WorldWideScience

Sample records for coevolution

  1. Coevolution of Symbiotic Species

    OpenAIRE

    Leok, Boon Tiong Melvin

    1996-01-01

    This paper will consider the coevolution of species which are symbiotic in their interaction. In particular, we shall analyse the interaction of squirrels and oak trees, and develop a mathematical framework for determining the coevolutionary equilibrium for consumption and production patterns.

  2. Coevolution of interacting fertilization proteins.

    Directory of Open Access Journals (Sweden)

    Nathaniel L Clark

    2009-07-01

    Full Text Available Reproductive proteins are among the fastest evolving in the proteome, often due to the consequences of positive selection, and their rapid evolution is frequently attributed to a coevolutionary process between interacting female and male proteins. Such a process could leave characteristic signatures at coevolving genes. One signature of coevolution, predicted by sexual selection theory, is an association of alleles between the two genes. Another predicted signature is a correlation of evolutionary rates during divergence due to compensatory evolution. We studied female-male coevolution in the abalone by resequencing sperm lysin and its interacting egg coat protein, VERL, in populations of two species. As predicted, we found intergenic linkage disequilibrium between lysin and VERL, despite our demonstration that they are not physically linked. This finding supports a central prediction of sexual selection using actual genotypes, that of an association between a male trait and its female preference locus. We also created a novel likelihood method to show that lysin and VERL have experienced correlated rates of evolution. These two signatures of coevolution can provide statistical rigor to hypotheses of coevolution and could be exploited for identifying coevolving proteins a priori. We also present polymorphism-based evidence for positive selection and implicate recent selective events at the specific structural regions of lysin and VERL responsible for their species-specific interaction. Finally, we observed deep subdivision between VERL alleles in one species, which matches a theoretical prediction of sexual conflict. Thus, abalone fertilization proteins illustrate how coevolution can lead to reproductive barriers and potentially drive speciation.

  3. Detection of significant protein coevolution.

    Science.gov (United States)

    Ochoa, David; Juan, David; Valencia, Alfonso; Pazos, Florencio

    2015-07-01

    The evolution of proteins cannot be fully understood without taking into account the coevolutionary linkages entangling them. From a practical point of view, coevolution between protein families has been used as a way of detecting protein interactions and functional relationships from genomic information. The most common approach to inferring protein coevolution involves the quantification of phylogenetic tree similarity using a family of methodologies termed mirrortree. In spite of their success, a fundamental problem of these approaches is the lack of an adequate statistical framework to assess the significance of a given coevolutionary score (tree similarity). As a consequence, a number of ad hoc filters and arbitrary thresholds are required in an attempt to obtain a final set of confident coevolutionary signals. In this work, we developed a method for associating confidence estimators (P values) to the tree-similarity scores, using a null model specifically designed for the tree comparison problem. We show how this approach largely improves the quality and coverage (number of pairs that can be evaluated) of the detected coevolution in all the stages of the mirrortree workflow, independently of the starting genomic information. This not only leads to a better understanding of protein coevolution and its biological implications, but also to obtain a highly reliable and comprehensive network of predicted interactions, as well as information on the substructure of macromolecular complexes using only genomic information. The software and datasets used in this work are freely available at: http://csbg.cnb.csic.es/pMT/. pazos@cnb.csic.es Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. Coevolution of nutrigenomics and society: ethical considerations

    NARCIS (Netherlands)

    Korthals, M.

    2011-01-01

    To optimize the coevolution of nutrigenomics and society (ie, the reciprocal stimulation of both developments), I analyzed chances for a fruitful match between normative concepts and strategies of both developments. Nutrigenomics embodies =3 normative concepts. First, food is exclusively interpreted

  5. Anytime Coevolution of Form and Function

    National Research Council Canada - National Science Library

    Bugajska, Magdalena D; Schultz, Alan C

    2003-01-01

    ...) for autonomous vehicles. This study focuses on coevolution of the characteristics such as beam width and range of individual sensors in the sensor suite, and the reactive strategies for collision-free navigation...

  6. Coevolution: A synergy in biology and ecology

    Directory of Open Access Journals (Sweden)

    WenJun Zhang

    2015-06-01

    Full Text Available Synergy refers to that in an open and complex system consisting of a large number of subsystems, far from equilibrium, its subsystems interact in a nonlinear way to produce synergistic effects and thus make the system generate a self-organization structure in space/time with certain functions. Biologists and ecologists, tend to use coevolution/coadaptation to represent the terminology "synergy". Coevolution and research methodology were briefly discussed in present paper.

  7. On meme--gene coevolution.

    Science.gov (United States)

    Bull, L; Holland, O; Blackmore, S

    2000-01-01

    In this article we examine the effects of the emergence of a new replicator, memes, on the evolution of a pre-existing replicator, genes. Using a version of the NKCS model we examine the effects of increasing the rate of meme evolution in relation to the rate of gene evolution, for various degrees of interdependence between the two replicators. That is, the effects of memes' (suggested) more rapid rate of evolution in comparison to that of genes is investigated using a tunable model of coevolution. It is found that, for almost any degree of interdependence between the two replicators, as the rate of meme evolution increases, a phase transition-like dynamic occurs under which memes have a significantly detrimental effect on the evolution of genes, quickly resulting in the cessation of effective gene evolution. Conversely, the memes experience a sharp increase in benefit from increasing their rate of evolution. We then examine the effects of enabling genes to reduce the percentage of gene-detrimental evolutionary steps taken by memes. Here a critical region emerges as the comparative rate of meme evolution increases, such that if genes cannot effectively select memes a high percentage of the time, they suffer from meme evolution as if they had almost no selective capability.

  8. Coevolution Based Adaptive Monte Carlo Localization (CEAMCL

    Directory of Open Access Journals (Sweden)

    Luo Ronghua

    2008-11-01

    Full Text Available An adaptive Monte Carlo localization algorithm based on coevolution mechanism of ecological species is proposed. Samples are clustered into species, each of which represents a hypothesis of the robot's pose. Since the coevolution between the species ensures that the multiple distinct hypotheses can be tracked stably, the problem of premature convergence when using MCL in highly symmetric environments can be solved. And the sample size can be adjusted adaptively over time according to the uncertainty of the robot's pose by using the population growth model. In addition, by using the crossover and mutation operators in evolutionary computation, intra-species evolution can drive the samples move towards the regions where the desired posterior density is large. So a small size of samples can represent the desired density well enough to make precise localization. The new algorithm is termed coevolution based adaptive Monte Carlo localization (CEAMCL. Experiments have been carried out to prove the efficiency of the new localization algorithm.

  9. Collaborative Problem-solution Co-evolution in Creative Design

    DEFF Research Database (Denmark)

    Wiltschnig, Stefan; Christensen, Bo; J. Ball, Linden

    2013-01-01

    . The analysis revealed that co-evolution episodes occurred regularly and embodied various directional transitions between problem and solution spaces. Moreover, the team leader often initiated this co-evolution. Co-evolution episodes linked with other creative activities such as analogising and mental...

  10. Physical mode of bacteria and virus coevolution

    Science.gov (United States)

    Han, Pu; Niestemski, Liang; Deem, Michael

    2013-03-01

    Single-cell hosts such as bacteria or archaea possess an adaptive, heritable immune system that protects them from viral invasion. This system, known as the CRISPR-Cas system, allows the host to recognize and incorporate short foreign DNA or RNA sequences from viruses or plasmids. The sequences form what are called ``spacers'' in the CRISPR. Spacers in the CRISPR loci provide a record of the host and predator coevolution history. We develop a physical model to study the dynamics of this coevolution due to immune pressure. Hosts and viruses reproduce, die, and evolve due to viral infection pressure, host immune pressure, and mutation. We will discuss the differing effects of point mutation and recombination on CRISPR evolution. We will also discuss the effect of different spacer deletion mechanisms. We will describe population structure of hosts and viruses, how spacer diversity depends on position within CRISPR, and match of the CRISPR spacers to the virus population.

  11. Coevolution of nutrigenomics and society: ethical considerations.

    Science.gov (United States)

    Korthals, Michiel

    2011-12-01

    To optimize the coevolution of nutrigenomics and society (ie, the reciprocal stimulation of both developments), I analyzed chances for a fruitful match between normative concepts and strategies of both developments. Nutrigenomics embodies ≥ 3 normative concepts. First, food is exclusively interpreted in terms of disease prevention. Second, striving for health is interpreted as the quantification of risks and prevention of diseases through positive food-gene interactions. The third normative idea is that disease prevention by the minimization of risks is an individual's task. My thesis was that these concepts of nutrigenomics would not easily match with concepts of food and health of various food styles in Western societies, which, for instance, parents in the case of metabolic programming endorse and with a philosophical view of the relation between food, health, and the meaning of life. Next, I reflected on the nonsynchronized coevolution of nutrigenomics and society because of this mismatch and introduced the concept of the fair representation of food styles in nutrigenomic developments. To synchronize and optimize the coevolution of nutrigenomics and society, I propose that the research policy of nutrigenomics should change to a research partnership with society on the basis of fair representation.

  12. Co-Evolution: Law and Institutions in International Ethics Research

    NARCIS (Netherlands)

    Millar-Schijf, Carla C.J.M.; Cheng, Philip Y.K.; Choi, Chong-Ju

    2009-01-01

    Despite the importance of the co-evolution approach in various branches of research, such as strategy, organisation theory, complexity, population ecology, technology and innovation (Lewin et al., 1999; March, 1991), co-evolution has been relatively neglected in international business and ethics

  13. Coevolution of coloration and colour vision?

    Science.gov (United States)

    Lind, Olle; Henze, Miriam J; Kelber, Almut; Osorio, Daniel

    2017-07-05

    The evolutionary relationship between signals and animal senses has broad significance, with potential consequences for speciation, and for the efficacy and honesty of biological communication. Here we outline current understanding of the diversity of colour vision in two contrasting groups: the phylogenetically conservative birds, and the more variable butterflies. Evidence for coevolution of colour signals and vision exists in both groups, but is limited to observations of phenotypic differences between visual systems, which might be correlated with coloration. Here, to illustrate how one might interpret the evolutionary significance of such differences, we used colour vision modelling based on an avian eye to evaluate the effects of variation in three key characters: photoreceptor spectral sensitivity, oil droplet pigmentation and the proportions of different photoreceptor types. The models predict that physiologically realistic changes in any one character will have little effect, but complementary shifts in all three can substantially affect discriminability of three types of natural spectra. These observations about the adaptive landscape of colour vision may help to explain the general conservatism of photoreceptor spectral sensitivities in birds. This approach can be extended to other types of eye and spectra to inform future work on coevolution of coloration and colour vision.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

  14. The coevolution of recognition and social behavior.

    Science.gov (United States)

    Smead, Rory; Forber, Patrick

    2016-05-26

    Recognition of behavioral types can facilitate the evolution of cooperation by enabling altruistic behavior to be directed at other cooperators and withheld from defectors. While much is known about the tendency for recognition to promote cooperation, relatively little is known about whether such a capacity can coevolve with the social behavior it supports. Here we use evolutionary game theory and multi-population dynamics to model the coevolution of social behavior and recognition. We show that conditional harming behavior enables the evolution and stability of social recognition, whereas conditional helping leads to a deterioration of recognition ability. Expanding the model to include a complex game where both helping and harming interactions are possible, we find that conditional harming behavior can stabilize recognition, and thereby lead to the evolution of conditional helping. Our model identifies a novel hypothesis for the evolution of cooperation: conditional harm may have coevolved with recognition first, thereby helping to establish the mechanisms necessary for the evolution of cooperation.

  15. On Design Mining: Coevolution and Surrogate Models.

    Science.gov (United States)

    Preen, Richard J; Bull, Larry

    2017-01-01

    Design mining is the use of computational intelligence techniques to iteratively search and model the attribute space of physical objects evaluated directly through rapid prototyping to meet given objectives. It enables the exploitation of novel materials and processes without formal models or complex simulation. In this article, we focus upon the coevolutionary nature of the design process when it is decomposed into concurrent sub-design-threads due to the overall complexity of the task. Using an abstract, tunable model of coevolution, we consider strategies to sample subthread designs for whole-system testing and how best to construct and use surrogate models within the coevolutionary scenario. Drawing on our findings, we then describe the effective design of an array of six heterogeneous vertical-axis wind turbines.

  16. Practical aspects of protein co-evolution.

    Science.gov (United States)

    Ochoa, David; Pazos, Florencio

    2014-01-01

    Co-evolution is a fundamental aspect of Evolutionary Theory. At the molecular level, co-evolutionary linkages between protein families have been used as indicators of protein interactions and functional relationships from long ago. Due to the complexity of the problem and the amount of genomic data required for these approaches to achieve good performances, it took a relatively long time from the appearance of the first ideas and concepts to the quotidian application of these approaches and their incorporation to the standard toolboxes of bioinformaticians and molecular biologists. Today, these methodologies are mature (both in terms of performance and usability/implementation), and the genomic information that feeds them large enough to allow their general application. This review tries to summarize the current landscape of co-evolution-based methodologies, with a strong emphasis on describing interesting cases where their application to important biological systems, alone or in combination with other computational and experimental approaches, allowed getting new insight into these.

  17. NEW CO-EVOLUTION STRATEGIES OF THIRD MILLENNIUM; METHODOLOGICAL ASPECT

    Directory of Open Access Journals (Sweden)

    E. K. Bulygo

    2006-01-01

    Full Text Available The paper is devoted to an application of the co-evolution methodology to the social space. Principles of instability and non-linearity that are typical for contemporary natural science are used as a theoretical background of a new social methodology. Authors try to prove that the co-evolution strategy has a long pre-history in the ancient oriental philosophy and manifests itself in forms of modem culture

  18. Co-evolution of electric and telecommunications networks

    Energy Technology Data Exchange (ETDEWEB)

    Rivkin, S.R.

    1998-05-01

    There are potentially significant societal benefits in co-evolution between electricity and telecommunications in the areas of common infrastructure, accelerated deployment of distributed energy, tighter integration of information flow for energy management and distribution, and improved customer care. With due regard for natural processes that are more potent than any regulation and more real than any ideology, the gains from co-evolution would far outweigh the attenuated and speculative savings from restructuring of electricity that is too simplistic.

  19. Modeling Coevolution between Language and Memory Capacity during Language Origin

    Science.gov (United States)

    Gong, Tao; Shuai, Lan

    2015-01-01

    Memory is essential to many cognitive tasks including language. Apart from empirical studies of memory effects on language acquisition and use, there lack sufficient evolutionary explorations on whether a high level of memory capacity is prerequisite for language and whether language origin could influence memory capacity. In line with evolutionary theories that natural selection refined language-related cognitive abilities, we advocated a coevolution scenario between language and memory capacity, which incorporated the genetic transmission of individual memory capacity, cultural transmission of idiolects, and natural and cultural selections on individual reproduction and language teaching. To illustrate the coevolution dynamics, we adopted a multi-agent computational model simulating the emergence of lexical items and simple syntax through iterated communications. Simulations showed that: along with the origin of a communal language, an initially-low memory capacity for acquired linguistic knowledge was boosted; and such coherent increase in linguistic understandability and memory capacities reflected a language-memory coevolution; and such coevolution stopped till memory capacities became sufficient for language communications. Statistical analyses revealed that the coevolution was realized mainly by natural selection based on individual communicative success in cultural transmissions. This work elaborated the biology-culture parallelism of language evolution, demonstrated the driving force of culturally-constituted factors for natural selection of individual cognitive abilities, and suggested that the degree difference in language-related cognitive abilities between humans and nonhuman animals could result from a coevolution with language. PMID:26544876

  20. The potential of a population genomics approach to analyse geographic mosaics of plant–insect coevolution

    NARCIS (Netherlands)

    Vermeer, K.M.C.A.; Dicke, M.; Jong, de P.W.

    2011-01-01

    A central issue in the evolutionary ecology of species interactions is coevolution, which involves the reciprocal selection between individuals of interacting species. Understanding the importance of coevolution in shaping species interactions requires the consideration of spatial variation in their

  1. Coevolution of Glauber-like Ising dynamics and topology

    Science.gov (United States)

    Mandrà, Salvatore; Fortunato, Santo; Castellano, Claudio

    2009-11-01

    We study the coevolution of a generalized Glauber dynamics for Ising spins with tunable threshold and of the graph topology where the dynamics takes place. This simple coevolution dynamics generates a rich phase diagram in the space of the two parameters of the model, the threshold and the rewiring probability. The diagram displays phase transitions of different types: spin ordering, percolation, and connectedness. At variance with traditional coevolution models, in which all spins of each connected component of the graph have equal value in the stationary state, we find that, for suitable choices of the parameters, the system may converge to a state in which spins of opposite sign coexist in the same component organized in compact clusters of like-signed spins. Mean field calculations enable one to estimate some features of the phase diagram.

  2. Co-evolution of social networks and continuous actor attributes

    NARCIS (Netherlands)

    Niezink, Nynke M.D.; Snijders, Tom A.B.

    2017-01-01

    Social networks and the attributes of the actors in these networks are not static; they may develop interdependently over time. The stochastic actor-oriented model allows for statistical inference on the mechanisms driving this co-evolution process. In earlier versions of this model, dynamic actor

  3. Coevolution of variability models and related software artifacts

    DEFF Research Database (Denmark)

    Passos, Leonardo; Teixeira, Leopoldo; Dinztner, Nicolas

    2015-01-01

    models coevolve with other artifact types, we study a large and complex real-world variant-rich software system: the Linux kernel. Specifically, we extract variability-coevolution patterns capturing changes in the variability model of the Linux kernel with subsequent changes in Makefiles and C source...

  4. Coevolution of game and network structure with adjustable linking

    Science.gov (United States)

    Qin, Shao-Meng; Zhang, Guo-Yong; Chen, Yong

    2009-12-01

    Most papers about the evolutionary game on graph assume the statistic network structure. However, in the real world, social interaction could change the relationship among people. And the change of social structure will also affect people’s strategies. We build a coevolution model of prisoner’s dilemma game and network structure to study the dynamic interaction in the real world. Differing from other coevolution models, players rewire their network connections according to the density of cooperation and other players’ payoffs. We use a parameter α to control the effect of payoff in the process of rewiring. Based on the asynchronous update rule and Monte Carlo simulation, we find that, when players prefer to rewire their links to those who are richer, the temptation can increase the cooperation density.

  5. Coevolution of Cryptosporidium tyzzeri and the house mouse (Mus musculus)

    Czech Academy of Sciences Publication Activity Database

    Kváč, Martin; McEvoy, J.; Loudová, M.; Stenger, B.; Sak, Bohumil; Květoňová, Dana; Ditrich, Oleg; Rašková, Veronika; Moriarty, E.; Rost, M.; Macholán, Miloš; Piálek, Jaroslav

    2013-01-01

    Roč. 43, č. 10 (2013), s. 805-817 ISSN 0020-7519 R&D Projects: GA ČR GA206/08/0640; GA MŠk(CZ) LH11061 Institutional support: RVO:60077344 ; RVO:67985904 ; RVO:68081766 Keywords : Cryptosporidium tyzzeri * house mouse * hybrid zone * coevolution Subject RIV: EG - Zoology; GJ - Animal Vermins ; Diseases, Veterinary Medicine (BC-A) Impact factor: 3.404, year: 2013

  6. HIV-1 protease-substrate coevolution in nelfinavir resistance.

    Science.gov (United States)

    Kolli, Madhavi; Ozen, Ayşegül; Kurt-Yilmaz, Nese; Schiffer, Celia A

    2014-07-01

    Resistance to various human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs) challenges the effectiveness of therapies in treating HIV-1-infected individuals and AIDS patients. The virus accumulates mutations within the protease (PR) that render the PIs less potent. Occasionally, Gag sequences also coevolve with mutations at PR cleavage sites contributing to drug resistance. In this study, we investigated the structural basis of coevolution of the p1-p6 cleavage site with the nelfinavir (NFV) resistance D30N/N88D protease mutations by determining crystal structures of wild-type and NFV-resistant HIV-1 protease in complex with p1-p6 substrate peptide variants with L449F and/or S451N. Alterations of residue 30's interaction with the substrate are compensated by the coevolving L449F and S451N cleavage site mutations. This interdependency in the PR-p1-p6 interactions enhances intermolecular contacts and reinforces the overall fit of the substrate within the substrate envelope, likely enabling coevolution to sustain substrate recognition and cleavage in the presence of PR resistance mutations. Resistance to human immunodeficiency virus type 1 (HIV-1) protease inhibitors challenges the effectiveness of therapies in treating HIV-1-infected individuals and AIDS patients. Mutations in HIV-1 protease selected under the pressure of protease inhibitors render the inhibitors less potent. Occasionally, Gag sequences also mutate and coevolve with protease, contributing to maintenance of viral fitness and to drug resistance. In this study, we investigated the structural basis of coevolution at the Gag p1-p6 cleavage site with the nelfinavir (NFV) resistance D30N/N88D protease mutations. Our structural analysis reveals the interdependency of protease-substrate interactions and how coevolution may restore substrate recognition and cleavage in the presence of protease drug resistance mutations. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  7. Heuristic urban transportation network design method, a multilayer coevolution approach

    Science.gov (United States)

    Ding, Rui; Ujang, Norsidah; Hamid, Hussain bin; Manan, Mohd Shahrudin Abd; Li, Rong; Wu, Jianjun

    2017-08-01

    The design of urban transportation networks plays a key role in the urban planning process, and the coevolution of urban networks has recently garnered significant attention in literature. However, most of these recent articles are based on networks that are essentially planar. In this research, we propose a heuristic multilayer urban network coevolution model with lower layer network and upper layer network that are associated with growth and stimulate one another. We first use the relative neighbourhood graph and the Gabriel graph to simulate the structure of rail and road networks, respectively. With simulation we find that when a specific number of nodes are added, the total travel cost ratio between an expanded network and the initial lower layer network has the lowest value. The cooperation strength Λ and the changeable parameter average operation speed ratio Θ show that transit users' route choices change dramatically through the coevolution process and that their decisions, in turn, affect the multilayer network structure. We also note that the simulated relation between the Gini coefficient of the betweenness centrality, Θ and Λ have an optimal point for network design. This research could inspire the analysis of urban network topology features and the assessment of urban growth trends.

  8. Coevolution of CRISPR bacteria and phage in 2 dimensions

    Science.gov (United States)

    Han, Pu; Deem, Michael

    2014-03-01

    CRISPR (cluster regularly interspaced short palindromic repeats) is a newly discovered adaptive, heritable immune system of prokaryotes. It can prevent infection of prokaryotes by phage. Most bacteria and almost all archae have CRISPR. The CRISPR system incorporates short nucleotide sequences from viruses. These incorporated sequences provide a historical record of the host and predator coevolution. We simulate the coevolution of bacteria and phage in 2 dimensions. Each phage has multiple proto-spacers that the bacteria can incorporate. Each bacterium can store multiple spacers in its CRISPR. Phages can escape recognition by the CRISPR system via point mutation or recombination. We will discuss the different evolutionary consequences of point mutation or recombination on the coevolution of bacteria and phage. We will also discuss an intriguing ``dynamic phase transition'' in the number of phage as a function of time and mutation rate. We will show that due to the arm race between phages and bacteria, the frequency of spacers and proto-spacers in a population can oscillate quite rapidly.

  9. Co-evolution in innovation systems : the case of pharmaceutical biotechnology

    NARCIS (Netherlands)

    Gilsing, V.A.; Nooteboom, B.

    2004-01-01

    This paper sets out a theoretical framework for an explanation of the co-evolution of the institutional selection environment and organizations in innovation systems. The paper demonstrates that coevolution can be understood in terms of how exploitation and exploration build on each other, in a

  10. Coevolution of Artificial Agents Using Evolutionary Computation in Bargaining Game

    Directory of Open Access Journals (Sweden)

    Sangwook Lee

    2015-01-01

    Full Text Available Analysis of bargaining game using evolutionary computation is essential issue in the field of game theory. This paper investigates the interaction and coevolutionary process among heterogeneous artificial agents using evolutionary computation (EC in the bargaining game. In particular, the game performance with regard to payoff through the interaction and coevolution of agents is studied. We present three kinds of EC based agents (EC-agent participating in the bargaining game: genetic algorithm (GA, particle swarm optimization (PSO, and differential evolution (DE. The agents’ performance with regard to changing condition is compared. From the simulation results it is found that the PSO-agent is superior to the other agents.

  11. Assembly constraints drive co-evolution among ribosomal constituents.

    Science.gov (United States)

    Mallik, Saurav; Akashi, Hiroshi; Kundu, Sudip

    2015-06-23

    Ribosome biogenesis, a central and essential cellular process, occurs through sequential association and mutual co-folding of protein-RNA constituents in a well-defined assembly pathway. Here, we construct a network of co-evolving nucleotide/amino acid residues within the ribosome and demonstrate that assembly constraints are strong predictors of co-evolutionary patterns. Predictors of co-evolution include a wide spectrum of structural reconstitution events, such as cooperativity phenomenon, protein-induced rRNA reconstitutions, molecular packing of different rRNA domains, protein-rRNA recognition, etc. A correlation between folding rate of small globular proteins and their topological features is known. We have introduced an analogous topological characteristic for co-evolutionary network of ribosome, which allows us to differentiate between rRNA regions subjected to rapid reconstitutions from those hindered by kinetic traps. Furthermore, co-evolutionary patterns provide a biological basis for deleterious mutation sites and further allow prediction of potential antibiotic targeting sites. Understanding assembly pathways of multicomponent macromolecules remains a key challenge in biophysics. Our study provides a 'proof of concept' that directly relates co-evolution to biophysical interactions during multicomponent assembly and suggests predictive power to identify candidates for critical functional interactions as well as for assembly-blocking antibiotic target sites. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  12. CMCpy: Genetic Code-Message Coevolution Models in Python

    Science.gov (United States)

    Becich, Peter J.; Stark, Brian P.; Bhat, Harish S.; Ardell, David H.

    2013-01-01

    Code-message coevolution (CMC) models represent coevolution of a genetic code and a population of protein-coding genes (“messages”). Formally, CMC models are sets of quasispecies coupled together for fitness through a shared genetic code. Although CMC models display plausible explanations for the origin of multiple genetic code traits by natural selection, useful modern implementations of CMC models are not currently available. To meet this need we present CMCpy, an object-oriented Python API and command-line executable front-end that can reproduce all published results of CMC models. CMCpy implements multiple solvers for leading eigenpairs of quasispecies models. We also present novel analytical results that extend and generalize applications of perturbation theory to quasispecies models and pioneer the application of a homotopy method for quasispecies with non-unique maximally fit genotypes. Our results therefore facilitate the computational and analytical study of a variety of evolutionary systems. CMCpy is free open-source software available from http://pypi.python.org/pypi/CMCpy/. PMID:23532367

  13. Rogue sperm indicate sexually antagonistic coevolution in nematodes.

    Directory of Open Access Journals (Sweden)

    Ronald E Ellis

    2014-07-01

    Full Text Available Intense reproductive competition often continues long after animals finish mating. In many species, sperm from one male compete with those from others to find and fertilize oocytes. Since this competition occurs inside the female reproductive tract, she often influences the outcome through physical or chemical factors, leading to cryptic female choice. Finally, traits that help males compete with each other are sometimes harmful to females, and female countermeasures may thwart the interests of males, which can lead to an arms race between the sexes known as sexually antagonistic coevolution. New studies from Caenorhabditis nematodes suggest that males compete with each other by producing sperm that migrate aggressively and that these sperm may be more likely to win access to oocytes. However, one byproduct of this competition appears to be an increased probability that these sperm will go astray, invading the ovary, prematurely activating oocytes, and sometimes crossing basement membranes and leaving the gonad altogether. These harmful effects are sometimes observed in crosses between animals of the same species but are most easily detected in interspecies crosses, leading to dramatically lowered fitness, presumably because the competitiveness of the sperm and the associated female countermeasures are not precisely matched. This mismatch is most obvious in crosses involving individuals from androdioecious species (which have both hermaphrodites and males, as predicted by the lower levels of sperm competition these species experience. These results suggest a striking example of sexually antagonistic coevolution and dramatically expand the value of nematodes as a laboratory system for studying postcopulatory interactions.

  14. The coevolution of long-term pair bonds and cooperation.

    Science.gov (United States)

    Song, Z; Feldman, M W

    2013-05-01

    The evolution of social traits may not only depend on but also change the social structure of the population. In particular, the evolution of pairwise cooperation, such as biparental care, depends on the pair-matching distribution of the population, and the latter often emerges as a collective outcome of individual pair-bonding traits, which are also under selection. Here, we develop an analytical model and individual-based simulations to study the coevolution of long-term pair bonds and cooperation in parental care, where partners play a Snowdrift game in each breeding season. We illustrate that long-term pair bonds may coevolve with cooperation when bonding cost is below a threshold. As long-term pair bonds lead to assortative interactions through pair-matching dynamics, they may promote the prevalence of cooperation. In addition to the pay-off matrix of a single game, the evolutionarily stable equilibrium also depends on bonding cost and accidental divorce rate, and it is determined by a form of balancing selection because the benefit from pair-bond maintenance diminishes as the frequency of cooperators increases. Our findings highlight the importance of ecological factors affecting social bonding cost and stability in understanding the coevolution of social behaviour and social structures, which may lead to the diversity of biological social systems. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  15. Multispecies Coevolution Particle Swarm Optimization Based on Previous Search History

    Directory of Open Access Journals (Sweden)

    Danping Wang

    2017-01-01

    Full Text Available A hybrid coevolution particle swarm optimization algorithm with dynamic multispecies strategy based on K-means clustering and nonrevisit strategy based on Binary Space Partitioning fitness tree (called MCPSO-PSH is proposed. Previous search history memorized into the Binary Space Partitioning fitness tree can effectively restrain the individuals’ revisit phenomenon. The whole population is partitioned into several subspecies and cooperative coevolution is realized by an information communication mechanism between subspecies, which can enhance the global search ability of particles and avoid premature convergence to local optimum. To demonstrate the power of the method, comparisons between the proposed algorithm and state-of-the-art algorithms are grouped into two categories: 10 basic benchmark functions (10-dimensional and 30-dimensional, 10 CEC2005 benchmark functions (30-dimensional, and a real-world problem (multilevel image segmentation problems. Experimental results show that MCPSO-PSH displays a competitive performance compared to the other swarm-based or evolutionary algorithms in terms of solution accuracy and statistical tests.

  16. The evolution of reduced antagonism--A role for host-parasite coevolution.

    Science.gov (United States)

    Gibson, A K; Stoy, K S; Gelarden, I A; Penley, M J; Lively, C M; Morran, L T

    2015-11-01

    Why do some host-parasite interactions become less antagonistic over evolutionary time? Vertical transmission can select for reduced antagonism. Vertical transmission also promotes coevolution between hosts and parasites. Therefore, we hypothesized that coevolution itself may underlie transitions to reduced antagonism. To test the coevolution hypothesis, we selected for reduced antagonism between the host Caenorhabditis elegans and its parasite Serratia marcescens. This parasite is horizontally transmitted, which allowed us to study coevolution independently of vertical transmission. After 20 generations, we observed a response to selection when coevolution was possible: reduced antagonism evolved in the copassaged treatment. Reduced antagonism, however, did not evolve when hosts or parasites were independently selected without coevolution. In addition, we found strong local adaptation for reduced antagonism between replicate host/parasite lines in the copassaged treatment. Taken together, these results strongly suggest that coevolution was critical to the rapid evolution of reduced antagonism. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  17. The coevolution of genes and genetic codes: Crick's frozen accident revisited.

    Science.gov (United States)

    Sella, Guy; Ardell, David H

    2006-09-01

    The standard genetic code is the nearly universal system for the translation of genes into proteins. The code exhibits two salient structural characteristics: it possesses a distinct organization that makes it extremely robust to errors in replication and translation, and it is highly redundant. The origin of these properties has intrigued researchers since the code was first discovered. One suggestion, which is the subject of this review, is that the code's organization is the outcome of the coevolution of genes and genetic codes. In 1968, Francis Crick explored the possible implications of coevolution at different stages of code evolution. Although he argues that coevolution was likely to influence the evolution of the code, he concludes that it falls short of explaining the organization of the code we see today. The recent application of mathematical modeling to study the effects of errors on the course of coevolution, suggests a different conclusion. It shows that coevolution readily generates genetic codes that are highly redundant and similar in their error-correcting organization to the standard code. We review this recent work and suggest that further affirmation of the role of coevolution can be attained by investigating the extent to which the outcome of coevolution is robust to other influences that were present during the evolution of the code.

  18. Robustness of coevolution in resolving prisoner's dilemma games on interdependent networks subject to attack

    Science.gov (United States)

    Liu, Penghui; Liu, Jing

    2017-08-01

    Recently, coevolution between strategy and network structure has been established as a rule to resolve social dilemmas and reach optimal situations for cooperation. Many follow-up researches have focused on studying how coevolution helps networks reorganize to deter the defectors and many coevolution methods have been proposed. However, the robustness of the coevolution rules against attacks have not been studied much. Since attacks may directly influence the original evolutionary process of cooperation, the robustness should be an important index while evaluating the quality of a coevolution method. In this paper, we focus on investigating the robustness of an elementary coevolution method in resolving the prisoner's dilemma game upon the interdependent networks. Three different types of time-independent attacks, named as edge attacks, instigation attacks and node attacks have been employed to test its robustness. Through analyzing the simulation results obtained, we find this coevolution method is relatively robust against the edge attack and the node attack as it successfully maintains cooperation in the population over the entire attack range. However, when the instigation probability of the attacked individuals is large or the attack range of instigation attack is wide enough, coevolutionary rule finally fails in maintaining cooperation in the population.

  19. Cosmological coevolution of Yang-Mills fields and perfect fluids

    International Nuclear Information System (INIS)

    Barrow, John D.; Jin, Yoshida; Maeda, Kei-ichi

    2005-01-01

    We study the coevolution of Yang-Mills fields and perfect fluids in Bianchi type I universes. We investigate numerically the evolution of the universe and the Yang-Mills fields during the radiation and dust eras of a universe that is almost isotropic. The Yang-Mills field undergoes small amplitude chaotic oscillations, as do the three expansion scale factors which are also displayed by the expansion scale factors of the universe. The results of the numerical simulations are interpreted analytically and compared with past studies of the cosmological evolution of magnetic fields in radiation and dust universes. We find that, whereas magnetic universes are strongly constrained by the microwave background anisotropy, Yang-Mills universes are principally constrained by primordial nucleosynthesis but the bound is comparatively weak with Ω YM rad

  20. Coevolution of landesque capital intensive agriculture and sociopolitical hierarchy.

    Science.gov (United States)

    Sheehan, Oliver; Watts, Joseph; Gray, Russell D; Atkinson, Quentin D

    2018-04-03

    One of the defining trends of the Holocene has been the emergence of complex societies. Two essential features of complex societies are intensive resource use and sociopolitical hierarchy. Although it is widely agreed that these two phenomena are associated cross-culturally and have both contributed to the rise of complex societies, the causality underlying their relationship has been the subject of longstanding debate. Materialist theories of cultural evolution tend to view resource intensification as driving the development of hierarchy, but the reverse order of causation has also been advocated, along with a range of intermediate views. Phylogenetic methods have the potential to test between these different causal models. Here we report the results of a phylogenetic study that modeled the coevolution of one type of resource intensification-the development of landesque capital intensive agriculture-with political complexity and social stratification in a sample of 155 Austronesian-speaking societies. We found support for the coevolution of landesque capital with both political complexity and social stratification, but the contingent and nondeterministic nature of both of these relationships was clear. There was no indication that intensification was the "prime mover" in either relationship. Instead, the relationship between intensification and social stratification was broadly reciprocal, whereas political complexity was more of a driver than a result of intensification. These results challenge the materialist view and emphasize the importance of both material and social factors in the evolution of complex societies, as well as the complex and multifactorial nature of cultural evolution. Copyright © 2018 the Author(s). Published by PNAS.

  1. The co-evolution of gossip and friendship in workplace social networks

    NARCIS (Netherlands)

    Ellwardt, Lea; Steglich, Christian; Wittek, Rafael

    2012-01-01

    This study investigates the co-evolution of friendship and gossip in organizations. Two contradicting perspectives are tested. The social capital perspective predicts that friendship causes gossip between employees, defined as informal evaluative talking about absent colleagues. The evolutionary

  2. Niche construction, sources of selection and trait coevolution.

    Science.gov (United States)

    Laland, Kevin; Odling-Smee, John; Endler, John

    2017-10-06

    Organisms modify and choose components of their local environments. This 'niche construction' can alter ecological processes, modify natural selection and contribute to inheritance through ecological legacies. Here, we propose that niche construction initiates and modifies the selection directly affecting the constructor, and on other species, in an orderly, directed and sustained manner. By dependably generating specific environmental states, niche construction co-directs adaptive evolution by imposing a consistent statistical bias on selection. We illustrate how niche construction can generate this evolutionary bias by comparing it with artificial selection. We suggest that it occupies the middle ground between artificial and natural selection. We show how the perspective leads to testable predictions related to: (i) reduced variance in measures of responses to natural selection in the wild; (ii) multiple trait coevolution, including the evolution of sequences of traits and patterns of parallel evolution; and (iii) a positive association between niche construction and biodiversity. More generally, we submit that evolutionary biology would benefit from greater attention to the diverse properties of all sources of selection.

