mediate the speed at which evolutionary rescue occurs, but not the final outcome of recovery in abundance and diversity. These findings extend recent experiments on evolutionary rescue to the case of metacommunities undergoing adaptive diversification, and should motivate new theory on this question. Our findings are also relevant to evolutionary conservation biology and research on antimicrobial resistance.
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27
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Peniston JH, Barfield M, Gonzalez A, Holt RD. Environmental fluctuations can promote evolutionary rescue in high-extinction-risk scenarios. Proc Biol Sci 2020; 287:20201144. [PMID: 32752990 DOI: 10.1098/rspb.2020.1144] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Substantial environmental change can force a population onto a path towards extinction, but under some conditions, adaptation by natural selection can rescue the population and allow it to persist. This process, known as evolutionary rescue, is believed to be less likely to occur with greater magnitudes of random environmental fluctuations because environmental variation decreases expected population size, increases variance in population size and increases evolutionary lag. However, previous studies of evolutionary rescue in fluctuating environments have only considered scenarios in which evolutionary rescue was likely to occur. We extend these studies to assess how baseline extinction risk (which we manipulated via changes in the initial population size, degree of environmental change or mutation rate) influences the effects of environmental variation on evolutionary rescue following an abrupt environmental change. Using a combination of analytical models and stochastic simulations, we show that autocorrelated environmental variation hinders evolutionary rescue in low-extinction-risk scenarios but facilitates rescue in high-risk scenarios. In these high-risk cases, the chance of a run of good years counteracts the otherwise negative effects of environmental variation on evolutionary demography. These findings can inform the development of effective conservation practices that consider evolutionary responses to abrupt environmental changes.
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Affiliation(s)
- James H Peniston
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Michael Barfield
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Andrew Gonzalez
- Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Robert D Holt
- Department of Biology, University of Florida, Gainesville, FL, USA
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28
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Osmond MM, Coop G. Genetic Signatures of Evolutionary Rescue by a Selective Sweep. Genetics 2020; 215:813-829. [PMID: 32398227 PMCID: PMC7337082 DOI: 10.1534/genetics.120.303173] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 05/06/2020] [Indexed: 12/31/2022] Open
Abstract
One of the most useful models in population genetics is that of a selective sweep and the consequent hitch-hiking of linked neutral alleles. While variations on this model typically assume constant population size, many instances of strong selection and rapid adaptation in nature may co-occur with complex demography. Here, we extend the hitch-hiking model to evolutionary rescue, where adaptation and demography not only co-occur but are intimately entwined. Our results show how this feedback between demography and evolution determines-and restricts-the genetic signatures of evolutionary rescue, and how these differ from the signatures of sweeps in populations of constant size. In particular, we find rescue to harden sweeps from standing variance or new mutation (but not from migration), reduce genetic diversity both at the selected site and genome-wide, and increase the range of observed Tajima's D values. For a given initial rate of population decline, the feedback between demography and evolution makes all of these differences more dramatic under weaker selection, where bottlenecks are prolonged. Nevertheless, it is likely difficult to infer the co-incident timing of the sweep and bottleneck from these simple signatures, never mind a feedback between them. Temporal samples spanning contemporary rescue events may offer one way forward.
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Affiliation(s)
- Matthew M Osmond
- Center for Population Biology and Department of Evolution and Ecology, University of California, Davis, California 95616
| | - Graham Coop
- Center for Population Biology and Department of Evolution and Ecology, University of California, Davis, California 95616
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29
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Tomasini M, Peischl S. When does gene flow facilitate evolutionary rescue? Evolution 2020; 74:1640-1653. [DOI: 10.1111/evo.14038] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/03/2020] [Accepted: 06/06/2020] [Indexed: 12/28/2022]
Affiliation(s)
- Matteo Tomasini
- Interfaculty Bioinformatics UnitUniversity of Bern Bern 3012 Switzerland
- Computational and Molecular Population Genetics Laboratory, Institute of Ecology and EvolutionUniversity of Bern Bern 3012 Switzerland
- Swiss Institute for Bioinformatics Lausanne 1015 Switzerland
- Current Address: Department of Integrative BiologyMichigan State University East Lansing Michigan 48824
| | - Stephan Peischl
- Interfaculty Bioinformatics UnitUniversity of Bern Bern 3012 Switzerland
- Swiss Institute for Bioinformatics Lausanne 1015 Switzerland
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30
