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‣ Allozymatic divergence between border populations of two cryptic species of the Drosophila buzzatii cluster species (Diptera: Drosophilidae)

MATEUS, Rogrio R.; MACHADO, Luciana P. B.; MORAES, Evandro M.; SENE, Fabio M.
Fonte: PERGAMON-ELSEVIER SCIENCE LTD Publicador: PERGAMON-ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
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Drosophila antonietae and Drosophila gouveai are allopatric, cactophilic, cryptic and endemic of South America species, which aedeagus morphology is considered the main diagnostic character. In this work, single close populations from the edge distributions of each species, located in an ""introgressive corridor"", were analyzed regarding temporal isozenzymatic genetic variability. Isocitrate dehydrogenase (Idh) appeared as a diagnostic locus between D. antonieate and D. gouveai because each population was fixed for different alleles. Moreover, several polymorphic loci showed accentuated divergence in the allele frequency, as evidenced by Nei`s l(0.3188) and D (1.1432), and also by Reynolds` genetic distance and identity (1.3207 and 0.7331, respectively). Our results showed that, in spite of the very similar external morphology, related evolutionary histories, close distributions, and events of introgression in the studied area, these cryptic species have high allozymatic differentiation, and this is discussed here. (C) 2010 Elsevier Ltd. All rights reserved.; FAPESP[97/13822-4]; FAPESP[1998/1790-3]; FAPESP[98/00974-3]; CNPq; CAPES; FINEP; FAEPA; Universidade de São Paulo USP

‣ Copia Retrotransposon in the Zaprionus Genus: Another Case of Transposable Element Sharing with the Drosophila melanogaster Subgroup

SETTA, Nathalia de; SLUYS, Marie-Anne Van; CAPY, Pierre; CARARETO, Claudia Marcia Aparecida
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
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Copia is a retrotransposon that appears to be distributed widely among the Drosophilidae subfamily. Evolutionary analyses of regulatory regions have indicated that the Copia retrotransposon evolved through both positive and purifying selection, and that horizontal transfer (HT) could also explain its patchy distribution of the among the subfamilies of the melanogaster subgroup. Additionally, Copia elements could also have transferred between melanogaster subgroup and other species of Drosophilidae-D. willistoni and Z. tuberculatus. In this study, we surveyed seven species of the Zaprionus genus by sequencing the LTR-ULR and reverse transcriptase regions, and by using RT-PCR in order to understand the distribution and evolutionary history of Copia in the Zaprionus genus. The Copia element was detected, and was transcriptionally active, in all species investigated. Structural and selection analysis revealed Zaprionus elements to be closely related to the most ancient subfamily of the melanogaster subgroup, and they seem to be evolving mainly under relaxed purifying selection. Taken together, these results allowed us to classify the Zaprionus sequences as a new subfamily-ZapCopia, a member of the Copia retrotransposon family of the melanogaster subgroup. These findings indicate that the Copia retrotransposon is an ancient component of the genomes of the Zaprionus species and broaden our understanding of the diversity of retrotransposons in the Zaprionus genus.; Comité Français d´Evaluation de la Coopération Universitaire avec le Brésil (COFECUB); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); CAPES-COFECUB; FAPESP[MAVS-04/02851-9]; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); CNPq

‣ Phylogeny, species limits, and biogeography of the Brazilian lizards of the genus Eurolophosaurus (Squamata : Tropiduridae) as inferred from mitochondrial DNA sequences

PASSONI, Jose Carlos; BENOZZATI, Maria Lucia; RODRIGUES, Miguel Trefaut
Fonte: ACADEMIC PRESS INC ELSEVIER SCIENCE Publicador: ACADEMIC PRESS INC ELSEVIER SCIENCE
Tipo: Artigo de Revista Científica
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Phylogenetic relationships and divergence times for 10 populations of the three recognized ""species"" of Brazilian lizards of genus Eurolophosaurus were estimated from 1229 bp of cyt b, COI, 12S, and 16S rRNA mitochondrial gene segments. Eurolophosaurus is monophyletic and the basal split within the genus separates E divaricatus from a clade comprising E amathites and E nanuzae. Three populations of E divaricatus, which occurs along the western bank of Rio S (a) over tildeo Francisco, were consistently grouped together. Oil the east bank of the river, E amathites and E nanuzae from state of Bahia were recovered as the sister group of E nanuzae populations from state of Minas Gerais. The paraphyly of E nanuzae and the high divergence levels among populations of E divaricatus strongly suggest that species limits in Eurolophosaurus should be revised. Even considering an extreme evolutionary rate of 2.8% sequence divergence per million years for the four gene segments analyzed together, E. divaricatus would have separated from the two other species by at least 5.5 my ago, and E. amathites from E nanuzae populations from Bahia and Minas Gerais, respectively, by 1.5 and 3.5 my. The paleolacustrine hypothesis and changes in the course of the river potentially explain faunal divergence in the area...

