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Connelly AD, Ryan MJ. Phenotypic Variation in an Asexual-Sexual Fish System: Visual Lateralization. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.605943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Sexual reproduction is nearly ubiquitous in the vertebrate world, yet its evolution and maintenance remain a conundrum due to the cost of males. Conversely, asexually reproducing species should enjoy a twofold population increase and thus replace sexual species all else being equal, but the prevalence of asexual species is rare. However, stable coexistence between asexuals and sexuals does occur and can shed light on the mechanisms asexuals may use in order to persist in this sex-dominated world. The asexual Amazon molly (Poecilia formosa) is required to live in sympatry with one of its sexual sperm hosts –sailfin molly (Poecilia latipinna) and Atlantic molly (Poecilia mexicana)—and are ecological equivalents to their host species in nearly every way except for reproductive method. Here, we compare the visual lateralization between Amazon mollies and sailfin mollies from San Marcos, Texas. Neither Amazon mollies nor sailfin mollies exhibited a significant eye bias. Additionally, Amazon mollies exhibited similar levels of variation in visual lateralization compared to the sailfin molly. Further investigation into the source of this variation –clonal lineages or plasticity—is needed to better understand the coexistence of this asexual-sexual system.
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2
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Schwabl P, Imamura H, Van den Broeck F, Costales JA, Maiguashca-Sánchez J, Miles MA, Andersson B, Grijalva MJ, Llewellyn MS. Meiotic sex in Chagas disease parasite Trypanosoma cruzi. Nat Commun 2019; 10:3972. [PMID: 31481692 PMCID: PMC6722143 DOI: 10.1038/s41467-019-11771-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 07/27/2019] [Indexed: 12/11/2022] Open
Abstract
Genetic exchange enables parasites to rapidly transform disease phenotypes and exploit new host populations. Trypanosoma cruzi, the parasitic agent of Chagas disease and a public health concern throughout Latin America, has for decades been presumed to exchange genetic material rarely and without classic meiotic sex. We present compelling evidence from 45 genomes sequenced from southern Ecuador that T. cruzi in fact maintains truly sexual, panmictic groups that can occur alongside others that remain highly clonal after past hybridization events. These groups with divergent reproductive strategies appear genetically isolated despite possible co-occurrence in vectors and hosts. We propose biological explanations for the fine-scale disconnectivity we observe and discuss the epidemiological consequences of flexible reproductive modes. Our study reinvigorates the hunt for the site of genetic exchange in the T. cruzi life cycle, provides tools to define the genetic determinants of parasite virulence, and reforms longstanding theory on clonality in trypanosomatid parasites.
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Affiliation(s)
- Philipp Schwabl
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Hideo Imamura
- Unit of Molecular Parasitology, Institute of Tropical Medicine Antwerp, 155 Nationalestraat, 2000, Antwerp, Belgium
| | - Frederik Van den Broeck
- Unit of Molecular Parasitology, Institute of Tropical Medicine Antwerp, 155 Nationalestraat, 2000, Antwerp, Belgium
| | - Jaime A Costales
- Center for Research on Health in Latin America, School of Biological Sciences, Pontifical Catholic University of Ecuador, Quito, Ecuador
| | - Jalil Maiguashca-Sánchez
- Center for Research on Health in Latin America, School of Biological Sciences, Pontifical Catholic University of Ecuador, Quito, Ecuador
| | - Michael A Miles
- London School of Hygiene & Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Bjorn Andersson
- Department of Cell and Molecular Biology, Science for Life Laboratory, Karolinska Institutet, Biomedicum 9C, 171 77, Stockholm, Sweden
| | - Mario J Grijalva
- Center for Research on Health in Latin America, School of Biological Sciences, Pontifical Catholic University of Ecuador, Quito, Ecuador
- Infectious and Tropical Disease Institute, Biomedical Sciences Department, Heritage College of Osteopathic Medicine, Ohio University, 45701, Athens, OH, USA
| | - Martin S Llewellyn
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK.