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Acosta MM, Bram JT, Sim D, Read AF. Effect of drug dose and timing of treatment on the emergence of drug resistance in vivo in a malaria model. Evol Med Public Health 2020; 2020:196-210. [PMID: 33209305 PMCID: PMC7652304 DOI: 10.1093/emph/eoaa016] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 05/15/2020] [Accepted: 05/26/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND OBJECTIVES There is a significant interest in identifying clinically effective drug treatment regimens that minimize the de novo evolution of antimicrobial resistance in pathogen populations. However, in vivo studies that vary treatment regimens and directly measure drug resistance evolution are rare. Here, we experimentally investigate the role of drug dose and treatment timing on resistance evolution in an animal model. METHODOLOGY In a series of experiments, we measured the emergence of atovaquone-resistant mutants of Plasmodium chabaudi in laboratory mice, as a function of dose or timing of treatment (day post-infection) with the antimalarial drug atovaquone. RESULTS The likelihood of high-level resistance emergence increased with atovaquone dose. When varying the timing of treatment, treating either very early or late in infection reduced the risk of resistance. When we varied starting inoculum, resistance was more likely at intermediate inoculum sizes, which correlated with the largest population sizes at time of treatment. CONCLUSIONS AND IMPLICATIONS (i) Higher doses do not always minimize resistance emergence and can promote the emergence of high-level resistance. (ii) Altering treatment timing affects the risk of resistance emergence, likely due to the size of the population at the time of treatment, although we did not test the effect of immunity whose influence may have been important in the case of late treatment. (iii) Finding the 'right' dose and 'right' time to maximize clinical gains and limit resistance emergence can vary depending on biological context and was non-trivial even in our simplified experiments. LAY SUMMARY In a mouse model of malaria, higher drug doses led to increases in drug resistance. The timing of drug treatment also impacted resistance emergence, likely due to the size of the population at the time of treatment.
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Affiliation(s)
- Mónica M Acosta
- Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA 16802, USA
| | - Joshua T Bram
- Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA 16802, USA
| | - Derek Sim
- Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA 16802, USA
| | - Andrew F Read
- Department of Biology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA 16802, USA
- Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA
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31
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Vinton AC, Vasseur DA. Evolutionary tracking is determined by differential selection on demographic rates and density dependence. Ecol Evol 2020; 10:5725-5736. [PMID: 32607186 PMCID: PMC7319176 DOI: 10.1002/ece3.6311] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 03/27/2020] [Accepted: 04/01/2020] [Indexed: 11/11/2022] Open
Abstract
Recent ecological forecasts predict that ~25% of species worldwide will go extinct by 2050. However, these estimates are primarily based on environmental changes alone and fail to incorporate important biological mechanisms such as genetic adaptation via evolution. Thus, environmental change can affect population dynamics in ways that classical frameworks can neither describe nor predict. Furthermore, often due to a lack of data, forecasting models commonly describe changes in population demography by summarizing changes in fecundity and survival concurrently with the intrinsic growth rate (r). This has been shown to be an oversimplification as the environment may impose selective pressure on specific demographic rates (birth and death) rather than directly on r (the difference between the birth and death rates). This differential pressure may alter population response to density, in each demographic rate, further diluting the information combined to produce r. Thus, when we consider the potential for persistence via adaptive evolution, populations with the same r can have different abilities to persist amidst environmental change. Therefore, we cannot adequately forecast population response to climate change without accounting for demography and selection on density dependence. Using a continuous-time Markov chain model to describe the stochastic dynamics of the logistic model of population growth and allow for trait evolution via mutations arising during birth events, we find persistence via evolutionary tracking more likely when environmental change alters birth rather than the death rate. Furthermore, species that evolve responses to changes in the strength of density dependence due to environmental change are less vulnerable to extinction than species that undergo selection independent of population density. By incorporating these key demographic considerations into our predictive models, we can better understand how species will respond to climate change.
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Affiliation(s)
| | - David Alan Vasseur
- Department of Ecology and Evolutionary BiologyYale UniversityNew HavenConnecticut
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32
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Fugère V, Hébert MP, da Costa NB, Xu CCY, Barrett RDH, Beisner BE, Bell G, Fussmann GF, Shapiro BJ, Yargeau V, Gonzalez A. Community rescue in experimental phytoplankton communities facing severe herbicide pollution. Nat Ecol Evol 2020; 4:578-588. [PMID: 32123321 DOI: 10.1038/s41559-020-1134-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 01/30/2020] [Indexed: 12/16/2022]
Abstract
Community rescue occurs when ecological or evolutionary processes restore positive growth in a highly stressful environment that was lethal to the community in its ancestral form, thus averting biomass collapse in a deteriorating environment. Laboratory evidence suggests that community rescue is most likely in high-biomass communities that have previously experienced moderate doses of sublethal stress. We assessed this result under more natural conditions, in a mesocosm experiment with phytoplankton communities exposed to the ubiquitous herbicide glyphosate. We tested whether community biomass and prior herbicide exposure would facilitate community rescue after severe contamination. We found that prior exposure to glyphosate was a very strong predictor of the rescue outcome, while high community biomass was not. Furthermore, although glyphosate had negative effects on diversity, it did not influence community composition significantly, suggesting a modest role for genus sorting in this rescue process. Our results expand the scope of community rescue theory to complex ecosystems and confirm that prior stress exposure is a key predictor of rescue.