‣ Bayesian coalescent analysis reveals a high rate of molecular evolution in GB virus C

ROMANO, Camila M.; ZANOTTO, Paolo M. de A.; HOLMES, Edward C.
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artigo de Revista Científica
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GB virus C/hepatitis G (GBV-C) is an RNA virus of the family Flaviviridae. Despite replicating with an RNA-dependent RNA polymerase, some previous estimates of rates of evolutionary change in GBV-C suggest that it fixes mutations at the anomalously low rate of similar to 100(-7) nucleotide substitution per site, per year. However, these estimates were largely based on the assumption that GBV-C and its close relative GBV-A (New World monkey GB viruses) codiverged with their primate hosts over millions of years. Herein, we estimated the substitution rate of GBV-C using the largest set of dated GBV-C isolates compiled to date and a Bayesian coalescent approach that utilizes the year of sampling and so is independent of the assumption of codivergence. This revealed a rate of evolutionary change approximately four orders of magnitude higher than that estimated previously, in the range of 10(-2) to 10(-3) sub/site/year, and hence in line with those previously determined for RNA viruses in general and the Flaviviridae in particular. In addition, we tested the assumption of host-virus codivergence in GBV-A by performing a reconciliation analysis of host and virus phylogenies. Strikingly, we found no statistical evidence for host-virus codivergence in GBV-A...

‣ Patterns and processes of diversification in a widespread and ecologically diverse avian group, the buteonine hawks (Aves, Accipitridae)

AMARAL, Fabio Raposo do; SHELDON, Frederick H.; GAMAUF, Anita; HARING, Elisabeth; RIESING, Martin; SILVEIRA, Luis F.; WAJNTAL, Anita
Fonte: ACADEMIC PRESS INC ELSEVIER SCIENCE Publicador: ACADEMIC PRESS INC ELSEVIER SCIENCE
Tipo: Artigo de Revista Científica
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Buteonine hawks represent one of the most diverse groups in the Accipitridae, with 58 species distributed in a variety of habitats on almost all continents. Variations in migratory behavior, remarkable dispersal capability, and unusual diversity in Central and South America make buteonine hawks an excellent model for studies in avian evolution. To evaluate the history of their global radiation, we used an integrative approach that coupled estimation of the phylogeny using a large sequence database (based on 6411 bp of mitochondrial markers and one nuclear intron from 54 species), divergence time estimates, and ancestral state reconstructions. Our findings suggest that Neotropical buteonines resulted from a long evolutionary process that began in the Miocene and extended to the Pleistocene. Colonization of the Nearctic, and eventually the Old World, occurred from South America, promoted by the evolution of seasonal movements and development of land bridges. Migratory behavior evolved several times and may have contributed not only to colonization of the Holarctic, but also derivation of insular species. In the Neotropics, diversification of the buteonines included four disjunction events across the Andes. Adaptation of monophyletic taxa to wet environments occurred more than once...

‣ Parasites—the new frontier: celebrating Darwin 200

Schmid-Hempel, Paul
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
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To Darwin, parasites were fascinating examples of adaptation but their significance as selective factors for a wide range of phenomena has only been studied in depth over the last few decades. This work has had its roots in behavioural/evolutionary ecology on the one hand, and in population biology/ecology on the other, thus shaping a new comprehensive field of ‘evolutionary parasitology’. Taking parasites into account has been a success story and has shed new light on several old questions such as sexual selection, the evolution of sex and recombination, changes in behaviour, adaptive life histories, and so forth. In the process, the topic of ecological immunology has emerged, which analyses immune defences in a framework of costs and benefits. Throughout, a recurrent theme is how to appropriately integrate the underlying mechanisms as evolved boundary conditions into a framework of studying the adaptive value of traits. On the conceptual side, major questions remain and await further study.