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3
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Amat I, van Alphen JJ, Kacelnik A, Desouhant E, Bernstein C. Adaptations to different habitats in sexual and asexual populations of parasitoid wasps: a meta-analysis. PeerJ 2017; 5:e3699. [PMID: 28924495 PMCID: PMC5600175 DOI: 10.7717/peerj.3699] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/26/2017] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Coexistence of sexual and asexual populations remains a key question in evolutionary ecology. We address the question how an asexual and a sexual form of the parasitoid Venturia canescens can coexist in southern Europe. We test the hypothesis that both forms are adapted to different habitats within their area of distribution. Sexuals inhabit natural environments that are highly unpredictable, and where density of wasps and their hosts is low and patchily distributed. Asexuals instead are common in anthropic environments (e.g., grain stores) where host outbreaks offer periods when egg-load is the main constraint on reproductive output. METHODS We present a meta-analysis of known adaptations to these habitats. Differences in behavior, physiology and life-history traits between sexual and asexual wasps were standardized in term of effect size (Cohen's d value; Cohen, 1988). RESULTS Seeking consilience from the differences between multiple traits, we found that sexuals invest more in longevity at the expense of egg-load, are more mobile, and display higher plasticity in response to thermal variability than asexual counterparts. DISCUSSION Thus, each form has consistent multiple adaptations to the ecological circumstances in the contrasting environments.
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Affiliation(s)
- Isabelle Amat
- UMR CNRS 5558 Biométrie et Biologie Evolutive, Univ Lyon; Université Claude Bernard (Lyon I), Villeurbanne, France
| | | | - Alex Kacelnik
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Emmanuel Desouhant
- UMR CNRS 5558 Biométrie et Biologie Evolutive, Univ Lyon; Université Claude Bernard (Lyon I), Villeurbanne, France
| | - Carlos Bernstein
- UMR CNRS 5558 Biométrie et Biologie Evolutive, Univ Lyon; Université Claude Bernard (Lyon I), Villeurbanne, France
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Vrijenhoek RC, Pfeiler E, Wetherington JD. BALANCING SELECTION IN A DESERT STREAM‐DWELLING FISH,
POECILIOPSIS MONACHA. Evolution 2017; 46:1642-1657. [DOI: 10.1111/j.1558-5646.1992.tb01159.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/1991] [Accepted: 03/07/1992] [Indexed: 11/28/2022]
Affiliation(s)
- Robert C. Vrijenhoek
- Center for Theoretical and Applied Genetics Rutgers University New Brunswick NJ 08903–0231 USA
| | - Edward Pfeiler
- Departamento de Ciencias Marinas Instituto Tecnológico y de Estudios Superiores de Monterrey Guaymas Sonora 85400 MEXICO
| | - Jeffrey D. Wetherington
- Center for Theoretical and Applied Genetics Rutgers University New Brunswick NJ 08903–0231 USA
- Agricultural Products Division Dupont Company Wilmington DE 19880‐0402 USA
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5
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Wetherington JD, Kotora KE, Vrijenhoek RC. A TEST OF THE SPONTANEOUS HETEROSIS HYPOTHESIS FOR UNISEXUAL VERTEBRATES. Evolution 2017; 41:721-731. [DOI: 10.1111/j.1558-5646.1987.tb05848.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/1986] [Accepted: 02/19/1987] [Indexed: 11/27/2022]
Affiliation(s)
- Jeffrey D. Wetherington
- Department of Biological Sciences and Bureau of Biological Research Rutgers University P.O. Box 1059 Piscataway NJ 08855
| | - Karen E. Kotora
- Department of Biological Sciences and Bureau of Biological Research Rutgers University P.O. Box 1059 Piscataway NJ 08855
| | - Robert C. Vrijenhoek
- Department of Biological Sciences and Bureau of Biological Research Rutgers University P.O. Box 1059 Piscataway NJ 08855
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6
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Jokela J, Lively CM, Fox JA, Dybdahl MF. FLAT REACTION NORMS AND "FROZEN" PHENOTYPIC VARIATION IN CLONAL SNAILS (POTAMOPYRGUS ANTIPODARUM). Evolution 2017; 51:1120-1129. [PMID: 28565497 DOI: 10.1111/j.1558-5646.1997.tb03959.x] [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: 11/08/1996] [Accepted: 04/21/1997] [Indexed: 11/27/2022]
Abstract