  3. The Co-evolution of Neuroimaging and Psychiatric Neurosurgery.

    Science.gov (United States)

    Dyster, Timothy G; Mikell, Charles B; Sheth, Sameer A

    2016-01-01

    The role of neuroimaging in psychiatric neurosurgery has evolved significantly throughout the field's history. Psychiatric neurosurgery initially developed without the benefit of information provided by modern imaging modalities, and thus lesion targets were selected based on contemporary theories of frontal lobe dysfunction in psychiatric disease. However, by the end of the 20th century, the availability of structural and functional magnetic resonance imaging (fMRI) allowed for the development of mechanistic theories attempting to explain the anatamofunctional basis of these disorders, as well as the efficacy of stereotactic neuromodulatory treatments. Neuroimaging now plays a central and ever-expanding role in the neurosurgical management of psychiatric disorders, by influencing the determination of surgical candidates, allowing individualized surgical targeting and planning, and identifying network-level changes in the brain following surgery. In this review, we aim to describe the coevolution of psychiatric neurosurgery and neuroimaging, including ways in which neuroimaging has proved useful in elucidating the therapeutic mechanisms of neuromodulatory procedures. We focus on ablative over stimulation-based procedures given their historical precedence and the greater opportunity they afford for post-operative re-imaging, but also discuss important contributions from the deep brain stimulation (DBS) literature. We conclude with a discussion of how neuroimaging will transition the field of psychiatric neurosurgery into the era of precision medicine.

  4. Critical mass of public goods and its coevolution with cooperation

    Science.gov (United States)

    Shi, Dong-Mei; Wang, Bing-Hong

    2017-07-01

    In this study, the enhancing parameter represented the value of the public goods to the public in public goods game, and was rescaled to a Fermi-Dirac distribution function of critical mass. Public goods were divided into two categories, consumable and reusable public goods, and their coevolution with cooperative behavior was studied. We observed that for both types of public goods, cooperation was promoted as the enhancing parameter increased when the value of critical mass was not very large. An optimal value of critical mass which led to the best cooperation was identified. We also found that cooperations emerged earlier for reusable public goods, and defections became extinct earlier for the consumable public goods. Moreover, we observed that a moderate depreciation rate for public goods resulted in an optimal cooperation, and this range became wider as the enhancing parameter increased. The noise influence on cooperation was studied, and it was shown that cooperation density varied non-monotonically as noise amplitude increased for reusable public goods, whereas decreased monotonically for consumable public goods. Furthermore, existence of the optimal critical mass was also identified in other three regular networks. Finally, simulation results were utilized to analyze the provision of public goods in detail.

  5. Coevolution of Cooperation and Layer Selection Strategy in Multiplex Networks

    Directory of Open Access Journals (Sweden)

    Katsuki Hayashi

    2016-11-01

    Full Text Available Recently, the emergent dynamics in multiplex networks, composed of layers of multiple networks, has been discussed extensively in network sciences. However, little is still known about whether and how the evolution of strategy for selecting a layer to participate in can contribute to the emergence of cooperative behaviors in multiplex networks of social interactions. To investigate these issues, we constructed a coevolutionary model of cooperation and layer selection strategies in which each an individual selects one layer from multiple layers of social networks and plays the Prisoner’s Dilemma with neighbors in the selected layer. We found that the proportion of cooperative strategies increased with increasing the number of layers regardless of the degree of dilemma, and this increase occurred due to a cyclic coevolution process of game strategies and layer selection strategies. We also showed that the heterogeneity of links among layers is a key factor for multiplex networks to facilitate the evolution of cooperation, and such positive effects on cooperation were observed regardless of the difference in the stochastic properties of network topologies.

  6. Paternal care and litter size coevolution in mammals.

    Science.gov (United States)

    Stockley, Paula; Hobson, Liane

    2016-04-27

    Biparental care of offspring occurs in diverse mammalian genera and is particularly common among species with socially monogamous mating systems. Despite numerous well-documented examples, however, the evolutionary causes and consequences of paternal care in mammals are not well understood. Here, we investigate the evolution of paternal care in relation to offspring production. Using comparative analyses to test for evidence of evolutionary associations between male care and life-history traits, we explore if biparental care is likely to have evolved because of the importance of male care to offspring survival, or if evolutionary increases in offspring production are likely to result from the evolution of biparental care. Overall, we find no evidence that paternal care has evolved in response to benefits of supporting females to rear particularly costly large offspring or litters. Rather, our findings suggest that increases in offspring production are more likely to follow the evolution of paternal care, specifically where males contribute depreciable investment such as provisioning young. Through coevolution with litter size, we conclude that paternal care in mammals is likely to play an important role in stabilizing monogamous mating systems and could ultimately promote the evolution of complex social behaviours. © 2016 The Authors.

  7. New Measurement for Correlation of Co-evolution Relationship of Subsequences in Protein.

    Science.gov (United States)

    Gao, Hongyun; Yu, Xiaoqing; Dou, Yongchao; Wang, Jun

    2015-12-01

    Many computational tools have been developed to measure the protein residues co-evolution. Most of them only focus on co-evolution for pairwise residues in a protein sequence. However, number of residues participate in co-evolution might be multiple. And some co-evolved residues are clustered in several distinct regions in primary structure. Therefore, the co-evolution among the adjacent residues and the correlation between the distinct regions offer insights into function and evolution of the protein and residues. Subsequence is used to represent the adjacent multiple residues in one distinct region. In the paper, co-evolution relationship in each subsequence is represented by mutual information matrix (MIM). Then, Pearson's correlation coefficient: R value is developed to measure the similarity correlation of two MIMs. MSAs from Catalytic Data Base (Catalytic Site Atlas, CSA) are used for testing. R value characterizes a specific class of residues. In contrast to individual pairwise co-evolved residues, adjacent residues without high individual MI values are found since the co-evolved relationship among them is similar to that among another set of adjacent residues. These subsequences possess some flexibility in the composition of side chains, such as the catalyzed environment.

  8. Genetic and linguistic coevolution in Northern Island Melanesia.

    Science.gov (United States)

    Hunley, Keith; Dunn, Michael; Lindström, Eva; Reesink, Ger; Terrill, Angela; Healy, Meghan E; Koki, George; Friedlaender, Françoise R; Friedlaender, Jonathan S

    2008-10-01

    Recent studies have detailed a remarkable degree of genetic and linguistic diversity in Northern Island Melanesia. Here we utilize that diversity to examine two models of genetic and linguistic coevolution. The first model predicts that genetic and linguistic correspondences formed following population splits and isolation at the time of early range expansions into the region. The second is analogous to the genetic model of isolation by distance, and it predicts that genetic and linguistic correspondences formed through continuing genetic and linguistic exchange between neighboring populations. We tested the predictions of the two models by comparing observed and simulated patterns of genetic variation, genetic and linguistic trees, and matrices of genetic, linguistic, and geographic distances. The data consist of 751 autosomal microsatellites and 108 structural linguistic features collected from 33 Northern Island Melanesian populations. The results of the tests indicate that linguistic and genetic exchange have erased any evidence of a splitting and isolation process that might have occurred early in the settlement history of the region. The correlation patterns are also inconsistent with the predictions of the isolation by distance coevolutionary process in the larger Northern Island Melanesian region, but there is strong evidence for the process in the rugged interior of the largest island in the region (New Britain). There we found some of the strongest recorded correlations between genetic, linguistic, and geographic distances. We also found that, throughout the region, linguistic features have generally been less likely to diffuse across population boundaries than genes. The results from our study, based on exceptionally fine-grained data, show that local genetic and linguistic exchange are likely to obscure evidence of the early history of a region, and that language barriers do not particularly hinder genetic exchange. In contrast, global patterns may

  9. Genetic and linguistic coevolution in Northern Island Melanesia.

    Directory of Open Access Journals (Sweden)

    Keith Hunley

    2008-10-01

    Full Text Available Recent studies have detailed a remarkable degree of genetic and linguistic diversity in Northern Island Melanesia. Here we utilize that diversity to examine two models of genetic and linguistic coevolution. The first model predicts that genetic and linguistic correspondences formed following population splits and isolation at the time of early range expansions into the region. The second is analogous to the genetic model of isolation by distance, and it predicts that genetic and linguistic correspondences formed through continuing genetic and linguistic exchange between neighboring populations. We tested the predictions of the two models by comparing observed and simulated patterns of genetic variation, genetic and linguistic trees, and matrices of genetic, linguistic, and geographic distances. The data consist of 751 autosomal microsatellites and 108 structural linguistic features collected from 33 Northern Island Melanesian populations. The results of the tests indicate that linguistic and genetic exchange have erased any evidence of a splitting and isolation process that might have occurred early in the settlement history of the region. The correlation patterns are also inconsistent with the predictions of the isolation by distance coevolutionary process in the larger Northern Island Melanesian region, but there is strong evidence for the process in the rugged interior of the largest island in the region (New Britain. There we found some of the strongest recorded correlations between genetic, linguistic, and geographic distances. We also found that, throughout the region, linguistic features have generally been less likely to diffuse across population boundaries than genes. The results from our study, based on exceptionally fine-grained data, show that local genetic and linguistic exchange are likely to obscure evidence of the early history of a region, and that language barriers do not particularly hinder genetic exchange. In contrast

  10. Co-evolution of insect proteases and plant protease inhibitors.

    Science.gov (United States)

    Jongsma, Maarten A; Beekwilder, Jules

    2011-08-01

    Plants are at the basis of the food chain, but there is no such thing as a "free lunch" for herbivores. To promote reproductive success, plants evolved multi-layered defensive tactics to avoid or discourage herbivory. To the detriment of plants, herbivores, in turn, evolved intricate strategies to find, eat, and successfully digest essential plant parts to raise their own offspring. In this battle the digestive tract is the arena determining final victory or defeat as measured by growth or starvation of the herbivore. Earlier, specific molecular opponents were identified as proteases and inhibitors: digestive proteases of herbivores evolved structural motifs to occlude plant protease inhibitors, or alternatively, the insects evolved proteases capable of specifically degrading the host plant inhibitors. In response plant inhibitors evolved hyper-variable and novel protein folds to remain active against potential herbivores. At the level of protease regulation in herbivorous insects, it was shown that inhibition-insensitive digestive proteases are up-regulated when sensitive proteases are inhibited. The way this regulation operates in mammals is known as negative feedback by gut-luminal factors, so-called 'monitor peptides' that are sensitive to the concentration of active enzymes. We propose that regulation of gut enzymes by endogenous luminal factors has been an open invitation to plants to "hijack" this regulation by evolving receptor antagonists, although yet these plant factors have not been identified. In future research the question of the co-evolution of insect proteases and plant inhibitors should, therefore, be better approached from a systems level keeping in mind that evolution is fundamentally opportunistic and that the plant's fitness is primarily improved by lowering the availability of essential amino acids to an herbivore by any available mechanism.

  11. Co-evolution and thresholds in arid floodplain wetland ecosystems.

    Science.gov (United States)

    Sandi, Steven; Rodriguez, Jose; Riccardi, Gerardo; Wen, Li; Saintilan, Neil

    2017-04-01

    Vegetation in arid floodplain wetlands consist of water dependent and flood tolerant species that rely on periodical floods in order to maintain healthy conditions. The floodplain often consist of a complex system of marshes, swamps and lagoons interconnected by a network of streams and poorly defined rills. Over time, feedbacks develop between vegetation and flow paths producing areas of flow obstruction and flow concentration, which combined with depositional and erosional process lead to a continuous change on the position and characteristics of inundation areas. This coevolution of flow paths and vegetation can reach a threshold that triggers major channel transformations and abandonment of wetland areas, in a process that is irreversible. The Macquarie Marshes is a floodplain wetland complex in the semi-arid region of north western NSW, Australia. The site is characterised by a low-gradient topography that leads to channel breakdown processes where the river network becomes practically non-existent and the flow extends over large areas of wetland that later re-join and reform channels exiting the system. Due to a combination of climatic and anthropogenic pressures, the wetland ecosystem in the Macquarie Marshes has deteriorated over the past few decades. This has been linked to decreasing inundation frequencies and extent, with whole areas of flood dependent species such as Water Couch and Common Reed undergoing complete succession to terrestrial species and dryland. In this presentation we provide an overview of an ecogeomorphological model that we have developed in order to simulate the complex dynamics of the marshes. The model combines hydrodynamic, vegetation and channel evolution modules. We focus on the vegetation component of the model and the transitional rules to predict wetland invasion by terrestrial vegetation.

  12. Data from: Rapid multiple-level coevolution in experimental populations of yeast killer and non-killer strains

    NARCIS (Netherlands)

    Pieczynska, M.D.; Wloch-Salamon, D.; Korona, R.; Visser, de J.A.G.M.

    2016-01-01

    Coevolution between different biological entities is considered an important evolutionary mechanism at all levels of biological organization. Here we provide evidence for coevolution of a yeast killer strain (K) carrying cytoplasmic dsRNA viruses coding for anti-competitor toxins and an isogenic

  13. Studying the co-evolution of protein families with the Mirrortree web server.

    Science.gov (United States)

    Ochoa, David; Pazos, Florencio

    2010-05-15

    The Mirrortree server allows to graphically and interactively study the co-evolution of two protein families, and investigate their possible interactions and functional relationships in a taxonomic context. The server includes the possibility of starting from single sequences and hence it can be used by non-expert users. The web server is freely available at http://csbg.cnb.csic.es/mtserver. It was tested in the main web browsers. Adobe Flash Player is required at the client side to perform the interactive assessment of co-evolution. pazos@cnb.csic.es Supplementary data are available at Bioinformatics online.

  14. Co-evolution as Tool for Diversifying Flavor and Aroma Profiles of Wines

    Directory of Open Access Journals (Sweden)

    Peter Morrison-Whittle

    2018-05-01

    Full Text Available The products of microbial metabolism form an integral part of human industry and have been shaped by evolutionary processes, accidentally and deliberately, for thousands of years. In the production of wine, a great many flavor and aroma compounds are produced by yeast species and are the targets of research for commercial breeding programs. Here we demonstrate how co-evolution with multiple species can generate novel interactions through serial co-culture in grape juice. We find that after ~65 generations, co-evolved strains and strains evolved independently show significantly different growth aspects and exhibit significantly different metabolite profiles. We show significant impact of co-evolution of Candida glabrata and Pichia kudriavzevii on the production of metabolites that affect the flavor and aroma of experimental wines. While co-evolved strains do exhibit novel interactions that affect the reproductive success of interacting species, we found no evidence of cross-feeding behavior. Our findings yield promising avenues for developing commercial yeast strains by using co-evolution to diversify the metabolic output of target species without relying on genetic modification or breeding technologies. Such approaches open up exciting new possibilities for harnessing microbial co-evolution in areas of agriculture and food related research generally.

  15. The Coevolution of "Tyrannosaurus" & Its Prey: Could "Tyrannosaurus" Chase down & Kill a "Triceratops" for Lunch?

    Science.gov (United States)

    May, S. Randolph

    2014-01-01

    Students will analyze the coevolution of the predator-prey relationships between "Tyrannosaurus rex" and its prey species using analyses of animal speeds from fossilized trackways, prey-animal armaments, adaptive behaviors, bite marks on prey-animal fossils, predator-prey ratios, and scavenger competition. The students will be asked to…

  16. Transition management as a model for managing processes of co-evolution towards sustainable development

    NARCIS (Netherlands)

    R. Kemp (René); D.A. Loorbach (Derk); J. Rotmans (Jan)

    2007-01-01

    textabstractSustainable development requires changes in socio-technical systems and wider societal change - in beliefs, values and governance that co-evolve with technology changes. In this article we present a practical model for managing processes of co-evolution: transition management. Transition

  17. Catchment coevolution: A useful framework for improving predictions of hydrological change?

    Science.gov (United States)

    Troch, Peter A.

    2017-04-01

    The notion that landscape features have co-evolved over time is well known in the Earth sciences. Hydrologists have recently called for a more rigorous connection between emerging spatial patterns of landscape features and the hydrological response of catchments, and have termed this concept catchment coevolution. In this presentation we present a general framework of catchment coevolution that could improve predictions of hydrologic change. We first present empirical evidence of the interaction and feedback of landscape evolution and changes in hydrological response. From this review it is clear that the independent drivers of catchment coevolution are climate, geology, and tectonics. We identify common currency that allows comparing the levels of activity of these independent drivers, such that, at least conceptually, we can quantify the rate of evolution or aging. Knowing the hydrologic age of a catchment by itself is not very meaningful without linking age to hydrologic response. Two avenues of investigation have been used to understand the relationship between (differences in) age and hydrological response: (i) one that is based on relating present landscape features to runoff processes that are hypothesized to be responsible for the current fingerprints in the landscape; and (ii) one that takes advantage of an experimental design known as space-for-time substitution. Both methods have yielded significant insights in the hydrologic response of landscapes with different histories. If we want to make accurate predictions of hydrologic change, we will also need to be able to predict how the catchment will further coevolve in association with changes in the activity levels of the drivers (e.g., climate). There is ample evidence in the literature that suggests that whole-system prediction of catchment coevolution is, at least in principle, plausible. With this imperative we outline a research agenda that implements the concepts of catchment coevolution for building

  18. A coevolution analysis for identifying protein-protein interactions by Fourier transform

    Science.gov (United States)

    Yin, Changchuan; Yau, Stephen S. -T.

    2017-01-01

    Protein-protein interactions (PPIs) play key roles in life processes, such as signal transduction, transcription regulations, and immune response, etc. Identification of PPIs enables better understanding of the functional networks within a cell. Common experimental methods for identifying PPIs are time consuming and expensive. However, recent developments in computational approaches for inferring PPIs from protein sequences based on coevolution theory avoid these problems. In the coevolution theory model, interacted proteins may show coevolutionary mutations and have similar phylogenetic trees. The existing coevolution methods depend on multiple sequence alignments (MSA); however, the MSA-based coevolution methods often produce high false positive interactions. In this paper, we present a computational method using an alignment-free approach to accurately detect PPIs and reduce false positives. In the method, protein sequences are numerically represented by biochemical properties of amino acids, which reflect the structural and functional differences of proteins. Fourier transform is applied to the numerical representation of protein sequences to capture the dissimilarities of protein sequences in biophysical context. The method is assessed for predicting PPIs in Ebola virus. The results indicate strong coevolution between the protein pairs (NP-VP24, NP-VP30, NP-VP40, VP24-VP30, VP24-VP40, and VP30-VP40). The method is also validated for PPIs in influenza and E.coli genomes. Since our method can reduce false positive and increase the specificity of PPI prediction, it offers an effective tool to understand mechanisms of disease pathogens and find potential targets for drug design. The Python programs in this study are available to public at URL (https://github.com/cyinbox/PPI). PMID:28430779

  19. A coevolution analysis for identifying protein-protein interactions by Fourier transform.

    Directory of Open Access Journals (Sweden)

    Changchuan Yin

    Full Text Available Protein-protein interactions (PPIs play key roles in life processes, such as signal transduction, transcription regulations, and immune response, etc. Identification of PPIs enables better understanding of the functional networks within a cell. Common experimental methods for identifying PPIs are time consuming and expensive. However, recent developments in computational approaches for inferring PPIs from protein sequences based on coevolution theory avoid these problems. In the coevolution theory model, interacted proteins may show coevolutionary mutations and have similar phylogenetic trees. The existing coevolution methods depend on multiple sequence alignments (MSA; however, the MSA-based coevolution methods often produce high false positive interactions. In this paper, we present a computational method using an alignment-free approach to accurately detect PPIs and reduce false positives. In the method, protein sequences are numerically represented by biochemical properties of amino acids, which reflect the structural and functional differences of proteins. Fourier transform is applied to the numerical representation of protein sequences to capture the dissimilarities of protein sequences in biophysical context. The method is assessed for predicting PPIs in Ebola virus. The results indicate strong coevolution between the protein pairs (NP-VP24, NP-VP30, NP-VP40, VP24-VP30, VP24-VP40, and VP30-VP40. The method is also validated for PPIs in influenza and E.coli genomes. Since our method can reduce false positive and increase the specificity of PPI prediction, it offers an effective tool to understand mechanisms of disease pathogens and find potential targets for drug design. The Python programs in this study are available to public at URL (https://github.com/cyinbox/PPI.

  20. Co-evolution of Industry Strategies and Government Policies: The Case of the Brazilian Automotive Industry

    Directory of Open Access Journals (Sweden)

    Roberto Gonzalez Duarte

    2017-07-01

    Full Text Available This study examines the evolution of the automotive industry in Brazil and its key drivers. We argue that the rules of the game – industry policies – are an outcome of exchanges between the host government and industry. These arise from changes in economic and political environments and interdependence between industry and the country’s economy. To this end, we draw upon literature on institutions and co-evolution to understand the industry footprint over a 50-year period, as well as its relationship with changes in government policies. This study generates new insights on institutional and co-evolution political perspectives by showing that the rules of the game are not only the making of the government, but are also the result of interdependencies between industry and government.

  1. The role of ecology, neutral processes and antagonistic coevolution in an apparent sexual arms race.

    Science.gov (United States)

    Perry, Jennifer C; Garroway, Colin J; Rowe, Locke

    2017-09-01

    Some of the strongest examples of a sexual 'arms race' come from observations of correlated evolution in sexually antagonistic traits among populations. However, it remains unclear whether these cases truly represent sexually antagonistic coevolution; alternatively, ecological or neutral processes might also drive correlated evolution. To investigate these alternatives, we evaluated the contributions of intersex genetic correlations, ecological context, neutral genetic divergence and sexual coevolution in the correlated evolution of antagonistic traits among populations of Gerris incognitus water striders. We could not detect intersex genetic correlations for these sexually antagonistic traits. Ecological variation was related to population variation in the key female antagonistic trait (spine length, a defence against males), as well as body size. Nevertheless, population covariation between sexually antagonistic traits remained substantial and significant even after accounting for all of these processes. Our results therefore provide strong evidence for a contemporary sexual arms race. © 2017 John Wiley & Sons Ltd/CNRS.

  2. Plastid-Nuclear Interaction and Accelerated Coevolution in Plastid Ribosomal Genes in Geraniaceae.

    Science.gov (United States)

    Weng, Mao-Lun; Ruhlman, Tracey A; Jansen, Robert K

    2016-06-27

    Plastids and mitochondria have many protein complexes that include subunits encoded by organelle and nuclear genomes. In animal cells, compensatory evolution between mitochondrial and nuclear-encoded subunits was identified and the high mitochondrial mutation rates were hypothesized to drive compensatory evolution in nuclear genomes. In plant cells, compensatory evolution between plastid and nucleus has rarely been investigated in a phylogenetic framework. To investigate plastid-nuclear coevolution, we focused on plastid ribosomal protein genes that are encoded by plastid and nuclear genomes from 27 Geraniales species. Substitution rates were compared for five sets of genes representing plastid- and nuclear-encoded ribosomal subunit proteins targeted to the cytosol or the plastid as well as nonribosomal protein controls. We found that nonsynonymous substitution rates (dN) and the ratios of nonsynonymous to synonymous substitution rates (ω) were accelerated in both plastid- (CpRP) and nuclear-encoded subunits (NuCpRP) of the plastid ribosome relative to control sequences. Our analyses revealed strong signals of cytonuclear coevolution between plastid- and nuclear-encoded subunits, in which nonsynonymous substitutions in CpRP and NuCpRP tend to occur along the same branches in the Geraniaceae phylogeny. This coevolution pattern cannot be explained by physical interaction between amino acid residues. The forces driving accelerated coevolution varied with cellular compartment of the sequence. Increased ω in CpRP was mainly due to intensified positive selection whereas increased ω in NuCpRP was caused by relaxed purifying selection. In addition, the many indels identified in plastid rRNA genes in Geraniaceae may have contributed to changes in plastid subunits. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  3. Plastid–Nuclear Interaction and Accelerated Coevolution in Plastid Ribosomal Genes in Geraniaceae

    Science.gov (United States)

    Weng, Mao-Lun; Ruhlman, Tracey A.; Jansen, Robert K.

    2016-01-01

    Plastids and mitochondria have many protein complexes that include subunits encoded by organelle and nuclear genomes. In animal cells, compensatory evolution between mitochondrial and nuclear-encoded subunits was identified and the high mitochondrial mutation rates were hypothesized to drive compensatory evolution in nuclear genomes. In plant cells, compensatory evolution between plastid and nucleus has rarely been investigated in a phylogenetic framework. To investigate plastid–nuclear coevolution, we focused on plastid ribosomal protein genes that are encoded by plastid and nuclear genomes from 27 Geraniales species. Substitution rates were compared for five sets of genes representing plastid- and nuclear-encoded ribosomal subunit proteins targeted to the cytosol or the plastid as well as nonribosomal protein controls. We found that nonsynonymous substitution rates (dN) and the ratios of nonsynonymous to synonymous substitution rates (ω) were accelerated in both plastid- (CpRP) and nuclear-encoded subunits (NuCpRP) of the plastid ribosome relative to control sequences. Our analyses revealed strong signals of cytonuclear coevolution between plastid- and nuclear-encoded subunits, in which nonsynonymous substitutions in CpRP and NuCpRP tend to occur along the same branches in the Geraniaceae phylogeny. This coevolution pattern cannot be explained by physical interaction between amino acid residues. The forces driving accelerated coevolution varied with cellular compartment of the sequence. Increased ω in CpRP was mainly due to intensified positive selection whereas increased ω in NuCpRP was caused by relaxed purifying selection. In addition, the many indels identified in plastid rRNA genes in Geraniaceae may have contributed to changes in plastid subunits. PMID:27190001

  4. Coevolution of amino acid residues in the key photosynthetic enzyme Rubisco

    Directory of Open Access Journals (Sweden)

    Kapralov Maxim V

    2011-09-01

    Full Text Available Abstract Background One of the key forces shaping proteins is coevolution of amino acid residues. Knowing which residues coevolve in a particular protein may facilitate our understanding of protein evolution, structure and function, and help to identify substitutions that may lead to desired changes in enzyme kinetics. Rubisco, the most abundant enzyme in biosphere, plays an essential role in the process of carbon fixation through photosynthesis, thus facilitating life on Earth. This makes Rubisco an important model system for studying the dynamics of protein fitness optimization on the evolutionary landscape. In this study we investigated the selective and coevolutionary forces acting on large subunit of land plants Rubisco using Markov models of codon substitution and clustering approaches applied to amino acid substitution histories. Results We found that both selection and coevolution shape Rubisco, and that positively selected and coevolving residues have their specifically favored amino acid composition and pairing preference. The mapping of these residues on the known Rubisco tertiary structures showed that the coevolving residues tend to be in closer proximity with each other compared to the background, while positively selected residues tend to be further away from each other. This study also reveals that the residues under positive selection or coevolutionary force are located within functionally important regions and that some residues are targets of both positive selection and coevolution at the same time. Conclusion Our results demonstrate that coevolution of residues is common in Rubisco of land plants and that there is an overlap between coevolving and positively selected residues. Knowledge of which Rubisco residues are coevolving and positively selected could be used for further work on structural modeling and identification of substitutions that may be changed in order to improve efficiency of this important enzyme in crops.

  5. Coevolution in host-parasite systems: behavioural strategies of slave-making ants and their hosts.

    OpenAIRE

    Foitzik, S.; DeHeer, C. J.; Hunjan, D. N.; Herbers, J. M.

    2001-01-01

    Recently, avian brood parasites and their hosts have emerged as model systems for the study of host-parasite coevolution. However, empirical studies of the highly analogous social parasites, which use the workers of another eusocial species to raise their own young, have never explicitly examined the dynamics of these systems from a coevolutionary perspective. Here, we demonstrate interpopulational variation in behavioural interactions between a socially parasitic slave-maker ant and its host...

  6. Host specificity and coevolution of Flavobacteriaceae endosymbionts within the siphonous green seaweed Bryopsis

    OpenAIRE

    Hollants, J.; Leliaert, F.; Verbruggen, H.; De Clerck, O.; Willems, A.

    2013-01-01

    The siphonous green seaweed Bryopsis harbors complex intracellular bacterial communities. Previous studies demonstrated that certain species form close, obligate associations with Flavobacteriaceae. A predominant imprint of host evolutionary history on the presence of these bacteria suggests a highly specialized association. In this study we elaborate on previous results by expanding the taxon sampling and testing for host–symbiont coevolution Therefore, we optimized a PCR protocol to directl...

  7. Dilemma solving by the coevolution of networks and strategy in a 2 x 2 game.

    Science.gov (United States)

    Tanimoto, Jun

    2007-08-01

    A 2 x 2 game model implemented by a coevolution mechanism of both networks and strategy, inspired by the work of Zimmermann and Eguiluz [Phys. Rev. E72, 056118 (2005)] is established. Network adaptation is the manner in which an existing link between two agents is destroyed and how a new one is established to replace it. The strategy is defined as whether an agent offers cooperation (C) or defection (D) . Both the networks and strategy are synchronously renovated in a simulation time step. A series of numerical experiments, considering various 2 x 2 game structures, reveals that the proposed coevolution mechanism can solve dilemmas in several game classes. The effect of solving a dilemma means mutual-cooperation reciprocity (R reciprocity), which is brought about by emerging several cooperative hub agents who have plenty of links. This effect can be primarily observed in game classes of the prisoner's dilemma and stag hunt. The coevolution mechanism, however, seems counterproductive for game classes of leader and hero, where the alternating reciprocity (ST reciprocity) is meaningful.

  8. Coevolution study of mitochondria respiratory chain proteins: toward the understanding of protein--protein interaction.

    Science.gov (United States)

    Yang, Ming; Ge, Yan; Wu, Jiayan; Xiao, Jingfa; Yu, Jun

    2011-05-20

    Coevolution can be seen as the interdependency between evolutionary histories. In the context of protein evolution, functional correlation proteins are ever-present coordinated evolutionary characters without disruption of organismal integrity. As to complex system, there are two forms of protein--protein interactions in vivo, which refer to inter-complex interaction and intra-complex interaction. In this paper, we studied the difference of coevolution characters between inter-complex interaction and intra-complex interaction using "Mirror tree" method on the respiratory chain (RC) proteins. We divided the correlation coefficients of every pairwise RC proteins into two groups corresponding to the binary protein--protein interaction in intra-complex and the binary protein--protein interaction in inter-complex, respectively. A dramatical discrepancy is detected between the coevolution characters of the two sets of protein interactions (Wilcoxon test, p-value = 4.4 × 10(-6)). Our finding reveals some critical information on coevolutionary study and assists the mechanical investigation of protein--protein interaction. Furthermore, the results also provide some unique clue for supramolecular organization of protein complexes in the mitochondrial inner membrane. More detailed binding sites map and genome information of nuclear encoded RC proteins will be extraordinary valuable for the further mitochondria dynamics study. Copyright © 2011. Published by Elsevier Ltd.

  9. Wing patterning genes and coevolution of Müllerian mimicry in Heliconius butterflies: Support from phylogeography, cophylogeny, and divergence times.

    Science.gov (United States)

    Hoyal Cuthill, Jennifer F; Charleston, Michael

    2015-12-01

    Examples of long-term coevolution are rare among free-living organisms. Müllerian mimicry in Heliconius butterflies had been suggested as a key example of coevolution by early genetic studies. However, research over the last two decades has been dominated by the idea that the best-studied comimics, H. erato and H. melpomene, did not coevolve at all. Recently sequenced genes associated with wing color pattern phenotype offer a new opportunity to resolve this controversy. Here, we test the hypothesis of coevolution between H. erato and H. melpomene using Bayesian multilocus analysis of five color pattern genes and five neutral genetic markers. We first explore the extent of phylogenetic agreement versus conflict between the different genes. Coevolution is then tested against three aspects of the mimicry diversifications: phylogenetic branching patterns, divergence times, and, for the first time, phylogeographic histories. We show that all three lines of evidence are compatible with strict coevolution of the diverse mimicry wing patterns, contrary to some recent suggestions. Instead, these findings tally with a coevolutionary diversification driven primarily by the ecological force of Müllerian mimicry. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  10. Convergent coevolution in the domestication of coral mushrooms by fungus-growing ants

    DEFF Research Database (Denmark)

    Munkacsi, A.B.; Pan, J.J.; Villesen, P.

    2004-01-01

    family Pterulaceae using phylogenetic reconstructions based on broad taxon sampling, including the first mushroom collected from the garden of an ant species in the A. pilosum group. The domestication of the pterulaceous cultivar is independent from the domestication of the gilled mushrooms cultivated...... of parallel coevolution, where the symbionts of each functional group are members of monophyletic groups. However, there is one outstanding exception in the fungus-growing ant system, the unidentified cultivar grown only by ants in the Apterostigma pilosum group. We classify this cultivar in the coral-mushroom...

  11. Social evolution. Oxytocin-gaze positive loop and the coevolution of human-dog bonds.

    Science.gov (United States)

    Nagasawa, Miho; Mitsui, Shouhei; En, Shiori; Ohtani, Nobuyo; Ohta, Mitsuaki; Sakuma, Yasuo; Onaka, Tatsushi; Mogi, Kazutaka; Kikusui, Takefumi

    2015-04-17

    Human-like modes of communication, including mutual gaze, in dogs may have been acquired during domestication with humans. We show that gazing behavior from dogs, but not wolves, increased urinary oxytocin concentrations in owners, which consequently facilitated owners' affiliation and increased oxytocin concentration in dogs. Further, nasally administered oxytocin increased gazing behavior in dogs, which in turn increased urinary oxytocin concentrations in owners. These findings support the existence of an interspecies oxytocin-mediated positive loop facilitated and modulated by gazing, which may have supported the coevolution of human-dog bonding by engaging common modes of communicating social attachment. Copyright © 2015, American Association for the Advancement of Science.

  12. Coevolution analysis of Hepatitis C virus genome to identify the structural and functional dependency network of viral proteins

    Science.gov (United States)

    Champeimont, Raphaël; Laine, Elodie; Hu, Shuang-Wei; Penin, Francois; Carbone, Alessandra

    2016-05-01

    A novel computational approach of coevolution analysis allowed us to reconstruct the protein-protein interaction network of the Hepatitis C Virus (HCV) at the residue resolution. For the first time, coevolution analysis of an entire viral genome was realized, based on a limited set of protein sequences with high sequence identity within genotypes. The identified coevolving residues constitute highly relevant predictions of protein-protein interactions for further experimental identification of HCV protein complexes. The method can be used to analyse other viral genomes and to predict the associated protein interaction networks.

  13. Dynamical trade-offs arise from antagonistic coevolution and decrease intraspecific diversity.

    Science.gov (United States)

    Huang, Weini; Traulsen, Arne; Werner, Benjamin; Hiltunen, Teppo; Becks, Lutz

    2017-12-12

    Trade-offs play an important role in evolution. Without trade-offs, evolution would maximize fitness of all traits leading to a "master of all traits". The shape of trade-offs has been shown to determine evolutionary trajectories and is often assumed to be static and independent of the actual evolutionary process. Here we propose that coevolution leads to a dynamical trade-off. We test this hypothesis in a microbial predator-prey system and show that the bacterial growth-defense trade-off changes from concave to convex, i.e., defense is effective and cheap initially, but gets costly when predators coevolve. We further explore the impact of such dynamical trade-offs by a novel mathematical model incorporating de novo mutations for both species. Predator and prey populations diversify rapidly leading to higher prey diversity when the trade-off is concave (cheap). Coevolution results in more convex (costly) trade-offs and lower prey diversity compared to the scenario where only the prey evolves.

  14. Cooperation enhanced by the coevolution of teaching activity in evolutionary prisoner's dilemma games with voluntary participation.

    Directory of Open Access Journals (Sweden)

    Chen Shen

    Full Text Available Voluntary participation, as an additional strategy involved in repeated games, has been proved to be an efficient way to promote the evolution of cooperation theoretically and empirically. Besides, current studies show that the coevolution of teaching activity can promote cooperation. Thus, inspired by aforementioned above, we investigate the effect of coevolution of teaching activity on the evolution of cooperation for prisoner's dilemma game with voluntary participation: when the focal player successfully enforces its strategy on the opponent, his teaching ability will get an increase. Through numerical simulation, we have shown that voluntary participation could effectively promote the fraction of cooperation, which is also affected by the value of increment. Furthermore, we investigate the influence of the increment value on the density of different strategies and find that there exists an optimal increment value that plays an utmost role on the evolutionary dynamics. With regard to this observation, we unveil that an optimal value of increment can lead to strongest heterogeneity in agents' teaching ability, further promoting the evolution of cooperation.