‣ Public Goods with Punishment and Abstaining in Finite and Infinite Populations

Hauert, Christoph; Traulsen, Arne; Brandt, Hannelore; Nowak, Martin A.; Sigmund, Karl
Fonte: Massachusetts Institute of Technology Press Publicador: Massachusetts Institute of Technology Press
Tipo: Artigo de Revista Científica
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The evolution and maintenance of cooperation in human and animal societies challenges various disciplines ranging from evolutionary biology, to anthropology, social sciences and economics. In social interactions, cooperators increase the welfare of the group at some cost to themselves whereas defectors attempt to free-ride and neither provide benefits nor incur costs. The problem of cooperation becomes even more pronounced when increasing the number of interacting individuals. Punishment and voluntary participation have been identified as possible factors to support cooperation and prevent cheating. Typically, punishment behavior is unable to gain a foothold in a population, while volunteering alone can efficiently prevent deadlocks in states of mutual defection but is unable to stabilize cooperation. The combined effects of the two mechanisms have surprisingly different consequences in finite and infinite populations. Here we provide a detailed comparison of the two scenarios and demonstrate that driven by the inherent stochasticity of finite populations, the possibility to abstain from social interactions plays a pivotal role, which paves the way for the establishment of cooperation and punishment.; Organismic and Evolutionary Biology

‣ Calculating Evolutionary Dynamics in Structured Populations

Nathanson, Charles Gordon; Tarnita, Corina Elena; Nowak, Martin A.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
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Evolution is shaping the world around us. At the core of every evolutionary process is a population of reproducing individuals. The outcome of an evolutionary process depends on population structure. Here we provide a general formula for calculating evolutionary dynamics in a wide class of structured populations. This class includes the recently introduced “games in phenotype space” and “evolutionary set theory.” There can be local interactions for determining the relative fitness of individuals, but we require global updating, which means all individuals compete uniformly for reproduction. We study the competition of two strategies in the context of an evolutionary game and determine which strategy is favored in the limit of weak selection. We derive an intuitive formula for the structure coefficient, σ, and provide a method for efficient numerical calculation.; Mathematics; Organismic and Evolutionary Biology

‣ Comparative Genomic Characterization of Francisella tularensis Strains Belonging to Low and High Virulence Subspecies

Champion, Mia D.; Zeng, Qiandong; Nix, Eli B.; Nano, Francis E.; Keim, Paul; Kodira, Chinnappa D.; Koehrsen, Michael; Pearson, Matthew; Howarth, Clint; Larson, Lisa; White, Jared; Alvarado, Lucia; Forsman, Mats; Bearden, Scott W.; Sjöstedt, Anders; Titba
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
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Tularemia is a geographically widespread, severely debilitating, and occasionally lethal disease in humans. It is caused by infection by a gram-negative bacterium, Francisella tularensis. In order to better understand its potency as an etiological agent as well as its potential as a biological weapon, we have completed draft assemblies and report the first complete genomic characterization of five strains belonging to the following different Francisella subspecies (subsp.): the F. tularensis subsp. tularensis FSC033, F. tularensis subsp. holarctica FSC257 and FSC022, and F. tularensis subsp. novicida GA99-3548 and GA99-3549 strains. Here, we report the sequencing of these strains and comparative genomic analysis with recently available public Francisella sequences, including the rare F. tularensis subsp. mediasiatica FSC147 strain isolate from the Central Asian Region. We report evidence for the occurrence of large-scale rearrangement events in strains of the holarctica subspecies, supporting previous proposals that further phylogenetic subdivisions of the Type B clade are likely. We also find a significant enrichment of disrupted or absent ORFs proximal to predicted breakpoints in the FSC022 strain, including a genetic component of the Type I restriction-modification defense system. Many of the pseudogenes identified are also disrupted in the closely related rarely human pathogenic F. tularensis subsp. mediasiatica FSC147 strain...