The Frozen Niche-Variation hypothesis (FNV) suggests that clones randomly sample and "freeze" the genotypes of their ancestral sexual populations. Hence, each clone expresses only a fraction of the total niche-use variation observed in the sexual population, which may lead to selection for ecological specialization and coexistence of clones. A generalized form of the FNV model suggests that the same is true for life-history (as well as other) traits that have important fitness consequences, but do not relate directly to niche use. We refer to the general form of the model as the Frozen Phenotypic Variation (FPV) model. A mixed population of sexual and parthenogenetic snails (Potamopyrgus antipodarum) in a New Zealand lake allowed us to examine the phenotypic variation expressed by coexisting clones in two benthic habitats, and to compare that variation to the sexual population. Three clones were found primarily in an aquatic macrophyte zone composed of Isoetes kirkii (1.5-3.0 m deep), and three additional clones were found in a deeper macrophyte zone composed of Elodea canadensis (4.0-6.0 m deep). These clones showed significant variation between habitats, which mirrored that observed in the sexual population. Specifically, clones and sexuals from the deeper habitat matured at a larger size and had larger broods. There was also significant among-clone variation within habitats; and as expected under the FPV model, the within-clone coefficients of variation for size at maturity were low in both habitats when compared to the sexual population. In addition, we found four clones that were common in both macrophyte zones. The reaction norms of these clones were flat across habitats, suggesting little phenotypic plasticity for morphology or life-history traits. Flat reaction norms, high among-clone variation, and low coefficients of variation (relative to the sexual population) are in accordance with the FPV model for the origin of clonal lineages. We also measured the prevalence of infection by trematode larvae to determine whether clones are inherently more or less infectable, or whether they are freezing phenotypic variation for resistance from the sexual population. We did this in the deep habitats of the lake where recycling of the parasite by the vertebrate host is unlikely, thereby reducing the complications raised by frequency-dependent responses of parasites to host genotypes. We found no indication that clones are either more or less infectable than the resident sexual population. Taken together, our results suggest that phenotypic variation for both life-history traits and resistance to parasites is frozen by clones from the local sexual population.
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Affiliation(s)
- Jukka Jokela
- Department of Biology, Indiana University, Bloomington, Indiana, 47405
| | - Curtis M Lively
- Department of Biology, Indiana University, Bloomington, Indiana, 47405
| | - Jennifer A Fox
- Department of Biology, Indiana University, Bloomington, Indiana, 47405
| | - Mark F Dybdahl
- Department of Biology, Indiana University, Bloomington, Indiana, 47405
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7
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Semlitsch RD, Hotz H, Guex GD. COMPETITION AMONG TADPOLES OF COEXISTING HEMICLONES OF HYBRIDOGENETIC RANA ESCULENTA: SUPPORT FOR THE FROZEN NICHE VARIATION MODEL. Evolution 2017; 51:1249-1261. [PMID: 28565500 DOI: 10.1111/j.1558-5646.1997.tb03972.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/1996] [Accepted: 02/26/1997] [Indexed: 11/28/2022]
Abstract
Vertebrate animals reproducing without genetic recombination typically are hybrids, which have large ranges, are locally abundant, and live in disturbed or harsh habitats. This holds for the hemiclonal hybridogenetic frog Rana esculenta: it is widespread in Europe and commonly is found in disturbed habitats such as gravel pits. We hypothesize that its widespread occurrence may either be the result of natural selection for a single hemiclone acting as a broadly adapted "general-purpose" genotype, or of interclonal selection, which maintains multiple hemiclones that each are relatively narrowly adapted and perform differently across environments, that is, the Frozen Niche Variation model. We tested these competing hypotheses using 1000-L outdoor artificial ponds to rear tadpoles of the parental species (Rana lessonae [LL] and Rana ridibunda [RR]) alone, and each of three hemiclones of Rana esculenta (GUT1, GUT2, GUT3) alone, and in mixed hemiclonal populations from hatching to metamorphosis. Tadpoles of three coexisting hemiclones from a single natural population (near Gütighausen, Switzerland) were reared in both two- and three-way mixtures in equal total numbers at high and low density. For each species and hemiclone, the proportion of tadpoles metamorphosing decreased as the density of tadpoles increased, with the three hemiclones spanning the range of values exhibited by the two parental species. LL and GUT1 tadpoles produced the highest proportion of metamorphs, whereas tadpoles of RR produced the fewest metamorphs at both densities. GUT1 tadpoles also produced the largest metamorphs at low density, GUT2 and GUT3 tadpoles produced smaller metamorphs than did GUT1 tadpoles at the low density, but the three hemiclones did not differ from each other at high density. The parental species (LL and RR) were intermediate in metamorphic size to the hemiclones at low density, but all genotypes converged on a similar size at high density. Length of the larval period also was affected by density, but its effect was dependent on genotype. GUT1 tadpoles had the shortest larval period at the low density, but larval period was longer and not different between GUT1, GUT3, and LL at high density. RR tadpoles had the longest larval period at both densities. The most dramatic results were that three genotypes (GUT1, GUT2, and RR) maintained rank order and increased days to metamorphosis from low to high density, whereas two genotypes (GUT3 and LL) changed rank order and decreased days to metamorphosis from low to high density. Mixtures of hemiclones in two- and three-way combinations facilitated the proportion of tadpoles metamorphosing for GUT1 and GUT2 at both densities, but only at the low density for GUT3 tadpoles. Results from this experiment are incompatible with the General-Purpose Genotype model as a global explanation of hybrid abundance in these frogs. Alternatively, the Frozen Niche Variation prediction of general performance superiority of clonal mixtures relative to single clone populations is strongly supported. The data confirm that fitness advantages of hemiclones change, depending on the environment, such that in temporally and spatially heterogeneous habitats like ponds, frequency-dependent selection among hemiclones may promote coexistence in hemiclonal assemblages. Yet, differential dispersal or colonization ability and historical factors affecting hemiclone distribution may also be important in shaping patterns of clonal coexistence.
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Affiliation(s)
| | - Hansjürg Hotz
- Zoological Museum, University of Zürich, CH-8057, Zürich, Switzerland
| | - Gaston-Denis Guex
- Zoological Museum, University of Zürich, CH-8057, Zürich, Switzerland
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8
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Wetherington JD, Weeks SC, Kotora KE, Vrijenhoek RC. GENOTYPIC AND ENVIRONMENTAL COMPONENTS OF VARIATION IN GROWTH AND REPRODUCTION OF FISH HEMICLONES (POECILIOPSIS: POECILIIDAE). Evolution 2017; 43:635-645. [PMID: 28568401 DOI: 10.1111/j.1558-5646.1989.tb04258.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/1988] [Accepted: 01/23/1989] [Indexed: 11/26/2022]
Abstract
The frozen-niche-variation model was proposed to account for the coexistence of genetically related clones in naturally occurring unisexual populations. This model is based on two assumptions: 1) ecologically different clones have multiple independent origins from sexual ancestors; and 2) the population of sexual ancestors contains genetic variability for ecologically relevant traits. To test these assumptions, we produced 14 new "hemiclones" (nonrecombining haploid genotypes) of fish (Poeciliopsis: Poeciliidae). Our ability to synthesize many new hemiclones demonstrates the feasibility of multiple independent origins of nonrecombining genotypes. A substantial proportion (10-50%) of the phenotypic variation among hemiclones in size at birth, juvenile growth rate, and fecundity had a genetic basis. Thus, we conclude that multiple origins can give rise to an assemblage of genetically distinct hemiclones, each with a unique combination of life-history traits. Additionally, a comparative analysis of two natural hemiclones revealed that the synthetic strains represent a broad field of variation from which natural hemiclones can be selected.