  15. Cross-Resistance: A Consequence of Bi-partite Host-Parasite Coevolution

    Science.gov (United States)

    Joop, Gerrit

    2018-01-01

    Host-parasite coevolution can influence interactions of the host and parasite with the wider ecological community. One way that this may manifest is in cross-resistance towards other parasites, which has been observed to occur in some host-parasite evolution experiments. In this paper, we test for cross-resistance towards Bacillus thuringiensis and Pseudomonas entomophila in the red flour beetle Tribolium castaneum, which was previously allowed to coevolve with the generalist entomopathogenic fungus Beauveria bassiana. We combine survival and gene expression assays upon infection to test for cross-resistance and underlying mechanisms. We show that larvae of T. castaneum that evolved with B. bassiana under coevolutionary conditions were positively cross-resistant to the bacterium B. thuringiensis, but not P. entomophila. Positive cross-resistance was mirrored at the gene expression level with markers that were representative of the oral route of infection being upregulated upon B. bassiana exposure. We find that positive cross-resistance towards B. thuringiensis evolved in T. castaneum as a consequence of its coevolutionary interactions with B. bassiana. This cross-resistance appears to be a consequence of resistance to oral toxicity. The fact that coevolution with B. bassiana results in resistance to B. thuringiensis, but not P. entomophila implies that B. thuringiensis and B. bassiana may share mechanisms of infection or toxicity not shared by P. entomophila. This supports previous suggestions that B. bassiana may possess Cry-like toxins, similar to those found in B. thuringiensis, which allow it to infect orally. PMID:29495405

  16. Co-Evolutions of Ecosystems, Societies, and Economy in Dryland Asia

    Science.gov (United States)

    Chen, Jiquan; Ouyang, Zutao; John, Ranjeet; Dong, Gang; Fan, Peilei

    2015-04-01

    This presentation aims at the interactive changes of the natural system (NS) and the human system (HS) as well as the feedbacks in time and space for dryland Asia where multiple administrative units from several countries experience similar climates, ecosystems, cultures, and traditions but different governments, land uses, economic development, and demographic changes (e.g., ethnical composition). We compiled and examined the changes in major measures for ecosystems (e.g., PAR, LAI, GPP, ET), economy (GDP, export/import, EGS), and human demography (e.g., population, health, education) between 1981 through 2011 (30+ variables) for six Central Asian countries (Afghanistan, Turkmenistan, Tajikistan, Uzbekistan, Kazakhstan, Kyrgyzstan) and two East Asian countries (Mongolia and China). Particular attention was made to understand the co-evolutions of the ratios between the elements of HS and NS, such as: GDP: GPP, PET: FWW, R: PDSI, EGS: GPP, etc., so that feedbacks and interactions can be empirically studied. Spatial and temporal changes of each measure, as well as their ratios, were quantified to highlight the relative contributions of human activities (e.g., policy) and biophysical changes (e.g., climate). We found some tight connections between the HS and NS variables, but the co-evolutions have to be understood in the context of governments, policy, and other major institutional shifts.

  17. Host specificity and coevolution of Flavobacteriaceae endosymbionts within the siphonous green seaweed Bryopsis.

    Science.gov (United States)

    Hollants, Joke; Leliaert, Frederik; Verbruggen, Heroen; De Clerck, Olivier; Willems, Anne

    2013-06-01

    The siphonous green seaweed Bryopsis harbors complex intracellular bacterial communities. Previous studies demonstrated that certain species form close, obligate associations with Flavobacteriaceae. A predominant imprint of host evolutionary history on the presence of these bacteria suggests a highly specialized association. In this study we elaborate on previous results by expanding the taxon sampling and testing for host-symbiont coevolution Therefore, we optimized a PCR protocol to directly and specifically amplify Flavobacteriaceae endosymbiont 16S rRNA gene sequences, which allowed us to screen a large number of algal samples without the need for cultivation or surface sterilization. We analyzed 146 Bryopsis samples, and 92 additional samples belonging to the Bryopsidales and other orders within the class Ulvophyceae. Results indicate that the Flavobacteriaceae endosymbionts are restricted to Bryopsis, and only occur within specific, warm-temperate and tropical clades of the genus. Statistical analyses (AMOVA) demonstrate a significant non-random host-symbiont association. Comparison of bacterial 16S rRNA and Bryopsis rbcL phylogenies, however, reveal complex host-symbiont evolutionary associations, whereby closely related hosts predominantly harbor genetically similar endosymbionts. Bacterial genotypes are rarely confined to a single Bryopsis species and most Bryopsis species harbored several Flavobacteriaceae, obscuring a clear pattern of coevolution. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Coevolution of antibiotic production and counter-resistance in soil bacteria.

    Science.gov (United States)

    Laskaris, Paris; Tolba, Sahar; Calvo-Bado, Leo; Wellington, Elizabeth M; Wellington, Liz

    2010-03-01

    We present evidence for the coexistence and coevolution of antibiotic resistance and biosynthesis genes in soil bacteria. The distribution of the streptomycin (strA) and viomycin (vph) resistance genes was examined in Streptomyces isolates. strA and vph were found either within a biosynthetic gene cluster or independently. Streptomyces griseus strains possessing the streptomycin cluster formed part of a clonal complex. All S. griseus strains possessing solely strA belonged to two clades; both were closely related to the streptomycin producers. Other more distantly related S. griseus strains did not contain strA. S. griseus strains with only vph also formed two clades, but they were more distantly related to the producers and to one another. The expression of the strA gene was constitutive in a resistance-only strain whereas streptomycin producers showed peak strA expression in late log phase that correlates with the switch on of streptomycin biosynthesis. While there is evidence that antibiotics have diverse roles in nature, our data clearly support the coevolution of resistance in the presence of antibiotic biosynthetic capability within closely related soil dwelling bacteria. This reinforces the view that, for some antibiotics at least, the primary role is one of antibiosis during competition in soil for resources.

  19. Cooperation enhanced by the coevolution of teaching activity in evolutionary prisoner's dilemma games with voluntary participation.

    Science.gov (United States)

    Shen, Chen; Chu, Chen; Geng, Yini; Jin, Jiahua; Chen, Fei; Shi, Lei

    2018-01-01

    Voluntary participation, as an additional strategy involved in repeated games, has been proved to be an efficient way to promote the evolution of cooperation theoretically and empirically. Besides, current studies show that the coevolution of teaching activity can promote cooperation. Thus, inspired by aforementioned above, we investigate the effect of coevolution of teaching activity on the evolution of cooperation for prisoner's dilemma game with voluntary participation: when the focal player successfully enforces its strategy on the opponent, his teaching ability will get an increase. Through numerical simulation, we have shown that voluntary participation could effectively promote the fraction of cooperation, which is also affected by the value of increment. Furthermore, we investigate the influence of the increment value on the density of different strategies and find that there exists an optimal increment value that plays an utmost role on the evolutionary dynamics. With regard to this observation, we unveil that an optimal value of increment can lead to strongest heterogeneity in agents' teaching ability, further promoting the evolution of cooperation.

  20. Evolutionary responses to a constructed niche: ancient Mesoamericans as a model of gene-culture coevolution.

    Directory of Open Access Journals (Sweden)

    Tábita Hünemeier

    Full Text Available Culture and genetics rely on two distinct but not isolated transmission systems. Cultural processes may change the human selective environment and thereby affect which individuals survive and reproduce. Here, we evaluated whether the modes of subsistence in Native American populations and the frequencies of the ABCA1*Arg230Cys polymorphism were correlated. Further, we examined whether the evolutionary consequences of the agriculturally constructed niche in Mesoamerica could be considered as a gene-culture coevolution model. For this purpose, we genotyped 229 individuals affiliated with 19 Native American populations and added data for 41 other Native American groups (n = 1905 to the analysis. In combination with the SNP cluster of a neutral region, this dataset was then used to unravel the scenario involved in 230Cys evolutionary history. The estimated age of 230Cys is compatible with its origin occurring in the American continent. The correlation of its frequencies with the archeological data on Zea pollen in Mesoamerica/Central America, the neutral coalescent simulations, and the F(ST-based natural selection analysis suggest that maize domestication was the driving force in the increase in the frequencies of 230Cys in this region. These results may represent the first example of a gene-culture coevolution involving an autochthonous American allele.

  1. Culture–gene coevolution of individualism–collectivism and the serotonin transporter gene

    Science.gov (United States)

    Chiao, Joan Y.; Blizinsky, Katherine D.

    2010-01-01

    Culture–gene coevolutionary theory posits that cultural values have evolved, are adaptive and influence the social and physical environments under which genetic selection operates. Here, we examined the association between cultural values of individualism–collectivism and allelic frequency of the serotonin transporter functional polymorphism (5-HTTLPR) as well as the role this culture–gene association may play in explaining global variability in prevalence of pathogens and affective disorders. We found evidence that collectivistic cultures were significantly more likely to comprise individuals carrying the short (S) allele of the 5-HTTLPR across 29 nations. Results further show that historical pathogen prevalence predicts cultural variability in individualism–collectivism owing to genetic selection of the S allele. Additionally, cultural values and frequency of S allele carriers negatively predict global prevalence of anxiety and mood disorder. Finally, mediation analyses further indicate that increased frequency of S allele carriers predicted decreased anxiety and mood disorder prevalence owing to increased collectivistic cultural values. Taken together, our findings suggest culture–gene coevolution between allelic frequency of 5-HTTLPR and cultural values of individualism–collectivism and support the notion that cultural values buffer genetically susceptible populations from increased prevalence of affective disorders. Implications of the current findings for understanding culture–gene coevolution of human brain and behaviour as well as how this coevolutionary process may contribute to global variation in pathogen prevalence and epidemiology of affective disorders, such as anxiety and depression, are discussed. PMID:19864286

  2. Culture-gene coevolution of individualism-collectivism and the serotonin transporter gene.

    Science.gov (United States)

    Chiao, Joan Y; Blizinsky, Katherine D

    2010-02-22

    Culture-gene coevolutionary theory posits that cultural values have evolved, are adaptive and influence the social and physical environments under which genetic selection operates. Here, we examined the association between cultural values of individualism-collectivism and allelic frequency of the serotonin transporter functional polymorphism (5-HTTLPR) as well as the role this culture-gene association may play in explaining global variability in prevalence of pathogens and affective disorders. We found evidence that collectivistic cultures were significantly more likely to comprise individuals carrying the short (S) allele of the 5-HTTLPR across 29 nations. Results further show that historical pathogen prevalence predicts cultural variability in individualism-collectivism owing to genetic selection of the S allele. Additionally, cultural values and frequency of S allele carriers negatively predict global prevalence of anxiety and mood disorder. Finally, mediation analyses further indicate that increased frequency of S allele carriers predicted decreased anxiety and mood disorder prevalence owing to increased collectivistic cultural values. Taken together, our findings suggest culture-gene coevolution between allelic frequency of 5-HTTLPR and cultural values of individualism-collectivism and support the notion that cultural values buffer genetically susceptible populations from increased prevalence of affective disorders. Implications of the current findings for understanding culture-gene coevolution of human brain and behaviour as well as how this coevolutionary process may contribute to global variation in pathogen prevalence and epidemiology of affective disorders, such as anxiety and depression, are discussed.

  3. Self-organization towards optimally interdependent networks by means of coevolution

    International Nuclear Information System (INIS)

    Wang, Zhen; Szolnoki, Attila; Perc, Matjaž

    2014-01-01

    Coevolution between strategy and network structure is established as a means to arrive at the optimal conditions needed to resolve social dilemmas. Yet recent research has highlighted that the interdependence between networks may be just as important as the structure of an individual network. We therefore introduce the coevolution of strategy and network interdependence to see whether this can give rise to elevated levels of cooperation in the prisoner's dilemma game. We show that the interdependence between networks self-organizes so as to yield optimal conditions for the evolution of cooperation. Even under extremely adverse conditions, cooperators can prevail where on isolated networks they would perish. This is due to the spontaneous emergence of a two-class society, with only the upper class being allowed to control and take advantage of the interdependence. Spatial patterns reveal that cooperators, once arriving at the upper class, are much more competent than defectors in sustaining compact clusters of followers. Indeed, the asymmetric exploitation of interdependence confers to them a strong evolutionary advantage that may resolve even the toughest of social dilemmas. (paper)

  4. Host-parasite coevolution can promote the evolution of seed banking as a bet-hedging strategy.

    Science.gov (United States)

    Verin, Mélissa; Tellier, Aurélien

    2018-04-20

    Seed (egg) banking is a common bet-hedging strategy maximizing the fitness of organisms facing environmental unpredictability by the delayed emergence of offspring. Yet, this condition often requires fast and drastic stochastic shifts between good and bad years. We hypothesize that the host seed banking strategy can evolve in response to coevolution with parasites because the coevolutionary cycles promote a gradually changing environment over longer times than seed persistence. We study the evolution of host germination fraction as a quantitative trait using both pairwise competition and multiple mutant competition methods, while the germination locus can be genetically linked or unlinked with the host locus under coevolution. In a gene-for-gene model of coevolution, hosts evolve a seed bank strategy under unstable coevolutionary cycles promoted by moderate to high costs of resistance or strong disease severity. Moreover, when assuming genetic linkage between coevolving and germination loci, the resistant genotype always evolves seed banking in contrast to susceptible hosts. Under a matching-allele interaction, both hosts' genotypes exhibit the same seed banking strategy irrespective of the genetic linkage between loci. We suggest host-parasite coevolution as an additional hypothesis for the evolution of seed banking as a temporal bet-hedging strategy. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

  5. The Coevolution of Life and Environment on Mars: An Ecosystem Perspective on the Robotic Exploration of Biosignatures

    Science.gov (United States)

    2018-01-01

    Abstract Earth's biological and environmental evolution are intertwined and inseparable. This coevolution has become a fundamental concept in astrobiology and is key to the search for life beyond our planet. In the case of Mars, whether a coevolution took place is unknown, but analyzing the factors at play shows the uniqueness of each planetary experiment regardless of similarities. Early Earth and early Mars shared traits. However, biological processes on Mars, if any, would have had to proceed within the distinctive context of an irreversible atmospheric collapse, greater climate variability, and specific planetary characteristics. In that, Mars is an important test bed for comparing the effects of a unique set of spatiotemporal changes on an Earth-like, yet different, planet. Many questions remain unanswered about Mars' early environment. Nevertheless, existing data sets provide a foundation for an intellectual framework where notional coevolution models can be explored. In this framework, the focus is shifted from planetary-scale habitability to the prospect of habitats, microbial ecotones, pathways to biological dispersal, biomass repositories, and their meaning for exploration. Critically, as we search for biosignatures, this focus demonstrates the importance of starting to think of early Mars as a biosphere and vigorously integrating an ecosystem approach to landing site selection and exploration. Key Words: Astrobiology—Biosignatures—Coevolution of Earth and life—Mars. Astrobiology 18, 1–27. PMID:29252008

  6. The Beringian Coevolution Project: Holistic collections of mammals and associated parasites reveal novel perspectives on changing environments in the north

    Science.gov (United States)

    The Beringian Coevolution Project (BCP), a field program underway in the Arctic since 1999, has focused on building key scientific infrastructure for integrated specimen-based studies on mammals and their associated parasites. BCP has contributed new insights across temporal and spatial scales into...

  7. The Coevolution of Life and Environment on Mars: An Ecosystem Perspective on the Robotic Exploration of Biosignatures.

    Science.gov (United States)

    Cabrol, Nathalie A

    2018-01-01

    Earth's biological and environmental evolution are intertwined and inseparable. This coevolution has become a fundamental concept in astrobiology and is key to the search for life beyond our planet. In the case of Mars, whether a coevolution took place is unknown, but analyzing the factors at play shows the uniqueness of each planetary experiment regardless of similarities. Early Earth and early Mars shared traits. However, biological processes on Mars, if any, would have had to proceed within the distinctive context of an irreversible atmospheric collapse, greater climate variability, and specific planetary characteristics. In that, Mars is an important test bed for comparing the effects of a unique set of spatiotemporal changes on an Earth-like, yet different, planet. Many questions remain unanswered about Mars' early environment. Nevertheless, existing data sets provide a foundation for an intellectual framework where notional coevolution models can be explored. In this framework, the focus is shifted from planetary-scale habitability to the prospect of habitats, microbial ecotones, pathways to biological dispersal, biomass repositories, and their meaning for exploration. Critically, as we search for biosignatures, this focus demonstrates the importance of starting to think of early Mars as a biosphere and vigorously integrating an ecosystem approach to landing site selection and exploration. Key Words: Astrobiology-Biosignatures-Coevolution of Earth and life-Mars. Astrobiology 18, 1-27.

  8. Coevolution of Interorganizational Psychological Contract and Interorganizational Relationship: A Case Study of Manufacturing Company in China

    Directory of Open Access Journals (Sweden)

    Wei He

    2017-01-01

    Full Text Available As the belief of the beholder in an exchange about the obligations that another party should have, interorganizational psychological contract (IPC from a micro perspective provides a new angle to study interorganizational relationship (IOR. This paper studies the interrelation and coevolution of IORs and IPCs by building a system dynamics (SD model. Firstly based on the structural analysis of the interrelations of IPC and IOR, this paper builds the qualitative causal loop diagram of the interrelations. Based on investigation of 55 manufacturing enterprises in China we further draw the stock and flow diagram. Then we apply the data of Jiangxi Motors Co., Ltd., to simulate the model. The results reveal the development and evolution of IORs and IPCs and their interrelations. Furthermore, the sensitivity analysis is conducted and the influences of trust on IORs and IPCs are discussed. Finally managerial implications and some recommendations are provided for the decision-making of developing IORs.

  9. The Co-evolution of Business Incubators and National Incubator Networks in Emerging Markets

    Directory of Open Access Journals (Sweden)

    David F. Robinson

    2010-11-01

    Full Text Available The study proposes a three stage model of the development of business incubation practices in emerging markets. The model addresses the diffusion of incubation practices to new markets, the institutionalization of those practices and the co-evolution of incubators and national networks of incubation. The model is based on interviews conducted in Bolivia, Peru, Chile, Argentina, and Brazil. New incubators in emerging markets often face strong cultural norms and institutional impediments to helping entrepreneurs start new businesses. As incubation becomes better established in a country, incubators provide more advanced technical, legal and market-based advice. Networks of incubators form to share specialized services across many incubators, to allocate government funding to incubators, and to lobby for public and private support of innovation.

  10. Effects of adaptive degrees of trust on coevolution of quantum strategies on scale-free networks

    Science.gov (United States)

    Li, Qiang; Chen, Minyou; Perc, Matjaž; Iqbal, Azhar; Abbott, Derek

    2013-10-01

    We study the impact of adaptive degrees of trust on the evolution of cooperation in the quantum prisoner's dilemma game. In addition to the strategies, links between players are also subject to evolution. Starting with a scale-free interaction network, players adjust trust towards their neighbors based on received payoffs. The latter governs the strategy adoption process, while trust governs the rewiring of links. As soon as the degree of trust towards a neighbor drops to zero, the link is rewired to another randomly chosen player within the network. We find that for small temptations to defect cooperators always dominate, while for intermediate and strong temptations a single quantum strategy is able to outperform all other strategies. In general, reciprocal trust remains within close relationships and favors the dominance of a single strategy. Due to coevolution, the power-law degree distributions transform to Poisson distributions.

  11. A model of designing as the intersection between uncertainty perception, information processing, and coevolution

    DEFF Research Database (Denmark)

    Lasso, Sarah Venturim; Cash, Philip; Daalhuizen, Jaap

    2016-01-01

    , the designer's perceived uncertainty is the motivation to start a process of collecting, exchanging, and integrating knowledge. This has been formalised in Information-Processing Theory and more generally described by authors such as Aurisicchio et al. (2013) who describe design as an information...... takes the first steps towards linking these disparate perspectives in a model of designing that synthesises coevolution and information processing. How designers act has been shown to play an important role in the process of New Product Development (NPD) (See e.g. Badke-Schaub and Frankenberger, 2012...... transformation process. Here the aim of the activity is to reduce the perceived uncertainty through identifying and integrating external information and knowledge within the design team. For2example, when perceiving uncertainty the designer might seek new information online, process this information, and share...

  12. The hitchhiker's guide to altruism: gene-culture coevolution, and the internalization of norms.

    Science.gov (United States)

    Gintis, Herbert

    2003-02-21

    An internal norm is a pattern of behavior enforced in part by internal sanctions, such as shame, guilt and loss of self-esteem, as opposed to purely external sanctions, such as material rewards and punishment. The ability to internalize norms is widespread among humans, although in some so-called "sociopaths", this capacity is diminished or lacking. Suppose there is one genetic locus that controls the capacity to internalize norms. This model shows that if an internal norm is fitness enhancing, then for plausible patterns of socialization, the allele for internalization of norms is evolutionarily stable. This framework can be used to model Herbert Simon's (1990) explanation of altruism, showing that altruistic norms can "hitchhike" on the general tendency of internal norms to be personally fitness-enhancing. A multi-level selection, gene-culture coevolution argument then explains why individually fitness-reducing internal norms are likely to be prosocial as opposed to socially harmful.

  13. A non-classical phase diagram for virus-bacterial co-evolution mediated by CRISPR

    Science.gov (United States)

    Han, Pu; Deem, Michael

    CRISPR is a newly discovered prokaryotic immune system. Bacteria and archaea with this system incorporate genetic material from invading viruses into their genomes, providing protection against future infection by similar viruses. Due to the cost of CRISPR, bacteria can lose the acquired immunity. We will show an intriguing phase diagram of the virus extinction probability, which when the rate of losing the acquired immunity is small, is more complex than that of the classic predator-prey model. As the CRISPR incorporates genetic material, viruses are under pressure to evolve to escape the recognition by CRISPR, and this co-evolution leads to a non-trivial phase structure that cannot be explained by the classical predator-prey model.

  14. Limited ability driven phase transitions in the coevolution process in Axelrod's model

    Science.gov (United States)

    Wang, Bing; Han, Yuexing; Chen, Luonan; Aihara, Kazuyuki

    2009-04-01

    We study the coevolution process in Axelrod's model by taking into account of agents' abilities to access information, which is described by a parameter α to control the geographical range of communication. We observe two kinds of phase transitions in both cultural domains and network fragments, which depend on the parameter α. By simulation, we find that not all rewiring processes pervade the dissemination of culture, that is, a very limited ability to access information constrains the cultural dissemination, while an exceptional ability to access information aids the dissemination of culture. Furthermore, by analyzing the network characteristics at the frozen states, we find that there exists a stage at which the network develops to be a small-world network with community structures.

  15. Limited ability driven phase transitions in the coevolution process in Axelrod's model

    Energy Technology Data Exchange (ETDEWEB)

    Wang Bing [ERATO Aihara Complexity Modelling Project, JST, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Institute of Industrial Science, University of Tokyo, Tokyo (Japan)], E-mail: bingbignmath@gmail.com; Han Yuexing [Graduate School of Information System, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu-Shi, Tokyo (Japan); Chen Luonan [Department of Electrical Engineering and Electronics, Osaka Sangyo University, Daito, Osaka 574-8530 (Japan); Aihara, Kazuyuki [ERATO Aihara Complexity Modelling Project, JST, Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Institute of Industrial Science, University of Tokyo, Tokyo (Japan)

    2009-04-13

    We study the coevolution process in Axelrod's model by taking into account of agents' abilities to access information, which is described by a parameter {alpha} to control the geographical range of communication. We observe two kinds of phase transitions in both cultural domains and network fragments, which depend on the parameter {alpha}. By simulation, we find that not all rewiring processes pervade the dissemination of culture, that is, a very limited ability to access information constrains the cultural dissemination, while an exceptional ability to access information aids the dissemination of culture. Furthermore, by analyzing the network characteristics at the frozen states, we find that there exists a stage at which the network develops to be a small-world network with community structures.

  16. The Role of Microbial Electron Transfer in the Coevolution of the Biosphere and Geosphere.

    Science.gov (United States)

    Jelen, Benjamin I; Giovannelli, Donato; Falkowski, Paul G

    2016-09-08

    All life on Earth is dependent on biologically mediated electron transfer (i.e., redox) reactions that are far from thermodynamic equilibrium. Biological redox reactions originally evolved in prokaryotes and ultimately, over the first ∼2.5 billion years of Earth's history, formed a global electronic circuit. To maintain the circuit on a global scale requires that oxidants and reductants be transported; the two major planetary wires that connect global metabolism are geophysical fluids-the atmosphere and the oceans. Because all organisms exchange gases with the environment, the evolution of redox reactions has been a major force in modifying the chemistry at Earth's surface. Here we briefly review the discovery and consequences of redox reactions in microbes with a specific focus on the coevolution of life and geochemical phenomena.

  17. Aspiration-based coevolution of link weight promotes cooperation in the spatial prisoner's dilemma game

    Science.gov (United States)

    Shen, Chen; Chu, Chen; Shi, Lei; Perc, Matjaž; Wang, Zhen

    2018-05-01

    In this article, we propose an aspiration-based coevolution of link weight, and explore how this set-up affects the evolution of cooperation in the spatial prisoner's dilemma game. In particular, an individual will increase the weight of its link to its neighbours only if the payoff received via this interaction exceeds a pre-defined aspiration. Conversely, if the received payoff is below this aspiration, the link weight with the corresponding neighbour will decrease. Our results show that an appropriate aspiration level leads to a high-cooperation plateau, whereas too high or too low aspiration will impede the evolution of cooperation. We explain these findings with a comprehensive analysis of transition points and with a systematic analysis of typical configuration patterns. The presented results provide further theoretical insights with regards to the impact of different aspiration levels on cooperation in human societies.

  18. Co-evolution of transcriptional silencing proteins and the DNA elements specifying their assembly.

    Directory of Open Access Journals (Sweden)

    Oliver A Zill

    Full Text Available Co-evolution of transcriptional regulatory proteins and their sites of action has been often hypothesized but rarely demonstrated. Here we provide experimental evidence of such co-evolution in yeast silent chromatin, a finding that emerged from studies of hybrids formed between two closely related Saccharomyces species. A unidirectional silencing incompatibility between S. cerevisiae and S. bayanus led to a key discovery: asymmetrical complementation of divergent orthologs of the silent chromatin component Sir4. In S. cerevisiae/S. bayanus interspecies hybrids, ChIP-Seq analysis revealed a restriction against S. cerevisiae Sir4 associating with most S. bayanus silenced regions; in contrast, S. bayanus Sir4 associated with S. cerevisiae silenced loci to an even greater degree than did S. cerevisiae's own Sir4. Functional changes in silencer sequences paralleled changes in Sir4 sequence and a reduction in Sir1 family members in S. cerevisiae. Critically, species-specific silencing of the S. bayanus HMR locus could be reconstituted in S. cerevisiae by co-transfer of the S. bayanus Sir4 and Kos3 (the ancestral relative of Sir1 proteins. As Sir1/Kos3 and Sir4 bind conserved silencer-binding proteins, but not specific DNA sequences, these rapidly evolving proteins served to interpret differences in the two species' silencers presumably involving emergent features created by the regulatory proteins that bind sequences within silencers. The results presented here, and in particular the high resolution ChIP-Seq localization of the Sir4 protein, provided unanticipated insights into the mechanism of silent chromatin assembly in yeast.

  19. The role of soil moisture on the coevolution of soil and vegetation in mountain grasslands

    Science.gov (United States)

    Bertoldi, Giacomo; Claudia, Notarnicola; Brenner, Johannes; Castelli, Mariapina; Greifeneder, Felix; Niedrist, Georg; Seeber, Julia; Tappeiner, Ulrike

    2016-04-01

    One of the key variables controlling the organization of vegetation and the coevolution of soils and landforms is soil moisture content (SMC). For this reason, understanding the controls on the spatial and temporal patterns of SMC is essential to predict how perturbations in vegetation and climate will affect mountain ecosystem functioning. In this contribution, we focus on the dynamic of surface SMC of water-limited alpine grasslands in the Long Term Ecological Research area Mazia Valley in the European Alps. We analyze the impacts of different land managements (meadows versus pastures) and its relationships with climate and topography. The area has been equipped since 2009 with a network of more than 20 stations, measuring SMC and climatic variables and with two eddy-covariance stations, measuring surface fluxes over meadows and pastures. Monthly biomass production data have been collected and detailed soil and spatial soil moisture surveys are available. Moreover, high spatial resolution SMC maps have been derived from satellites Synthetic Aperture Radar Radar (SAR) images (Sentinel 1 and RADARSAT2 images). Both ground surveys and remote sensing observations show persistent landscape-level patterns. Meadows, in general located in flatter areas, tend to be wetter. This leads to higher vegetation productivity and to the development of soils with higher water holding capacity, thus to a positive feedback on SMC. In contrast, pastures, located on steeper slopes with lower vegetation density and higher soil erosion, tend to be drier, leading to a negative feedback on SMC and soil development. This co-evolution of land cover and SMC leads therefore to persistent spatial patterns. In order to understand quantitatively such linked interactions, a sensitivity analysis has been performed with the GEOtop hydrological model. Results show how both abiotic (mainly slope and elevation) and anthropogenic (irrigation and soil management) factors exert a significant control on

  20. Coevolution of patch-type dependent emigration and patch-type dependent immigration.

    Science.gov (United States)

    Weigang, Helene C

    2017-08-07

    The three phases of dispersal - emigration, transfer and immigration - are affecting each other and the former and latter decisions may depend on patch types. Despite the inevitable fact of the complexity of the dispersal process, patch-type dependencies of dispersal decisions modelled as emigration and immigration are usually missing in theoretical dispersal models. Here, I investigate the coevolution of patch-type dependent emigration and patch-type dependent immigration in an extended Hamilton-May model. The dispersing population inhabits a landscape structured into many patches of two types and disperses during a continuous-time season. The trait under consideration is a four dimensional vector consisting of two values for emigration probability from the patches and two values for immigration probability into the patches of each type. Using the adaptive dynamics approach I show that four qualitatively different dispersal strategies may evolve in different parameter regions, including a counterintuitive strategy, where patches of one type are fully dispersed from (emigration probability is one) but individuals nevertheless always immigrate into them during the dispersal season (immigration probability is one). I present examples of evolutionary branching in a wide parameter range, when the patches with high local death rate during the dispersal season guarantee a high expected disperser output. I find that two dispersal strategies can coexist after evolutionary branching: a strategy with full immigration only into the patches with high expected disperser output coexists with a strategy that immigrates into any patch. Stochastic simulations agree with the numerical predictions. Since evolutionary branching is also found when immigration evolves alone, the present study is adding coevolutionary constraints on the emigration traits and hence finds that the coevolution of a higher dimensional trait sometimes hinders evolutionary diversification. Copyright © 2017

  1. Co-evolution model of Colletotrichum lindemuthianum (melanconiaceae, melanconiales races that occur in some Brazilian regions

    Directory of Open Access Journals (Sweden)

    Ana Lilia Alzate-Marin

    1999-03-01

    Full Text Available Colletotrichum lindemuthianum, the causal agent of anthracnose in the common bean (Phaseolus vulgaris L., displays a high level of virulence diversity, which explains the large number of existing pathotypes. Several lines of evidence indicate that such diversity is, at least in part, due to plant and pathogen co-evolution. A co-evolution model based on the binary classification of 25 races identified in Brazil by inoculation of differential cultivars and random amplified polymorphic DNA (RAPD data is proposed. In this model, races 8 and 64 that infected bean cultivar Cornell 49-242 (Are gene and Mexico 222 (Mexico I gene are considered to be sources of two important evolutionary routes. Inferences about undescribed races from Brazil could be made.Colletotrichum lindemuthianum (Sacc. & Magn. Scrib., agente causal da antracnose do feijoeiro comum (Phaseolus vulgaris L., possui alto nível de diversidade de virulência, o que explica o elevado número de patótipos existentes. A partir de trabalhos anteriores sobre a classificação binária de 25 raças identificadas no Brasil e sua relação com agrupamentos RAPD, foi possível construir um modelo de evolução de tais raças. As raças 8 e 64, que foram compatíveis com os cultivares Cornell 49-242 (gene Are e México 222 (gene México I, se apresentam como possíveis origens de duas importantes rotas de evolução. Inferências de raças ainda não detectadas no Brasil puderam ser feitas.

  2. Cross-Resistance: A Consequence of Bi-partite Host-Parasite Coevolution

    Directory of Open Access Journals (Sweden)

    Tilottama Biswas

    2018-02-01

    Full Text Available Host-parasite coevolution can influence interactions of the host and parasite with the wider ecological community. One way that this may manifest is in cross-resistance towards other parasites, which has been observed to occur in some host-parasite evolution experiments. In this paper, we test for cross-resistance towards Bacillus thuringiensis and Pseudomonas entomophila in the red flour beetle Tribolium castaneum, which was previously allowed to coevolve with the generalist entomopathogenic fungus Beauveria bassiana. We combine survival and gene expression assays upon infection to test for cross-resistance and underlying mechanisms. We show that larvae of T. castaneum that evolved with B. bassiana under coevolutionary conditions were positively cross-resistant to the bacterium B. thuringiensis, but not P. entomophila. Positive cross-resistance was mirrored at the gene expression level with markers that were representative of the oral route of infection being upregulated upon B. bassiana exposure. We find that positive cross-resistance towards B. thuringiensis evolved in T. castaneum as a consequence of its coevolutionary interactions with B. bassiana. This cross-resistance appears to be a consequence of resistance to oral toxicity. The fact that coevolution with B. bassiana results in resistance to B. thuringiensis, but not P. entomophila implies that B. thuringiensis and B. bassiana may share mechanisms of infection or toxicity not shared by P. entomophila. This supports previous suggestions that B. bassiana may possess Cry-like toxins, similar to those found in B. thuringiensis, which allow it to infect orally.

  3. Plant lock and ant key: pairwise coevolution of an exclusion filter in an ant-plant mutualism.

    Science.gov (United States)

    Brouat, C; Garcia, N; Andary, C; McKey, D

    2001-10-22

    Although observations suggest pairwise coevolution in specific ant-plant symbioses, coevolutionary processes have rarely been demonstrated. We report on, what is to the authors' knowledge, the strongest evidence yet for reciprocal adaptation of morphological characters in a species-specific ant-plant mutualism. The plant character is the prostoma, which is a small unlignified organ at the apex of the domatia in which symbiotic ants excavate an entrance hole. Each myrmecophyte in the genus Leonardoxa has evolved a prostoma with a different shape. By performing precise measurements on the prostomata of three related myrmecophytes, on their specific associated ants and on the entrance holes excavated by symbiotic ants at the prostomata, we showed that correspondence of the plant and ant traits forms a morphological and behavioural filter. We have strong evidence for coevolution between the dimensions and shape of the symbiotic ants and the prostoma in one of the three ant-Leonardoxa associations.

  4. The Coevolution of Life and Environment on Mars: An Ecosystem Perspective on the Robotic Exploration of Biosignatures

    Science.gov (United States)

    Cabrol, Nathalie A.

    2018-01-01

    Earth's biological and environmental evolution are intertwined and inseparable. This coevolution has become a fundamental concept in astrobiology and is key to the search for life beyond our planet. In the case of Mars, whether a coevolution took place is unknown, but analyzing the factors at play shows the uniqueness of each planetary experiment regardless of similarities. Early Earth and early Mars shared traits. However, biological processes on Mars, if any, would have had to proceed within the distinctive context of an irreversible atmospheric collapse, greater climate variability, and specific planetary characteristics. In that, Mars is an important test bed for comparing the effects of a unique set of spatiotemporal changes on an Earth-like, yet different, planet. Many questions remain unanswered about Mars' early environment. Nevertheless, existing data sets provide a foundation for an intellectual framework where notional coevolution models can be explored. In this framework, the focus is shifted from planetary-scale habitability to the prospect of habitats, microbial ecotones, pathways to biological dispersal, biomass repositories, and their meaning for exploration. Critically, as we search for biosignatures, this focus demonstrates the importance of starting to think of early Mars as a biosphere and vigorously integrating an ecosystem approach to landing site selection and exploration.

  5. Coexistence via coevolution driven by reduced allelochemical effects and increased tolerance to competition between invasive and native plants.

    Science.gov (United States)

    Huang, Fangfang; Lankau, Richard; Peng, Shaolin

    2018-04-01

    Coevolution can promote long-term coexistence of two competing species if selection acts to reduce the fitness inequality between competitors and/or strengthen negative frequency dependence within each population. However, clear coevolution between plant competitors has been rarely documented. Plant invasions offer opportunities to capture the process of coevolution. Here we investigated how the developing relationship between an invasive forb, Alliaria petiolata, and a native competitor, Pilea pumila, may affect their long-term coexistence, by testing the competitive effects of populations of varying lengths of co-occurrence on each other across a chronosequence of invasion history. Alliaria petiolata and P. pumila tended to develop greater tolerance to competition over invasion history. Their coexistence was promoted more by increases in stabilizing relative to equalizing processes. These changes likely stem in part from reductions in allelopathic traits in the invader and evolution of tolerance in the native. These results suggested that some native species can evolve tolerance against the competitive effects of strong invaders, which likely promoted their persistence in invaded communities. However, the potential for coevolutionary rescue of competing populations is likely to vary across native species, and evolutionary processes should not be expected to compensate for the ecological consequences of exotic invasions. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  6. Cooperative Coevolution with Formula-Based Variable Grouping for Large-Scale Global Optimization.