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Affiliation(s)
- Vincent Fugère
- Department of Biology, McGill University, Montreal, Québec, Canada. .,Department of Biological Sciences, University of Québec at Montréal, Montreal, Québec, Canada.
| | - Marie-Pier Hébert
- Department of Biology, McGill University, Montreal, Québec, Canada.,Department of Biological Sciences, University of Québec at Montréal, Montreal, Québec, Canada
| | | | - Charles C Y Xu
- Department of Biology, McGill University, Montreal, Québec, Canada.,Redpath Museum, McGill University, Montreal, Québec, Canada
| | - Rowan D H Barrett
- Department of Biology, McGill University, Montreal, Québec, Canada.,Redpath Museum, McGill University, Montreal, Québec, Canada
| | - Beatrix E Beisner
- Department of Biological Sciences, University of Québec at Montréal, Montreal, Québec, Canada
| | - Graham Bell
- Department of Biology, McGill University, Montreal, Québec, Canada
| | | | - B Jesse Shapiro
- Département des Sciences Biologiques, Université de Montréal, Montreal, Québec, Canada
| | - Viviane Yargeau
- Department of Chemical Engineering, McGill University, Montreal, Québec, Canada
| | - Andrew Gonzalez
- Department of Biology, McGill University, Montreal, Québec, Canada.
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33
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Unckless RL, Orr HA. The Population Genetics of Evolutionary Rescue in Diploids: X Chromosomal versus Autosomal Rescue. Am Nat 2020; 195:561-568. [PMID: 32097044 DOI: 10.1086/707139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Most population genetic theory assumes that populations adapt to an environmental change without a change in population size. However, environmental changes might be so severe that populations decline in size and, without adaptation, become extinct. This "evolutionary rescue" scenario differs from traditional models of adaptation in that rescue involves a race between adaptation and extinction. While most previous work has usually focused on models of evolutionary rescue in haploids, here we consider diploids. In many species, diploidy introduces a novel feature into adaptation: adaptive evolution might occur either on sex chromosomes or on autosomes. Previous studies of nonrescue adaptation revealed that the relative rates of adaptation on the X chromosome versus autosomes depend on the dominance of beneficial mutations, reflecting differences in effective population size and the efficacy of selection. Here, we extend these results to evolutionary rescue and find that, given equal-sized chromosomes, there is greater parameter space in which the X is more likely to contribute to adaptation than the autosomes relative to standard nonrescue models. We also discuss how subtle effects of dominance can increase the chance of evolutionary rescue in diploids when absolute heterozygote fitness is close to 1. These effects do not arise in standard nonrescue models.
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34
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Barton S, Jenkins J, Buckling A, Schaum CE, Smirnoff N, Raven JA, Yvon-Durocher G. Evolutionary temperature compensation of carbon fixation in marine phytoplankton. Ecol Lett 2020; 23:722-733. [PMID: 32059265 PMCID: PMC7078849 DOI: 10.1111/ele.13469] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 01/11/2020] [Indexed: 12/01/2022]
Abstract
The efficiency of carbon sequestration by the biological pump could decline in the coming decades because respiration tends to increase more with temperature than photosynthesis. Despite these differences in the short‐term temperature sensitivities of photosynthesis and respiration, it remains unknown whether the long‐term impacts of global warming on metabolic rates of phytoplankton can be modulated by evolutionary adaptation. We found that respiration was consistently more temperature dependent than photosynthesis across 18 diverse marine phytoplankton, resulting in universal declines in the rate of carbon fixation with short‐term increases in temperature. Long‐term experimental evolution under high temperature reversed the short‐term stimulation of metabolic rates, resulting in increased rates of carbon fixation. Our findings suggest that thermal adaptation may therefore have an ameliorating impact on the efficiency of phytoplankton as primary mediators of the biological carbon pump.