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Affiliation(s)
- Jeffrey D Wetherington
- Center for Theoretical and Applied Genetics, Cook College, Rutgers University, P.O. Box 231, New Brunswick, NJ, 08903
| | - Stephen C Weeks
- Center for Theoretical and Applied Genetics, Cook College, Rutgers University, P.O. Box 231, New Brunswick, NJ, 08903
| | - Karen E Kotora
- Center for Theoretical and Applied Genetics, Cook College, Rutgers University, P.O. Box 231, New Brunswick, NJ, 08903
| | - Robert C Vrijenhoek
- Center for Theoretical and Applied Genetics, Cook College, Rutgers University, P.O. Box 231, New Brunswick, NJ, 08903
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9
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Dawley RM, Goddard KA. DIPLOID-TRIPLOID MOSAICS AMONG UNISEXUAL HYBRIDS OF THE MINNOWS PHOXINUS EOS
AND PHOXINUS NEOGAEUS. Evolution 2017; 42:649-659. [DOI: 10.1111/j.1558-5646.1988.tb02484.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/1987] [Accepted: 01/29/1988] [Indexed: 11/30/2022]
Affiliation(s)
- Robert M. Dawley
- Section of Ecology and Systematics; Cornell University; Ithaca NY 14850
| | - Kathryn A. Goddard
- Department of Ecology and Evolutionary Biology; University of Connecticut; Storrs CT 06268
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10
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Fox JA, Dybdahl MF, Jokela J, Lively CM. GENETIC STRUCTURE OF COEXISTING SEXUAL AND CLONAL SUBPOPULATIONS IN A FRESHWATER SNAIL (POTAMOPYRGUS ANTIPODARUM). Evolution 2017; 50:1541-1548. [PMID: 28565708 DOI: 10.1111/j.1558-5646.1996.tb03926.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/1995] [Accepted: 09/19/1995] [Indexed: 11/28/2022]
Abstract
We examined clonal diversity and the distribution of both clonal and sexual genotypes in a single population of freshwater snails (Potamopyrgus antipodarum) in which diploid sexual individuals and triploid parthenogens coexist. A genetic analysis of individuals from three habitat zones in Lake Alexandrina, New Zealand revealed extremely high clonal diversity: 165 genotypes among 605 clonal individuals. The frequency of triploid clonal individuals increased with increasing depth in the lake, and most of the individual clones were habitat specific, suggesting that differences among habitats are important in structuring the clonal subpopulation. There were also high levels of clonal diversity within habitats, suggesting frequent origins of habitat-specific clones. In contrast, diploid sexual individuals were proportionately more common in the shallow regions of the lake (where infection by trematode larvae is highest), and there was no significant spatial structure in the sexual subpopulation. We suggest that habitat specialization by clones, as well as parasite-mediated selection against common clones, are important factors affecting the structure of this mixed population of sexual and clonal snails.
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Affiliation(s)
- Jennifer A Fox
- Department of Biology, Indiana University, Bloomington, Indiana, 47405
| | - Mark F Dybdahl
- Department of Biology, Indiana University, Bloomington, Indiana, 47405
| | - Jukka Jokela
- Department of Biology, Indiana University, Bloomington, Indiana, 47405.,Laboratory of Ecological Zoology, University of Turku, FIN-20500, Finland
| | - Curtis M Lively
- Department of Biology, Indiana University, Bloomington, Indiana, 47405
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11
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Vrijenhoek RC, Pfeiler E. DIFFERENTIAL SURVIVAL OF SEXUAL AND ASEXUAL
POECILIOPSIS
DURING ENVIRONMENTAL STRESS. Evolution 2017; 51:1593-1600. [DOI: 10.1111/j.1558-5646.1997.tb01482.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/1997] [Accepted: 06/03/1997] [Indexed: 12/01/2022]
Affiliation(s)
- Robert C. Vrijenhoek
- Center for Theoretical and Applied Genetics Rutgers University New Brunswick New Jersey 08903‐0231
| | - Edward Pfeiler
- Departamento de Ciencias Marinas Instituto Tecnológico y de Estudios Superiores de Monterrey Guaymas Sonora 85400 Mexico
- Department of Biology Arizona State University Tempe Arizona 85287‐1501 Mexico
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12