    Science.gov (United States)

    Wang, Yuping; Liu, Haiyan; Wei, Fei; Zong, Tingting; Li, Xiaodong

    2017-08-09

    For a large-scale global optimization (LSGO) problem, divide-and-conquer is usually considered an effective strategy to decompose the problem into smaller subproblems, each of which can then be solved individually. Among these decomposition methods, variable grouping is shown to be promising in recent years. Existing variable grouping methods usually assume the problem to be black-box (i.e., assuming that an analytical model of the objective function is unknown), and they attempt to learn appropriate variable grouping that would allow for a better decomposition of the problem. In such cases, these variable grouping methods do not make a direct use of the formula of the objective function. However, it can be argued that many real-world problems are white-box problems, that is, the formulas of objective functions are often known a priori. These formulas of the objective functions provide rich information which can then be used to design an effective variable group method. In this article, a formula-based grouping strategy (FBG) for white-box problems is first proposed. It groups variables directly via the formula of an objective function which usually consists of a finite number of operations (i.e., four arithmetic operations "[Formula: see text]", "[Formula: see text]", "[Formula: see text]", "[Formula: see text]" and composite operations of basic elementary functions). In FBG, the operations are classified into two classes: one resulting in nonseparable variables, and the other resulting in separable variables. In FBG, variables can be automatically grouped into a suitable number of non-interacting subcomponents, with variables in each subcomponent being interdependent. FBG can easily be applied to any white-box problem and can be integrated into a cooperative coevolution framework. Based on FBG, a novel cooperative coevolution algorithm with formula-based variable grouping (so-called CCF) is proposed in this article for decomposing a large-scale white-box problem

  7. Origin of the cell nucleus, mitosis and sex: roles of intracellular coevolution

    Directory of Open Access Journals (Sweden)

    Cavalier-Smith Thomas

    2010-02-01

    Full Text Available Abstract Background The transition from prokaryotes to eukaryotes was the most radical change in cell organisation since life began, with the largest ever burst of gene duplication and novelty. According to the coevolutionary theory of eukaryote origins, the fundamental innovations were the concerted origins of the endomembrane system and cytoskeleton, subsequently recruited to form the cell nucleus and coevolving mitotic apparatus, with numerous genetic eukaryotic novelties inevitable consequences of this compartmentation and novel DNA segregation mechanism. Physical and mutational mechanisms of origin of the nucleus are seldom considered beyond the long-standing assumption that it involved wrapping pre-existing endomembranes around chromatin. Discussions on the origin of sex typically overlook its association with protozoan entry into dormant walled cysts and the likely simultaneous coevolutionary, not sequential, origin of mitosis and meiosis. Results I elucidate nuclear and mitotic coevolution, explaining the origins of dicer and small centromeric RNAs for positionally controlling centromeric heterochromatin, and how 27 major features of the cell nucleus evolved in four logical stages, making both mechanisms and selective advantages explicit: two initial stages (origin of 30 nm chromatin fibres, enabling DNA compaction; and firmer attachment of endomembranes to heterochromatin protected DNA and nascent RNA from shearing by novel molecular motors mediating vesicle transport, division, and cytoplasmic motility. Then octagonal nuclear pore complexes (NPCs arguably evolved from COPII coated vesicle proteins trapped in clumps by Ran GTPase-mediated cisternal fusion that generated the fenestrated nuclear envelope, preventing lethal complete cisternal fusion, and allowing passive protein and RNA exchange. Finally, plugging NPC lumens by an FG-nucleoporin meshwork and adopting karyopherins for nucleocytoplasmic exchange conferred compartmentation

  8. Origin of the cell nucleus, mitosis and sex: roles of intracellular coevolution.

    Science.gov (United States)

    Cavalier-Smith, Thomas

    2010-02-04

    The transition from prokaryotes to eukaryotes was the most radical change in cell organisation since life began, with the largest ever burst of gene duplication and novelty. According to the coevolutionary theory of eukaryote origins, the fundamental innovations were the concerted origins of the endomembrane system and cytoskeleton, subsequently recruited to form the cell nucleus and coevolving mitotic apparatus, with numerous genetic eukaryotic novelties inevitable consequences of this compartmentation and novel DNA segregation mechanism. Physical and mutational mechanisms of origin of the nucleus are seldom considered beyond the long-standing assumption that it involved wrapping pre-existing endomembranes around chromatin. Discussions on the origin of sex typically overlook its association with protozoan entry into dormant walled cysts and the likely simultaneous coevolutionary, not sequential, origin of mitosis and meiosis. I elucidate nuclear and mitotic coevolution, explaining the origins of dicer and small centromeric RNAs for positionally controlling centromeric heterochromatin, and how 27 major features of the cell nucleus evolved in four logical stages, making both mechanisms and selective advantages explicit: two initial stages (origin of 30 nm chromatin fibres, enabling DNA compaction; and firmer attachment of endomembranes to heterochromatin) protected DNA and nascent RNA from shearing by novel molecular motors mediating vesicle transport, division, and cytoplasmic motility. Then octagonal nuclear pore complexes (NPCs) arguably evolved from COPII coated vesicle proteins trapped in clumps by Ran GTPase-mediated cisternal fusion that generated the fenestrated nuclear envelope, preventing lethal complete cisternal fusion, and allowing passive protein and RNA exchange. Finally, plugging NPC lumens by an FG-nucleoporin meshwork and adopting karyopherins for nucleocytoplasmic exchange conferred compartmentation advantages. These successive changes took place

  9. Biomimicry of symbiotic multi-species coevolution for discrete and continuous optimization in RFID networks

    Directory of Open Access Journals (Sweden)

    Na Lin

    2017-03-01

    Full Text Available In recent years, symbiosis as a rich source of potential engineering applications and computational model has attracted more and more attentions in the adaptive complex systems and evolution computing domains. Inspired by different symbiotic coevolution forms in nature, this paper proposed a series of multi-swarm particle swarm optimizers called PS2Os, which extend the single population particle swarm optimization (PSO algorithm to interacting multi-swarms model by constructing hierarchical interaction topologies and enhanced dynamical update equations. According to different symbiotic interrelationships, four versions of PS2O are initiated to mimic mutualism, commensalism, predation, and competition mechanism, respectively. In the experiments, with five benchmark problems, the proposed algorithms are proved to have considerable potential for solving complex optimization problems. The coevolutionary dynamics of symbiotic species in each PS2O version are also studied respectively to demonstrate the heterogeneity of different symbiotic interrelationships that effect on the algorithm’s performance. Then PS2O is used for solving the radio frequency identification (RFID network planning (RNP problem with a mixture of discrete and continuous variables. Simulation results show that the proposed algorithm outperforms the reference algorithms for planning RFID networks, in terms of optimization accuracy and computation robustness.

  10. The Ecological Dynamics of Natural Selection: Traits and the Coevolution of Community Structure.

    Science.gov (United States)

    McPeek, Mark A

    2017-05-01

    Natural selection has both genetic and ecological dynamics. The fitnesses of individuals change with their ecological context, and so the form and strength of selective agents change with abiotic factors and the phenotypes and abundances of interacting species. I use standard models of consumer-resource interactions to explore the ecological dynamics of natural selection and how various trait types influence these dynamics and the resulting structure of a community of coevolving species. Evolutionary optima favored by natural selection depend critically on the abundances of interacting species, and the traits of species can undergo dynamic cycling in limited areas of parameter space. The ecological dynamics of natural selection can also drive shifts from one adaptive peak to another, and these ecologically driven adaptive peak shifts are fundamental to the dynamics of niche differentiation. Moreover, this ecological differentiation is fostered in more productive and more benign environments where species interactions are stronger and where the selection gradients generated by species interactions are stronger. Finally, community structure resulting from coevolution depends fundamentally on the types of traits that underlie species interactions. The ecological dynamics of the process cannot be simplified, neglected, or ignored if we are to build a predictive theory of natural selection.

  11. Coevolution of parental investment and sexually selected traits drives sex-role divergence.

    Science.gov (United States)

    Fromhage, Lutz; Jennions, Michael D

    2016-08-18

    Sex-role evolution theory attempts to explain the origin and direction of male-female differences. A fundamental question is why anisogamy, the difference in gamete size that defines the sexes, has repeatedly led to large differences in subsequent parental care. Here we construct models to confirm predictions that individuals benefit less from caring when they face stronger sexual selection and/or lower certainty of parentage. However, we overturn the widely cited claim that a negative feedback between the operational sex ratio and the opportunity cost of care selects for egalitarian sex roles. We further argue that our model does not predict any effect of the adult sex ratio (ASR) that is independent of the source of ASR variation. Finally, to increase realism and unify earlier models, we allow for coevolution between parental investment and investment in sexually selected traits. Our model confirms that small initial differences in parental investment tend to increase due to positive evolutionary feedback, formally supporting long-standing, but unsubstantiated, verbal arguments.

  12. Coevolution within a transcriptional network by compensatory trans and cis mutations

    KAUST Repository

    Kuo, D.

    2010-10-26

    Transcriptional networks have been shown to evolve very rapidly, prompting questions as to how such changes arise and are tolerated. Recent comparisons of transcriptional networks across species have implicated variations in the cis-acting DNA sequences near genes as the main cause of divergence. What is less clear is how these changes interact with trans-acting changes occurring elsewhere in the genetic circuit. Here, we report the discovery of a system of compensatory trans and cis mutations in the yeast AP-1 transcriptional network that allows for conserved transcriptional regulation despite continued genetic change. We pinpoint a single species, the fungal pathogen Candida glabrata, in which a trans mutation has occurred very recently in a single AP-1 family member, distinguishing it from its Saccharomyces ortholog. Comparison of chromatin immunoprecipitation profiles between Candida and Saccharomyces shows that, despite their different DNA-binding domains, the AP-1 orthologs regulate a conserved block of genes. This conservation is enabled by concomitant changes in the cis-regulatory motifs upstream of each gene. Thus, both trans and cis mutations have perturbed the yeast AP-1 regulatory system in such a way as to compensate for one another. This demonstrates an example of “coevolution” between a DNA-binding transcription factor and its cis-regulatory site, reminiscent of the coevolution of protein binding partners.

  13. Coevolution of network structure and cooperation in the public goods game

    International Nuclear Information System (INIS)

    Wang Lei; Xia Chengyi; Wang Juan

    2013-01-01

    Recently, the emergence of cooperation has become a central topic in the evolutionary game field, and coevolution of game dynamics and network topology structure can give us a fresh viewpoint of how the network evolves and cooperation arises. In this paper, we show in detail a picture of the co-evolutionary behaviors between the microscopic structure of the network and cooperation promotion in the public goods game (PGG). Based on a mechanism named after evolutionary preferential attachment (EPA), in which the growth of the network depends on the outcome of PGG dynamics, we explore the structural properties of networks and cooperative behaviors taking place on the networks created by EPA rules. Extensive simulation results indicate that the structure of the resulting networks displays a transition from homogeneous to heterogeneous properties as the selection strength ϵ increases, and the cooperative behaviors have a non-trivial state in which cooperators and defectors can simultaneously occupy the hub nodes in the network. Current results are of interest for us to further understand the cooperation persistence and structure evolution in many natural, social and economical systems. (paper)

  14. Coevolution between human's anticancer activities and functional foods from crop origin center in the world.

    Science.gov (United States)

    Zeng, Ya-Wen; Du, Juan; Pu, Xiao-Ying; Yang, Jia-Zhen; Yang, Tao; Yang, Shu-Ming; Yang, Xiao-Meng

    2015-01-01

    Cancer is the leading cause of death around the world. Anticancer activities from many functional food sources have been reported in years, but correlation between cancer prevalence and types of food with anticancer activities from crop origin center in the world as well as food source with human migration are unclear. Hunger from food shortage is the cause of early human evolution from Africa to Asia and later into Eurasia. The richest functional foods are found in crop origin centers, housing about 70% in the world populations. Crop origin centers have lower cancer incidence and mortality in the world, especially Central Asia, Middle East, Southwest China, India and Ethiopia. Asia and Africa with the richest anticancer crops is not only the most important evolution base of humans and origin center of anticancer functional crop, but also is the lowest mortality and incidence of cancers in the world. Cancer prevention of early human migrations was associated with functional foods from crop origin centers, especially Asia with four centers and one subcenter of crop origin, accounting for 58% of the world population. These results reveal that coevolution between human's anticancer activities associated with functional foods for crop origin centers, especially in Asia and Africa.

  15. Co-evolution of Massive Black Holes and Their Host Galaxies

    Science.gov (United States)

    Chen, Y. M.

    2010-07-01

    A scenario of co-evolution of supermassive black holes (SMBHs) and galaxies has been clearly conducted by the important evidence from observational results of quasar host galaxies and the relation between spheroid and SMBH mass. There are a plenty of unresolved problems and questions, some being basic, to be addressed in this scenario. The main goal of the present thesis is focusing on the mysterious scenario including growth of primordial black holes, cosmological evolution of spins and duty cycle of SMBHs, and interaction between the SMBH activity and star formation in galaxies from low to high redshifts. We review the main progress of this field over the past decade since the discovery of Magorrian relation and present comments on some questions in light of our view of points. The key questions to be addressed in this thesis work are: (1) how does the fast growth of primordial black holes influence their evolution? (2) what is the equation to describe the co-evolution of SMBHs and galaxies? (3) what is the mechanism to control the co-evolution? (4) how to transport the fueling gas from kpc scale to the center? It has been suggested that fast growth of primordial black holes via super-Eddington accretion is a promising way to form SMBHs in high redshift universe. Neutrino cooling has been employed and expedites the growth. We consider the Compton heating of the surroundings of the primordial black holes. We find that the realistic accretion rate is only a few percent of the Eddington rate, and the accretion is episodic. It implies that the fast growth via super-Eddington is not feasible. These conclusions have been confirmed by the detailed numerical simulations of Milosavljevic et al. (2008). The difficulties of the fast growth via accretion of baryon particles make the formation of SMBHs elusive in high redshift universe. We developed a new formulation to calculate the duty cycle of SMBHs based on the Soltan argument. We show it can be expressed by the mass

  16. A Time-Domain Structural Damage Detection Method Based on Improved Multiparticle Swarm Coevolution Optimization Algorithm

    Directory of Open Access Journals (Sweden)

    Shao-Fei Jiang

    2014-01-01

    Full Text Available Optimization techniques have been applied to structural health monitoring and damage detection of civil infrastructures for two decades. The standard particle swarm optimization (PSO is easy to fall into the local optimum and such deficiency also exists in the multiparticle swarm coevolution optimization (MPSCO. This paper presents an improved MPSCO algorithm (IMPSCO firstly and then integrates it with Newmark’s algorithm to localize and quantify the structural damage by using the damage threshold proposed. To validate the proposed method, a numerical simulation and an experimental study of a seven-story steel frame were employed finally, and a comparison was made between the proposed method and the genetic algorithm (GA. The results show threefold: (1 the proposed method not only is capable of localization and quantification of damage, but also has good noise-tolerance; (2 the damage location can be accurately detected using the damage threshold proposed in this paper; and (3 compared with the GA, the IMPSCO algorithm is more efficient and accurate for damage detection problems in general. This implies that the proposed method is applicable and effective in the community of damage detection and structural health monitoring.

  17. Coevolution between flight morphology, vertical stratification and sexual dimorphism: what can we learn from tropical butterflies?

    Science.gov (United States)

    Graça, M B; Pequeno, P A C L; Franklin, E; Morais, J W

    2017-10-01

    Occurrence patterns are partly shaped by the affinity of species with habitat conditions. For winged organisms, flight-related attributes are vital for ecological performance. However, due to the different reproductive roles of each sex, we expect divergence in flight energy budget, and consequently different selection responses between sexes. We used tropical frugivorous butterflies as models to investigate coevolution between flight morphology, sex dimorphism and vertical stratification. We studied 94 species of Amazonian fruit-feeding butterflies sampled in seven sites across 3341 ha. We used wing-thorax ratio as a proxy for flight capacity and hierarchical Bayesian modelling to estimate stratum preference. We detected a strong phylogenetic signal in wing-thorax ratio in both sexes. Stouter fast-flying species preferred the canopy, whereas more slender slow-flying species preferred the understorey. However, this relationship was stronger in females than in males, suggesting that female phenotype associates more intimately with habitat conditions. Within species, males were stouter than females and sexual dimorphism was sharper in understorey species. Because trait-habitat relationships were independent from phylogeny, the matching between flight morphology and stratum preference is more likely to reflect adaptive radiation than shared ancestry. This study sheds light on the impact of flight and sexual dimorphism on the evolution and ecological adaptation of flying organisms. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  18. Coevolution of the Toll-Like Receptor 4 Complex with Calgranulins and Lipopolysaccharide

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    Andrea N. Loes

    2018-02-01

    Full Text Available Toll-like receptor 4 (TLR4 induces inflammation in response to both pathogen- and host-derived molecules. Lipopolysaccharide (LPS recognition by TLR4 has been shown to occur across the amniotes, but endogenous signaling through TLR4 has not been validated outside of placental mammals. To determine whether endogenous danger signaling is also shared across amniotes, we studied the evolution of TLR4-activation by the calgranulin proteins (S100A8, S100A9, and S100A12, a clade of host molecules that potently activate TLR4 in placental mammals. We performed phylogenetic and syntenic analysis and found MRP-126—a gene in birds and reptiles—is likely orthologous to the mammalian calgranulins. We then used an ex vivo TLR4 activation assay to establish that calgranulin pro-inflammatory activity is not specific to placental mammals, but is also exhibited by representative marsupial and sauropsid species. This activity is strongly dependent on the cofactors CD14 and MD-2 for all species studied, suggesting a conserved mode of activation across the amniotes. Ortholog complementation experiments between the calgranulins, TLR4, CD14, and MD-2 revealed extensive lineage specific-coevolution and multi-way interactions between components that are necessary for the activation of NF-κB signaling by calgranulins and LPS. Our work demonstrates that calgranulin activation of TLR4 evolved at least ~320 million years ago and has been conserved in the amniote innate immune system.

  19. Coevolution of bed surface patchiness and channel morphology: 2. Numerical experiments

    Science.gov (United States)

    Nelson, Peter A.; McDonald, Richard R.; Nelson, Jonathan M.; Dietrich, William E.

    2015-01-01

    In gravel bed rivers, bed topography and the bed surface grain size distribution evolve simultaneously, but it is not clear how feedbacks between topography and grain sorting affect channel morphology. In this, the second of a pair of papers examining interactions between bed topography and bed surface sorting in gravel bed rivers, we use a two-dimensional morphodynamic model to perform numerical experiments designed to explore the coevolution of both free and forced bars and bed surface patches. Model runs were carried out on a computational grid simulating a 200 m long, 2.75 m wide, straight, rectangular channel, with an initially flat bed at a slope of 0.0137. Over five numerical experiments, we varied (a) whether an obstruction was present, (b) whether the sediment was a gravel mixture or a single size, and (c) whether the bed surface grain size feeds back on the hydraulic roughness field. Experiments with channel obstructions developed a train of alternate bars that became stationary and were connected to the obstruction. Freely migrating alternate bars formed in the experiments without channel obstructions. Simulations incorporating roughness feedbacks between the bed surface and flow field produced flatter, broader, and longer bars than simulations using constant roughness or uniform sediment. Our findings suggest that patches are not simply a by-product of bed topography, but they interact with the evolving bed and influence morphologic evolution.

  20. Sexually antagonistic coevolution for sexual harassment can act as a barrier to further invasions by parthenogenesis.

    Science.gov (United States)

    Kawatsu, Kazutaka

    2013-02-01

    The assumption of a twofold cost of sex not only complicates the maintenance of sex but also sets conditions for sexual conflict: in organisms with the twofold cost, males often sexually harass females. Sexual harassment is detrimental to female fitness and thus might help maintain sexual populations if male harassment inflicts a harsher cost on parthenogens than on sexual females (asymmetric harassment cost). However, the generality of this concept is now considered doubtful because selective harassment of parthenogens results in loss of mating opportunities for males. Using three mathematical models, I show here that sexual harassment still can impose the asymmetric cost on parthenogens. First, I apply the Lotka-Volterra model to show the degree of asymmetric harassment cost that permits sex to be maintained stably in the population. Second, using adaptive dynamics, I examine whether sexually antagonistic coevolution for sexual harassment, which occurs only in sexual populations, can promote the asymmetric harassment cost. Finally, an individual-based model, which assumes a spatial structure unlike that in the other two, demonstrates that the asymmetric evolution of harassment cost prevents further invasions of parthenogens from different patches into sexual lineages; these mechanisms may account for allopatric distributions of sexual and parthenogenetic lineages as well as the maintenance of sex.

  1. Energy Levels and Co-evolution of Product Innovation in Supply Chain Clusters

    Science.gov (United States)

    Ji, Guojun

    In the last decade supply chain clusters phenomenon has emerged as a new approach in product innovation studies. This article makes three contributions to the approach by addressing some open issues. The first contribution is to explicitly incorporate the energy levels in the analysis. Hence, the unit of analysis is widened from sectoral systems of innovation to socio-technical systems. Hence, the unit of analysis is widened from sectoral systems of innovation to socio-technical systems. The second contribution is to suggest an analytical distinction between different evolution method, actors involved in them, and the institutions which guide actor's perceptions and activities. Thirdly, the article opens up the black box of institutions, making them an integral part of supply chain. The article provides a coherent conceptual multi-level perspective, using insights from sociology, institutional theory and innovation studies. The perspective is particularly useful to analyze long-term dynamics supply chain clusters phenomenon, shifts from one energy level to another and the co-evolution of product innovation.

  2. Antagonistic Coevolution Drives Whack-a-Mole Sensitivity in Gene Regulatory Networks.

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    Jeewoen Shin

    2015-10-01

    Full Text Available Robustness, defined as tolerance to perturbations such as mutations and environmental fluctuations, is pervasive in biological systems. However, robustness often coexists with its counterpart, evolvability--the ability of perturbations to generate new phenotypes. Previous models of gene regulatory network evolution have shown that robustness evolves under stabilizing selection, but it is unclear how robustness and evolvability will emerge in common coevolutionary scenarios. We consider a two-species model of coevolution involving one host and one parasite population. By using two interacting species, key model parameters that determine the fitness landscapes become emergent properties of the model, avoiding the need to impose these parameters externally. In our study, parasites are modeled on species such as cuckoos where mimicry of the host phenotype confers high fitness to the parasite but lower fitness to the host. Here, frequent phenotype changes are favored as each population continually adapts to the other population. Sensitivity evolves at the network level such that point mutations can induce large phenotype changes. Crucially, the sensitive points of the network are broadly distributed throughout the network and continually relocate. Each time sensitive points in the network are mutated, new ones appear to take their place. We have therefore named this phenomenon "whack-a-mole" sensitivity, after a popular fun park game. We predict that this type of sensitivity will evolve under conditions of strong directional selection, an observation that helps interpret existing experimental evidence, for example, during the emergence of bacterial antibiotic resistance.

  3. Coevolution between a family of parasite virulence effectors and a class of LINE-1 retrotransposons.

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    Soledad Sacristán

    2009-10-01

    Full Text Available Parasites are able to evolve rapidly and overcome host defense mechanisms, but the molecular basis of this adaptation is poorly understood. Powdery mildew fungi (Erysiphales, Ascomycota are obligate biotrophic parasites infecting nearly 10,000 plant genera. They obtain their nutrients from host plants through specialized feeding structures known as haustoria. We previously identified the AVR(k1 powdery mildew-specific gene family encoding effectors that contribute to the successful establishment of haustoria. Here, we report the extensive proliferation of the AVR(k1 gene family throughout the genome of B. graminis, with sequences diverging in formae speciales adapted to infect different hosts. Also, importantly, we have discovered that the effectors have coevolved with a particular family of LINE-1 retrotransposons, named TE1a. The coevolution of these two entities indicates a mutual benefit to the association, which could ultimately contribute to parasite adaptation and success. We propose that the association would benefit 1 the powdery mildew fungus, by providing a mechanism for amplifying and diversifying effectors and 2 the associated retrotransposons, by providing a basis for their maintenance through selection in the fungal genome.

  4. Biomimicry of symbiotic multi-species coevolution for discrete and continuous optimization in RFID networks.

    Science.gov (United States)

    Lin, Na; Chen, Hanning; Jing, Shikai; Liu, Fang; Liang, Xiaodan

    2017-03-01

    In recent years, symbiosis as a rich source of potential engineering applications and computational model has attracted more and more attentions in the adaptive complex systems and evolution computing domains. Inspired by different symbiotic coevolution forms in nature, this paper proposed a series of multi-swarm particle swarm optimizers called PS 2 Os, which extend the single population particle swarm optimization (PSO) algorithm to interacting multi-swarms model by constructing hierarchical interaction topologies and enhanced dynamical update equations. According to different symbiotic interrelationships, four versions of PS 2 O are initiated to mimic mutualism, commensalism, predation, and competition mechanism, respectively. In the experiments, with five benchmark problems, the proposed algorithms are proved to have considerable potential for solving complex optimization problems. The coevolutionary dynamics of symbiotic species in each PS 2 O version are also studied respectively to demonstrate the heterogeneity of different symbiotic interrelationships that effect on the algorithm's performance. Then PS 2 O is used for solving the radio frequency identification (RFID) network planning (RNP) problem with a mixture of discrete and continuous variables. Simulation results show that the proposed algorithm outperforms the reference algorithms for planning RFID networks, in terms of optimization accuracy and computation robustness.

  5. Coevolution between invasive and native plants driven by chemical competition and soil biota.

    Science.gov (United States)

    Lankau, Richard A

    2012-07-10

    Although reciprocal evolutionary responses between interacting species are a driving force behind the diversity of life, pairwise coevolution between plant competitors has received less attention than other species interactions and has been considered relatively less important in explaining ecological patterns. However, the success of species transported across biogeographic boundaries suggests a stronger role for evolutionary relationships in shaping plant interactions. Alliaria petiolata is a Eurasian species that has invaded North American forest understories, where it competes with native understory species in part by producing compounds that directly and indirectly slow the growth of competing species. Here I show that populations of A. petiolata from areas with a greater density of interspecific competitors invest more in a toxic allelochemical under common conditions. Furthermore, populations of a native competitor from areas with highly toxic invaders are more tolerant to competition from the invader, suggesting coevolutionary dynamics between the species. Field reciprocal transplants confirmed that native populations more tolerant to the invader had higher fitness when the invader was common, but these traits came at a cost when the invader was rare. Exotic species are often detrimentally dominant in their new range due to their evolutionary novelty; however, the development of new coevolutionary relationships may act to integrate exotic species into native communities.

  6. Coevolution between positive reciprocity, punishment, and partner switching in repeated interactions.

    Science.gov (United States)

    Wubs, Matthias; Bshary, Redouan; Lehmann, Laurent

    2016-06-15

    Cooperation based on mutual investments can occur between unrelated individuals when they are engaged in repeated interactions. Individuals then need to use a conditional strategy to deter their interaction partners from defecting. Responding to defection such that the future payoff of a defector is reduced relative to cooperating with it is called a partner control mechanism. Three main partner control mechanisms are (i) to switch from cooperation to defection when being defected ('positive reciprocity'), (ii) to actively reduce the payoff of a defecting partner ('punishment'), or (iii) to stop interacting and switch partner ('partner switching'). However, such mechanisms to stabilize cooperation are often studied in isolation from each other. In order to better understand the conditions under which each partner control mechanism tends to be favoured by selection, we here analyse by way of individual-based simulations the coevolution between positive reciprocity, punishment, and partner switching. We show that random interactions in an unstructured population and a high number of rounds increase the likelihood that selection favours partner switching. In contrast, interactions localized in small groups (without genetic structure) increase the likelihood that selection favours punishment and/or positive reciprocity. This study thus highlights the importance of comparing different control mechanisms for cooperation under different conditions. © 2016 The Author(s).

  7. Visualization on the Web of 20 Years of Crop Rotation and Wildlife Co-Evolutions

    Science.gov (United States)

    Plumejeaud-Perreau, Christine; Poitevin, Cyril; Bretagnolle, Vincent

    2018-05-01

    The accumulation of evidences of the effects of intensive agricultural practices against wildlife fauna and flora, and biodiversity in general, has been largely published in scientific papers (Tildman, 1999). However, data serving as sup-port to their conclusions are often kept hidden behind research institutions. This paper presents a data visualization sys-tem opened on the Web allowing citizens to get a comprehensive access to data issued from such kind of research institution, collected for more than 20 years. The Web Information System has been thought in order to ease the comparison of data issues from various databases describing the same object, the agricultural landscape, at different scales and through different observation devices. An interactive visualization is proposed in order to check co-evolution of fauna and flora together with agricultural practices. It mixes aerial orthoimagery produced since 1950 with vectorial data showing the evolutions of agricultural parcels with those of a few sentinel species such as the Montagu's harrier. This is made through a composition of maps, charts and time lines, and specific tools for comparison. A particular concern is given to the observation effort bias in order to show meaningful statistical aggregates.

  8. Coevolution between Nuclear-Encoded DNA Replication, Recombination, and Repair Genes and Plastid Genome Complexity.

    Science.gov (United States)

    Zhang, Jin; Ruhlman, Tracey A; Sabir, Jamal S M; Blazier, John Chris; Weng, Mao-Lun; Park, Seongjun; Jansen, Robert K

    2016-02-17

    Disruption of DNA replication, recombination, and repair (DNA-RRR) systems has been hypothesized to cause highly elevated nucleotide substitution rates and genome rearrangements in the plastids of angiosperms, but this theory remains untested. To investigate nuclear-plastid genome (plastome) coevolution in Geraniaceae, four different measures of plastome complexity (rearrangements, repeats, nucleotide insertions/deletions, and substitution rates) were evaluated along with substitution rates of 12 nuclear-encoded, plastid-targeted DNA-RRR genes from 27 Geraniales species. Significant correlations were detected for nonsynonymous (dN) but not synonymous (dS) substitution rates for three DNA-RRR genes (uvrB/C, why1, and gyrA) supporting a role for these genes in accelerated plastid genome evolution in Geraniaceae. Furthermore, correlation between dN of uvrB/C and plastome complexity suggests the presence of nucleotide excision repair system in plastids. Significant correlations were also detected between plastome complexity and 13 of the 90 nuclear-encoded organelle-targeted genes investigated. Comparisons revealed significant acceleration of dN in plastid-targeted genes of Geraniales relative to Brassicales suggesting this correlation may be an artifact of elevated rates in this gene set in Geraniaceae. Correlation between dN of plastid-targeted DNA-RRR genes and plastome complexity supports the hypothesis that the aberrant patterns in angiosperm plastome evolution could be caused by dysfunction in DNA-RRR systems. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  9. The plurality of values in sustainable agriculture models: diverse lock-in and coevolution patterns

    Directory of Open Access Journals (Sweden)

    Gael Plumecocq

    2018-03-01

    Full Text Available In Western economies, several agriculture models coexist. For instance, intensive agriculture organization, which has increased yields while causing major pollution and resource depletion, competes with alternative models, which tackle these sustainability issues and lead to lower yields. An agronomical typology of current agriculture models in Western societies is proposed that describes multiple sustainability issues through an agroecological perspective. However, in order to choose between these agroecological pathways, we must understand their social structure and the principles underlying them. Thus, our purpose is to characterize the institutional aspects of the alternative models using socioeconomic convention theory. We conducted a series of workshops with specialists in the natural sciences (agronomy, landscape ecology, and entomology and social sciences (economics and sociology to describe sustainable agriculture models. This characterization revealed the values underlying six different sustainable agriculture models, their forms of organization, and the institutions governing them. We discuss the implications of the coexistence of these six models in light of sustainable transition issues. From this coexistence perspective, transition (i refers to an intertwined process of legitimation and disqualification, and (ii means seeing pathways as the multiplicity and degree of interconnection between models. Therefore, we (i identified the elements in each model that legitimize its mode of organization, and (ii disqualified the elements that are incompatible with the principles underlying the model's practices. Moreover, we emphasize that multiple transition pathways are possible based on complex, complementary combinations of different models. This revealed the intricate processes of competition and complementarity involving these models. Finally, our study on the coexistence, interdependence, and coevolution of multiple agriculture models

  10. The coevolution of supermassive black holes and massive galaxies at high redshift

    Energy Technology Data Exchange (ETDEWEB)

    Lapi, A.; Raimundo, S.; Aversa, R.; Cai, Z.-Y.; Celotti, A.; De Zotti, G.; Danese, L. [SISSA, Via Bonomea 265, I-34136 Trieste (Italy); Negrello, M. [INAF-Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy)

    2014-02-20

    We exploit the recent, wide samples of far-infrared (FIR) selected galaxies followed up in X-rays and of X-ray/optically selected active galactic nuclei (AGNs) followed up in the FIR band, along with the classic data on AGNs and stellar luminosity functions at high redshift z ≳ 1.5, to probe different stages in the coevolution of supermassive black holes (BHs) and host galaxies. The results of our analysis indicate the following scenario: (1) the star formation in the host galaxy proceeds within a heavily dust-enshrouded medium at an almost constant rate over a timescale ≲ 0.5-1 Gyr and then abruptly declines due to quasar feedback, over the same timescale; (2) part of the interstellar medium loses angular momentum, reaches the circum-nuclear regions at a rate proportional to the star formation, and is temporarily stored in a massive reservoir/proto-torus wherefrom it can be promptly accreted; (3) the BH grows by accretion in a self-regulated regime with radiative power that can slightly exceed the Eddington limit L/L {sub Edd} ≲ 4, particularly at the highest redshifts; (4) for massive BHs, the ensuing energy feedback at its maximum exceeds the stellar one and removes the interstellar gas, thus stopping the star formation and the fueling of the reservoir; (5) afterward, if the latter has retained enough gas, a phase of supply-limited accretion follows, exponentially declining with a timescale of about two e-folding times. We also discuss how the detailed properties and the specific evolution of the reservoir can be investigated via coordinated, high-resolution observations of star-forming, strongly lensed galaxies in the (sub-)mm band with ALMA and in the X-ray band with Chandra and the next-generation X-ray instruments.

  11. Co-evolution of SNF spliceosomal proteins with their RNA targets in trans-splicing nematodes.

    Science.gov (United States)

    Strange, Rex Meade; Russelburg, L Peyton; Delaney, Kimberly J

    2016-08-01

    Although the mechanism of pre-mRNA splicing has been well characterized, the evolution of spliceosomal proteins is poorly understood. The U1A/U2B″/SNF family (hereafter referred to as the SNF family) of RNA binding spliceosomal proteins participates in both the U1 and U2 small interacting nuclear ribonucleoproteins (snRNPs). The highly constrained nature of this system has inhibited an analysis of co-evolutionary trends between the proteins and their RNA binding targets. Here we report accelerated sequence evolution in the SNF protein family in Phylum Nematoda, which has allowed an analysis of protein:RNA co-evolution. In a comparison of SNF genes from ecdysozoan species, we found a correlation between trans-splicing species (nematodes) and increased phylogenetic branch lengths of the SNF protein family, with respect to their sister clade Arthropoda. In particular, we found that nematodes (~70-80 % of pre-mRNAs are trans-spliced) have experienced higher rates of SNF sequence evolution than arthropods (predominantly cis-spliced) at both the nucleotide and amino acid levels. Interestingly, this increased evolutionary rate correlates with the reliance on trans-splicing by nematodes, which would alter the role of the SNF family of spliceosomal proteins. We mapped amino acid substitutions to functionally important regions of the SNF protein, specifically to sites that are predicted to disrupt protein:RNA and protein:protein interactions. Finally, we investigated SNF's RNA targets: the U1 and U2 snRNAs. Both are more divergent in nematodes than arthropods, suggesting the RNAs have co-evolved with SNF in order to maintain the necessarily high affinity interaction that has been characterized in other species.

  12. Co-evolution of elliptical galaxies and their central black holes

    International Nuclear Information System (INIS)

    Ciotti, I.

    2009-01-01

    After the discovery that supermassive black holes (SMBHs) are ubiquitous at the center of stellar spheroids and that their mass M BH , in the range 10 6 M-10 9 M, is tightly related to global properties of the host stellar system, the idea of the co-evolution of elliptical galaxies and of their SMBHs has become a central topic of modern astrophysics. Here, I summarize some consequences that can be derived from the galaxy Scaling Laws (SLs) and present a coherent scenario for the formation and evolution of elliptical galaxies and their central SMBHs, focusing in particular on the establishment and maintenance of their SLs. In particular, after a first observationally based part, the discussion focuses on the physical interpretation of the Fundamental Plane. Then, two important processes in principle able to destroy the galaxy and SMBH SLs, namely galaxy merging and cooling flows, are analyzed. Arguments supporting the necessity to clearly distinguish between the origin and maintenance of the different SLs, and the unavoidable occurrence of SMBH feedback on the galaxy ISM in the late stages of galaxy evolution (when elliptical galaxies are sometimes considered as dead, red objects), are then presented. At the end of the paper I will discuss some implications of the recent discovery of super-dense ellipticals in the distant Universe. In particular, I will argue that, if confirmed, these new observations would lead to the conclusion that at early epochs a relation between the stellar mass of the galaxy and the mass of the central SMBH should hold, consistent with the present day Magorrian relation, while the proportionality coefficient between M BH and the scale of velocity dispersion of the hosting spheroids should be significantly smaller than that at the present epoch

  13. Coevolution of honest signaling and cooperative norms by cultural group selection.

    Science.gov (United States)

    Scheuring, István

    2010-08-01

    Evolution of cooperative norms is studied in a population where individual and group level selection are both in operation. Individuals play indirect reciprocity game within their group and follow second order norms. Individuals are norm-followers, and imitate their successful group mates. Aside from direct observation individuals can be informed about the previous actions and reputations by information transferred by others. A potential donor estimates the reputation of a potential receiver either by her own observation or by the opinion of the majority of others (indirect observation). Following a previous study (Scheuring, 2009) we assume that norms determine only the probabilities of actions, and mutants can differ in these probabilities. Similarly, we assume that individuals follow a stochastic information transfer strategy. The central question is whether cooperative norm and honest social information transfer can emerge in a population where initially only non-cooperative norms were present, and the transferred information was not sufficiently honest. It is shown that evolution can lead to a cooperative state where information transferred in a reliable manner, where generous cooperative strategies are dominant. This cooperative state emerges along a sharp transition of norms. We studied the characteristics of actions and strategies in this transition by classifying the stochastic norms, and found that a series of more and more judging strategies invade each other before the stabilization of the so-called generous judging strategy. Numerical experiments on the coevolution of social parameters (e.g. probability of direct observation and the number of indirect observers) reveal that it is advantageous to lean on indirect observation even if information transfer is much noisier than for direct observation, which is because to follow the majorities' opinion suppresses information noise meaningfully.