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Affiliation(s)
- Samuel Barton
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - James Jenkins
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - Angus Buckling
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
| | - C-Elisa Schaum
- Institute for Hydrobiology and Fisheries, Section Oceanography, Hamburg University, 22767, Hamburg, Germany
| | - Nicholas Smirnoff
- Biosciences, College of Life and Environmental Sciences, Geoffrey Pope Building University of Exeter, Exeter, EX4 4QD, UK
| | - John A Raven
- Division of Plant Science, University of Dundee at the James Hutton Institute, Invergowrie, Dundee, DD2 5DA, UK.,Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia.,School of Biology, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Gabriel Yvon-Durocher
- Environment and Sustainability Institute, University of Exeter, Penryn Campus, Penryn, Cornwall, TR10 9FE, UK
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35
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Anciaux Y, Lambert A, Ronce O, Roques L, Martin G. Population persistence under high mutation rate: From evolutionary rescue to lethal mutagenesis. Evolution 2019; 73:1517-1532. [DOI: 10.1111/evo.13771] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 04/24/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Yoann Anciaux
- Bioinformatics Research Center (BiRC)Aarhus University C.F. Møllers Allé 8 8000 Aarhus Denmark
| | - Amaury Lambert
- Center for Interdisciplinary Research in Biology (CIRB), Collège de France, CNRS UMR 7241, INSERM U1050PSL Research University Paris France
- Laboratoire de Probabilités, Statistique et Modélisation (LPSM)Sorbonne Université CNRS UMR 8001 Paris France
| | - Ophélie Ronce
- Institut des Sciences de l'Evolution de MontpellierUniversité de Montpellier, CNRS, IRD, EPHE Montpellier France
| | | | - Guillaume Martin
- Institut des Sciences de l'Evolution de MontpellierUniversité de Montpellier, CNRS, IRD, EPHE Montpellier France
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36
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Rêgo A, Messina FJ, Gompert Z. Dynamics of genomic change during evolutionary rescue in the seed beetle
Callosobruchus maculatus. Mol Ecol 2019; 28:2136-2154. [DOI: 10.1111/mec.15085] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 03/18/2019] [Accepted: 03/18/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Alexandre Rêgo
- Department of Biology Utah State University Logan Utah
- Ecology Center Utah State University Logan Utah
| | - Frank J. Messina
- Department of Biology Utah State University Logan Utah
- Ecology Center Utah State University Logan Utah
| | - Zachariah Gompert
- Department of Biology Utah State University Logan Utah
- Ecology Center Utah State University Logan Utah
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37
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Raatz M, van Velzen E, Gaedke U. Co-adaptation impacts the robustness of predator-prey dynamics against perturbations. Ecol Evol 2019; 9:3823-3836. [PMID: 31015969 PMCID: PMC6468077 DOI: 10.1002/ece3.5006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/21/2019] [Accepted: 02/01/2019] [Indexed: 02/06/2023] Open
Abstract
Global change threatens the maintenance of ecosystem functions that are shaped by the persistence and dynamics of populations. It has been shown that the persistence of species increases if they possess larger trait adaptability. Here, we investigate whether trait adaptability also affects the robustness of population dynamics of interacting species and thereby shapes the reliability of ecosystem functions that are driven by these dynamics. We model co-adaptation in a predator-prey system as changes to predator offense and prey defense due to evolution or phenotypic plasticity. We investigate how trait adaptation affects the robustness of population dynamics against press perturbations to environmental parameters and against pulse perturbations targeting species abundances and their trait values. Robustness of population dynamics is characterized by resilience, elasticity, and resistance. In addition to employing established measures for resilience and elasticity against pulse perturbations (extinction probability and return time), we propose the warping distance as a new measure for resistance against press perturbations, which compares the shapes and amplitudes of pre- and post-perturbation population dynamics. As expected, we find that the robustness of population dynamics depends on the speed of adaptation, but in nontrivial ways. Elasticity increases with speed of adaptation as the system returns more rapidly to the pre-perturbation state. Resilience, in turn, is enhanced by intermediate speeds of adaptation, as here trait adaptation dampens biomass oscillations. The resistance of population dynamics strongly depends on the target of the press perturbation, preventing a simple relationship with the adaptation speed. In general, we find that low robustness often coincides with high amplitudes of population dynamics. Hence, amplitudes may indicate the robustness against perturbations also in other natural systems with similar dynamics. Our findings show that besides counteracting extinctions, trait adaptation indeed strongly affects the robustness of population dynamics against press and pulse perturbations.