‣ Runs of Homozygosity Implicate Autozygosity as a Schizophrenia Risk Factor

Keller, Matthew C.; Simonson, Matthew A.; Ripke, Stephan; Gejman, Pablo V.; Lencz, Todd; Levinson, Douglas F.; Sullivan, Patrick F.; Neale, Benjamin Michael; Howrigan, Daniel Patrick; Lee, Sang Hong
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
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Autozygosity occurs when two chromosomal segments that are identical from a common ancestor are inherited from each parent. This occurs at high rates in the offspring of mates who are closely related (inbreeding), but also occurs at lower levels among the offspring of distantly related mates. Here, we use runs of homozygosity in genome-wide SNP data to estimate the proportion of the autosome that exists in autozygous tracts in 9,388 cases with schizophrenia and 12,456 controls. We estimate that the odds of schizophrenia increase by (sim 17 \% ) for every (1 \% ) increase in genome-wide autozygosity. This association is not due to one or a few regions, but results from many autozygous segments spread throughout the genome, and is consistent with a role for multiple recessive or partially recessive alleles in the etiology of schizophrenia. Such a bias towards recessivity suggests that alleles that increase the risk of schizophrenia have been selected against over evolutionary time.

‣ Dual Host-Virus Arms Races Shape an Essential Housekeeping Protein

Demogines, Ann; Abraham, Jonathan; Choe, Hyeryun; Farzan, Michael; Sawyer, Sara L.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
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Transferrin Receptor (TfR1) is the cell-surface receptor that regulates iron uptake into cells, a process that is fundamental to life. However, TfR1 also facilitates the cellular entry of multiple mammalian viruses. We use evolutionary and functional analyses of TfR1 in the rodent clade, where two families of viruses bind this receptor, to mechanistically dissect how essential housekeeping genes like TFR1 successfully balance the opposing selective pressures exerted by host and virus. We find that while the sequence of rodent TfR1 is generally conserved, a small set of TfR1 residue positions has evolved rapidly over the speciation of rodents. Remarkably, all of these residues correspond to the two virus binding surfaces of TfR1. We show that naturally occurring mutations at these positions block virus entry while simultaneously preserving iron-uptake functionalities, both in rodent and human TfR1. Thus, by constantly replacing the amino acids encoded at just a few residue positions, TFR1 divorces adaptation to ever-changing viruses from preservation of key cellular functions. These dynamics have driven genetic divergence at the TFR1 locus that now enforces species-specific barriers to virus transmission, limiting both the cross-species and zoonotic transmission of these viruses.

‣ Introduction to Focus Issue: Genetic Interactions

Segrè, Daniel; Marx, Christopher J
Fonte: AIP Publishing Publicador: AIP Publishing
Tipo: Artigo de Revista Científica
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The perturbation of a gene in an organism’s genome often causes changes in the organism’s observable properties or phenotypes. It is not obvious a priori whether the simultaneous perturbation of two genes produces a phenotypic change that is easily predictable from the changes caused by individual perturbations. In fact, this is often not the case: the nonlinearity and interdependence between genetic variants in determining phenotypes, also known as epistasis, is a prevalent phenomenon in biological systems. This focus issue presents recent developments in the study of epistasis and genetic interactions, emphasizing the broad implications of this phenomenon in evolutionary biology, functional genomics, and human diseases.; Organismic and Evolutionary Biology

‣ Proteome-wide evolutionary analysis reveals lineage-specific adaptations and improves funtional annotation of Schistosoma mansoni proteins.

SILVA, L.; MARCET-HOUBEN, M.; NAHUM, L.; ZERLOTINI, A.; GALBADÓN, T.; OLIVEIRA, G.
Fonte: In: INTERNATIONAL CONFERENCE OF THE BRAZILIAN ASSOCIATION FOR BIOINFORMATICS AND COMPUTATIONAL BIOLOGY, 8., 2012, Campinas. Abstract book... Ribeirão Preto: AB3C, 2012. Publicador: In: INTERNATIONAL CONFERENCE OF THE BRAZILIAN ASSOCIATION FOR BIOINFORMATICS AND COMPUTATIONAL BIOLOGY, 8., 2012, Campinas. Abstract book... Ribeirão Preto: AB3C, 2012.
Tipo: Resumo em anais de congresso (ALICE) Formato: Não paginado.
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In this context, comparative proteomic analysis can shed new light on the evolutionary processes that shaped hostparasite interaction over evolutionary time. Taking advantage of the benefits provided by a largescale phylogenetic analysis, in the present work, we reconstructed the evolutionary history of each protein encoded in the S. mansoni genome in comparison with other 12 taxa to gain insights into lineage-specific evolutionary events, potentially related to the parasitic lifestyle, as well as to improve functional annotation. Results The collection of trees reconstructed in this work includes 7,964 phylogenies, which comprises the evolutionary histories of all parasite proteins and their homologs across 12 other organisms. This analysis allowed a deeper understanding of genomic complexity and evolutionary adaptations to a parasitic lifestyle.; 2012; X-MEETING 2012.