  14. Metabolic Coevolution in the Bacterial Symbiosis of Whiteflies and Related Plant Sap-Feeding Insects.

    Science.gov (United States)

    Luan, Jun-Bo; Chen, Wenbo; Hasegawa, Daniel K; Simmons, Alvin M; Wintermantel, William M; Ling, Kai-Shu; Fei, Zhangjun; Liu, Shu-Sheng; Douglas, Angela E

    2015-09-15

    Genomic decay is a common feature of intracellular bacteria that have entered into symbiosis with plant sap-feeding insects. This study of the whitefly Bemisia tabaci and two bacteria (Portiera aleyrodidarum and Hamiltonella defensa) cohoused in each host cell investigated whether the decay of Portiera metabolism genes is complemented by host and Hamiltonella genes, and compared the metabolic traits of the whitefly symbiosis with other sap-feeding insects (aphids, psyllids, and mealybugs). Parallel genomic and transcriptomic analysis revealed that the host genome contributes multiple metabolic reactions that complement or duplicate Portiera function, and that Hamiltonella may contribute multiple cofactors and one essential amino acid, lysine. Homologs of the Bemisia metabolism genes of insect origin have also been implicated in essential amino acid synthesis in other sap-feeding insect hosts, indicative of parallel coevolution of shared metabolic pathways across multiple symbioses. Further metabolism genes coded in the Bemisia genome are of bacterial origin, but phylogenetically distinct from Portiera, Hamiltonella and horizontally transferred genes identified in other sap-feeding insects. Overall, 75% of the metabolism genes of bacterial origin are functionally unique to one symbiosis, indicating that the evolutionary history of metabolic integration in these symbioses is strongly contingent on the pattern of horizontally acquired genes. Our analysis, further, shows that bacteria with genomic decay enable host acquisition of complex metabolic pathways by multiple independent horizontal gene transfers from exogenous bacteria. Specifically, each horizontally acquired gene can function with other genes in the pathway coded by the symbiont, while facilitating the decay of the symbiont gene coding the same reaction. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  15. Comparative Phylogenetic Studies on Schistosoma japonicum and Its Snail Intermediate Host Oncomelania hupensis: Origins, Dispersal and Coevolution.

    Directory of Open Access Journals (Sweden)

    Stephen W Attwood

    Full Text Available Schistosoma japonicum causes major public health problems in China and the Philippines; this parasite, which is transmitted by freshwater snails of the species Oncomelania hupensis, causes the disease intestinal schistosomiasis in humans and cattle. Researchers working on Schistosoma in Africa have described the relationship between the parasites and their snail intermediate hosts as coevolved or even as an evolutionary arms race. In the present study this hypothesis of coevolution is evaluated for S. japonicum and O. hupensis. The origins and radiation of the snails and the parasite across China, and the taxonomic validity of the sub-species of O. hupensis, are also assessed.The findings provide no evidence for coevolution between S. japonicum and O. hupensis, and the phylogeographical analysis suggests a heterochronous radiation of the parasites and snails in response to different palaeogeographical and climatic triggers. The results are consistent with a hypothesis of East to West colonisation of China by Oncomelania with a re-invasion of Japan by O. hupensis from China. The Taiwan population of S. japonicum appears to be recently established in comparison with mainland Chinese populations.The snail and parasite populations of the western mountain region of China (Yunnan and Sichuan appear to have been isolated from Southeast Asian populations since the Pleistocene; this has implications for road and rail links being constructed in the region, which will breach biogeographical barriers between China and Southeast Asia. The results also have implications for the spread of S. japonicum. In the absence of coevolution, the parasite may more readily colonise new snail populations to which it is not locally adapted, or even new intermediate host species; this can facilitate its dispersal into new areas. Additional work is required to assess further the risk of spread of S. japonicum.

  16. Socio-hydrologic Perspectives of the Co-evolution of Humans and Water in the Tarim River Basin, Western China

    Science.gov (United States)

    Liu, Ye; Tian, Fuqiang; Hu, Heping; Liu, Dengfeng; Sivapalan, Murugesu

    2013-04-01

    Socio-hydrology studies the co-evolution of coupled human-water systems, which is of great importance for long-term sustainable water resource management in basins suffering from serious eco-environmental degradation. Process socio-hydrology can benefit from the exploring the patterns of historical co-evolution of coupled human-water systems as a way to discovering the organizing principles that may underpin their co-evolution. As a self-organized entity, the human-water system in a river basin would evolve into certain steady states over a sufficiently long time but then could also experience sudden shifts due to internal or external disturbances that exceed system thresholds. In this study, we discuss three steady states (also called stages in the social sciences, including natural, human exploitation and recovery stages) and transitions between these during the past 1500 years in the Tarim River Basin of Western China, which a rich history of civilization including its place in the famous Silk Road that connected China to Europe. Specifically, during the natural stage with a sound environment that existed before the 19th century, shifts in the ecohydrological regime were mainly caused by environmental changes such river channel migration and climate change. During the human exploitation stages in the 5th and again in the 19th-20th centuries, however, humans gradually became the main drivers for system evolution, during which the basin experienced rapid population growth, fast socio-economic development and intense human activities. By the 1970s, after 200 years of colonization, the Tarim River Basin evolved into a new regime with vulnerable ecosystem and water system, and suffered from serious water shortages and desertification. Human society then began to take a critical look into the effects of their activities and reappraise the impact of human development on the ecohydrological system, which eventually led the basin into a treatment and recovery stage

  17. A role for habitat area in the geographic mosaic of coevolution between red crossbills and lodgepole pine.

    Science.gov (United States)

    Siepielski, A M; Benkman, C W

    2005-07-01

    Understanding how resource abundance limits adaptive evolution and influences species interactions is an important step towards developing insight into the role of microevolutionary processes in establishing macroevolutionary patterns. We examined how variation in resource abundance (forest area of lodgepole pine Pinus contorta ssp. latifolia) influenced patterns of co-adaptation and coevolution between red crossbill (Loxia curvirostra complex) and lodgepole pine populations. First, we found that crossbill abundance increased logarithmically as forest area increased in mountain ranges lacking a preemptive competitor (pine squirrels Tamiasciurus hudsonicus). Second, seed defences against predation by crossbills increased with increases in crossbill density, suggesting that seed defences have likely evolved in proportion to the intensity of selection that crossbills exert. Third, the average bill size of crossbill populations increased with increasing seed defences, which implies that crossbill offenses increased with increases in seed defences. The large bill size on the largest range is the result of coevolution with lodgepole pine with this crossbill population perhaps speciating. Local adaptation of crossbill populations on smaller ranges, however, is more likely the result of resident crossbills representing a subset of the potential colonists (phenotypic sorting) than of local evolution. In the smallest range, migration and possibly more frequent extinction likely impede local adaptation and may result in maladaptation.

  18. Identification of coevolving residues and coevolution potentials emphasizing structure, bond formation and catalytic coordination in protein evolution.

    Directory of Open Access Journals (Sweden)

    Daniel Y Little

    Full Text Available The structure and function of a protein is dependent on coordinated interactions between its residues. The selective pressures associated with a mutation at one site should therefore depend on the amino acid identity of interacting sites. Mutual information has previously been applied to multiple sequence alignments as a means of detecting coevolutionary interactions. Here, we introduce a refinement of the mutual information method that: 1 removes a significant, non-coevolutionary bias and 2 accounts for heteroscedasticity. Using a large, non-overlapping database of protein alignments, we demonstrate that predicted coevolving residue-pairs tend to lie in close physical proximity. We introduce coevolution potentials as a novel measure of the propensity for the 20 amino acids to pair amongst predicted coevolutionary interactions. Ionic, hydrogen, and disulfide bond-forming pairs exhibited the highest potentials. Finally, we demonstrate that pairs of catalytic residues have a significantly increased likelihood to be identified as coevolving. These correlations to distinct protein features verify the accuracy of our algorithm and are consistent with a model of coevolution in which selective pressures towards preserving residue interactions act to shape the mutational landscape of a protein by restricting the set of admissible neutral mutations.

  19. Emergent dynamics of fairness in the spatial coevolution of proposer and responder species in the ultimatum game.

    Directory of Open Access Journals (Sweden)

    Reiji Suzuki

    Full Text Available While spatially local interactions are ubiquitous between coevolving species sharing recourses (e.g., plant-insect interactions, their effects on such coevolution processes of strategies involving the share of a resource are still not clearly understood. We construct a two-dimensional spatial model of the coevolution of the proposer and responder species in the ultimatum game (UG, in which a pair of proposer and responder individuals at each site plays the UG. We investigate the effects of the locality of interactions and the intensity of selection on the emergence of fairness between these species. We show that the lower intensity of selection favors fair strategies in general, and there are no significant differences in the evolution of fairness between the cases with local and global interactions when the intensity of selection is low. However, as the intensity of selection becomes higher, the spatially local interactions contribute to the evolution of fairer strategies more than the global interactions, even though fair strategies become more difficult to evolve. This positive effect of spatial interactions is expected to be due to the mutual benefit of fairness for both proposer and responder species in future generations, which brings about a dynamic evolution process of fairness.

  20. Contrasting Patterns in Mammal–Bacteria Coevolution: Bartonella and Leptospira in Bats and Rodents

    Science.gov (United States)

    Lei, Bonnie R.; Olival, Kevin J.

    2014-01-01

    Background Emerging bacterial zoonoses in bats and rodents remain relatively understudied. We conduct the first comparative host–pathogen coevolutionary analyses of bacterial pathogens in these hosts, using Bartonella spp. and Leptospira spp. as a model. Methodology/Principal Findings We used published genetic data for 51 Bartonella genotypes from 24 bat species, 129 Bartonella from 38 rodents, and 26 Leptospira from 20 bats. We generated maximum likelihood and Bayesian phylogenies for hosts and bacteria, and tested for coevoutionary congruence using programs ParaFit, PACO, and Jane. Bartonella spp. and their bat hosts had a significant coevolutionary fit (ParaFitGlobal = 1.9703, P≤0.001; m2 global value = 7.3320, P≤0.0001). Bartonella spp. and rodent hosts also indicated strong overall patterns of cospeciation (ParaFitGlobal = 102.4409, P≤0.001; m2 global value = 86.532, P≤0.0001). In contrast, we were unable to reject independence of speciation events in Leptospira and bats (ParaFitGlobal = 0.0042, P = 0.84; m2 global value = 4.6310, P = 0.5629). Separate analyses of New World and Old World data subsets yielded results congruent with analysis from entire datasets. We also conducted event-based cophylogeny analyses to reconstruct likely evolutionary histories for each group of pathogens and hosts. Leptospira and bats had the greatest number of host switches per parasite (0.731), while Bartonella and rodents had the fewest (0.264). Conclusions/Significance In both bat and rodent hosts, Bartonella exhibits significant coevolution with minimal host switching, while Leptospira in bats lacks evolutionary congruence with its host and has high number of host switches. Reasons underlying these variable coevolutionary patterns in host range are likely due to differences in disease-specific transmission and host ecology. Understanding the coevolutionary patterns and frequency of host-switching events between bacterial pathogens and

  1. Modelling the co-evolution of indirect genetic effects and inherited variability.

    Science.gov (United States)

    Marjanovic, Jovana; Mulder, Han A; Rönnegård, Lars; Bijma, Piter

    2018-03-28

    When individuals interact, their phenotypes may be affected not only by their own genes but also by genes in their social partners. This phenomenon is known as Indirect Genetic Effects (IGEs). In aquaculture species and some plants, however, competition not only affects trait levels of individuals, but also inflates variability of trait values among individuals. In the field of quantitative genetics, the variability of trait values has been studied as a quantitative trait in itself, and is often referred to as inherited variability. Such studies, however, consider only the genetic effect of the focal individual on trait variability and do not make a connection to competition. Although the observed phenotypic relationship between competition and variability suggests an underlying genetic relationship, the current quantitative genetic models of IGE and inherited variability do not allow for such a relationship. The lack of quantitative genetic models that connect IGEs to inherited variability limits our understanding of the potential of variability to respond to selection, both in nature and agriculture. Models of trait levels, for example, show that IGEs may considerably change heritable variation in trait values. Currently, we lack the tools to investigate whether this result extends to variability of trait values. Here we present a model that integrates IGEs and inherited variability. In this model, the target phenotype, say growth rate, is a function of the genetic and environmental effects of the focal individual and of the difference in trait value between the social partner and the focal individual, multiplied by a regression coefficient. The regression coefficient is a genetic trait, which is a measure of cooperation; a negative value indicates competition, a positive value cooperation, and an increasing value due to selection indicates the evolution of cooperation. In contrast to the existing quantitative genetic models, our model allows for co-evolution of

  2. Coevolution of floodplain and riparian forest dynamics on large, meandering rivers

    Science.gov (United States)

    Stella, J. C.; Riddle, J. D.; Battles, J. J.

    2012-12-01

    On large meandering rivers, riparian forests coevolve with the floodplains that support them. Floodplain characteristics such as local disturbance regime, deposition rates and sediment texture drive plant community dynamics, which in turn feed back to the abiotic processes. We investigated floodplain and riparian forest coevolution along the along the Sacramento River (California, USA), a large, mediterranean-climate river that has been extensively regulated for 70 years, but whose 160-km middle reach (Red Bluff to Colusa) retains some channel mobility and natural forest stands. Guided by maps of floodplain change over time and current vegetation cover, we conducted an extensive forest inventory and chronosequence analysis to quantify how abiotic conditions and forest structural characteristics such as tree density, basal area and biomass vary with floodplain age. We inventoried 285 fixed-area plots distributed across 19 large point bars within vegetation patches ranging in age from 4 to 107 years. Two successional trajectories were evident: (1) shifting species dominance over time within forested areas, from willow to cottonwood to walnut, boxelder and valley oak; and (2) patches of shrub willow (primarily Salix exigua) that maintained dominance throughout time. Sediment accretion was reduced in the persistent willow plots compared to the successional forest stands, suggesting an association between higher flood energy and arrested succession. Forested stands 40-60 years old were the most extensive across the chronosequence in terms of floodplain area, and supported the highest biomass, species diversity, and functional wildlife habitat. These stands were dominated by Fremont cottonwood (Populus fremontii) and reached their maxima in terms of tree size and biomass at age 50 years. The persistent willow stands reached their structural maxima earlier (32 years) and supported lower biomass. Basal area and abundance of large trees decreased in stands >90 years old

  3. Coevolution and hierarchical interactions of Tomato mosaic virus and the resistance gene Tm-1.

    Directory of Open Access Journals (Sweden)

    Kazuhiro Ishibashi

    Full Text Available During antagonistic coevolution between viruses and their hosts, viruses have a major advantage by evolving more rapidly. Nevertheless, viruses and their hosts coexist and have coevolved, although the processes remain largely unknown. We previously identified Tm-1 that confers resistance to Tomato mosaic virus (ToMV, and revealed that it encodes a protein that binds ToMV replication proteins and inhibits RNA replication. Tm-1 was introgressed from a wild tomato species Solanum habrochaites into the cultivated tomato species Solanum lycopersicum. In this study, we analyzed Tm-1 alleles in S. habrochaites. Although most part of this gene was under purifying selection, a cluster of nonsynonymous substitutions in a small region important for inhibitory activity was identified, suggesting that the region is under positive selection. We then examined the resistance of S. habrochaites plants to ToMV. Approximately 60% of 149 individuals from 24 accessions were resistant to ToMV, while the others accumulated detectable levels of coat protein after inoculation. Unexpectedly, many S. habrochaites plants were observed in which even multiplication of the Tm-1-resistance-breaking ToMV mutant LT1 was inhibited. An amino acid change in the positively selected region of the Tm-1 protein was responsible for the inhibition of LT1 multiplication. This amino acid change allowed Tm-1 to bind LT1 replication proteins without losing the ability to bind replication proteins of wild-type ToMV. The antiviral spectra and biochemical properties suggest that Tm-1 has evolved by changing the strengths of its inhibitory activity rather than diversifying the recognition spectra. In the LT1-resistant S. habrochaites plants inoculated with LT1, mutant viruses emerged whose multiplication was not inhibited by the Tm-1 allele that confers resistance to LT1. However, the resistance-breaking mutants were less competitive than the parental strains in the absence of Tm-1. Based on

  4. Studying the co-evolution of production and test code in open source and industrial developer test processes through repository mining

    NARCIS (Netherlands)

    Zaidman, A.; Van Rompaey, B.; Van Deursen, A.; Demeyer, S.

    2010-01-01

    Many software production processes advocate rigorous development testing alongside functional code writing, which implies that both test code and production code should co-evolve. To gain insight in the nature of this co-evolution, this paper proposes three views (realized by a tool called TeMo)

  5. Comparing the co-evolution of production and test code in open source and industrial developer test processes through repository mining

    NARCIS (Netherlands)

    Van Rompaey, B.; Zaidman, A.E.; Van Deursen, A.; Demeyer, S.

    2008-01-01

    This paper represents an extension to our previous work: Mining software repositories to study coevolution of production & test code. Proceedings of the International Conference on Software Testing, Verification, and Validation (ICST), IEEE Computer Society, 2008; doi:10.1109/ICST.2008.47

  6. Coevolution between Hispaniolan crossbills and pine: does more time allow for greater phenotypic escalation at lower latitude?

    Science.gov (United States)

    Parchman, Thomas L; Benkman, Craig W; Mezquida, Eduardo T

    2007-09-01

    Crossbills (Aves: Loxia) and several conifers have coevolved in predator-prey arms races over the last 10,000 years. However, the extent to which coevolutionary arms races have contributed to the adaptive radiation of crossbills or to any other adaptive radiation is largely unknown. Here we extend our previous studies of geographically structured coevolution by considering a crossbill-conifer interaction that has persisted for a much longer time period and involves a conifer with more variable annual seed production. We examined geographic variation in the cone and seed traits of two sister species of pines, Pinus occidentalis and P. cubensis, on the islands of Hispaniola and Cuba, respectively. We also compared the Hispaniolan crossbill (Loxia megaplaga) to its sister taxa the North American white-winged crossbill (Loxia leucoptera leucoptera). The Hispaniolan crossbill is endemic to Hispaniola whereas Cuba lacks crossbills. In addition and in contrast to previous studies, the variation in selection experienced by these pines due to crossbills is not confounded by the occurrence of selection by tree squirrels (Tamiasciurus and Sciurus). As predicted if P. occidentalis has evolved defenses in response to selection exerted by crossbills, cones of P. occidentalis have scales that are 53% thicker than those of P. cubensis. Cones of P. occidentalis, but not P. cubensis, also have well-developed spines, a known defense against vertebrate seed predators. Consistent with patterns of divergence seen in crossbills coevolving locally with other conifers, the Hispaniolan crossbill has evolved a bill that is 25% deeper than the white-winged crossbill. Together with phylogenetic analyses, our results suggest that predator-prey coevolution between Hispaniolan crossbills and P. occidentalis over approximately 600,000 years has caused substantial morphological evolution in both the crossbill and pine. This also indicates that cone crop fluctuations do not prevent crossbills and

  7. The Co-evolution of Bullying Perpetration, Homophobic Teasing, and a School Friendship Network.

    Science.gov (United States)

    Merrin, Gabriel J; Haye, Kayla de la; Espelage, Dorothy L; Ewing, Brett; Tucker, Joan S; Hoover, Matthew; Green, Harold D

    2018-03-01

    Bullying and homophobic teasing behaviors affect the lives of many school aged children, often co-occur, and tend to peak in middle school. While bullying and homophobic teasing behaviors are known to be peer group phenomena, studies typically examine the associations at the individual or school levels. An examination of these behaviors at the peer group level can aid in our understanding of the formation and maintenance of peer groups that engage in these forms of aggressive behavior (selection), and the extent to which friends and the peer group impact individual rates of these aggressive behaviors (influence). In this longitudinal study, we assess the co-evolution of friendship networks, bullying perpetration, and homophobic teasing among middle school students (n = 190) using a Stochastic Actor-Based Model (SABM) for longitudinal networks. Data were collected from 6-8th-grade students (Baseline age 12-15; 53% Female; 47% Male) across three waves of data. The sample was diverse with 58% African American, 31% White, and 11% Hispanic. Since bullying and homophobic teasing behaviors are related yet distinct forms of peer aggression, to capture the unique and combined effects of these behaviors we ran models separately and then together in a competing model. Results indicated that on average individuals with higher rates of bullying perpetration and homophobic teasing were associated with becoming increasingly popular as a friend. However, the effects were not linear, and individuals with the highest rates of bullying perpetration and homophobic teasing were less likely to receive friendship nominations. There was no evidence that bullying perpetration or homophobic teasing were associated with the number of friendship nominations made. Further, there was a preference for individuals to form or maintain friendships with peers who engaged in similar rates of homophobic name-calling; however, this effect was not found for bullying perpetration. Additionally

  8. The Co-evolution of Language and the Brain: A Review of Two Contrastive Views (Pinker & Deacon)

    DEFF Research Database (Denmark)

    Christensen, Ken Ramshøj

    2001-01-01

    in a larger symbolic computational chain controlled by regions in the frontal parts of the brain. To Deacon, a symbolic learning algorithm drives language acquisition. The increase in size of the human brain in relation to the body may be due to a “cognitive arms race”. Both Pinker and Deacon agree......This article is a review of two contrastive views on the co-evolution of language and the brain – The Language Instinct by Steven Pinker (1994) and The Symbolic Species by Terrence Deacon (1997). As language is a trait unique to mankind it can not be equated with nonlinguistic communication – human...... or nonhuman. This points to a special human brain architecture. Pinker’s claim is that certain areas on the left side of the brain constitute a language organ and that language acquisition is instinctual. To Deacon, however, those areas are non-language-specific computational centers. Moreover, they are parts...

  9. Co-evolution of intelligent socio-technical systems modelling and applications in large scale emergency and transport domains

    CERN Document Server

    2013-01-01

    As the interconnectivity between humans through technical devices is becoming ubiquitous, the next step is already in the making: ambient intelligence, i.e. smart (technical) environments, which will eventually play the same active role in communication as the human players, leading to a co-evolution in all domains where real-time communication is essential. This topical volume, based on the findings of the Socionical European research project, gives equal attention to two highly relevant domains of applications: transport, specifically traffic, dynamics from the viewpoint of a socio-technical interaction and evacuation scenarios for large-scale emergency situations. Care was taken to investigate as much as possible the limits of scalability and to combine the modeling using complex systems science approaches with relevant data analysis.

  10. Diversity patterns amongst herbivorous dinosaurs and plants during the Cretaceous: implications for hypotheses of dinosaur/angiosperm co-evolution.

    Science.gov (United States)

    Butler, R J; Barrett, P M; Kenrick, P; Penn, M G

    2009-03-01

    Palaeobiologists frequently attempt to identify examples of co-evolutionary interactions over extended geological timescales. These hypotheses are often intuitively appealing, as co-evolution is so prevalent in extant ecosystems, and are easy to formulate; however, they are much more difficult to test than their modern analogues. Among the more intriguing deep time co-evolutionary scenarios are those that relate changes in Cretaceous dinosaur faunas to the primary radiation of flowering plants. Demonstration of temporal congruence between the diversifications of co-evolving groups is necessary to establish whether co-evolution could have occurred in such cases, but is insufficient to prove whether it actually did take place. Diversity patterns do, however, provide a means for falsifying such hypotheses. We have compiled a new database of Cretaceous dinosaur and plant distributions from information in the primary literature. This is used as the basis for plotting taxonomic diversity and occurrence curves for herbivorous dinosaurs (Sauropodomorpha, Stegosauria, Ankylosauria, Ornithopoda, Ceratopsia, Pachycephalosauria and herbivorous theropods) and major groups of plants (angiosperms, Bennettitales, cycads, cycadophytes, conifers, Filicales and Ginkgoales) that co-occur in dinosaur-bearing formations. Pairwise statistical comparisons were made between various floral and faunal groups to test for any significant similarities in the shapes of their diversity curves through time. We show that, with one possible exception, diversity patterns for major groups of herbivorous dinosaurs are not positively correlated with angiosperm diversity. In other words, at the level of major clades, there is no support for any diffuse co-evolutionary relationship between herbivorous dinosaurs and flowering plants. The diversification of Late Cretaceous pachycephalosaurs (excluding the problematic taxon Stenopelix) shows a positive correlation, but this might be spuriously related to

  11. The aminoacyl-tRNA synthetases had only a marginal role in the origin of the organization of the genetic code: Evidence in favor of the coevolution theory.

    Science.gov (United States)

    Di Giulio, Massimo

    2017-11-07

    The coevolution theory of the origin of the genetic code suggests that the organization of the genetic code coevolved with the biosynthetic relationships between amino acids. The mechanism that allowed this coevolution was based on tRNA-like molecules on which-this theory-would postulate the biosynthetic transformations between amino acids to have occurred. This mechanism makes a prediction on how the role conducted by the aminoacyl-tRNA synthetases (ARSs), in the origin of the genetic code, should have been. Indeed, if the biosynthetic transformations between amino acids occurred on tRNA-like molecules, then there was no need to link amino acids to these molecules because amino acids were already charged on tRNA-like molecules, as the coevolution theory suggests. In spite of the fact that ARSs make the genetic code responsible for the first interaction between a component of nucleic acids and that of proteins, for the coevolution theory the role of ARSs should have been entirely marginal in the genetic code origin. Therefore, I have conducted a further analysis of the distribution of the two classes of ARSs and of their subclasses-in the genetic code table-in order to perform a falsification test of the coevolution theory. Indeed, in the case in which the distribution of ARSs within the genetic code would have been highly significant, then the coevolution theory would be falsified since the mechanism on which it is based would not predict a fundamental role of ARSs in the origin of the genetic code. I found that the statistical significance of the distribution of the two classes of ARSs in the table of the genetic code is low or marginal, whereas that of the subclasses of ARSs statistically significant. However, this is in perfect agreement with the postulates of the coevolution theory. Indeed, the only case of statistical significance-regarding the classes of ARSs-is appreciable for the CAG code, whereas for its complement-the UNN/NUN code-only a marginal

  12. Modeling human-water-systems: towards a comprehensive and spatially distributed assessment of co-evolutions for river basins in Central Europe

    OpenAIRE

    P. Krahe; E. Nilson; M. Knoche; A.-D. Ebner von Eschenbach

    2016-01-01

    In the context of river basin and flood risk management there is a growing need to improve the understanding of and the feedbacks between the driving forces “climate and socio-economy” and water systems. We make use of a variety of data resources to illustrate interrelationships between different constituents of the human-water-systems. Taking water storage for energy production as an example we present a first analysis on the co-evolution of socio-economic and hydrological ...

  13. Phylogenetic placement of an unusual coral mushroom challenges the classic hypothesis of strict coevolution in the apterostigma pilosum group ant-fungus mutualism.

    Science.gov (United States)

    Dentinger, Bryn T M; Lodge, D Jean; Munkacsi, Andrew B; Desjardin, Dennis E; McLaughlin, David J

    2009-08-01

    The approximately 50 million-year-old fungus-farming ant mutualism is a classic example of coevolution, involving ants that subsist on asexual, fungal biomass, in turn propagating the fungus clonally through nest-to-nest transmission. Most mutualistic ants cultivate two closely related groups of gilled mushrooms, whereas one small group of ants in the genus Apterostigma cultivates a distantly related lineage comprised of the G2 and G4 groups. The G2 and G4 fungi were previously shown to form a monophyletic group sister to the thread-like coral mushroom family Pterulaceae. Here, we identify an enigmatic coral mushroom that produces both fertile and sterile fruiting structures as the closest free-living relative of the G4 fungi, challenging the monophyly of the Apterostigma-cultivated fungi for the first time. Both nonparametric bootstrap and Bayesian posterior probability support the node leading to the G4 cultivars and a free-living Pterula mushroom. These data suggest three scenarios that contradict the hypothesis of strict coevolution: (1) multiple domestications, (2) escape from domestication, (3) selection of single cultivar lineages from an ancestral mixed-fungus garden. These results illustrate how incomplete phylogenies for coevolved symbionts impede our understanding of the patterns and processes of coevolution.

  14. Insights into recent and ancient trends in the co-evolution of Earth and life as revealed by microbial genomics

    Science.gov (United States)

    Anderson, R. E.; Huber, J. A.; Parsons, C.; Stüeken, E.

    2017-12-01

    Since the origin of life over 4 billion years ago, life has fundamentally altered the habitability of Earth. Similarly, the environment molds the evolutionary trajectory of life itself through natural selection. Microbial genomes retain a "memory" of the co-evolution of life and Earth and can be analyzed to better understand trends and events in both the recent and distant past. To examine evolutionary trends in the more recent past, we have used metagenomics analyses to investigate which environmental factors play the strongest role in driving the evolution of microbes in deep-sea hydrothermal vents, which are thought to have been important habitats in the earliest stages of life's evolution. We have shown that microbial populations in a deep, basalt-hosted system appear to be under stronger purifying selection than populations inhabiting a cooler serpentinizing system less than 20 km away, suggesting that environmental context and geochemistry have an important impact on evolutionary rates and trends. We also found evidence that viruses play an important role in driving evolution in these habitats. Changing environmental conditions may also effect long-term evolutionary trends in Earth's distant past, as revealed by comparative genomics. By reconciling phylogenetic trees for microbial species with trees of metabolic genes, we can determine approximately when crucial metabolic genes began to spread across the tree of life through horizontal gene transfer. Using these methods, we conducted an analysis of the relative timing of the spread of genes related to the nitrogen cycle. Our results indicate that the rate of horizontal gene transfer for important genes related to denitrification increased after the Great Oxidation Event, concurrent with geochemical evidence for increasing availability of nitrate, suggesting that the oxygenation of the atmosphere and surface ocean may have been an important determining factor for the spread of denitrification genes across the

  15. Mesozoic fossils (>145 Mya suggest the antiquity of the subgenera of Daphnia and their coevolution with chaoborid predators

    Directory of Open Access Journals (Sweden)

    Taylor Derek J

    2011-05-01

    Full Text Available Abstract Background The timescale of the origins of Daphnia O. F. Mueller (Crustacea: Cladocera remains controversial. The origin of the two main subgenera has been associated with the breakup of the supercontinent Pangaea. This vicariance hypothesis is supported by reciprocal monophyly, present day associations with the former Gondwanaland and Laurasia regions, and mitochondrial DNA divergence estimates. However, previous multilocus nuclear DNA sequence divergence estimates at Daphnia. Results We describe new fossils of ephippia from the Khotont site in Mongolia associated with the Jurassic-Cretaceous boundary (about 145 MYA that are morphologically similar to several modern genera of the family Daphniidae, including the two major subgenera of Daphnia, i.e., Daphnia s. str. and Ctenodaphnia. The daphniid fossils co-occurred with fossils of the predaceous phantom midge (Chaoboridae. Conclusions Our findings indicate that the main subgenera of Daphnia are likely much older than previously known from fossils (at least 100 MY older or from nuclear DNA estimates of divergence. The results showing co-occurrence of the main subgenera far from the presumed Laurasia/Gondwanaland dispersal barrier shortly after formation suggests that vicariance from the breakup of Pangaea is an unlikely explanation for the origin of the main subgenera. The fossil impressions also reveal that the coevolution of a dipteran predator (Chaoboridae with the subgenus Daphnia is much older than previously known -- since the Mesozoic.

  16. Mesozoic fossils (>145 Mya) suggest the antiquity of the subgenera of Daphnia and their coevolution with chaoborid predators.

    Science.gov (United States)

    Kotov, Alexey A; Taylor, Derek J

    2011-05-19

    The timescale of the origins of Daphnia O. F. Mueller (Crustacea: Cladocera) remains controversial. The origin of the two main subgenera has been associated with the breakup of the supercontinent Pangaea. This vicariance hypothesis is supported by reciprocal monophyly, present day associations with the former Gondwanaland and Laurasia regions, and mitochondrial DNA divergence estimates. However, previous multilocus nuclear DNA sequence divergence estimates at Pangaea. We examined new and existing cladoceran fossils from a Mesozoic Mongolian site, in hopes of gaining insights into the timescale of the evolution of Daphnia. We describe new fossils of ephippia from the Khotont site in Mongolia associated with the Jurassic-Cretaceous boundary (about 145 MYA) that are morphologically similar to several modern genera of the family Daphniidae, including the two major subgenera of Daphnia, i.e., Daphnia s. str. and Ctenodaphnia. The daphniid fossils co-occurred with fossils of the predaceous phantom midge (Chaoboridae). Our findings indicate that the main subgenera of Daphnia are likely much older than previously known from fossils (at least 100 MY older) or from nuclear DNA estimates of divergence. The results showing co-occurrence of the main subgenera far from the presumed Laurasia/Gondwanaland dispersal barrier shortly after formation suggests that vicariance from the breakup of Pangaea is an unlikely explanation for the origin of the main subgenera. The fossil impressions also reveal that the coevolution of a dipteran predator (Chaoboridae) with the subgenus Daphnia is much older than previously known -- since the Mesozoic.

  17. Replicated population divergence caused by localized coevolution? A test of three hypotheses in the red crossbill-lodgepole pine system.

    Science.gov (United States)

    Edelaar, P; Benkman, C W

    2006-09-01

    Several lines of evidence support the hypothesis that local populations of red crossbills (Loxia curvirostra complex) enter into a predator-prey arms race with lodgepole pine (Pinus contorta latifolia) in the absence of competing pine squirrels (Tamiasciurus hudsonicus). Nevertheless, the alternative hypotheses that neutral evolution or factors other than squirrels have caused crossbill population differentiation have not been thoroughly tested. We compared crossbill and pine cone morphology between island populations where squirrels are absent or present, and mainland sites where squirrels are present, in order to distinguish among these hypotheses. All comparisons supported an effect of squirrel absence, not island status, on crossbill and cone morphology. Hence our results provide further evidence that strong localized coevolutionary interactions in a geographic mosaic have driven adaptive population differentiation. In addition, vocal differentiation of crossbills was related to the absence of squirrels, but not to island status. As morphological and vocal differentiation is correlated with reproductive isolation in crossbills, the geographic mosaic of coevolution also seems to promote ecological speciation.

  18. The RNA-world and co-evolution hypothesis and the origin of life: Implications, research strategies and perspectives

    Science.gov (United States)

    Lahav, Noam

    1993-01-01

    The applicability of the RNA-world and co-evolution hypothesis to the study of the very first stages of the origin of life is discussed. The discussion focuses on the basic differences between the two hypotheses and their implications, with regard to the reconstruction methodology, ribosome emergence, balance between ribozymes and protein enzymes, and their major difficultites. Additional complexities of the two hypotheses, such as membranes and the energy source of the first reactions, are not treated in the present work. A central element in the proposed experimental strategies is the study of the catalytic activites of very small peptides and RNA-like oligomers, according to existing, as well as to yet-to-be-invented scenarios of the two hypothesis under consideration. It is suggested that the novel directed molecular evolution technology, and molecular computational modeling, can be applied to this research. This strategy is assumed to be essential for the suggested goal of future studies of the origin of life, namely, the establishment of a `Primordial Darwinian entity'.

  19. The RNA-world and co-evolution hypotheses and the origin of life: Implications, research strategies and perspectives

    Science.gov (United States)

    Lahav, Noam

    1993-12-01

    The applicability of the RNA-world and co-evolution hypotheses to the study of the very first stages of the origin of life is discussed. The discussion focuses on the basic differences between the two hypotheses and their implications, with regard to the reconstruction methodology, ribosome emergence, balance between ribozymes and protein enzymes, and their major difficulties. Additional complexities of the two hypotheses, such as membranes and the energy source of the first reactions, are not treated in the present work. A central element in the proposed experimental strategies is the study of the catalytic activities of very small peptides and RNA-like oligomers, according to existing, as well as to yet-to-be-invented scenarios of the two hypotheses under consideration. It is suggested that the noveldirected molecular evolution technology, andmolecular computational modeling, can be applied to this research. This strategy is assumed to be essential for the suggested goal of future studies of the origin of life, namely, the establishment of a ‘Primordial Darwinian entity’.

  20. Co-Evolution and Bio-Social Construction: The Kichwa Agroforestry Systems (Chakras in the Ecuadorian Amazonia

    Directory of Open Access Journals (Sweden)

    Daniel Coq-Huelva

    2017-10-01

    Full Text Available Polycultured agrarian systems in Ecuadorian Amazonia (also called chakras or swollen gardens are characterised by a market-oriented crop for the generation of monetary income, for example, cocoa, other agricultural products (e.g., banana and cassava, and livestock for family farm consumption. Moreover, a chakra is an outstanding example of agroforestry production, in which ecological, social and economic elements co-evolve from a set of close and strong connections. In this context, the conservation and transformation of their biological subsystems can be understood as the result of complex interactions between anthropogenic and non-anthropogenic factors. In turn, such interactions are essential to provide food and monetary income to the indigenous community. Relevant agency capabilities exist that could cause an agroforestry system to take a different path of co-evolution, that is, towards greater or lesser sustainability associated with different levels of complexity. In conclusion, chakras have key ecological features that can mitigate the impact of human population growth in Amazonia. Additionally, chakras have their own processes of social self-regulation which enhance the possibilities of adaptation of Kichwa communities to changing environmental conditions, being essential elements in local food sovereignty, equitable gender relations and the respect of ancestral wisdom.