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Affiliation(s)
- Michael Raatz
- Institute of Biochemistry and BiologyUniversity of PotsdamPotsdamGermany
| | - Ellen van Velzen
- Institute of Biochemistry and BiologyUniversity of PotsdamPotsdamGermany
| | - Ursula Gaedke
- Institute of Biochemistry and BiologyUniversity of PotsdamPotsdamGermany
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38
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Chavhan YD, Ali SI, Dey S. Larger Numbers Can Impede Adaptation in Asexual Populations despite Entailing Greater Genetic Variation. Evol Biol 2019. [DOI: 10.1007/s11692-018-9467-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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39
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Environmental pleiotropy and demographic history direct adaptation under antibiotic selection. Heredity (Edinb) 2018; 121:438-448. [PMID: 30190561 PMCID: PMC6180006 DOI: 10.1038/s41437-018-0137-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 07/10/2018] [Accepted: 07/12/2018] [Indexed: 01/10/2023] Open
Abstract
Evolutionary rescue following environmental change requires mutations permitting population growth in the new environment. If change is severe enough to prevent most of the population reproducing, rescue becomes reliant on mutations already present. If change is sustained, the fitness effects in both environments, and how they are associated—termed ‘environmental pleiotropy’—may determine which alleles are ultimately favoured. A population’s demographic history—its size over time—influences the variation present. Although demographic history is known to affect the probability of evolutionary rescue, how it interacts with environmental pleiotropy during severe and sustained environmental change remains unexplored. Here, we demonstrate how these factors interact during antibiotic resistance evolution, a key example of evolutionary rescue fuelled by pre-existing mutations with pleiotropic fitness effects. We combine published data with novel simulations to characterise environmental pleiotropy and its effects on resistance evolution under different demographic histories. Comparisons among resistance alleles typically revealed no correlation for fitness—i.e., neutral pleiotropy—above and below the sensitive strain’s minimum inhibitory concentration. Resistance allele frequency following experimental evolution showed opposing correlations with their fitness effects in the presence and absence of antibiotic. Simulations demonstrated that effects of environmental pleiotropy on allele frequencies depended on demographic history. At the population level, the major influence of environmental pleiotropy was on mean fitness, rather than the probability of evolutionary rescue or diversity. Our work suggests that determining both environmental pleiotropy and demographic history is critical for predicting resistance evolution, and we discuss the practicalities of this during in vivo evolution.
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40
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Landscape-Scale Factors Affecting the Prevalence of Escherichia coli in Surface Soil Include Land Cover Type, Edge Interactions, and Soil pH. Appl Environ Microbiol 2018. [PMID: 29523546 DOI: 10.1128/aem.02714-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli is deposited into soil with feces and exhibits subsequent population decline with concomitant environmental selection. Environmentally persistent strains exhibit longer survival times during this selection process, and some strains have adapted to soil and sediments. A georeferenced collection of E. coli isolates was developed comprising 3,329 isolates from 1,428 soil samples that were collected from a landscape spanning the transition from the grasslands to the eastern deciduous forest biomes. The isolate collection and sample database were analyzed together to discover how land cover, site characteristics, and soil chemistry influence the prevalence of cultivable E. coli in surface soil. Soils from forests and pasture lands had equally high prevalences of E. coli Edge interactions were also observed among land cover types, with proximity to forests and pastures affecting the likelihood of E. coli isolation from surrounding soils. E. coli is thought to be more prevalent in sediments with high moisture, but this was observed only in grass- or crop-dominated lands in this study. Because differing E. coli phylogroups are thought to have differing ecology profiles, isolates were also typed using a novel single-nucleotide polymorphism (SNP) genotyping assay. Phylogroup B1 was the dominant group isolated from soil, as has been reported in all other surveys of environmental E. coli Although differences were small, isolates belonging to phylogroups B2 and D were associated with wooded areas, slightly more acidic soils, and soil sampling after rainfall events. In contrast, isolates from phylogroups B1 and E were associated with pasture lands.IMPORTANCE The consensus is that complex niches or life cycles should select for complex genomes in organisms. There is much unexplained biodiversity in E. coli, and its cycling through complex extrahost environments may be a cause. In order to understand the evolutionary processes that lead to adaptation for survival and growth in soil, an isolate collection that associates soil conditions and isolate genome sequences is required. An equally important question is whether traits selected in soil or other extrahost habitats can be transmitted to E. coli residing in hosts via gene flow. The new findings about the distribution of E. coli in soil at the landscape scale (i) enhance our capability to study how extrahost environments influence the evolution of E. coli and other bacteria, (ii) advance our knowledge of the environmental biology of this microbe, and (iii) further affirm the emerging scientific consensus that E. coli in waterways originates from nonpoint sources not associated with human activity or livestock farming.