‣ Evolutionary game theory: Temporal and spatial effects beyond replicator dynamics

Pérez Roca, Carlos; Cuesta, José A.; Sánchez, Angel
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica Formato: application/pdf
Publicado em /12/2009 Português
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Evolutionary game dynamics is one of the most fruitful frameworks for studying evolution in different disciplines, from Biology to Economics. Within this context, the approach of choice for many researchers is the so-called replicator equation, that describes mathematically the idea that those individuals performing better have more offspring and thus their frequency in the population grows. While very many interesting results have been obtained with this equation in the three decades elapsed since it was first proposed, it is important to realize the limits of its applicability. One particularly relevant issue in this respect is that of non-mean-field effects, that may arise from temporal fluctuations or from spatial correlations, both neglected in the replicator equation. This review discusses these temporal and spatial effects focusing on the non-trivial modifications they induce when compared to the outcome of replicator dynamics. Alongside this question, the hypothesis of linearity and its relation to the choice of the rule for strategy update is also analyzed. The discussion is presented in terms of the emergence of cooperation, as one of the current key problems in Biology and in other disciplines.; This work has been supported by projects MOSAICO...

‣ Feedback between population and evolutionary dynamics determines the fate of social microbial populations

Sanchez, Alvaro; Gore, Jeff
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 13/01/2013 Português
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The evolutionary spread of cheater strategies can destabilize populations engaging in cooperative behaviors, thus demonstrating that evolutionary changes can have profound implications for populations dynamics. At the same time, the relative fitness of cooperative traits often depends upon population density, thus leading to the potential for bidirectional coupling between population density and the evolution of a cooperative trait. Despite the potential importance of these eco evolutionary feedback loops, they have not yet been demonstrated experimentally in social species and their ecological implications are poorly understood. Here, we demonstrate the presence of a strong feedback loop between population dynamics and the evolutionary dynamics of a social microbial gene, SUC2, in laboratory yeast populations whose cooperative growth is mediated by the SUC2 gene. We directly visualize eco evolutionary trajectories of hundreds of populations over fifty generations, allowing us to characterize the phase space describing the interplay of evolution and ecology in this system. Small populations collapse despite continual evolution towards increased cooperative allele frequencies; large populations with a sufficient number of cooperators spiral to a stable state of coexistence between cooperator and cheater strategies. The presence of cheaters does not significantly affect the equilibrium population density...

‣ A Simple Model of Unbounded Evolutionary Versatility as a Largest-Scale Trend in Organismal Evolution

Turney, Peter D.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 10/12/2002 Português
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The idea that there are any large-scale trends in the evolution of biological organisms is highly controversial. It is commonly believed, for example, that there is a large-scale trend in evolution towards increasing complexity, but empirical and theoretical arguments undermine this belief. Natural selection results in organisms that are well adapted to their local environments, but it is not clear how local adaptation can produce a global trend. In this paper, I present a simple computational model, in which local adaptation to a randomly changing environment results in a global trend towards increasing evolutionary versatility. In this model, for evolutionary versatility to increase without bound, the environment must be highly dynamic. The model also shows that unbounded evolutionary versatility implies an accelerating evolutionary pace. I believe that unbounded increase in evolutionary versatility is a large-scale trend in evolution. I discuss some of the testable predictions about organismal evolution that are suggested by the model.; Comment: 32 pages

‣ Evolutionary Dynamics with Fluctuating Population Sizes

Chotibut, Thiparat; Nelson, David R.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 20/12/2014 Português
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Game theory ideas provide a useful framework for studying evolutionary dynamics in a well-mixed environment. This approach, however, typically enforces a strictly fixed overall population size, deemphasizing natural growth processes. We study a competitive Lotka-Volterra model, with number fluctuations, that accounts for natural population growth and encompasses interaction scenarios typical of evolutionary games. In an appropriate limit, the model describes standard evolutionary games with both genetic drift and overall population size fluctuations. We demonstrate a novel mechanism for neutral evolution in a well-mixed Moran model such that population size fluctuations favor a fixation of one species over the other. We derive an effective evolutionary dynamics for fluctuation-induced selection by adiabatic elimination of a fast variable. The method can be extended to study the interplay between selection, genetic drift, and population size fluctuations in other scenarios. We also investigate strong mutualism, in a limit where a varying population size can strongly influence the evolutionary dynamics. We analytically and numerically determine fixation probabilities as well as mean fixation times using matched asymptotic expansions...