  1. Adaptive co-evolution of strategies and network leading to optimal cooperation level in spatial prisoner's dilemma game

    International Nuclear Information System (INIS)

    Han-Shuang, Chen; Zhong-Huai, Hou; Hou-Wen, Xin; Ji-Qian, Zhang

    2010-01-01

    We study evolutionary prisoner's dilemma game on adaptive networks where a population of players co-evolves with their interaction networks. During the co-evolution process, interacted players with opposite strategies either rewire the link between them with probability p or update their strategies with probability 1 – p depending on their payoffs. Numerical simulation shows that the final network is either split into some disconnected communities whose players share the same strategy within each community or forms a single connected network in which all nodes are in the same strategy. Interestingly, the density of cooperators in the final state can be maximised in an intermediate range of p via the competition between time scale of the network dynamics and that of the node dynamics. Finally, the mean-field analysis helps to understand the results of numerical simulation. Our results may provide some insight into understanding the emergence of cooperation in the real situation where the individuals' behaviour and their relationship adaptively co-evolve. (general)

  2. Differential susceptibility to plasticity: a 'missing link' between gene-culture co-evolution and neuropsychiatric spectrum disorders?

    Directory of Open Access Journals (Sweden)

    Wurzman Rachel

    2012-04-01

    Full Text Available Abstract Brüne's proposal that erstwhile 'vulnerability' genes need to be reconsidered as 'plasticity' genes, given the potential for certain environments to yield increased positive function in the same domain as potential dysfunction, has implications for psychiatric nosology as well as a more dynamic understanding of the relationship between genes and culture. In addition to validating neuropsychiatric spectrum disorder nosologies by calling for similar methodological shifts in gene-environment-interaction studies, Brüne's position elevates the importance of environmental contexts - inclusive of socio-cultural variables - as mechanisms that contribute to clinical presentation. We assert that when models of susceptibility to plasticity and neuropsychiatric spectrum disorders are concomitantly considered, a new line of inquiry emerges into the co-evolution and co-determination of socio-cultural contexts and endophenotypes. This presents potentially unique opportunities, benefits, challenges, and responsibilities for research and practice in psychiatry. Please see related manuscript: http://www.biomedcentral.com/1741-7015/10/38

  3. Quasi-biweekly oscillations of the South Asian monsoon and its co-evolution in the upper and lower troposphere

    Science.gov (United States)

    Ortega, Sebastián; Webster, Peter J.; Toma, Violeta; Chang, Hai-Ru

    2017-11-01

    The Upper Tropospheric Quasi-Biweekly Oscillation (UQBW) of the South Asian monsoon is studied using the potential vorticity field on the 370 K isentrope. The UQBW is shown to be a common occurrence in the upper troposphere during the monsoon, and its typical evolution is described. We suggest that the UQBW is a phenomenon of both the middle and tropical latitudes, owing its existence to the presence of the planetary-scale upper-tropospheric monsoon anticyclone. The UQBW is first identified as Rossby waves originating in the northern flank of the monsoon anticyclone. These Rossby waves break when reaching the Pacific Ocean, and their associated cyclonic PV anomalies move southward to the east of Asia and then westward across the Indian Ocean and Africa advected by the monsoon anticyclone. A strong correlation, or co-evolution, between the UQBW and quasi-biweekly oscillations in the lower troposphere (QBW) is also found. In particular, analysis of vertically-integrated horizontal moisture transport, 850 hPa geopotential, and outgoing long-wave radiation show that the UQBW is usually observed at the same time as, and co-evolves with, the lower tropospheric QBW over South Asia. We discuss the nature of the UQBW, and its possible physical link with the QBW.

  4. Germ warfare in a microbial mat community: CRISPRs provide insights into the co-evolution of host and viral genomes.

    Directory of Open Access Journals (Sweden)

    John F Heidelberg

    Full Text Available CRISPR arrays and associated cas genes are widespread in bacteria and archaea and confer acquired resistance to viruses. To examine viral immunity in the context of naturally evolving microbial populations we analyzed genomic data from two thermophilic Synechococcus isolates (Syn OS-A and Syn OS-B' as well as a prokaryotic metagenome and viral metagenome derived from microbial mats in hotsprings at Yellowstone National Park. Two distinct CRISPR types, distinguished by the repeat sequence, are found in both the Syn OS-A and Syn OS-B' genomes. The genome of Syn OS-A contains a third CRISPR type with a distinct repeat sequence, which is not found in Syn OS-B', but appears to be shared with other microorganisms that inhabit the mat. The CRISPR repeats identified in the microbial metagenome are highly conserved, while the spacer sequences (hereafter referred to as "viritopes" to emphasize their critical role in viral immunity were mostly unique and had no high identity matches when searched against GenBank. Searching the viritopes against the viral metagenome, however, yielded several matches with high similarity some of which were within a gene identified as a likely viral lysozyme/lysin protein. Analysis of viral metagenome sequences corresponding to this lysozyme/lysin protein revealed several mutations all of which translate into silent or conservative mutations which are unlikely to affect protein function, but may help the virus evade the host CRISPR resistance mechanism. These results demonstrate the varied challenges presented by a natural virus population, and support the notion that the CRISPR/viritope system must be able to adapt quickly to provide host immunity. The ability of metagenomics to track population-level variation in viritope sequences allows for a culture-independent method for evaluating the fast co-evolution of host and viral genomes and its consequence on the structuring of complex microbial communities.

  5. Distinct co-evolution patterns of genes associated to DNA polymerase III DnaE and PolC

    Directory of Open Access Journals (Sweden)

    Engelen Stefan

    2012-02-01

    Full Text Available Abstract Background Bacterial genomes displaying a strong bias between the leading and the lagging strand of DNA replication encode two DNA polymerases III, DnaE and PolC, rather than a single one. Replication is a highly unsymmetrical process, and the presence of two polymerases is therefore not unexpected. Using comparative genomics, we explored whether other processes have evolved in parallel with each polymerase. Results Extending previous in silico heuristics for the analysis of gene co-evolution, we analyzed the function of genes clustering with dnaE and polC. Clusters were highly informative. DnaE co-evolves with the ribosome, the transcription machinery, the core of intermediary metabolism enzymes. It is also connected to the energy-saving enzyme necessary for RNA degradation, polynucleotide phosphorylase. Most of the proteins of this co-evolving set belong to the persistent set in bacterial proteomes, that is fairly ubiquitously distributed. In contrast, PolC co-evolves with RNA degradation enzymes that are present only in the A+T-rich Firmicutes clade, suggesting at least two origins for the degradosome. Conclusion DNA replication involves two machineries, DnaE and PolC. DnaE co-evolves with the core functions of bacterial life. In contrast PolC co-evolves with a set of RNA degradation enzymes that does not derive from the degradosome identified in gamma-Proteobacteria. This suggests that at least two independent RNA degradation pathways existed in the progenote community at the end of the RNA genome world.

  6. Conflict RNA modification, host-parasite co-evolution, and the origins of DNA and DNA-binding proteins1.

    Science.gov (United States)

    McLaughlin, Paul J; Keegan, Liam P

    2014-08-01

    Nearly 150 different enzymatically modified forms of the four canonical residues in RNA have been identified. For instance, enzymes of the ADAR (adenosine deaminase acting on RNA) family convert adenosine residues into inosine in cellular dsRNAs. Recent findings show that DNA endonuclease V enzymes have undergone an evolutionary transition from cleaving 3' to deoxyinosine in DNA and ssDNA to cleaving 3' to inosine in dsRNA and ssRNA in humans. Recent work on dsRNA-binding domains of ADARs and other proteins also shows that a degree of sequence specificity is achieved by direct readout in the minor groove. However, the level of sequence specificity observed is much less than that of DNA major groove-binding helix-turn-helix proteins. We suggest that the evolution of DNA-binding proteins following the RNA to DNA genome transition represents the major advantage that DNA genomes have over RNA genomes. We propose that a hypothetical RNA modification, a RRAR (ribose reductase acting on genomic dsRNA) produced the first stretches of DNA in RNA genomes. We discuss why this is the most satisfactory explanation for the origin of DNA. The evolution of this RNA modification and later steps to DNA genomes are likely to have been driven by cellular genome co-evolution with viruses and intragenomic parasites. RNA modifications continue to be involved in host-virus conflicts; in vertebrates, edited cellular dsRNAs with inosine-uracil base pairs appear to be recognized as self RNA and to suppress activation of innate immune sensors that detect viral dsRNA.

  7. The co-evolution of microstructure features in self-ion irradiated HT9 at very high damage levels

    Energy Technology Data Exchange (ETDEWEB)

    Getto, E., E-mail: getto@usna.edu [Department of Mechanical Engineering, United States Naval Academy, Annapolis, MD, 21402 (United States); Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI, 48109 (United States); Vancoevering, G.; Was, G.S. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI, 48109 (United States)

    2017-02-15

    Understanding the void swelling and phase evolution of reactor structural materials at very high damage levels is essential to maintaining safety and longevity of components in Gen IV fast reactors. A combination of ion irradiation and modeling was utilized to understand the microstructure evolution of ferritic-martensitic alloy HT9 at high dpa. Self-ion irradiation experiments were performed on alloy HT9 to determine the co-evolution of voids, dislocations and precipitates up to 650 dpa at 460 °C. Modeling of microstructure evolution was conducted using the modified Radiation Induced Microstructure Evolution (RIME) model, which utilizes a mean field rate theory approach with grouped cluster dynamics. Irradiations were performed with 5 MeV raster-scanned Fe{sup 2+} ions on samples pre-implanted with 10 atom parts per million He. The swelling, dislocation and precipitate evolution at very high dpa was determined using Analytical Electron Microscopy in Scanning Transmission Electron Microscopy (STEM) mode. Experimental results were then interpreted using the RIME model. A microstructure consisting only of dislocations and voids is insufficient to account for the swelling evolution observed experimentally at high damage levels in a complicated microstructure such as irradiated alloy HT9. G phase was found to have a minimal effect on either void or dislocation evolution. M{sub 2}X played two roles; a variable biased sink for defects, and as a vehicle for removal of carbon from solution, thus promoting void growth. When accounting for all microstructure interactions, swelling at high damage levels is a dynamic process that continues to respond to other changes in the microstructure as long as they occur.

  8. The E-MOSAICS project: simulating the formation and co-evolution of galaxies and their star cluster populations

    Science.gov (United States)

    Pfeffer, Joel; Kruijssen, J. M. Diederik; Crain, Robert A.; Bastian, Nate

    2018-04-01

    We introduce the MOdelling Star cluster population Assembly In Cosmological Simulations within EAGLE (E-MOSAICS) project. E-MOSAICS incorporates models describing the formation, evolution, and disruption of star clusters into the EAGLE galaxy formation simulations, enabling the examination of the co-evolution of star clusters and their host galaxies in a fully cosmological context. A fraction of the star formation rate of dense gas is assumed to yield a cluster population; this fraction and the population's initial properties are governed by the physical properties of the natal gas. The subsequent evolution and disruption of the entire cluster population are followed accounting for two-body relaxation, stellar evolution, and gravitational shocks induced by the local tidal field. This introductory paper presents a detailed description of the model and initial results from a suite of 10 simulations of ˜L⋆ galaxies with disc-like morphologies at z = 0. The simulations broadly reproduce key observed characteristics of young star clusters and globular clusters (GCs), without invoking separate formation mechanisms for each population. The simulated GCs are the surviving population of massive clusters formed at early epochs (z ≳ 1-2), when the characteristic pressures and surface densities of star-forming gas were significantly higher than observed in local galaxies. We examine the influence of the star formation and assembly histories of galaxies on their cluster populations, finding that (at similar present-day mass) earlier-forming galaxies foster a more massive and disruption-resilient cluster population, while galaxies with late mergers are capable of forming massive clusters even at late cosmic epochs. We find that the phenomenological treatment of interstellar gas in EAGLE precludes the accurate modelling of cluster disruption in low-density environments, but infer that simulations incorporating an explicitly modelled cold interstellar gas phase will overcome

  9. Potential arms race in the coevolution of primates and angiosperms: brazzein sweet proteins and gorilla taste receptors.

    Science.gov (United States)

    Guevara, Elaine E; Veilleux, Carrie C; Saltonstall, Kristin; Caccone, Adalgisa; Mundy, Nicholas I; Bradley, Brenda J

    2016-09-01

    We explored whether variation in the sweet taste receptor protein T1R3 in primates could contribute to differences in sweet taste repertoire among species, potentially reflecting coevolution with local plants. Specifically, we examined which primates are likely to be sweet "tasters" of brazzein, a protein found in the fruit of the African plant Pentadiplandra brazzeana that tastes intensely sweet to humans, but provides little energy. Sweet proteins like brazzein are thought to mimic the taste of sugars to entice seed dispersers. We examined the evolution of T1R3 and assessed whether primates are likely "deceived" by such biochemical mimicry. Using published and new sequence data for TAS1R3, we characterized 57 primates and other mammals at the two amino acid sites necessary to taste brazzein to determine which species are tasters. We further used dN/dS-based methods to look for statistical evidence of accelerated evolution in this protein across primate lineages. The taster genotype is shared across most catarrhines, suggesting that most African primates can be "tricked" into eating and dispersing P. brazzeana's seeds for little caloric gain. Western gorillas (Gorilla gorilla), however, exhibit derived mutations at the two brazzein-critical positions, and although fruit is a substantial portion of the western gorilla diet, they have not been observed to eat P. brazzeana. Our analyses of protein evolution found no signature of positive selection on TAS1R3 along the gorilla lineage. We propose that the gorilla-specific mutations at the TAS1R3 locus encoding T1R3 could be a counter-adaptation to the false sweet signal of brazzein. © 2016 Wiley Periodicals, Inc.

  10. Gene loss, adaptive evolution and the co-evolution of plumage coloration genes with opsins in birds.

    Science.gov (United States)

    Borges, Rui; Khan, Imran; Johnson, Warren E; Gilbert, M Thomas P; Zhang, Guojie; Jarvis, Erich D; O'Brien, Stephen J; Antunes, Agostinho

    2015-10-06

    The wide range of complex photic systems observed in birds exemplifies one of their key evolutionary adaptions, a well-developed visual system. However, genomic approaches have yet to be used to disentangle the evolutionary mechanisms that govern evolution of avian visual systems. We performed comparative genomic analyses across 48 avian genomes that span extant bird phylogenetic diversity to assess evolutionary changes in the 17 representatives of the opsin gene family and five plumage coloration genes. Our analyses suggest modern birds have maintained a repertoire of up to 15 opsins. Synteny analyses indicate that PARA and PARIE pineal opsins were lost, probably in conjunction with the degeneration of the parietal organ. Eleven of the 15 avian opsins evolved in a non-neutral pattern, confirming the adaptive importance of vision in birds. Visual conopsins sw1, sw2 and lw evolved under negative selection, while the dim-light RH1 photopigment diversified. The evolutionary patterns of sw1 and of violet/ultraviolet sensitivity in birds suggest that avian ancestors had violet-sensitive vision. Additionally, we demonstrate an adaptive association between the RH2 opsin and the MC1R plumage color gene, suggesting that plumage coloration has been photic mediated. At the intra-avian level we observed some unique adaptive patterns. For example, barn owl showed early signs of pseudogenization in RH2, perhaps in response to nocturnal behavior, and penguins had amino acid deletions in RH2 sites responsible for the red shift and retinal binding. These patterns in the barn owl and penguins were convergent with adaptive strategies in nocturnal and aquatic mammals, respectively. We conclude that birds have evolved diverse opsin adaptations through gene loss, adaptive selection and coevolution with plumage coloration, and that differentiated selective patterns at the species level suggest novel photic pressures to influence evolutionary patterns of more-recent lineages.

  11. Microbes, Mineral Evolution, and the Rise of Microcontinents-Origin and Coevolution of Life with Early Earth.

    Science.gov (United States)

    Grosch, Eugene G; Hazen, Robert M

    2015-10-01

    Earth is the most mineralogically diverse planet in our solar system, the direct consequence of a coevolving geosphere and biosphere. We consider the possibility that a microbial biosphere originated and thrived in the early Hadean-Archean Earth subseafloor environment, with fundamental consequences for the complex evolution and habitability of our planet. In this hypothesis paper, we explore possible venues for the origin of life and the direct consequences of microbially mediated, low-temperature hydrothermal alteration of the early oceanic lithosphere. We hypothesize that subsurface fluid-rock-microbe interactions resulted in more efficient hydration of the early oceanic crust, which in turn promoted bulk melting to produce the first evolved fragments of felsic crust. These evolved magmas most likely included sialic or tonalitic sheets, felsic volcaniclastics, and minor rhyolitic intrusions emplaced in an Iceland-type extensional setting as the earliest microcontinents. With the further development of proto-tectonic processes, these buoyant felsic crustal fragments formed the nucleus of intra-oceanic tonalite-trondhjemite-granitoid (TTG) island arcs. Thus microbes, by facilitating extensive hydrothermal alteration of the earliest oceanic crust through bioalteration, promoted mineral diversification and may have been early architects of surface environments and microcontinents on young Earth. We explore how the possible onset of subseafloor fluid-rock-microbe interactions on early Earth accelerated metavolcanic clay mineral formation, crustal melting, and subsequent metamorphic mineral evolution. We also consider environmental factors supporting this earliest step in geosphere-biosphere coevolution and the implications for habitability and mineral evolution on other rocky planets, such as Mars.

  12. Invasion fitness for gene-culture co-evolution in family-structured populations and an application to cumulative culture under vertical transmission.

    Science.gov (United States)

    Mullon, Charles; Lehmann, Laurent

    2017-08-01

    Human evolution depends on the co-evolution between genetically determined behaviors and socially transmitted information. Although vertical transmission of cultural information from parent to offspring is common in hominins, its effects on cumulative cultural evolution are not fully understood. Here, we investigate gene-culture co-evolution in a family-structured population by studying the invasion fitness of a mutant allele that influences a deterministic level of cultural information (e.g., amount of knowledge or skill) to which diploid carriers of the mutant are exposed in subsequent generations. We show that the selection gradient on such a mutant, and the concomitant level of cultural information it generates, can be evaluated analytically under the assumption that the cultural dynamic has a single attractor point, thereby making gene-culture co-evolution in family-structured populations with multigenerational effects mathematically tractable. We apply our result to study how genetically determined phenotypes of individual and social learning co-evolve with the level of adaptive information they generate under vertical transmission. We find that vertical transmission increases adaptive information due to kin selection effects, but when information is transmitted as efficiently between family members as between unrelated individuals, this increase is moderate in diploids. By contrast, we show that the way resource allocation into learning trades off with allocation into reproduction (the "learning-reproduction trade-off") significantly influences levels of adaptive information. We also show that vertical transmission prevents evolutionary branching and may therefore play a qualitative role in gene-culture co-evolutionary dynamics. More generally, our analysis of selection suggests that vertical transmission can significantly increase levels of adaptive information under the biologically plausible condition that information transmission between relatives is

  13. The role of insulin C-peptide in the coevolution analyses of the insulin signaling pathway: a hint for its functions.

    Directory of Open Access Journals (Sweden)

    Shuai Wang

    Full Text Available As the linker between the A chain and B chain of proinsulin, C-peptide displays high variability in length and amino acid composition, and has been considered as an inert byproduct of insulin synthesis and processing for many years. Recent studies have suggested that C-peptide can act as a bioactive hormone, exerting various biological effects on the pathophysiology and treatment of diabetes. In this study, we analyzed the coevolution of insulin molecules among vertebrates, aiming at exploring the evolutionary characteristics of insulin molecule, especially the C-peptide. We also calculated the correlations of evolutionary rates between the insulin and the insulin receptor (IR sequences as well as the domain-domain pairs of the ligand and receptor by the mirrortree method. The results revealed distinctive features of C-peptide in insulin intramolecular coevolution and correlated residue substitutions, which partly supported the idea that C-peptide can act as a bioactive hormone, with significant sequence features, as well as a linker assisting the formation of mature insulin during synthesis. Interestingly, the evolution of C-peptide exerted the highest correlation with that of the insulin receptor and its ligand binding domain (LBD, implying a potential relationship with the insulin signaling pathway.

  14. The co-evolution of microstructure features in self-ion irradiated HT9 at very high damage levels

    Science.gov (United States)

    Getto, Elizabeth Margaret

    The objective of this study was to understand the co-evolution of microstructure features in self-ion irradiated HT9 at very high damage levels. HT9 (heat 84425) was pre-implanted with 10 atom parts per million helium and then irradiated with 5 MeV Fe++ in the temperature range of 440-480°C to 188 dpa. A damage dependence study from 75 to 650 dpa was performed at the peak swelling temperature of 460°C. The swelling, dislocation and precipitate evolution was determined using Analytic Electron Microscopes in both Conventional Transmission electron microscopy (CTEM) and Scanning Transmission Electron Microscopy (STEM) modes. Void swelling reached a nominally linear rate of 0.03%/dpa from 188 to 650 dpa at 460°C. G phase precipitates were observed by 75 dpa and grew linearly up to 650 dpa. M 2X was observed by 250 dpa and peaked in volume fraction at 450 dpa. Dislocation loop evolution was observed up to 650 dpa including a step change in diameter between 375 and 450 dpa; which correlated with nucleation and growth of M2X. The experimental results were interpreted using a rate theory model, the Radiation Induced Microstructure Evolution (RIME), in the damage range from 188 to 650 dpa. A simple system of voids and dislocations was modeled in which the dislocations measured from experiment were used as input, or the dislocations were allowed to evolve dynamically, resulting in swelling that was overestimated by 63% relative to that observed experimentally. G phase had limited effect on the void or dislocation behavior. The behavior of M2X within the microstructure was characterized as a direct effect as a coherent sink, and as an indirect effect in consuming carbon from the matrix, which had the largest impact on both void and dislocation behavior. A slowly monotonically increasing swelling rate was observed both experimentally and computationally, with swelling rates of ˜0.025%/dpa and ˜0.036%/dpa before and after 450 dpa. The agreement in void behavior between

  15. Climate-vegetation-soil interactions and long-term hydrologic partitioning: signatures of catchment co-evolution

    Directory of Open Access Journals (Sweden)

    P. A. Troch

    2013-06-01

    subsurface storage release time scales produce significantly more E/P. Vegetation in these catchments have longer access to this additional groundwater source and thus are less prone to water stress. Further analysis reveals that climates that give rise to more (less E/P are associated with catchments that have vegetation with less (more efficient water use parameters. In particular, the climates with tendency to produce more E/P have catchments that have lower % root fraction and less light use efficiency. Our results suggest that their exists strong interactions between climate, vegetation and soil properties that lead to specific hydrologic partitioning at the catchment scale. This co-evolution of catchment vegetation and soils with climate needs to be further explored to improve our capabilities to predict hydrologic partitioning in ungauged basins.

  16. Co-evolution of technology and society: The multi-level perspective and a case study, the transition in water supply and personal hygiene in the Netherlands (1850-1930)

    NARCIS (Netherlands)

    Geels, F.W.

    2005-01-01

    This article deals with the systems level in Freeman and Perez's innovation typology (incremental, radical, system, techno-economic paradigm). Transitions at this level are understood as changes from one socio-technical system to another, involving co-evolution of technology and society. To

  17. Co-Evolution.

    Science.gov (United States)

    McGhee, Robert

    2002-01-01

    Discusses the role of techniques of DNA analysis in assessing the genetic relationships between various species. Focuses on wolf-dog evolution using DNA evidence and historical data about human/wolf-dog relationships. (DDR)

  18. Global Operations Coevolution

    DEFF Research Database (Denmark)

    Slepniov, Dmitrij; Wæhrens, Brian Vejrum; Gubi, Ebbe

    2013-01-01

    Companies are actively seeking competitive advantage through their choice of location and ownership of operations. The purpose of this chapter is to uncover hidden effects of this development and propose how companies can respond to them. The chapter draws on a case study of a Danish industrial e...... of analysis and involving temporal adaptations. In terms of managerial implications, the study provides managers with lessons for designing a robust system of globally dispersed operations.......Companies are actively seeking competitive advantage through their choice of location and ownership of operations. The purpose of this chapter is to uncover hidden effects of this development and propose how companies can respond to them. The chapter draws on a case study of a Danish industrial...... equipment firm and describes how its operations configuration has been changing over time. The chapter identifies the key determinants of this change and uncovers some of its hidden effects. The chapter closes with propositions for how to respond to these effects through the development of a distinct...

  19. Modeling human-water-systems: towards a comprehensive and spatially distributed assessment of co-evolutions for river basins in Central Europe

    Directory of Open Access Journals (Sweden)

    P. Krahe

    2016-05-01

    Full Text Available In the context of river basin and flood risk management there is a growing need to improve the understanding of and the feedbacks between the driving forces “climate and socio-economy” and water systems. We make use of a variety of data resources to illustrate interrelationships between different constituents of the human-water-systems. Taking water storage for energy production as an example we present a first analysis on the co-evolution of socio-economic and hydrological indicators. The findings will serve as for the development of conceptual, but fully coupled socio-hydrological models for selected sectors and regions. These models will be used to generate integrated scenarios of the climate and socio-economic change.

  20. A conceptual socio-hydrological model of the co-evolution of humans and water: case study of the Tarim River basin, western China

    Science.gov (United States)

    Liu, D.; Tian, F.; Lin, M.; Sivapalan, M.

    2015-02-01

    The complex interactions and feedbacks between humans and water are critically important issues but remain poorly understood in the newly proposed discipline of socio-hydrology (Sivapalan et al., 2012). An exploratory model with the appropriate level of simplification can be valuable for improving our understanding of the co-evolution and self-organization of socio-hydrological systems driven by interactions and feedbacks operating at different scales. In this study, a simplified conceptual socio-hydrological model based on logistic growth curves is developed for the Tarim River basin in western China and is used to illustrate the explanatory power of such a co-evolutionary model. The study area is the main stream of the Tarim River, which is divided into two modeling units. The socio-hydrological system is composed of four sub-systems, i.e., the hydrological, ecological, economic, and social sub-systems. In each modeling unit, the hydrological equation focusing on water balance is coupled to the other three evolutionary equations to represent the dynamics of the social sub-system (denoted by population), the economic sub-system (denoted by irrigated crop area ratio), and the ecological sub-system (denoted by natural vegetation cover), each of which is expressed in terms of a logistic growth curve. Four feedback loops are identified to represent the complex interactions among different sub-systems and different spatial units, of which two are inner loops occurring within each separate unit and the other two are outer loops linking the two modeling units. The feedback mechanisms are incorporated into the constitutive relations for model parameters, i.e., the colonization and mortality rates in the logistic growth curves that are jointly determined by the state variables of all sub-systems. The co-evolution of the Tarim socio-hydrological system is then analyzed with this conceptual model to gain insights into the overall system dynamics and its sensitivity to the

  1. Reciprocal interactions between fluvial processes and riparian plants at multiple scales: ecogeomorphic feedbacks drive coevolution of floodplain morphology and vegetation communities

    Science.gov (United States)

    Stella, J. C.; Kui, L.; Diehl, R. M.; Bywater-Reyes, S.; Wilcox, A. C.; Shafroth, P. B.; Lightbody, A.

    2017-12-01

    Fluvial forces interact with woody riparian plants in complex ways to influence the coevolution of river morphology and floodplain plant communities. Here, we report on an integrated suite of multi-disciplinary studies that contrast the responses of plants with different morphologies, tamarisk (Tamarix spp.) and cottonwood (Populus fremontii) in terms of (1) differences in vulnerability to scour and burial during floods; (2) interactions and feedbacks between plants and river morphodynamics; and (3) long-term coevolution of river floodplains and riparian communities following flow regulation from dams. The focus of these studies is sand-bed rivers in arid-land regions where invasion by tamarisk has strongly influenced riverine plant communities and geomorphic processes. We complemented a suite of field-scale flume experiments using live seedlings to quantify the initial stages of plant-river interactions with an analysis of long-term vegetation and geomorphic changes along the dammed Bill Williams River (AZ, USA) using time-series air photographs. Vegetation-fluvial interactions varied with plant characteristics, river hydraulics and sediment conditions, across the wide range of scales we investigated. In the flume studies, tamarisk's denser crowns and stiffer stems induced greater sedimentation compared to cottonwood. This resulted in tamarisk's greater mortality from burial as small seedlings under sediment equilibrium conditions but higher relative survival in larger floods under sediment deficit scenarios, in which more cottonwoods were lost to root scour. Sediment deficit conditions, as occurs downstream of dams, induced both greater scour and greater plant loss. With larger size and at higher densities, plants' vulnerability diminished due to greater root anchoring and canopy effects on hydraulics. At the corridor scale, we observed a pattern of plant encroachment during five decades of flow regulation, in which channel narrowing and simplification was more

  2. Host adaptation of Chlamydia pecorum towards low virulence evident in co-evolution of the ompA, incA, and ORF663 Loci.

    Science.gov (United States)

    Mohamad, Khalil Yousef; Kaltenboeck, Bernhard; Rahman, Kh Shamsur; Magnino, Simone; Sachse, Konrad; Rodolakis, Annie

    2014-01-01

    Chlamydia (C.) pecorum, an obligate intracellular bacterium, may cause severe diseases in ruminants, swine and koalas, although asymptomatic infections are the norm. Recently, we identified genetic polymorphisms in the ompA, incA and ORF663 genes that potentially differentiate between high-virulence C. pecorum isolates from diseased animals and low-virulence isolates from asymptomatic animals. Here, we expand these findings by including additional ruminant, swine, and koala strains. Coding tandem repeats (CTRs) at the incA locus encoded a variable number of repeats of APA or AGA amino acid motifs. Addition of any non-APA/AGA repeat motif, such as APEVPA, APAVPA, APE, or APAPE, associated with low virulence (PincA CTRs (P = 0.0028). In ORF663, high numbers of 15-mer CTRs correlated with low virulence (P = 0.0001). Correction for ompA phylogram position in ORF663 and incA abolished the correlation between genetic changes and virulence, demonstrating co-evolution of ompA, incA, and ORF663 towards low virulence. Pairwise divergence of ompA, incA, and ORF663 among isolates from healthy animals was significantly higher than among strains isolated from diseased animals (P≤10-5), confirming the longer evolutionary path traversed by low-virulence strains. All three markers combined identified 43 unique strains and 4 pairs of identical strains among all 57 isolates tested, demonstrating the suitability of these markers for epidemiological investigations.

  3. Should Law Keep Pace with Society? Relative Update Rates Determine the Co-Evolution of Institutional Punishment and Citizen Contributions to Public Goods

    Directory of Open Access Journals (Sweden)

    Daria Roithmayr

    2015-06-01

    Full Text Available Until recently, theorists considering the evolution of human cooperation have paid little attention to institutional punishment, a defining feature of large-scale human societies. Compared to individually-administered punishment, institutional punishment offers a unique potential advantage: the ability to control how quickly legal rules of punishment evolve relative to social behavior that legal punishment regulates. However, at what rate should legal rules evolve relative to society to maximize compliance? We investigate this question by modeling the co-evolution of law and cooperation in a public goods game with centralized punishment. We vary the rate at which States update their legal punishment strategy relative to Citizens’ updating of their contribution strategy and observe the effect on Citizen cooperation. We find that when States have unlimited resources, slower State updating lead to more Citizen cooperation: by updating more slowly, States force Citizens to adapt to the legal punishment rules. When States depend on Citizens to finance their punishment activities, however, we find evidence of a ‘Goldilocks’ effect: optimal compliance is achieved when legal rules evolve at a critical evolutionary rate that is slow enough to force citizens to adapt, but fast enough to enable states to quickly respond to outbreaks of citizen lawlessness.

  4. 21CMMC with a 3D light-cone: the impact of the co-evolution approximation on the astrophysics of reionisation and cosmic dawn.

    Science.gov (United States)

    Greig, Bradley; Mesinger, Andrei

    2018-03-01

    We extend 21CMMC, a Monte Carlo Markov Chain sampler of 3D reionisation simulations, to perform parameter estimation directly on 3D light-cones of the cosmic 21cm signal. This brings theoretical analysis closer to the tomographic 21-cm observations achievable with next generation interferometers like HERA and the SKA. Parameter recovery can therefore account for modes which evolve with redshift/frequency. Additionally, simulated data can be more easily corrupted to resemble real data. Using the light-cone version of 21CMMC, we quantify the biases in the recovered astrophysical parameters if we use the 21cm power spectrum from the co-evolution approximation to fit a 3D light-cone mock observation. While ignoring the light-cone effect under most assumptions will not significantly bias the recovered astrophysical parameters, it can lead to an underestimation of the associated uncertainty. However significant biases (˜few - 10 σ) can occur if the 21cm signal evolves rapidly (i.e. the epochs of reionisation and heating overlap significantly) and: (i) foreground removal is very efficient, allowing large physical scales (k {≲} 0.1 Mpc-1) to be used in the analysis or (ii) theoretical modelling is accurate to within ˜10 per cent in the power spectrum amplitude.

  5. Evolution of resistance to a multiple-herbivore community: genetic correlations, diffuse coevolution, and constraints on the plant's response to selection.

    Science.gov (United States)

    Wise, Michael J; Rausher, Mark D

    2013-06-01

    Although plants are generally attacked by a community of several species of herbivores, relatively little is known about the strength of natural selection for resistance in multiple-herbivore communities-particularly how the strength of selection differs among herbivores that feed on different plant organs or how strongly genetic correlations in resistance affect the evolutionary responses of the plant. Here, we report on a field study measuring natural selection for resistance in a diverse community of herbivores of Solanum carolinense. Using linear phenotypic-selection analyses, we found that directional selection acted to increase resistance to seven species. Selection was strongest to increase resistance to fruit feeders, followed by flower feeders, then leaf feeders. Selection favored a decrease in resistance to a stem borer. Bootstrapping analyses showed that the plant population contained significant genetic variation for each of 14 measured resistance traits and significant covariances in one-third of the pairwise combinations of resistance traits. These genetic covariances reduced the plant's overall predicted evolutionary response for resistance against the herbivore community by about 60%. Diffuse (co)evolution was widespread in this community, and the diffuse interactions had an overwhelmingly constraining (rather than facilitative) effect on the plant's evolution of resistance. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  6. Epigenomic Co-localization and Co-evolution Reveal a Key Role for 5hmC as a Communication Hub in the Chromatin Network of ESCs

    Directory of Open Access Journals (Sweden)

    David Juan

    2016-02-01

    Full Text Available Summary: Epigenetic communication through histone and cytosine modifications is essential for gene regulation and cell identity. Here, we propose a framework that is based on a chromatin communication model to get insight on the function of epigenetic modifications in ESCs. The epigenetic communication network was inferred from genome-wide location data plus extensive manual annotation. Notably, we found that 5-hydroxymethylcytosine (5hmC is the most-influential hub of this network, connecting DNA demethylation to nucleosome remodeling complexes and to key transcription factors of pluripotency. Moreover, an evolutionary analysis revealed a central role of 5hmC in the co-evolution of chromatin-related proteins. Further analysis of regions where 5hmC co-localizes with specific interactors shows that each interaction points to chromatin remodeling, stemness, differentiation, or metabolism. Our results highlight the importance of cytosine modifications in the epigenetic communication of ESCs. : 5-hydroxymethylcytosine (5hmC plays a key role in the epigenomic communication network of embryonic stem cells. Juan et al. build a communication network based in co-localization of epigenomic data and literature. The analysis of the network and its components reveals that proteins reading and editing 5hmC co-evolve and serve as links between diverse molecular processes.

  7. Controlled experiments of hillslope co-evolution at the Biosphere 2 Landscape Evolution Observatory: toward prediction of coupled hydrological, biogeochemical, and ecological change

    Science.gov (United States)

    Volkmann, T. H. M.; Sengupta, A.; Pangle, L.; Abramson, N.; Barron-Gafford, G.; Breshears, D. D.; Bugaj, A.; Chorover, J.; Dontsova, K.; Durcik, M.; Ferre, T. P. A.; Harman, C. J.; Hunt, E.; Huxman, T. E.; Kim, M.; Maier, R. M.; Matos, K.; Alves Meira Neto, A.; Meredith, L. K.; Monson, R. K.; Niu, G. Y.; Pelletier, J. D.; Rasmussen, C.; Ruiz, J.; Saleska, S. R.; Schaap, M. G.; Sibayan, M.; Tuller, M.; Van Haren, J. L. M.; Wang, Y.; Zeng, X.; Troch, P. A.