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41
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Kennedy DA, Read AF. Why does drug resistance readily evolve but vaccine resistance does not? Proc Biol Sci 2018; 284:rspb.2016.2562. [PMID: 28356449 PMCID: PMC5378080 DOI: 10.1098/rspb.2016.2562] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 02/28/2017] [Indexed: 01/12/2023] Open
Abstract
Why is drug resistance common and vaccine resistance rare? Drugs and vaccines both impose substantial pressure on pathogen populations to evolve resistance and indeed, drug resistance typically emerges soon after the introduction of a drug. But vaccine resistance has only rarely emerged. Using well-established principles of population genetics and evolutionary ecology, we argue that two key differences between vaccines and drugs explain why vaccines have so far proved more robust against evolution than drugs. First, vaccines tend to work prophylactically while drugs tend to work therapeutically. Second, vaccines tend to induce immune responses against multiple targets on a pathogen while drugs tend to target very few. Consequently, pathogen populations generate less variation for vaccine resistance than they do for drug resistance, and selection has fewer opportunities to act on that variation. When vaccine resistance has evolved, these generalities have been violated. With careful forethought, it may be possible to identify vaccines at risk of failure even before they are introduced.
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Affiliation(s)
- David A Kennedy
- Center for Infectious Disease Dynamics, Departments of Biology and Entomology, The Pennsylvania State University, University Park, PA, USA
| | - Andrew F Read
- Center for Infectious Disease Dynamics, Departments of Biology and Entomology, The Pennsylvania State University, University Park, PA, USA
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42
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Bleuven C, Landry CR. Molecular and cellular bases of adaptation to a changing environment in microorganisms. Proc Biol Sci 2017; 283:rspb.2016.1458. [PMID: 27798299 DOI: 10.1098/rspb.2016.1458] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 10/04/2016] [Indexed: 12/27/2022] Open
Abstract
Environmental heterogeneity constitutes an evolutionary challenge for organisms. While evolutionary dynamics under variable conditions has been explored for decades, we still know relatively little about the cellular and molecular mechanisms involved. It is of paramount importance to examine these molecular bases because they may play an important role in shaping the course of evolution. In this review, we examine the diversity of adaptive mechanisms in the face of environmental changes. We exploit the recent literature on microbial systems because those have benefited the most from the recent emergence of genetic engineering and experimental evolution followed by genome sequencing. We identify four emerging trends: (i) an adaptive molecular change in a pathway often results in fitness trade-off in alternative environments but the effects are dependent on a mutation's genetic background; (ii) adaptive changes often modify transcriptional and signalling pathways; (iii) several adaptive changes may occur within the same molecular pathway but be associated with pleiotropy of different signs across environments; (iv) because of their large associated costs, macromolecular changes such as gene amplification and aneuploidy may be a rapid mechanism of adaptation in the short-term only. The course of adaptation in a variable environment, therefore, depends on the complexity of the environment but also on the molecular relationships among the genes involved and between the genes and the phenotypes under selection.
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Affiliation(s)
- Clara Bleuven
- Département de Biologie, Université Laval, Québec, Québec, Canada .,Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, Canada.,PROTEO, The Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, Québec, Canada
| | - Christian R Landry
- Département de Biologie, Université Laval, Québec, Québec, Canada.,Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, Québec, Canada.,Big Data Research Center, Université Laval, Québec, Québec, Canada.,PROTEO, The Quebec Network for Research on Protein Function, Engineering, and Applications, Québec, Québec, Canada
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43
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Chevin LM, Cotto O, Ashander J. Stochastic Evolutionary Demography under a Fluctuating Optimum Phenotype. Am Nat 2017; 190:786-802. [PMID: 29166162 PMCID: PMC5958996 DOI: 10.1086/694121] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Many natural populations exhibit temporal fluctuations in abundance that are consistent with external forcing by a randomly changing environment. As fitness emerges from an interaction between the phenotype and the environment, such demographic fluctuations probably include a substantial contribution from fluctuating phenotypic selection. We study the stochastic population dynamics of a population exposed to random (plus possibly directional) changes in the optimum phenotype for a quantitative trait that evolves in response to this moving optimum. We derive simple analytical predictions for the distribution of log population size over time both transiently and at stationarity under Gompertz density regulation. These predictions are well matched by population- and individual-based simulations. The log population size is approximately reverse gamma distributed, with a negative skew causing an excess of low relative to high population sizes, thus increasing extinction risk relative to a symmetric (e.g., normal) distribution with the same mean and variance. Our analysis reveals how the mean and variance of log population size change with the variance and autocorrelation of deviations of the evolving mean phenotype from the optimum. We apply our results to the analysis of evolutionary rescue in a stochastic environment and show that random fluctuations in the optimum can substantially increase extinction risk by both reducing the expected growth rate and increasing the variance of population size by several orders of magnitude.