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Kirkendall LR, Stenseth NC. ECOLOGICAL AND EVOLUTIONARY STABILITY OF SPERM-DEPENDENT PARTHENOGENESIS: EFFECTS OF PARTIAL NICHE OVERLAP BETWEEN SEXUAL AND ASEXUAL FEMALES. Evolution 2017; 44:698-714. [DOI: 10.1111/j.1558-5646.1990.tb05949.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/1988] [Accepted: 12/20/1989] [Indexed: 11/28/2022]
Affiliation(s)
- Lawrence R. Kirkendall
- Division of Zoology, Department of Biology; University of Oslo; P.O. Box 1050, Blindern N-0316 Oslo 3 NORWAY
| | - Nils Chr. Stenseth
- Division of Zoology, Department of Biology; University of Oslo; P.O. Box 1050, Blindern N-0316 Oslo 3 NORWAY
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13
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Browne RA, Hoopes CW. GENOTYPE DIVERSITY AND SELECTION IN ASEXUAL BRINE SHRIMP (ARTEMIA). Evolution 2017; 44:1035-1051. [PMID: 28569030 DOI: 10.1111/j.1558-5646.1990.tb03824.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1988] [Accepted: 11/01/1989] [Indexed: 11/25/2022]
Abstract
An obligately asexual population of Artemia parthenogenetica at Salin de Giraud, France consists of numerous clones that are genetically and ecologically divergent. The clones are distributed in a nonrandom fashion among eight ponds of highly variable environments. A total of 63 allozymically unique genotypes were identified, with significant differences in numerous fitness traits found among a sample subset of clones. The frequencies of four alleles, as well as the percentage of loci polymorphic, were significantly correlated with salinity. Genotypes face rapid selection along salinity gradients in the field and this selection is reproducible in the lab. mtDNA analysis suggests that obligate asexuality in this population is of monophyletic origin.
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Affiliation(s)
- Robert A Browne
- Biology Department, Wake Forest University, Winston-Salem, North Carolina, 27109, USA.,State University of Ghent, Ghent, BELGIUM
| | - Charles W Hoopes
- Biology Department, Wake Forest University, Winston-Salem, North Carolina, 27109, USA
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14
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Lehto MP, Haag CR. Ecological differentiation between coexisting sexual and asexual strains of Daphnia pulex. J Anim Ecol 2010; 79:1241-50. [DOI: 10.1111/j.1365-2656.2010.01726.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Turcotte MM, Pires MN, Vrijenhoek RC, Reznick DN. Pre- and post-fertilization maternal provisioning in livebearing fish species and their hybrids (Poeciliidae:Poeciliopsis). Funct Ecol 2008. [DOI: 10.1111/j.1365-2435.2008.01461.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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CHRISTENSEN BENT, NOER HENNING, THEISEN BENTFRIIS. Differential responses to humidity and soil type among clones of triploid parthenogenetic Trichoniscus pusizzus (Isopoda, Crustacea). Hereditas 2008. [DOI: 10.1111/j.1601-5223.1988.tb00303.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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17
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Spitzer BW, Haygood R. Migration load and the coexistence of ecologically similar sexuals and asexuals. Am Nat 2007; 170:567-72. [PMID: 17891735 DOI: 10.1086/521235] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Accepted: 06/05/2007] [Indexed: 11/03/2022]
Abstract
The frozen niche variation hypothesis suggests that sexuals can coexist with closely related, ecologically similar asexuals because sexuals and narrowly adapted asexual clones use different resources. However, because a collection of clones can potentially dominate the entire resource axis, such coexistence is not stable. We show that if the sexual population inhabits multiple selection regimes and asexuals are intrinsically slightly less fit than sexuals, migration load in the sexual population allows sexuals and asexuals to coexist stably at the regional level. By decreasing sexuals' fitness, migration load allows asexuals to invade the sexual population. However, as the sexuals' range contracts, migration load decreases, preventing asexuals from driving sexuals to extinction. This "buffering" effect of migration load is even more relevant in models that include more realistic conditions, such as demographic asymmetries or explicit spatial structure.
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Affiliation(s)
- Brian W Spitzer
- Department of Biology, Gustavus Adolphus College, St. Peter, Minnesota 56082, USA.