    2017-12-01

    Understanding the process interactions and feedbacks among water, microbes, plants, and porous geological media is crucial for improving predictions of the response of Earth's critical zone to future climatic conditions. However, the integrated co-evolution of landscapes under change is notoriously difficult to investigate. Laboratory studies are typically limited in spatial and temporal scale, while field studies lack observational density and control. To bridge the gap between controlled lab and uncontrolled field studies, the University of Arizona - Biosphere 2 built a macrocosm experiment of unprecedented scale: the Landscape Evolution Observatory (LEO). LEO consists of three replicated, 330-m2 hillslope landscapes inside a 5000-m2 environmentally controlled facility. The engineered landscapes contain 1-m depth of basaltic tephra ground to homogenous loamy sand that will undergo physical, chemical, and mineralogical changes over many years. Each landscape contains a dense sensor network capable of resolving water, carbon, and energy cycling processes at sub-meter to whole-landscape scale. Embedded sampling devices allow for quantification of biogeochemical processes, and facilitate the use of chemical tracers applied with the artificial rainfall. LEO is now fully operational and intensive forcing experiments have been launched. While operating the massive infrastructure poses significant challenges, LEO has demonstrated the capacity of tracking multi-scale matter and energy fluxes at a level of detail impossible in field experiments. Initial sensor, sampler, and restricted soil coring data are already providing insights into the tight linkages between water flow, weathering, and (micro-) biological community development during incipient landscape evolution. Over the years to come, these interacting processes are anticipated to drive the model systems to increasingly complex states, potentially perturbed by changes in climatic forcing. By intensively monitoring

  8. Gene-Culture Coevolution in a Social Cetacean: Integrating Acoustic and Genetic Data to Understand Population Structure in the Short-Finned Pilot Whale (Globicephala macrorhynchus)

    Science.gov (United States)

    Van Cise, Amy

    repertoire or dialect. The qualitative correlation between social structure, cultural information transfer, and genetic structure suggest that gene-culture coevolution may be an important mechanism to the evolutionary ecology of short-finned pilot whales. Further research may reveal a similar structure in the transmission of ecological behaviors, such as diet preference, habitat use, or movements. The results of this research underscore the applicability of gene-culture coevolutionary theory to non-human taxa.

  9. Phenotype selection reveals coevolution of muscle glycogen and protein and PTEN as a gate keeper for the accretion of muscle mass in adult female mice.

    Directory of Open Access Journals (Sweden)

    Mandy Sawitzky

    Full Text Available We have investigated molecular mechanisms for muscle mass accretion in a non-inbred mouse model (DU6P mice characterized by extreme muscle mass. This extreme muscle mass was developed during 138 generations of phenotype selection for high protein content. Due to the repeated trait selection a complex setting of different mechanisms was expected to be enriched during the selection experiment. In muscle from 29-week female DU6P mice we have identified robust increases of protein kinase B activation (AKT, Ser-473, up to 2-fold if compared to 11- and 54-week DU6P mice or controls. While a number of accepted effectors of AKT activation, including IGF-I, IGF-II, insulin/IGF-receptor, myostatin or integrin-linked kinase (ILK, were not correlated with this increase, phosphatase and tensin homologue deleted on chromosome 10 (PTEN was down-regulated in 29-week female DU6P mice. In addition, higher levels of PTEN phosphorylation were found identifying a second mechanism of PTEN inhibition. Inhibition of PTEN and activation of AKT correlated with specific activation of p70S6 kinase and ribosomal protein S6, reduced phosphorylation of eukaryotic initiation factor 2α (eIF2α and higher rates of protein synthesis in 29-week female DU6P mice. On the other hand, AKT activation also translated into specific inactivation of glycogen synthase kinase 3ß (GSK3ß and an increase of muscular glycogen. In muscles from 29-week female DU6P mice a significant increase of protein/DNA was identified, which was not due to a reduction of protein breakdown or to specific increases of translation initiation. Instead our data support the conclusion that a higher rate of protein translation is contributing to the higher muscle mass in mid-aged female DU6P mice. Our results further reveal coevolution of high protein and high glycogen content during the selection experiment and identify PTEN as gate keeper for muscle mass in mid-aged female DU6P mice.

  10. The Coevolution of Digital Ecosystems

    Science.gov (United States)

    SungYong, Um

    2016-01-01

    Digital ecosystems are one of the most important strategic issues in the current digital economy. Digital ecosystems are dynamic and generative. They evolve as new firms join and as heterogeneous systems are integrated into other systems. These features digital ecosystems determine economic and technological success in the competition among…

  11. The Dynamical Theory of Coevolution

    NARCIS (Netherlands)

    Dieckmann, Ulf

    1997-01-01

    A unifying framework is presented for describing the phenotypic coevolutionary dynamics of a general ecological community. We start from an individual-based approach allowing for the interaction of an arbitrary number of species. The adaptive dynamics of species’ trait values are derived from the

  12. The lack of foundation in the mechanism on which are based the physico-chemical theories for the origin of the genetic code is counterposed to the credible and natural mechanism suggested by the coevolution theory.

    Science.gov (United States)

    Di Giulio, Massimo

    2016-06-21

    I analyze the mechanism on which are based the majority of theories that put to the center of the origin of the genetic code the physico-chemical properties of amino acids. As this mechanism is based on excessive mutational steps, I conclude that it could not have been operative or if operative it would not have allowed a full realization of predictions of these theories, because this mechanism contained, evidently, a high indeterminacy. I make that disapproving the four-column theory of the origin of the genetic code (Higgs, 2009) and reply to the criticism that was directed towards the coevolution theory of the origin of the genetic code. In this context, I suggest a new hypothesis that clarifies the mechanism by which the domains of codons of the precursor amino acids would have evolved, as predicted by the coevolution theory. This mechanism would have used particular elongation factors that would have constrained the evolution of all amino acids belonging to a given biosynthetic family to the progenitor pre-tRNA, that for first recognized, the first codons that evolved in a certain codon domain of a determined precursor amino acid. This happened because the elongation factors recognized two characteristics of the progenitor pre-tRNAs of precursor amino acids, which prevented the elongation factors from recognizing the pre-tRNAs belonging to biosynthetic families of different precursor amino acids. Finally, I analyze by means of Fisher's exact test, the distribution, within the genetic code, of the biosynthetic classes of amino acids and the ones of polarity values of amino acids. This analysis would seem to support the biosynthetic classes of amino acids over the ones of polarity values, as the main factor that led to the structuring of the genetic code, with the physico-chemical properties of amino acids playing only a subsidiary role in this evolution. As a whole, the full analysis brings to the conclusion that the coevolution theory of the origin of the

  13. Design, synthesis and evaluation of a potent substrate analog inhibitor identified by scanning Ala/Phe mutagenesis, mimicking substrate co-evolution, against multidrug-resistant HIV-1 protease

    International Nuclear Information System (INIS)

    Yedidi, Ravikiran S.; Muhuhi, Joseck M.; Liu, Zhigang; Bencze, Krisztina Z.; Koupparis, Kyriacos; O’Connor, Carrie E.; Kovari, Iulia A.; Spaller, Mark R.; Kovari, Ladislau C.

    2013-01-01

    Highlights: •Inhibitors against MDR HIV-1 protease were designed, synthesized and evaluated. •Lead peptide (6a) showed potent inhibition (IC 50 : 4.4 nM) of MDR HIV-1 protease. •(6a) Showed favorable binding isotherms against NL4-3 and MDR proteases. •(6a) Induced perturbations in the 15 N-HSQC spectrum of MDR HIV-1 protease. •Molecular modeling suggested that (6a) may induce total flap closure inMDR protease. -- Abstract: Multidrug-resistant (MDR) clinical isolate-769, human immunodeficiency virus type-1 (HIV-1) protease (PDB ID: (1TW7)), was shown to exhibit wide-open flaps and an expanded active site cavity, causing loss of contacts with protease inhibitors. In the current study, the expanded active site cavity of MDR769 HIV-1 protease was screened with a series of peptide-inhibitors that were designed to mimic the natural substrate cleavage site, capsid/p2. Scanning Ala/Phe chemical mutagenesis approach was incorporated into the design of the peptide series to mimic the substrate co-evolution. Among the peptides synthesized and evaluated, a lead peptide (6a) with potent activity (IC 50 : 4.4 nM) was identified against the MDR769 HIV-1 protease. Isothermal titration calorimetry data showed favorable binding profile for 6aagainst both wild type and MDR769 HIV-1 protease variants. Nuclear magnetic resonance spectrum of 15 N-labeled MDR769 HIV-1 protease in complex with 6a showed some major perturbations in chemical shift, supporting the peptide induced conformational changes in protease. Modeling analysis revealed multiple contacts between 6a and MDR769 HIV-1 protease. The lead peptide-inhibitor, 6a, with high potency and good binding profile can be used as the basis for developing potent small molecule inhibitors against MDR variants of HIV

  14. Design, synthesis and evaluation of a potent substrate analog inhibitor identified by scanning Ala/Phe mutagenesis, mimicking substrate co-evolution, against multidrug-resistant HIV-1 protease

    Energy Technology Data Exchange (ETDEWEB)

    Yedidi, Ravikiran S. [Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201 (United States); Muhuhi, Joseck M. [Department of Chemistry, Wayne State University, Detroit, MI 48202 (United States); Liu, Zhigang [Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201 (United States); Bencze, Krisztina Z. [Department of Chemistry, Fort Hays State University, Hays, KS 67601 (United States); Koupparis, Kyriacos [Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201 (United States); Department of Chemistry, Wayne State University, Detroit, MI 48202 (United States); O’Connor, Carrie E.; Kovari, Iulia A. [Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201 (United States); Spaller, Mark R. [Department of Chemistry, Wayne State University, Detroit, MI 48202 (United States); Kovari, Ladislau C., E-mail: kovari@med.wayne.edu [Department of Biochemistry and Molecular Biology, School of Medicine, Wayne State University, Detroit, MI 48201 (United States)

    2013-09-06

    Highlights: •Inhibitors against MDR HIV-1 protease were designed, synthesized and evaluated. •Lead peptide (6a) showed potent inhibition (IC{sub 50}: 4.4 nM) of MDR HIV-1 protease. •(6a) Showed favorable binding isotherms against NL4-3 and MDR proteases. •(6a) Induced perturbations in the {sup 15}N-HSQC spectrum of MDR HIV-1 protease. •Molecular modeling suggested that (6a) may induce total flap closure inMDR protease. -- Abstract: Multidrug-resistant (MDR) clinical isolate-769, human immunodeficiency virus type-1 (HIV-1) protease (PDB ID: (1TW7)), was shown to exhibit wide-open flaps and an expanded active site cavity, causing loss of contacts with protease inhibitors. In the current study, the expanded active site cavity of MDR769 HIV-1 protease was screened with a series of peptide-inhibitors that were designed to mimic the natural substrate cleavage site, capsid/p2. Scanning Ala/Phe chemical mutagenesis approach was incorporated into the design of the peptide series to mimic the substrate co-evolution. Among the peptides synthesized and evaluated, a lead peptide (6a) with potent activity (IC{sub 50}: 4.4 nM) was identified against the MDR769 HIV-1 protease. Isothermal titration calorimetry data showed favorable binding profile for 6aagainst both wild type and MDR769 HIV-1 protease variants. Nuclear magnetic resonance spectrum of {sup 15}N-labeled MDR769 HIV-1 protease in complex with 6a showed some major perturbations in chemical shift, supporting the peptide induced conformational changes in protease. Modeling analysis revealed multiple contacts between 6a and MDR769 HIV-1 protease. The lead peptide-inhibitor, 6a, with high potency and good binding profile can be used as the basis for developing potent small molecule inhibitors against MDR variants of HIV.

  15. Co-evolution of human leukocyte antigen (HLA class I ligands with killer-cell immunoglobulin-like receptors (KIR in a genetically diverse population of sub-Saharan Africans.

    Directory of Open Access Journals (Sweden)

    Paul J Norman

    2013-10-01

    Full Text Available Interactions between HLA class I molecules and killer-cell immunoglobulin-like receptors (KIR control natural killer cell (NK functions in immunity and reproduction. Encoded by genes on different chromosomes, these polymorphic ligands and receptors correlate highly with disease resistance and susceptibility. Although studied at low-resolution in many populations, high-resolution analysis of combinatorial diversity of HLA class I and KIR is limited to Asian and Amerindian populations with low genetic diversity. At the other end of the spectrum is the West African population investigated here: we studied 235 individuals, including 104 mother-child pairs, from the Ga-Adangbe of Ghana. This population has a rich diversity of 175 KIR variants forming 208 KIR haplotypes, and 81 HLA-A, -B and -C variants forming 190 HLA class I haplotypes. Each individual we studied has a unique compound genotype of HLA class I and KIR, forming 1-14 functional ligand-receptor interactions. Maintaining this exceptionally high polymorphism is balancing selection. The centromeric region of the KIR locus, encoding HLA-C receptors, is highly diverse whereas the telomeric region encoding Bw4-specific KIR3DL1, lacks diversity in Africans. Present in the Ga-Adangbe are high frequencies of Bw4-bearing HLA-B*53:01 and Bw4-lacking HLA-B*35:01, which otherwise are identical. Balancing selection at key residues maintains numerous HLA-B allotypes having and lacking Bw4, and also those of stronger and weaker interaction with LILRB1, a KIR-related receptor. Correspondingly, there is a balance at key residues of KIR3DL1 that modulate its level of cell-surface expression. Thus, capacity to interact with NK cells synergizes with peptide binding diversity to drive HLA-B allele frequency distribution. These features of KIR and HLA are consistent with ongoing co-evolution and selection imposed by a pathogen endemic to West Africa. Because of the prevalence of malaria in the Ga-Adangbe and

  16. After 100 years, is coevolution relevant?

    Science.gov (United States)

    Geral I. McDonald

    2011-01-01

    On the 100th anniversary of the introduction of Cronartium ribicola into western North America, it is fitting to assess the philosophical foundation of plant pathology and forest ecology. We should ask whether this foundation provides sufficient understanding of blister rust, other diseases of North American forests, and general forest ecology to insure the application...

  17. The coevolution of parochial altruism and war.

    Science.gov (United States)

    Choi, Jung-Kyoo; Bowles, Samuel

    2007-10-26

    Altruism-benefiting fellow group members at a cost to oneself-and parochialism-hostility toward individuals not of one's own ethnic, racial, or other group-are common human behaviors. The intersection of the two-which we term "parochial altruism"-is puzzling from an evolutionary perspective because altruistic or parochial behavior reduces one's payoffs by comparison to what one would gain by eschewing these behaviors. But parochial altruism could have evolved if parochialism promoted intergroup hostilities and the combination of altruism and parochialism contributed to success in these conflicts. Our game-theoretic analysis and agent-based simulations show that under conditions likely to have been experienced by late Pleistocene and early Holocene humans, neither parochialism nor altruism would have been viable singly, but by promoting group conflict, they could have evolved jointly.

  18. Coevolution of Binaries and Circumbinary Gaseous Disks

    Science.gov (United States)

    Fleming, David; Quinn, Thomas R.

    2018-04-01

    The recent discoveries of circumbinary planets by Kepler raise questions for contemporary planet formation models. Understanding how these planets form requires characterizing their formation environment, the circumbinary protoplanetary disk, and how the disk and binary interact. The central binary excites resonances in the surrounding protoplanetary disk that drive evolution in both the binary orbital elements and in the disk. To probe how these interactions impact both binary eccentricity and disk structure evolution, we ran N-body smooth particle hydrodynamics (SPH) simulations of gaseous protoplanetary disks surrounding binaries based on Kepler 38 for 10^4 binary orbital periods for several initial binary eccentricities. We find that nearly circular binaries weakly couple to the disk via a parametric instability and excite disk eccentricity growth. Eccentric binaries strongly couple to the disk causing eccentricity growth for both the disk and binary. Disks around sufficiently eccentric binaries strongly couple to the disk and develop an m = 1 spiral wave launched from the 1:3 eccentric outer Lindblad resonance (EOLR). This wave corresponds to an alignment of gas particle longitude of periastrons. We find that in all simulations, the binary semi-major axis decays due to dissipation from the viscous disk.

  19. Living Melodies - Coevolution Of Sonic Communication

    DEFF Research Database (Denmark)

    Dahlstedt, Palle; Nordahl, Mats G.

    2001-01-01

    The authors have constructed an artificial world of coevolving communicating agents. The behavior of the agents is described in terms of a simple genetic programming framework, which allows the evolution of foraging behavior and movement in order to reproduce, as well as sonic communication....... The sound of the entire world is used as musical raw material for the work. Musically interesting and useful structures are found to emerge....

  20. MISTIC: mutual information server to infer coevolution

    DEFF Research Database (Denmark)

    Simonetti, Franco L.; Teppa, Elin; Chernomoretz, Ariel

    2013-01-01

    of several information-related quantities using a circos representation. This provides an integrated view of the MSA in terms of (i) the mutual information (MI) between residue pairs, (ii) sequence conservation and (iii) the residue cumulative and proximity MI scores. Further, an interactive interface...... of circos representation of MI networks and the visualization of the cumulative MI and proximity MI concepts is novel....

  1. Coevolution of Firm Capabilities and Industry Competition

    NARCIS (Netherlands)

    M.W. Huygens (Marc); C.W.F. Baden-Fuller (Charles); F.A.J. van den Bosch (Frans); H.W. Volberda (Henk)

    2001-01-01

    textabstractThis paper proposes that rival firms not only search for new capabilities within their organization, but also for those that rest in their competitive environment. An integrated analysis of these search processes at both firm and industry levels of analysis shows how their interaction

  2. Coevolution of teaching activity promotes cooperation

    International Nuclear Information System (INIS)

    Szolnoki, Attila; Perc, Matjaz

    2008-01-01

    Evolutionary games are studied where the teaching activity of players can evolve in time. Initially all players following either the cooperative or defecting strategy are distributed on a square lattice. The rate of strategy adoption is determined by the payoff difference and a teaching activity characterizing the donor's capability to enforce its strategy on the opponent. Each successful strategy adoption process is accompanied by an increase in the donor's teaching activity. By applying an optimum value of the increment, this simple mechanism spontaneously creates relevant inhomogeneities in the teaching activities that support the maintenance of cooperation for both the prisoner's dilemma and the snowdrift game

  3. Modular co-evolution of metabolic networks

    Directory of Open Access Journals (Sweden)

    Yu Zhong-Hao

    2007-08-01

    Full Text Available Abstract Background The architecture of biological networks has been reported to exhibit high level of modularity, and to some extent, topological modules of networks overlap with known functional modules. However, how the modular topology of the molecular network affects the evolution of its member proteins remains unclear. Results In this work, the functional and evolutionary modularity of Homo sapiens (H. sapiens metabolic network were investigated from a topological point of view. Network decomposition shows that the metabolic network is organized in a highly modular core-periphery way, in which the core modules are tightly linked together and perform basic metabolism functions, whereas the periphery modules only interact with few modules and accomplish relatively independent and specialized functions. Moreover, over half of the modules exhibit co-evolutionary feature and belong to specific evolutionary ages. Peripheral modules tend to evolve more cohesively and faster than core modules do. Conclusion The correlation between functional, evolutionary and topological modularity suggests that the evolutionary history and functional requirements of metabolic systems have been imprinted in the architecture of metabolic networks. Such systems level analysis could demonstrate how the evolution of genes may be placed in a genome-scale network context, giving a novel perspective on molecular evolution.

  4. Co-evolução entre raças fisiológicas de colletotrichum lindemuthianum e feijoeiro Co-evolution of physiological races of colletotrichum lindemuthianum and common bean

    Directory of Open Access Journals (Sweden)

    Alisson Fernando Chiorato

    2006-01-01

    and fungus. The objective this study was to evaluate 220 accessions from Common Bean Germplasm Collection of Instituto Agronômico, IAC, us to infection by three physiological races of the pathogen (31, 65 and 89, and to investigate a possible co-evolution between the origin of the accessions and the pathogen. One hundred and twenty accessions of Mesoamerican origin, 57 Andean and 43 genetically improved cultivars were used in the study. Besides infection data, 23 morpho-agronomic descriptors were evaluated to characterize the plants. Statistical analyses were based on principal components as a way of showing in graphics the variability related to origin of pathogen and accessions. Fifty percent of the Mesoamerican accessions were susceptible to the three races, while only 33% of the Andean were susceptible. Also, of the genetically improved cultivars 79% were resistant to at least one physiological race, probably due to previous selections for resistance to C. lindemuthianum. Diagrams of the analysis of the principal components, showed that most of the resistant accessions clustered in the dispersion region of the Andean accessions. The results allowed the association between the origin of Phaseolus vulgaris and the anthracnose pathogen, increasing the biological understanding of the reaction defense to C. lindemuthianum infection, and orienting the choice of parents to be used in crossings aiming at resistance to C. lindemuthianum.

  5. Treinamento ambiental em organizações com certificação ISO 14001: estudo de múltiplos casos e identificação de coevolução com a gestão ambiental Environmental training in organizations with ISO 14001 certification: a multiple case study and identification of co-evolution with environmental management

    Directory of Open Access Journals (Sweden)

    Charbel José Chiappetta Jabbour

    2012-01-01

    Full Text Available O objetivo desta pesquisa é compreender as características do treinamento ambiental em algumas empresas brasileiras. Para tanto, foram realizados nove estudos de caso com empresas certificadas pela norma ISO 14001, todas líderes em seu segmento de mercado. Foram conduzidas diversas entrevistas em cada caso, coletados documentos e realizadas visitas para observação direta. Como resultado, apresentam-se as classificações dos casos nos estágios evolutivos da gestão ambiental, os temas mais frequentes do treinamento ambiental, a diferenciação dos temas de treinamento ambiental segundo o nível hierárquico organizacional, a classificação das empresas segundo o nível de aderência às atividades de treinamento ambiental recomendadas pela literatura e as boas práticas de treinamento ambiental oferecidas pelas empresas. A principal contribuição desta pesquisa é a identificação de coevolução entre o estágio de gestão ambiental das organizações e o nível do treinamento ambiental que elas possuem.The objective of this research is to understand the characteristics of environmental training at some Brazilian companies. Nine case studies were carried out in firms certified by ISO 14001. These companies are leaders in their market segments. Several interviews were conducted in each case. Documents were collected and visits for direct observation were made. Results present the classification of companies in evolutionary stages of environmental management, the most common topics of the training environment, the differentiation of environmental training topics according to the hierarchical levels and the best practices offered on environmental training. The main contribution of this research is the identification of the co-evolution between the stage of corporate environmental management and the level of environmental training.

  6. The Co-evolution of QSOs and Galaxies

    Science.gov (United States)

    Coziol, R.; Torres-Papaqui, J. P.; Andernach, H.

    2015-07-01

    Using two large samples of QSOs detected in the mid-infrared (MIR) with WISE, we find that the change of W2-W3 colors with redshift suggests that star formation in their host galaxies increases by a factor of 3 from z = 0 to 2.7, then stays constant up to z = 4, and decreases above z=4. This behavior is slightly different from the best fits for the star formation history of field galaxies as deduced from the Optical-UV and IR, but is consistent with what is observed for sub-mm galaxies at high z. Our results constitute the clearest evidence, so far, that QSO host galaxies form their stars before field galaxies, and are in good agreement with the hierarchical biased structure formation paradigm.

  7. Anthropomorphism in Human–Robot Co-evolution

    Directory of Open Access Journals (Sweden)

    Luisa Damiano

    2018-03-01

    Full Text Available Social robotics entertains a particular relationship with anthropomorphism, which it neither sees as a cognitive error, nor as a sign of immaturity. Rather it considers that this common human tendency, which is hypothesized to have evolved because it favored cooperation among early humans, can be used today to facilitate social interactions between humans and a new type of cooperative and interactive agents – social robots. This approach leads social robotics to focus research on the engineering of robots that activate anthropomorphic projections in users. The objective is to give robots “social presence” and “social behaviors” that are sufficiently credible for human users to engage in comfortable and potentially long-lasting relations with these machines. This choice of ‘applied anthropomorphism’ as a research methodology exposes the artifacts produced by social robotics to ethical condemnation: social robots are judged to be a “cheating” technology, as they generate in users the illusion of reciprocal social and affective relations. This article takes position in this debate, not only developing a series of arguments relevant to philosophy of mind, cognitive sciences, and robotic AI, but also asking what social robotics can teach us about anthropomorphism. On this basis, we propose a theoretical perspective that characterizes anthropomorphism as a basic mechanism of interaction, and rebuts the ethical reflections that a priori condemns “anthropomorphism-based” social robots. To address the relevant ethical issues, we promote a critical experimentally based ethical approach to social robotics, “synthetic ethics,” which aims at allowing humans to use social robots for two main goals: self-knowledge and moral growth.

  8. Anthropomorphism in Human–Robot Co-evolution

    Science.gov (United States)

    Damiano, Luisa; Dumouchel, Paul

    2018-01-01

    Social robotics entertains a particular relationship with anthropomorphism, which it neither sees as a cognitive error, nor as a sign of immaturity. Rather it considers that this common human tendency, which is hypothesized to have evolved because it favored cooperation among early humans, can be used today to facilitate social interactions between humans and a new type of cooperative and interactive agents – social robots. This approach leads social robotics to focus research on the engineering of robots that activate anthropomorphic projections in users. The objective is to give robots “social presence” and “social behaviors” that are sufficiently credible for human users to engage in comfortable and potentially long-lasting relations with these machines. This choice of ‘applied anthropomorphism’ as a research methodology exposes the artifacts produced by social robotics to ethical condemnation: social robots are judged to be a “cheating” technology, as they generate in users the illusion of reciprocal social and affective relations. This article takes position in this debate, not only developing a series of arguments relevant to philosophy of mind, cognitive sciences, and robotic AI, but also asking what social robotics can teach us about anthropomorphism. On this basis, we propose a theoretical perspective that characterizes anthropomorphism as a basic mechanism of interaction, and rebuts the ethical reflections that a priori condemns “anthropomorphism-based” social robots. To address the relevant ethical issues, we promote a critical experimentally based ethical approach to social robotics, “synthetic ethics,” which aims at allowing humans to use social robots for two main goals: self-knowledge and moral growth. PMID:29632507

  9. Anthropomorphism in Human-Robot Co-evolution.

    Science.gov (United States)

    Damiano, Luisa; Dumouchel, Paul

    2018-01-01

    Social robotics entertains a particular relationship with anthropomorphism, which it neither sees as a cognitive error, nor as a sign of immaturity. Rather it considers that this common human tendency, which is hypothesized to have evolved because it favored cooperation among early humans, can be used today to facilitate social interactions between humans and a new type of cooperative and interactive agents - social robots. This approach leads social robotics to focus research on the engineering of robots that activate anthropomorphic projections in users. The objective is to give robots "social presence" and "social behaviors" that are sufficiently credible for human users to engage in comfortable and potentially long-lasting relations with these machines. This choice of 'applied anthropomorphism' as a research methodology exposes the artifacts produced by social robotics to ethical condemnation: social robots are judged to be a "cheating" technology, as they generate in users the illusion of reciprocal social and affective relations. This article takes position in this debate, not only developing a series of arguments relevant to philosophy of mind, cognitive sciences, and robotic AI, but also asking what social robotics can teach us about anthropomorphism. On this basis, we propose a theoretical perspective that characterizes anthropomorphism as a basic mechanism of interaction, and rebuts the ethical reflections that a priori condemns "anthropomorphism-based" social robots. To address the relevant ethical issues, we promote a critical experimentally based ethical approach to social robotics, "synthetic ethics," which aims at allowing humans to use social robots for two main goals: self-knowledge and moral growth.

  10. Coevolution of Synchronization and Cooperation in Costly Networked Interactions

    Science.gov (United States)

    Antonioni, Alberto; Cardillo, Alessio

    2017-06-01

    Despite the large number of studies on synchronization, the hypothesis that interactions bear a cost for involved individuals has seldom been considered. The introduction of costly interactions leads, instead, to the formulation of a dichotomous scenario in which an individual may decide to cooperate and pay the cost in order to get synchronized with the rest of the population. Alternatively, the same individual can decide to free ride, without incurring any cost, waiting for others to get synchronized to his or her state. Thus, the emergence of synchronization may be seen as the byproduct of an evolutionary game in which individuals decide their behavior according to the benefit-to-cost ratio they accrued in the past. We study the onset of cooperation and synchronization in networked populations of Kuramoto oscillators and report how topology is essential in order for cooperation to thrive. We also display how different classes of topology foster synchronization differently both at microscopic and macroscopic levels.

  11. Design as co-evolution of problem, solution, and audience

    DEFF Research Database (Denmark)

    Halstrøm, Per Liljenberg; Galle, Per

    2014-01-01

    design beyond the level of definitions, reviewing canonical theories about design as a professional enterprise. We find that the well-established theoretical notion of ‘co-evolution’ of problem and solution in design has its merits in regard to understanding design deliberations; but also that existing......The meaning of ‘design’ can be captured in a general way by a good definition, but even the best definition cannot provide an understanding sufficiently deep to guide the professional designer or the student of design in the intricate deliberations of doing design in practice. Therefore we explore...

  12. Towards Co-evolution of Membrane Transport and Metabolism

    Science.gov (United States)

    Wei, Chenyu; Pohorille, Andrzej

    2014-01-01

    Protocellular boundaries were inextricably connected to the metabolism they encapsulated: to be inheritable, early metabolism must have led to an increased rate of growth and division of vesicles and, similarly, transport through vesicle boundaries must have supported the evolution of metabolism. Even though explaining how this coupling emerged and evolved in the absence of the complex machinery of modern cells is one of the key issues in studies on the origin of life, little is known about the biochemical and biophysical processes that might have been involved. This gap in our knowledge is a major impediment in efforts to construct scenarios for the origin of life and laboratory models of protocells. A combination of experimental and computational studies carried out by us and our collaborators is aimed at helping to close this gap. Properties of membranes might have contributed to the selection of RNA as an early biopolymer. A kinetic mechanism was proposed (Sacerdote & Szostak, 2005) in which ribose was supplied more quickly than other aldopentoses to primordial cells for preferential incorporation of ribonucleotides into nucleic acids. This proposal is based on a finding that ribose permeates membranes an order of magnitude faster than its diastereomers, arabinose and xylose. Our computer simulations, which yield permeation rates in excellent agreement with experiment, and kinetic modeling explain this phenomenon in terms of inter- and intramolecular interactions involving exocyclic hydroxyl groups attached to carbon atoms of the pyranose ring (Wei and Pohorille, 2009). They also constrain scenarios for the formation of the earliest nucleic acids (Wei and Pohorille, 2013). In one scenario, sugars permeate protocellular walls and subsequently are used to synthesize nucleic acids inside protocells. As long as this process proceeds at the rate faster than 6x10(exp -3)/s, ribose derivatives will be available for synthesis easier than their diastereomers. If nucleosides or their activated derivatives are synthesized outside protocells and subsequently transported across protocellular membranes the kinetic mechanism does not apply because all diastereomers, which have their sugars in the furanose rather than pyranose form, permeate the membrane at approximately the same rate. Properties of membranes might have been also coupled to metabolism involving peptides. Recently, Adamala and Szostak (2013) have shown that a dipeptide inside fatty-acid vesicles catalyzes the formation of another dipeptide that binds to vesicle walls and, by doing so, promotes their growth at the expense of other vesicles. This coupling of metabolism, permeability of vesicles and their growth is the first demonstration of evolutionary advantage imparted by small, membrane-bound peptides. Building on this work we have calculated the rate at which different blocked amino acids are delivered to a protocell for synthesis of dipeptides. We have further shown that the dipeptides are located at the water-membrane interface rather than in the center of the bilayer. On these basis it is anticipated that other dipeptides containing aromatic, but not necessarily hydrophobic amino acids (e.g. tyrosine) could have the same catalytic effects. Insight from these studies allows for estimating the rate of vesicle growth and the rates of dipeptide synthesis required to keep the system in balance. These results, in combination with our earlier studies, lead to a general scenario for evolution from membrane-bound dipeptides to ion channels in the origin of life.

  13. The co-evolution of fairness preferences and costly punishment.

    Directory of Open Access Journals (Sweden)

    Moritz Hetzer

    Full Text Available We study the co-evolutionary emergence of fairness preferences in the form of other-regarding behavior and its effect on the origination of costly punishment behavior in public good games. Our approach closely combines empirical results from three experiments with an evolutionary simulation model. In this way, we try to fill a gap between the evolutionary theoretical literature on cooperation and punishment on the one hand and the empirical findings from experimental economics on the other hand. As a principal result, we show that the evolution among interacting agents inevitably favors a sense for fairness in the form of "disadvantageous inequity aversion". The evolutionary dominance and stability of disadvantageous inequity aversion is demonstrated by enabling agents to co-evolve with different self- and other-regarding preferences in a competitive environment with limited resources. Disadvantageous inequity aversion leads to the emergence of costly ("altruistic" punishment behavior and quantitatively explains the level of punishment observed in contemporary lab experiments performed on subjects with a western culture. Our findings corroborate, complement, and interlink the experimental and theoretical literature that has shown the importance of other-regarding behavior in various decision settings.

  14. Co-evolution of demand and supply under competition

    NARCIS (Netherlands)

    Vermeulen, B.; Kok, de A.G.

    2009-01-01

    In this paper, we derive strategies to enforce dominance in a business-to-consumer market with heterogeneous, competing products, while the market segmentation evolves through interaction of demand and supply. By using evolutionary economic notions, we extend operations management studies on

  15. The Co-evolution of Concepts and Motivation.

    Science.gov (United States)

    Delton, Andrew W; Sell, Aaron

    2014-04-01

    Does the human mind contain evolved concepts? Many psychologists have doubted this or have investigated only a narrow set (e.g., object, number, cause). Does the human mind contain evolved motivational systems? Many more assent to this claim, holding that there are evolved motivational systems for, among other tasks, social affiliation, aggressive competition, and finding food. An emerging research program, however, reveals that these are not separate questions. Any evolved motivational system needs a wealth of conceptual structure that tethers the motivations to real world entities. For instance, what use is a fear of predators without knowing what predators are and how to respond to them effectively? As we illustrate with case studies of cooperation and conflict, there is no motivation without representation: To generate adaptive behavior, motivational systems must be interwoven with the concepts required to support them, and cannot be understood without explicit reference to those concepts.

  16. Transposable Elements Direct The Coevolution between Plants and Microbes

    NARCIS (Netherlands)

    Seidl, Michael F.; Thomma, Bart P.H.J.

    2017-01-01

    Transposable elements are powerful drivers of genome evolution in many eukaryotes. Although they are mostly considered as 'selfish' genetic elements, increasing evidence suggests that they contribute to genetic variability; particularly under stress conditions. Over the past few years, the role of

  17. Coevolution of a Persistent Plant Virus and Its Pepper Hosts.

    Science.gov (United States)

    Safari, Maliheh; Roossinck, Marilyn J

    2018-05-30

    There are many nonpathogenic viruses that are maintained in a persistent lifestyle in plants. Plant persistent viruses are widespread, replicating in their hosts for many generations. So far, Endornaviridae is the only family of plant persistent viruses with a single-stranded RNA genome, containing one large open reading frame. Bell pepper endornavirus (BPEV), Hot pepper endornavirus, Capsicum frutescens endornavirus 1 (CFEV 1) have been identified from peppers. Peppers are native to Central and South America and, as domesticated plants, human selection accelerated their evolution. We investigated the evolution of these endornaviruses in different peppers including Capsicum annuum, C. chacoense, C.chinense, C. frutescens, C.bacccutum, and C. pubescens using two fragments from the viral helicase (Hel) and RNA dependent RNA polymerase (RdRp) domains. In addition, using single nucleotide polymorphisms, we analyzed the pepper host populations and phylogenies. The endornaviruses phylogeny was correlated with its Capsicum species host. In this study, BPEV was limited to C. annuum species, and the RdRp and Hel phylogenies identified two clades that correlated with the host pungency. No C. annuum infected with CFEV 1 was found in this study, but the CFEV 1 RdRp fragment was recovered from C. chinense, C. frutescens, C. bacccutum, and C. pubescens. Hence, during pepper speciation, the ancestor of CFEV 1 may have evolved as a new endornavirus, BPEV, in C. annuum peppers.

  18. Coevolution mechanisms that adapt viruses to genetic code ...

    Indian Academy of Sciences (India)

    Recent work on virus × host inter- ... of long-term interdependent symbiotic relationship between them. ... Evolution in species of living organisms occurs based on the .... their parents (Francino and Ochman 1999; Lynn et al. 2002; ... dently some dozens of times. ... in the families of certain viruses, bacteria, fungi and inverte-.

  19. The Co-evolution of Honesty and Strategic Vigilance

    Science.gov (United States)

    Heintz, Christophe; Karabegovic, Mia; Molnar, Andras

    2016-01-01

    We hypothesize that when honesty is not motivated by selfish goals, it reveals social preferences that have evolved for convincing strategically vigilant partners that one is a person worth cooperating with. In particular, we explain how the patterns of dishonest behavior observed in recent experiments can be motivated by preferences for social and self-esteem. These preferences have evolved because they are adaptive in an environment where it is advantageous to be selected as a partner by others and where these others are strategically vigilant: they efficiently evaluate the expected benefit of cooperating with specific partners and attend to their intentions. We specify the adaptive value of strategic vigilance and preferences for social and self-esteem. We argue that evolved preferences for social and self-esteem are satisfied by applying mechanisms of strategic vigilance to one's own behavior. We further argue that such cognitive processes obviate the need for the evolution of preferences for fairness and social norm compliance. PMID:27790162

  20. Jeab at 50: coevolution of research and technology.

    Science.gov (United States)

    Lattal, Kennon A

    2008-01-01

    Evidence of how behavioral research and technology have evolved together abounds in the history of the Journal of the Experimental Analysis of Behavior (JEAB). Technology from outside the discipline (exogenous), from such disciplines as electronics and computer science, has been adapted for use in behavioral research. Technology from within the discipline (endogenous) has developed from both basic behavioral research and existing apparatus. All of these sources of technology have contributed to the corpus of behavioral research as it has evolved in JEAB. Such research, in turn, has provided the environmental pressure necessary for continuing technological evolution both within and outside the discipline. The new technology thus evolved further spurs research along in novel directions. This dynamic coevolutionary interplay between research and technology is an important variable in the past, present, and future of JEAB.