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Affiliation(s)
- Luis-Miguel Chevin
- CEFE UMR 5175, CNRS - Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, 1919 route de Mende, 34293 Montpellier, CEDEX 5, France
| | - Olivier Cotto
- CEFE UMR 5175, CNRS - Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, 1919 route de Mende, 34293 Montpellier, CEDEX 5, France
| | - Jaime Ashander
- CPB: Center for Population Biology, University of California-Davis, Davis, CA 95616, USA and UCLA Ecology & Evolutionary Biology, 610 Charles E Young Drive East, Terasaki Life Sciences Bldg Receiving Dock, Los Angeles, CA 90095
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44
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Affiliation(s)
- Graham Bell
- Biology Department, McGill University, Montreal, Quebec H3A 1B1, Canada
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45
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Gralka M, Fusco D, Martis S, Hallatschek O. Convection shapes the trade-off between antibiotic efficacy and the selection for resistance in spatial gradients. Phys Biol 2017; 14:045011. [PMID: 28649977 PMCID: PMC5728155 DOI: 10.1088/1478-3975/aa7bb3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Since penicillin was discovered about 90 years ago, we have become used to using drugs to eradicate unwanted pathogenic cells. However, using drugs to kill bacteria, viruses or cancer cells has the serious side effect of selecting for mutant types that survive the drug attack. A crucial question therefore is how one could eradicate as many cells as possible for a given acceptable risk of drug resistance evolution. We address this general question in a model of drug resistance evolution in spatial drug gradients, which recent experiments and theories have suggested as key drivers of drug resistance. Importantly, our model takes into account the influence of convection, resulting for instance from blood flow. Using stochastic simulations, we study the fates of individual resistance mutations and quantify the trade-off between the killing of wild-type cells and the rise of resistance mutations: shallow gradients and convection into the antibiotic region promote wild-type death, at the cost of increasing the establishment probability of resistance mutations. We can explain these observed trends by modeling the adaptation process as a branching random walk. Our analysis reveals that the trade-off between death and adaptation depends on the relative length scales of the spatial drug gradient and random dispersal, and the strength of convection. Our results show that convection can have a momentous effect on the rate of establishment of new mutations, and may heavily impact the efficiency of antibiotic treatment.
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Affiliation(s)
- Matti Gralka
- Department of Physics, University of California, Berkeley, CA 94720, United States of America
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46
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Gomulkiewicz R, Krone SM, Remien CH. Evolution and the duration of a doomed population. Evol Appl 2017; 10:471-484. [PMID: 28515780 PMCID: PMC5427677 DOI: 10.1111/eva.12467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/26/2017] [Indexed: 01/05/2023] Open
Abstract
Many populations are doomed to extinction, but little is known about how evolution contributes to their longevity. We address this by modeling an asexual population consisting of genotypes whose abundances change independently according to a system of continuous branching diffusions. Each genotype is characterized by its initial abundance, growth rate, and reproductive variance. The latter two components determine the genotype's "risk function" which describes its per capita probability of extinction at any time. We derive the probability distribution of extinction times for a polymorphic population, which can be expressed in terms of genotypic risk functions. We use this to explore how spontaneous mutation, abrupt environmental change, or population supplementation and removal affect the time to extinction. Results suggest that evolution based on new mutations does little to alter the time to extinction. Abrupt environmental changes that affect all genotypes can have more substantial impact, but, curiously, a beneficial change does more to extend the lifetime of thriving than threatened populations of the same initial abundance. Our results can be used to design policies that meet specific conservation goals or management strategies that speed the elimination of agricultural pests or human pathogens.
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47
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Bay RA, Rose N, Barrett R, Bernatchez L, Ghalambor CK, Lasky JR, Brem RB, Palumbi SR, Ralph P. Predicting Responses to Contemporary Environmental Change Using Evolutionary Response Architectures. Am Nat 2017; 189:463-473. [DOI: 10.1086/691233] [Citation(s) in RCA: 95] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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48
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Killeen J, Gougat-Barbera C, Krenek S, Kaltz O. Evolutionary rescue and local adaptation under different rates of temperature increase: a combined analysis of changes in phenotype expression and genotype frequency in Paramecium microcosms. Mol Ecol 2017; 26:1734-1746. [PMID: 28222239 DOI: 10.1111/mec.14068] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 02/03/2017] [Accepted: 02/09/2017] [Indexed: 12/30/2022]
Abstract
Evolutionary rescue (ER) occurs when populations, which have declined due to rapid environmental change, recover through genetic adaptation. The success of this process and the evolutionary trajectory of the population strongly depend on the rate of environmental change. Here we investigated how different rates of temperature increase (from 23 to 32 °C) affect population persistence and evolutionary change in experimental microcosms of the protozoan Paramecium caudatum. Consistent with theory on ER, we found that those populations experiencing the slowest rate of temperature increase were the least likely to become extinct and tended to be the best adapted to the new temperature environment. All high-temperature populations were more tolerant to severe heat stress (35, 37 °C), indicating a common mechanism of heat protection. High-temperature populations also had superior growth rates at optimum temperatures, leading to the absence of a pattern of local adaptation to control (23 °C) and high-temperature (32 °C) environments. However, high-temperature populations had reduced growth at low temperatures (5-9 °C), causing a shift in the temperature niche. In part, the observed evolutionary change can be explained by selection from standing variation. Using mitochondrial markers, we found complete divergence between control and high-temperature populations in the frequencies of six initial founder genotypes. Our results confirm basic predictions of ER and illustrate how adaptation to an extreme local environment can produce positive as well as negative correlated responses to selection over the entire range of the ecological niche.