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18
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Plenet S, Joly P, Hervant F, Fromont E, Grolet O. Are hybridogenetic complexes structured by habitat in water frogs? J Evol Biol 2005; 18:1575-86. [PMID: 16313469 DOI: 10.1111/j.1420-9101.2005.00961.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The success and the evolutionary fate of hybridogenetic lineages are explained by both a generalistic heterosis hypothesis and an alternative hypothesis, the habitat segregation hypothesis. Because such hypotheses have rarely been tested at the level of whole habitats, our aim was to compare performances of two taxa within a hybridogenetic complex across diverse natural habitats. We took advantage of the waterfrog hybridogenetic complex (Rana esculenta and R. lessonae) by rearing tadpoles in natural contrasted habitats by means of enclosure experiments. We also monitored the frequency of each taxon in the waterfrog assemblages that naturally breed in the studied ponds. The hybridogenenetic taxon showed no evidence of broader tolerance as growth, development and physiology strongly varied in response to environmental heterogeneity. Our study reveals a differential success of the hybridogenetic taxon and its sexual host among environments. Moreover, hybridogenetic taxa rarely dominated the sexual species in natural assemblages. Consequently, our results show that the generalistic model does not explain the success of hybridogenetic lineages, but rather support the habitat segregation, among other alternative concepts.
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Affiliation(s)
- S Plenet
- UMR CNRS 5023 Ecologie des Hydrosystèmes Fluviaux, Bât Darwin C, Université Claude Bernard Lyon1, Villeurbanne Cédex, France.
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Loyning. Reproductive performance of clonal and sexual bark beetles (Coleoptera: Scolytidae) in the field. J Evol Biol 2000. [DOI: 10.1046/j.1420-9101.2000.00227.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Negovetic S, Jokela J. Food choice behaviour may promote habitat specificity in mixed populations of clonal and sexual Potamopyrgus antipodarum. Anim Behav 2000; 60:435-441. [PMID: 11032646 DOI: 10.1006/anbe.2000.1486] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Genetic polymorphism along an environmental gradient may be maintained if disruptive selection on habitat-specific traits leads to a correlated response in traits that reduce gene flow between habitats. We studied a short-distance cline in a population of freshwater snails Potamopyrgus antipodarum in which sexual and clonal snails coexist. Sexuals and clones show a life history cline by depth: snails reproduce at a smaller size in shallower habitats. Clones are also structured genetically across habitats and seem not to mix, even though habitats are within the dispersal distance of the snails and the opportunity for gene flow via migration must be considerable. Because habitat preference may promote divergence in both clones and sexuals along the depth gradient, we investigated whether snails show habitat-specific food choice behaviour that could reduce migration. We tested the food choice behaviour of the snails by exposing them simultaneously to food from their home and adjacent habitats. Both juvenile and adult snails from the shallow shore bank and a mid-water macrophyte habitat preferentially grazed on the vegetation of their original habitats. We suggest that the observed genetic and life history cline may be maintained by food choice behaviour that may promote a partial barrier to gene flow between the habitats. Copyright 2000 The Association for the Study of Animal Behaviour.
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Semlitsch RD, Schmiedehausen S, Hotz H, Beerli P. Genetic compatibility between sexual and clonal genomes in local populations of the hybridogeneticRana esculenta complex. Evol Ecol 1996. [DOI: 10.1007/bf01237883] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Weeks SC. Comparisons of life-history traits between clonal and sexual fish (Poeciliopsis:Poeciliidae) raised in monoculture and mixed treatments. Evol Ecol 1995. [DOI: 10.1007/bf01237772] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Divergent ecology of sympatric clones of the asexual gecko, Lepidodactylus lugubris. Oecologia 1994; 100:397-405. [DOI: 10.1007/bf00317861] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/1993] [Accepted: 08/22/1994] [Indexed: 10/26/2022]
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Hanley KA, Bolger DT, Case TJ. Comparative ecology of sexual and asexual gecko species (Lepidodactylus) in French Polynesia. Evol Ecol 1994. [DOI: 10.1007/bf01238194] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Phenotypic plasticity of life-history traits in clonal and sexual fish (Poeciliopsis) at high and low densities. Oecologia 1993; 93:307-314. [DOI: 10.1007/bf00317871] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/1992] [Accepted: 11/17/1992] [Indexed: 10/26/2022]
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