‣ Co-evolutionary dynamics of a host-parasite interaction model: obligate versus facultative social parasitism

Kang, Yun; Fewell, Jennifer Harrison
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 16/05/2015 Português
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To examine the co-evolution of quantitative traits in hosts and parasites, we present and study a co-evolutionary model of a social parasite-host system that incorporates (1) ecological dynamics that feed back into their co-evolutionary outcomes; (2) variation in whether the parasite is obligate or facultative; and (3) Holling Type II functional responses between host and parasite, which are particularly suitable for social parasites that face time costs for host location and its social manipulation. We perform local and global analyses for the co-evolutionary model and the corresponding ecological model. In the absence of evolution, the facultative parasite system can have one, two, or three interior equilibria, while the obligate parasite system can have either one or three interior equilibria. Multiple interior equilibria result in rich dynamics with multiple attractors. The ecological system, in particular, can exhibit bi-stability between the facultative-parasite-only equilibrium and the interior coexistence equilibrium when it has two interior equilibria. Our findings suggest that: (a) The host and parasite can select different strategies that may result in local extinction of one species. These strategies can have convergence stability (CS)...

‣ Ecosystem-Oriented Distributed Evolutionary Computing

Briscoe, Gerard; De Wilde, Philippe
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 22/11/2012 Português
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We create a novel optimisation technique inspired by natural ecosystems, where the optimisation works at two levels: a first optimisation, migration of genes which are distributed in a peer-to-peer network, operating continuously in time; this process feeds a second optimisation based on evolutionary computing that operates locally on single peers and is aimed at finding solutions to satisfy locally relevant constraints. We consider from the domain of computer science distributed evolutionary computing, with the relevant theory from the domain of theoretical biology, including the fields of evolutionary and ecological theory, the topological structure of ecosystems, and evolutionary processes within distributed environments. We then define ecosystem- oriented distributed evolutionary computing, imbibed with the properties of self-organisation, scalability and sustainability from natural ecosystems, including a novel form of distributed evolu- tionary computing. Finally, we conclude with a discussion of the apparent compromises resulting from the hybrid model created, such as the network topology.; Comment: 8 pages, 5 figures. arXiv admin note: text overlap with arXiv:1112.0204, arXiv:0712.4159, arXiv:0712.4153, arXiv:0712.4102, arXiv:0910.0674

‣ Ecological dynamics and the basis of sympatric phenotypic diversification

Mario Pineda-Krch; Richard Svanbäck; Michael Doebeli
Fonte: Nature Preceedings Publicador: Nature Preceedings
Tipo: Conferência ou Objeto de Conferência
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Theoretical and empirical studies are showing evidence in support of evolutionary branching and sympatric speciation due to frequency‐dependent competition. However, phenotypic diversification due to underlying genetic diversification is only one possible evolutionary response to disruptive selection. Another potentially general response is phenotypic diversification in the form of phenotypic plasticity. It has been suggested that genetic variation is favored in stable environments, whereas phenotypic plasticity is favored in unstable and fluctuating environments. We investigate the “competition” between the processes of evolutionary branching and the evolution of phenotypic plasticity in a predator‐prey model that allows both processes to occur. In this model, environmental fluctuations can be caused by complicated population dynamics. We found that the evolution of phenotypic plasticity was generally more likely than evolutionary branching when the ecological dynamics exhibited pronounced predator‐prey cycles, whereas the opposite was true when the ecological dynamics was more stable. At intermediate levels of density cycling, trimorphisms with two specialist branches and a phenotypically plastic generalist branch sometimes occurred. Our theoretical results suggest that ecological dynamics and evolutionary dynamics can often be tightly linked and that an explicit consideration of population dynamics may be essential to explain the evolutionary dynamics of diversification in natural populations.