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Affiliation(s)
- Joshua Killeen
- Institut des Sciences de l'Evolution Montpellier, UMR5554, Université de Montpellier, CC065, Place E. Bataillon, 34095, Montpellier Cedex 5, France
| | - Claire Gougat-Barbera
- Institut des Sciences de l'Evolution Montpellier, UMR5554, Université de Montpellier, CC065, Place E. Bataillon, 34095, Montpellier Cedex 5, France
| | - Sascha Krenek
- Institute of Hydrobiology, Technische Universität Dresden, 01062, Dresden, Germany
| | - Oliver Kaltz
- Institut des Sciences de l'Evolution Montpellier, UMR5554, Université de Montpellier, CC065, Place E. Bataillon, 34095, Montpellier Cedex 5, France
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Bono LM, Gensel CL, Pfennig DW, Burch CL. Evolutionary rescue and the coexistence of generalist and specialist competitors: an experimental test. Proc Biol Sci 2017; 282:20151932. [PMID: 26702041 DOI: 10.1098/rspb.2015.1932] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Competition for resources is thought to play a critical role in both the origins and maintenance of biodiversity. Although numerous laboratory evolution experiments have confirmed that competition can be a key driver of adaptive diversification, few have demonstrated its role in the maintenance of the resulting diversity. We investigate the conditions that favour the origin and maintenance of alternative generalist and specialist resource-use phenotypes within the same population. Previously, we confirmed that competition for hosts among φ6 bacteriophage in a mixed novel (non-permissive) and ancestral (permissive) host microcosm triggered the evolution of a generalist phenotype capable of infecting both hosts. However, because the newly evolved generalists tended to competitively exclude the ancestral specialists, coexistence between the two phenotypes was rare. Here, we show that reducing the relative abundance of the novel host slowed the increase in frequency of the generalist phenotype, allowing sufficient time for the specialist to further adapt to the ancestral host. This adaptation resulted in 'evolutionary rescue' of the specialists, preventing their competitive exclusion by the generalists. Thus, our results suggest that competition promotes both the origin and maintenance of biodiversity when it is strong enough to favour a novel resource-use phenotype, but weak enough to allow adaptation of both the novel and ancestral phenotypes to their respective niches.
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Affiliation(s)
- Lisa M Bono
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280, USA Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520-8106, USA
| | - Catharine L Gensel
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280, USA
| | - David W Pfennig
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280, USA
| | - Christina L Burch
- Department of Biology, University of North Carolina, Chapel Hill, NC 27599-3280, USA
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Antibiotic stress selects against cooperation in the pathogenic bacterium Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 2017; 114:546-551. [PMID: 28049833 DOI: 10.1073/pnas.1612522114] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cheats are a pervasive threat to public goods production in natural and human communities, as they benefit from the commons without contributing to it. Although ecological antagonisms such as predation, parasitism, competition, and abiotic environmental stress play key roles in shaping population biology, it is unknown how such stresses generally affect the ability of cheats to undermine cooperation. We used theory and experiments to address this question in the pathogenic bacterium, Pseudomonas aeruginosa Although public goods producers were selected against in all populations, our competition experiments showed that antibiotics significantly increased the advantage of nonproducers. Moreover, the dominance of nonproducers in mixed cultures was associated with higher resistance to antibiotics than in either monoculture. Mathematical modeling indicates that accentuated costs to producer phenotypes underlie the observed patterns. Mathematical analysis further shows how these patterns should generalize to other taxa with public goods behaviors. Our findings suggest that explaining the maintenance of cooperative public goods behaviors in certain natural systems will be more challenging than previously thought. Our results also have specific implications for the control of pathogenic bacteria using antibiotics and for understanding natural bacterial ecosystems, where subinhibitory concentrations of antimicrobials frequently occur.
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