  1. "JEAB" at 50: Coevolution of Research and Technology

    Science.gov (United States)

    Lattal, Kennon A.

    2008-01-01

    Evidence of how behavioral research and technology have evolved together abounds in the history of the "Journal of the Experimental Analysis of Behavior" ("JEAB"). Technology from outside the discipline (exogenous) from such disciplines as electronics and computer science has been adapted for use in behavioral research. Technology from within the…

  2. Finding Worst-Case Flexible Schedules using Coevolution

    DEFF Research Database (Denmark)

    Jensen, Mikkel Thomas

    2001-01-01

    Finding flexible schedules is important to industry, since in many environments changes such as machine breakdowns or the appearance of new jobs can happen at short notice.......Finding flexible schedules is important to industry, since in many environments changes such as machine breakdowns or the appearance of new jobs can happen at short notice....

  3. A hypothesis of coevolution between cooperation and responses to inequity

    Directory of Open Access Journals (Sweden)

    Sarah F Brosnan

    2011-04-01

    Full Text Available Recent evidence demonstrates that humans are not the only species to respond negatively to inequitable outcomes which are to their disadvantage. Several species respond negatively if they subsequently receive a less good reward than a social partner for completing the same task. While these studies suggest that the negative response to inequity is not a uniquely human behavior, they do not provide a functional explanation for the emergence of these responses due to similar characteristics among these species. Emerging data support the hypothesis that an aversion to inequity is a mechanism to promote successful long-term cooperative relationships amongst non-kin. In this paper, I discuss several converging lines of evidence which illustrate the need to further evaluate this relationship. First, cooperation can survive modest inequity; in explicitly cooperative interactions, individuals are willing to continue to cooperate despite inequitable outcomes as long as the partner’s overall behavior is equitable. Second, the context of inequity affects reactions to it in ways which support the idea that joint efforts lead to an expectation of joint payoffs. Finally, comparative studies indicate a link between the degree and extent of cooperation between unrelated individuals in a species and that species’ response to inequitable outcomes. This latter line of evidence indicates that this behavior evolved in conjunction with cooperation and may represent an adaptation to increase the payoffs associated with cooperative interactions. Together these data inform a testable working hypothesis for understanding decision-making in the context of inequity and provide a new, comparative framework for evaluating decision-making behavior.

  4. Constraints on the coevolution of contemporary human males and females

    DEFF Research Database (Denmark)

    Stearns, Stephen C.; Govindaraju, Diddahally R.; Ewbank, Douglas

    2012-01-01

    Because autosomal genes in sexually reproducing organisms spend on average half their time in each sex, and because the traits that they influence encounter different selection pressures in males and females, the evolutionary responses of one sex are constrained by processes occurring in the othe...... included (16.9 ± 15.7°), compared with when they were excluded (87.9 ± 31.6°). We conclude that intralocus sexual conflict constrains the joint evolutionary responses of the two sexes in a contemporary human population.......Because autosomal genes in sexually reproducing organisms spend on average half their time in each sex, and because the traits that they influence encounter different selection pressures in males and females, the evolutionary responses of one sex are constrained by processes occurring in the other...... sex. Although intralocus sexual conflict can restrict sexes from reaching their phenotypic optima, no direct evidence currently supports its operation in humans. Here, we show that the pattern of multivariate selection acting on human height, weight, blood pressure and glucose, total cholesterol...

  5. The Co-evolution of Internationalization and Technological Knowledge

    DEFF Research Database (Denmark)

    Geisler Asmussen, Christian; Hashai, Niron; Delios, Andrew

    2011-01-01

    but diminishing effect of technological knowledge on internationalization and vice versa. This relationship leads to equilibrium in the technological knowledge-internationalization space that dictates the patterns of technological and international evolution of MNEs. The model offers an integrative approach...

  6. Information-triggered Co-evolution: A Combined Process Perspective

    DEFF Research Database (Denmark)

    Cash, Philip; Gonçalves, Milene

    2017-01-01

    Core elements of design work include the development of problem/solution understanding, as well as information and knowledge sharing activities. However, their interrelationships have been little explored. As such, this work aims to take the first steps towards a more integrated evaluation......? A protocol analysis is used to provide the basis for characterization of different types of coevolutionary transition event. A number of distinct event types are described and significant differences in information use and team engagement are identified across transition events. Bringing these findings...... together, we propose a unitary model of the interaction between activity and understanding around co-evolutionary transition events. This has a number of implications for future theory building and testing in both design activity and wider design research....

  7. Rod monochromacy and the coevolution of cetacean retinal opsins.

    Directory of Open Access Journals (Sweden)

    Robert W Meredith

    2013-04-01

    Full Text Available Cetaceans have a long history of commitment to a fully aquatic lifestyle that extends back to the Eocene. Extant species have evolved a spectacular array of adaptations in conjunction with their deployment into a diverse array of aquatic habitats. Sensory systems are among those that have experienced radical transformations in the evolutionary history of this clade. In the case of vision, previous studies have demonstrated important changes in the genes encoding rod opsin (RH1, short-wavelength sensitive opsin 1 (SWS1, and long-wavelength sensitive opsin (LWS in selected cetaceans, but have not examined the full complement of opsin genes across the complete range of cetacean families. Here, we report protein-coding sequences for RH1 and both color opsin genes (SWS1, LWS from representatives of all extant cetacean families. We examine competing hypotheses pertaining to the timing of blue shifts in RH1 relative to SWS1 inactivation in the early history of Cetacea, and we test the hypothesis that some cetaceans are rod monochomats. Molecular evolutionary analyses contradict the "coastal" hypothesis, wherein SWS1 was pseudogenized in the common ancestor of Cetacea, and instead suggest that RH1 was blue-shifted in the common ancestor of Cetacea before SWS1 was independently knocked out in baleen whales (Mysticeti and in toothed whales (Odontoceti. Further, molecular evidence implies that LWS was inactivated convergently on at least five occasions in Cetacea: (1 Balaenidae (bowhead and right whales, (2 Balaenopteroidea (rorquals plus gray whale, (3 Mesoplodon bidens (Sowerby's beaked whale, (4 Physeter macrocephalus (giant sperm whale, and (5 Kogia breviceps (pygmy sperm whale. All of these cetaceans are known to dive to depths of at least 100 m where the underwater light field is dim and dominated by blue light. The knockout of both SWS1 and LWS in multiple cetacean lineages renders these taxa rod monochromats, a condition previously unknown among mammalian species.

  8. A mosaic of chemical coevolution in a large blue butterfly

    DEFF Research Database (Denmark)

    Nash, David R; Als, Thomas D; Maile, Roland

    2008-01-01

    Mechanisms of recognition are essential to the evolution of mutualistic and parasitic interactions between species. One such example is the larval mimicry that Maculinea butterfly caterpillars use to parasitize Myrmica ant colonies. We found that the greater the match between the surface chemistry...... of Maculinea alcon and two of its host Myrmica species, the more easily ant colonies were exploited. The geographic patterns of surface chemistry indicate an ongoing coevolutionary arms race between the butterflies and Myrmica rubra, which has significant genetic differentiation between populations......, but not between the butterflies and a second, sympatric host, Myrmica ruginodis, which has panmictic populations. Alternative hosts may therefore provide an evolutionary refuge for a parasite during periods of counteradaptation by their preferred hosts. Udgivelsesdato: 2008-Jan-4...

  9. Towards Co-evolution of Membranes and Metabolism

    Science.gov (United States)

    Wei, Chenyu; Wilson, Michael A.; Pohorille, Andrew

    2014-01-01

    Conceptually, the most robust way to explain how primitive cell-like structures acquired and increased their capabilities is on the basis of Darwinian evolution. A population of protocells containing material that produced more environmentally fit progeny would increase in time at the expense of other protocells. In this scenario, protocellular boundaries were inextricably connected to the metabolism they encapsulated: to be inheritable, early metabolism must have led to an increased rate of growth and division of vesicles and, similarly, transport through vesicle boundaries must have supported the evolution of metabolism. Everything that could not be delivered from the environment had to be produced and retained inside protocells. Despite their importance to the understanding of the origin of life, only a few cases of coupling between metabolism and membrane-related processes have been identified so far. For example, reactions inside fatty-acid vesicles have been linked to their competitive growth and division, and mechanisms by which membrane permeability might have coupled to information polymers have been proposed and explained. Most recently, it has been shown that a dipeptide inside fatty-acid vesicles catalyzes the formation of another dipeptide that binds to vesicle walls and, by doing so, promotes their growth at the expense of other vesicles, thus demonstrating evolutionary advantage of small, membrane-bound peptides. It has been shown that the appearance of phospholipids imparted selective advantage to protocells bound by phospholipid-containing membranes, eventually driving fatty-acid vesicles to extinction. Phospholipid membranes, however, are nearly impermeable to charged species. Yet, the ability to transport ions across membranes was vital for regulating cellular volume, pH homeostasis, generating energy and sensing the environment. To account for this, evolutionary scenarios for the emergence of simple ion channels, protein structures surrounding water-filled pores in the membrane that facilitate ion transport, have been developed. We will review recent progress in experimental and theoretical studies on coupling properties of membranes to metabolism, with the focus on how they impose constraints on scenarios for the origin of life, and discuss how these studies form the basis for future work on this topic.

  10. Challenges facing theories of music and language co-evolution ...

    African Journals Online (AJOL)

    Some of the issues raised include the definition of the term 'music', the status of music as some sort of communicative medium for the expression of emotion, musical meaning, musical universals and grammars, and the issue of empirical evidence from other disciplines. Journal of the Musical Arts in Africa Volume 6 2009, ...

  11. Ecological mechanisms for the coevolution of mating systems and defence.

    Science.gov (United States)

    Campbell, Stuart A

    2015-02-01

    The diversity of flowering plants is evident in two seemingly unrelated aspects of life history: sexual reproduction, exemplified by the stunning variation in flower form and function, and defence, often in the form of an impressive arsenal of secondary chemistry. Researchers are beginning to appreciate that plant defence and reproduction do not evolve independently, but, instead, may have reciprocal and interactive (coevolutionary) effects on each other. Understanding the mechanisms for mating-defence interactions promises to broaden our understanding of how ecological processes can generate these two rich sources of angiosperm diversity. Here, I review current research on the role of herbivory as a driver of mating system evolution, and the role of mating systems in the evolution of defence strategies. I outline different ecological mechanisms and processes that could generate these coevolutionary patterns, and summarize theoretical and empirical support for each. I provide a conceptual framework for linking plant defence with mating system theory to better integrate these two research fields.

  12. The co-evolution of honesty and strategic vigilance

    Directory of Open Access Journals (Sweden)

    Christophe Heintz

    2016-10-01

    Full Text Available We hypothesize that when honesty is not motivated by selfish goals, it reveals social preferences that have evolved for convincing strategically vigilant partners that one is a person worth cooperating with. In particular, we explain how the patterns of dishonest behavior observed in recent experiments can be motivated by preferences for social and self-esteem. These preferences have evolved because they are adaptive in an environment where it is advantageous to be selected as a partner by others and where these others are strategically vigilant: they efficiently evaluate the expected benefit of cooperating with specific partners and attend to their intentions. We specify the adaptive value of strategic vigilance and preferences for social and self esteem. We argue that evolved preferences for social and self-esteem are satisfied by applying mechanisms of strategic vigilance to one’s own behavior. We further argue that such cognitive processes obviate the need for the evolution of preferences for fairness and social norm compliance.

  13. Gaia Through Time: The Coevolution of Life and Climate

    Science.gov (United States)

    Kasting, J. F.; Haqq-Misra, J.

    2009-12-01

    Earth has the peculiar property of remaining continuously habitable in spite of severe climate change throughout its 4.6 billion year (Ga) history. Life on this planet also has a resilient history, originating soon after Earth cooled and surviving many threats to its existence. In the anoxic Archean (2.8 Ga), the biological activity of methanogens resulted in greenhouse warming by methane and other hydrocarbons to counteract the 20% luminosity reduction from the faint young Sun, leading to the photochemical production of a shielding stratospheric organic haze. A negative feedback loop between methanogen activity and haze thickness maintained warm surface temperatures in the late Archean. The rise of atmospheric oxygen (2.4 Ga) following growth in photosynthesis by cyanobacteria triggered a global glaciation and may have been the most devastating climate change in Earth's history, yet the biosphere recovered to a richly oxic environment in which breathable life became possible. The adaptation of life to a range of ecological niche space, including extreme environments, has contributed to the persistence of life through mass extinctions, most significantly the Permian-Triassic extinction ~250 million years ago (Ma) when up to 96% of marine species and 70% of terrestrial vertebrates vanished. Abrupt climate change has also challenged the survival of life, including the Neoproterozoic Snowball Earth episode (~650 Ma) where evidence from glacial deposits suggests the tropical oceans froze over. During this period life may have thrived in a manner analogous to the Antarctic dry valleys, where sufficient sunlight penetrates the ice to allow photosynthesis. Present day climate change is marked by human influence on atmospheric composition and widespread loss of biodiversity, but even the most severe projected scenarios fall short of the global ecological catastrophes experienced in Earth's past--events from which life has always recovered. The challenge of global warming, then, is not to protect life on this planet but to ensure our own survival and a sustainable future.

  14. Taxonomy, phylogeny, and coevolution of pines and their stem rusts

    Science.gov (United States)

    C. I. Millar; B. B. Kinloch

    1991-01-01

    We review and reinterpret major events in the evolution of pines and their stem rusts using information from their taxonomy, genetics, biogeography, and fossil history. Understanding of pine evolution has been significantly revised in the last 20 years. Pines appear to have evolved early in the Mesozoic and to have diversified and migrated throughout middle latitudes...

  15. Co-Evolution of Opinion and Strategy in Persuasion Dynamics:. AN Evolutionary Game Theoretical Approach

    Science.gov (United States)

    Ding, Fei; Liu, Yun; Li, Yong

    In this paper, a new model of opinion formation within the framework of evolutionary game theory is presented. The model simulates strategic situations when people are in opinion discussion. Heterogeneous agents adjust their behaviors to the environment during discussions, and their interacting strategies evolve together with opinions. In the proposed game, we take into account payoff discount to join a discussion, and the situation that people might drop out of an unpromising game. Analytical and emulational results show that evolution of opinion and strategy always tend to converge, with utility threshold, memory length, and decision uncertainty parameters influencing the convergence time. The model displays different dynamical regimes when we set differently the rule when people are at a loss in strategy.

  16. Co-evolution of hydrological components under climate change scenarios in the Mediterranean area

    Energy Technology Data Exchange (ETDEWEB)

    Viola, F., E-mail: francesco.viola77@unipa.it; Francipane, A.; Caracciolo, D.; Pumo, D.; La Loggia, G.; Noto, L.V.

    2016-02-15

    ABSTRACT: The Mediterranean area is historically characterized by high human pressure on water resources. Today, while climate is projected to be modified in the future, through precipitation decrease and temperature increase, that jointly and non-linearly may affect runoff, concerns about water availability are increasing. For these reasons, quantitative assessment of future modifications in the mean annual water availability are important; likewise, the description of the future interannual variability of some hydrological components such as runoff and evapotranspiration are highly wished for water management and ecosystems dynamics analyses. This study investigates at basin spatial scale future runoff and evapotranspiration, exploring their probability density functions and their interdependence as functions of climatic changes. In order to do that, a parsimonious conceptual lumped model is here used. The model is forced by different future climate scenarios, generated through a weather generator based on a stochastic downscaling of an ensemble of General Circulation Models (GCMs) realizations. The use of the adopted hydrological model, under reliable stochastic future climate scenarios, allows to project future values of evapotranspiration and runoff in a probabilistic framework and, at the same time, the evaluation of their bivariate frequency distributions for changes through the Multivariate Kernel Density Estimation method. As a case study, a benchmark Mediterranean watershed has been proposed (Imera Meridionale, Italy). Results suggest a radical shift and shape modification of the annual runoff and evapotranspiration probability density functions. Possible implications and impacts on water resources management are here addressed and discussed. - Highlights: • This study investigates at basin spatial scale future runoff and evapotranspiration. • A simple conceptual hydrological model and GCMs realizations have been coupled. • Radical shift and shape modification of the annual runoff and evapotranspiration pdf are foreseen. • Future evapotranspiration will lead to similar (same sign) and more marked modifications in runoff.

  17. Sandbox rheometry: Co-evolution of stress and strain in Riedel- and Critical Wedge-experiments

    Science.gov (United States)

    Ritter, Malte C.; Santimano, Tasca; Rosenau, Matthias; Leever, Karen; Oncken, Onno

    2018-01-01

    Analogue sandbox experiments have been used for a long time to understand tectonic processes, because they facilitate detailed measurements of deformation at a spatio-temporal resolution unachievable from natural data. Despite this long history, force measurements to further characterise the mechanical evolution in analogue sandbox experiments have only emerged recently. Combined continuous measurements of forces and deformation in such experiments, an approach here referred to as "sandbox rheometry", are a new tool that may help to better understand work budgets and force balances for tectonic systems and to derive constitutive laws for regional scale deformation. In this article we present an experimental device that facilitates precise measurements of boundary forces and surface deformation at high temporal and spatial resolution. We demonstrate its capabilities in two classical experiments: one of strike-slip deformation (the Riedel set-up) and one of compressional accretionary deformation (the Critical Wedge set-up). In these we are able to directly observe a correlation between strain weakening and strain localisation that had previously only been inferred, namely the coincidence of the maximum localisation rate with the onset of weakening. Additionally, we observe in the compressional experiment a hysteresis of localisation with respect to the mechanical evolution that reflects the internal structural complexity of an accretionary wedge.

  18. Co-evolution of secondary metabolite gene clusters and their host

    DEFF Research Database (Denmark)

    Kjærbølling, Inge; Vesth, Tammi Camilla; Frisvad, Jens Christian

    Secondary metabolite gene cluster evolution is mainly driven by two events: gene duplication and annexation and horizontal gene transfer. Here we use comparative genomics of Aspergillus species to investigate the evolution of secondary metabolite (SM) gene clusters across a wide spectrum of speci....... We investigate the dynamic evolutionary relationship between the cluster and the host by examining the genes within the cluster and the number of homologous genes found within the host and in closely related species.......Secondary metabolite gene cluster evolution is mainly driven by two events: gene duplication and annexation and horizontal gene transfer. Here we use comparative genomics of Aspergillus species to investigate the evolution of secondary metabolite (SM) gene clusters across a wide spectrum of species...

  19. Co-evolution of industry strategies and government policies: The case of the brazilian automotive industry

    NARCIS (Netherlands)

    Duarte, R.G. (Roberto Gonzalez); S.B. Rodrigues (Suzana)

    2017-01-01

    textabstractThis study examines the evolution of the automotive industry in Brazil and its key drivers. We argue that the rules of the game – industry policies – are an outcome of exchanges between the host government and industry. These arise from changes in economic and political environments and

  20. The Co-evolution of Climate Models and the Intergovernmental Panel on Climate Change

    Science.gov (United States)

    Somerville, R. C.

    2010-12-01

    As recently as the 1950s, global climate models, or GCMs, did not exist, and the notion that man-made carbon dioxide might lead to significant climate change was not regarded as a serious possibility by most experts. Today, of course, the prospect or threat of exactly this type of climate change dominates the science and ranks among the most pressing issues confronting all mankind. Indeed, the prevailing scientific view throughout the first half of the twentieth century was that adding carbon dioxide to the atmosphere would have only a negligible effect on climate. The science of climate change caused by atmospheric carbon dioxide changes has thus undergone a genuine revolution. An extraordinarily rapid development of global climate models has also characterized this period, especially in the three decades since about 1980. In these three decades, the number of GCMs has greatly increased, and their physical and computational aspects have both markedly improved. Modeling progress has been enabled by many scientific advances, of course, but especially by a massive increase in available computer power, with supercomputer speeds increasing by roughly a factor of a million in the three decades from about 1980 to 2010. This technological advance has permitted a rapid increase in the physical comprehensiveness of GCMs as well as in spatial computational resolution. In short, GCMs have dramatically evolved over time, in exactly the same recent period as popular interest and scientific concern about anthropogenic climate change have markedly increased. In parallel, a unique international organization, the Intergovernmental Panel on Climate Change, or IPCC, has also recently come into being and also evolved rapidly. Today, the IPCC has become widely respected and globally influential. The IPCC was founded in 1988, and its history is thus even shorter than that of GCMs. Yet, its stature today is such that a series of IPCC reports assessing climate change science has already been endorsed by many leading scientific professional societies and academies of science worldwide. These reports are considered as definitive summaries of the state of the science. In 2007, in recognition of its exceptional accomplishments, the IPCC shared the Nobel Peace Prize equally with Al Gore. The present era is characterized not only by the reality and seriousness of human-caused climate change, but also by a young yet powerful science that enables us to understand much about the climate change that has occurred already and that awaits in the future. The development of GCMs is a critical part of the scientific story, and the development of the IPCC is a key factor in connecting the science to the perceptions and priorities of the global public and policymakers. GCMs and the IPCC have co-evolved and strongly influenced one another, as both scientists and the world at large have worked to confront the challenge of climate change.

  1. Using Association Rules to Study the Co-evolution of Production & Test Code

    NARCIS (Netherlands)

    Lubsen, Z.; Zaidman, A.; Pinzger, M.

    2009-01-01

    Paper accepted for publication in the proceedings of the 6th International Working Conference on Mining Software Repositories (MSR 2009). Unit tests are generally acknowledged as an important aid to produce high quality code, as they provide quick feedback to developers on the correctness of their

  2. Studying Co-evolution of Production and Test Code Using Association Rule Mining

    NARCIS (Netherlands)

    Lubsen, Z.; Zaidman, A.; Pinzger, M.

    2009-01-01

    Long version of the short paper accepted for publication in the proceedings of the 6th International Working Conference on Mining Software Repositories (MSR 2009). Unit tests are generally acknowledged as an important aid to produce high quality code, as they provide quick feedback to developers on

  3. Mining Software Repositories to Study Co-Evolution of Production & Test Code

    NARCIS (Netherlands)

    Zaidman, A.E.; Van Rompaey, B.; Demeyer, S.; Van Deursen, A.

    2008-01-01

    Preprint of paper published in: ICST 2008 - Proceedings of the International Conference on Software Testing, Verification, and Validation, 2008; doi:10.1109/ICST.2008.47 Engineering software systems is a multidisciplinary activity, whereby a number of artifacts must be created — and maintained —

  4. Co-evolution of a broadly neutralizing HIV-1 antibody and founder virus

    Science.gov (United States)

    Liao, Hua-Xin; Lynch, Rebecca; Zhou, Tongqing; Gao, Feng; Alam, S. Munir; Boyd, Scott D.; Fire, Andrew Z.; Roskin, Krishna M.; Schramm, Chaim A.; Zhang, Zhenhai; Zhu, Jiang; Shapiro, Lawrence; Mullikin, James C.; Gnanakaran, S.; Hraber, Peter; Wiehe, Kevin; Kelsoe, Garnett; Yang, Guang; Xia, Shi-Mao; Montefiori, David C.; Parks, Robert; Lloyd, Krissey E.; Scearce, Richard M.; Soderberg, Kelly A.; Cohen, Myron; Kaminga, Gift; Louder, Mark K.; Tran, Lillan M.; Chen, Yue; Cai, Fangping; Chen, Sheri; Moquin, Stephanie; Du, Xiulian; Joyce, Gordon M.; Srivatsan, Sanjay; Zhang, Baoshan; Zheng, Anqi; Shaw, George M.; Hahn, Beatrice H.; Kepler, Thomas B.; Korber, Bette T.M.; Kwong, Peter D.; Mascola, John R.; Haynes, Barton F.

    2013-01-01

    Current HIV-1 vaccines elicit strain-specific neutralizing antibodies. However, cross-reactive neutralizing antibodies arise in ~20% of HIV-1-infected individuals, and details of their generation could provide a roadmap for effective vaccination. Here we report the isolation, evolution and structure of a broadly neutralizing antibody from an African donor followed from time of infection. The mature antibody, CH103, neutralized ~55% of HIV-1 isolates, and its co-crystal structure with gp120 revealed a novel loop-based mechanism of CD4-binding site recognition. Virus and antibody gene sequencing revealed concomitant virus evolution and antibody maturation. Notably, the CH103-lineage unmutated common ancestor avidly bound the transmitted/founder HIV-1 envelope glycoprotein, and evolution of antibody neutralization breadth was preceded by extensive viral diversification in and near the CH103 epitope. These data elucidate the viral and antibody evolution leading to induction of a lineage of HIV-1 broadly neutralizing antibodies and provide insights into strategies to elicit similar antibodies via vaccination. PMID:23552890

  5. Co-evolution of the brand effect and competitiveness in evolving networks

    International Nuclear Information System (INIS)

    Guo Jin-Li

    2014-01-01

    The principle that ‘the brand effect is attractive’ underlies the preferential attachment. Here we show that the brand effect is just one dimension of attractiveness. Another dimension is competitiveness. We firstly introduce a general framework that allows us to investigate the competitive aspect of real networks, instead of simply preferring popular nodes. Our model accurately describes the evolution of social and technological networks. The phenomenon that more competitive nodes become richer can help us to understand the evolution of many competitive systems in nature and society. In general, the paper provides an explicit analytical expression of degree distributions of the network. In particular, the model yields a nontrivial time evolution of nodes' properties and the scale-free behavior with exponents depending on the microscopic parameters characterizing the competition rules. Secondly, through theoretical analyses and numerical simulations, we reveal that our model has not only the universality for the homogeneous weighted network, but also the character for the heterogeneous weighted network. Thirdly, we also develop a model based on the profit-driven mechanism. It can better describe the observed phenomenon in enterprise cooperation networks. We show that the standard preferential attachment, the growing random graph, the initial attractiveness model, the fitness model, and weighted networks can all be seen as degenerate cases of our model. (general)

  6. Privileged Biofuels, Marginalized Indigenous Peoples: The Coevolution of Biofuels Development in the Tropics

    Science.gov (United States)

    Montefrio, Marvin Joseph F.

    2012-01-01

    Biofuels development has assumed an important role in integrating Indigenous peoples and other marginalized populations in the production of biofuels for global consumption. By combining the theories of commoditization and the environmental sociology of networks and flows, the author analyzed emerging trends and possible changes in institutions…

  7. The co-evolution of power and friendship networks in an organization.

    NARCIS (Netherlands)

    Labun, Alona; Wittek, Rafael; Steglich, Christian

    2016-01-01

    Despite the pivotal role that both power and interpersonal trust play in a multitude of social exchange situations, relatively little is known about their interplay. Moreover, previous theorizing makes competing claims. Do we consider our relatively more powerful exchange partners to be less

  8. Phylogenetic analysis of glucosyltransferases and implications for the coevolution of mutans streptococci with their mammalian hosts.

    Directory of Open Access Journals (Sweden)

    Silvia Argimón

    Full Text Available Glucosyltransferases (Gtfs catalyze the synthesis of glucans from sucrose and are produced by several species of lactic-acid bacteria. The oral bacterium Streptococcus mutans produces large amounts of glucans through the action of three Gtfs. GtfD produces water-soluble glucan (WSG, GtfB synthesizes water-insoluble glucans (WIG and GtfC produces mainly WIG but also WSG. These enzymes, especially those synthesizing WIG, are of particular interest because of their role in the formation of dental plaque, an environment where S. mutans can thrive and produce lactic acid, promoting the formation of dental caries. We sequenced the gtfB, gtfC and gtfD genes from several mutans streptococcal strains isolated from the oral cavity of humans and searched for their homologues in strains isolated from chimpanzees and macaque monkeys. The sequence data were analyzed in conjunction with the available Gtf sequences from other bacteria in the genera Streptococcus, Lactobacillus and Leuconostoc to gain insights into the evolutionary history of this family of enzymes, with a particular emphasis on S. mutans Gtfs. Our analyses indicate that streptococcal Gtfs arose from a common ancestral progenitor gene, and that they expanded to form two clades according to the type of glucan they synthesize. We also show that the clade of streptococcal Gtfs synthesizing WIG appeared shortly after the divergence of viviparous, dentate mammals, which potentially contributed to the formation of dental plaque and the establishment of several streptococci in the oral cavity. The two S. mutans Gtfs capable of WIG synthesis, GtfB and GtfC, are likely the product of a gene duplication event. We dated this event to coincide with the divergence of the genomes of ancestral early primates. Thus, the acquisition and diversification of S. mutans Gtfs predates modern humans and is unrelated to the increase in dietary sucrose consumption.

  9. The bacterial parasite Pasteuria ramosa is not killed if it fails to infect: implications for coevolution.

    Science.gov (United States)

    King, Kayla C; Auld, Stuart K J R; Wilson, Philip J; James, Janna; Little, Tom J

    2013-02-01

    Strong selection on parasites, as well as on hosts, is crucial for fueling coevolutionary dynamics. Selection will be especially strong if parasites that encounter resistant hosts are destroyed and diluted from the local environment. We tested whether spores of the bacterial parasite Pasteuria ramosa were passed through the gut (the route of infection) of their host, Daphnia magna, and whether passaged spores remained viable for a "second chance" at infecting a new host. In particular, we tested if this viability (estimated via infectivity) depended on host genotype, whether or not the genotype was susceptible, and on initial parasite dose. Our results show that Pasteuria spores generally remain viable after passage through both susceptible and resistant Daphnia. Furthermore, these spores remained infectious even after being frozen for several weeks. If parasites can get a second chance at infecting hosts in the wild, selection for infection success in the first instance will be reduced. This could also weaken reciprocal selection on hosts and slow the coevolutionary process.

  10. Co-evolution of the brand effect and competitiveness in evolving networks

    Science.gov (United States)

    Guo, Jin-Li

    2014-07-01

    The principle that ‘the brand effect is attractive’ underlies the preferential attachment. Here we show that the brand effect is just one dimension of attractiveness. Another dimension is competitiveness. We firstly introduce a general framework that allows us to investigate the competitive aspect of real networks, instead of simply preferring popular nodes. Our model accurately describes the evolution of social and technological networks. The phenomenon that more competitive nodes become richer can help us to understand the evolution of many competitive systems in nature and society. In general, the paper provides an explicit analytical expression of degree distributions of the network. In particular, the model yields a nontrivial time evolution of nodes' properties and the scale-free behavior with exponents depending on the microscopic parameters characterizing the competition rules. Secondly, through theoretical analyses and numerical simulations, we reveal that our model has not only the universality for the homogeneous weighted network, but also the character for the heterogeneous weighted network. Thirdly, we also develop a model based on the profit-driven mechanism. It can better describe the observed phenomenon in enterprise cooperation networks. We show that the standard preferential attachment, the growing random graph, the initial attractiveness model, the fitness model, and weighted networks can all be seen as degenerate cases of our model.

  11. Co-Evolution of Mobile Language Learning: Going Global with Games Consoles in Higher Education

    Science.gov (United States)

    Hemmi, Akiko; Narumi-Munro, Fumiko; Alexander, Wilma; Parker, Helen; Yamauchi, Yoko

    2014-01-01

    Game consoles have been adopted as a learning platform in school education. However, there is a scarcity of studies examining the utility of games consoles with built-in WiFi as affordable learning platforms in universities. This paper contributes to knowledge about the capacity of the Nintendo DSi to create new learning spaces mediated and…

  12. Creation and dynamical co-evolution of electron and ion channel transport barriers

    International Nuclear Information System (INIS)

    Newman, D.E.

    2002-01-01

    A wide variety of magnetic confinement devices have found transitions to an enhanced confinement regime. Simple dynamical models have been able to capture much of the dynamics of these barriers however an open question has been the disconnected nature of the electron thermal transport channel sometimes observed in the presence of a standard ('ion channel' barrier. By adding to simple barrier model an evolution equation for electron fluctuations we can investigate the interaction between the formation of the standard ion channel barrier and the somewhat less common electron channel barrier. Barrier formation in the electron channel is even more sensitive to the alignment of the various gradients making up the sheared radial electric field than the ion barrier is. Electron channel heat transport is found to significantly increase after the formation of the ion channel barrier but before the electron channel barrier is formed. This increased transport is important in the barrier evolution. (author)

  13. The co-evolution of seawater δ18O and δD

    Science.gov (United States)

    Pope, E. C.

    2017-12-01

    The δ18O of marine carbonate and silica precipitates has increased by 15‰ over the last ca. 3.5 billion years. Whether this shift reflects a parallel increase in oxygen isotope compositions of seawater with time, Precambrian atmospheric temperatures >55°C, or complete alteration of ancient samples during diagenesis, remains controversial despite nearly a half-century of debate. Early mass balance models of the modern ocean system suggested near constant δ18OSEAWATER over time due to the buffering capacity of fresh oceanic crust. However, fluxes controlling 18O sources and sinks to the ocean (high-temperature alteration of the seafloor, and low-temperature weathering of continental and ocean crust, respectively) have not remained fixed throughout Earth history. I adapted published mass balance models for δ18OSEAWATER to evaluate how continental growth, the subaerial emergence of continents, and decreasing mantle temperature affect the magnitude of 18O sources and sinks, and thus the evolution of seawater δ18O since the early Archean. These factors also affect the δD of seawater, which is controlled by the flux of water between mantle, crustal and glacial reservoirs, such that its evolution can be used as an independent constraint on the magnitude that these variables have had on δ18O evolution. The models indicate that a key parameter controlling δ18OSEAWATER is the flux of water between the mantle and free water of the exosphere. Recent geophysical models suggest that the capacity for subducting slabs to sequester water into the deep ocean has increased as the mantle has cooled. Hydrous minerals in subducted oceanic crust have a net δ18O lower than seawater. Incomplete recycling of water from these phases in subduction zones results in progressive removal of 16O from the ocean and thus can explain a significant portion of the increase in δ18O recorded in the marine sediment record. However, mass balance constraints on the global hydrogen budget limits the amount of water which could be sequestered in the mantle. An increase in δDSEAWATER by approximately 25 ± 5‰ since ca. 3.8 Ga, as reflected in the composition of oceanic serpentinites and hydrous silicate minerals formed in subduction-related metasomatic environments, is mostly compensated for by continental growth and the mass of modern glaciers.

  14. Coevolution of economic behaviour and instituions: towards a theory of institutional change.

    NARCIS (Netherlands)

    van den Bergh, J.C.J.M.; Stagl, S.

    2003-01-01

    Traditionally, economics has regarded institutions, notably norms and regulations, as fixed or exogenous. Surprisingly few insights on institutional evolution from natural and social sciences have made their way into economics. This article gives an overview of evolutionary theories of institutions

  15. Coevolution of economic behaviour and institutions: towards a theory of institutional change

    NARCIS (Netherlands)

    van den Bergh, J.C.J.M.

    2003-01-01

    Traditionally, economics has regarded institutions, notably norms and regulations, as fixed or exogenous. Surprisingly few insights on institutional evolution from natural and social sciences have made their way into economics. This article gives an overview of evolutionary theories of institutions

  16. Coevolution of aspirations and cooperation in spatial prisoner's dilemma game

    International Nuclear Information System (INIS)

    Chen, Wei; Wu, Te; Li, Zhiwu; Wang, Long

    2015-01-01

    Suboptimal outcomes are often more acceptable than the best ones when the latter are hard or even impossible to find. In order to describe the emergence of cooperation when suboptimal alternatives prevail, an evolutionary game model is established by considering the effects of aspirations. A win-stay-lose-shift like rule for strategy updating is proposed. The rule prescribes that if the payoff of the current strategy is greater than the aspiration, the strategy remains, otherwise the strategy changes. Aspiration updating allows for individuals to adjust their expected payoff levels. It is shown that suboptimal alternatives can promote the emergence and persistence of cooperation over a wide range of the temptation to defect. Furthermore, a nontrivial phenomenon is found that cooperators prevail as the temptation increases when it is small. The aspirations are stabilized at an intermediate level which can most facilitate cooperation. The obtained results also show that the average level of aspirations decreases as the temptation increases. Furthermore, the variance of aspiration levels is minimized for an intermediate level of temptation. (paper)

  17. Co-evolution of polygonal and scalloped terrains, southwestern Utopia Planitia, Mars

    Science.gov (United States)

    Haltigin, T. W.; Pollard, W. H.; Dutilleul, P.; Osinski, G. R.; Koponen, L.

    2014-02-01

    Thermal contraction crack polygons and scalloped depressions, two of the most common landforms found in Utopia Planitia, Mars, have previously been linked to the presence of ice-rich deposits in the subsurface. Although the formation and evolution of these features individually are relatively well understood, little to no effort has been directed towards elucidating possible interactions that occur between them during their development. Thus, the overarching goal of this research was to investigate if there is an evolutionary link between polygonal and scalloped terrains by correlating metrics representing polygon and scallop maturity. A variety of statistical analyses were performed using HiRISE and MOLA datasets to quantify interactions between four sets of polygonal and scalloped terrains. Our results demonstrate the existence of a negative relationship between polygonal subdivision and surface elevation, indicating that polygon networks become more ‘evolved’ as the surface subsides. These results suggest that the permafrost landscape in Utopia Planitia may once have been extremely ice-rich, and that multiple geomorphic processes may be responsible for its evolution. Ultimately, this work demonstrates that landscape reconstruction is more complete when a system approach is followed, quantifying interactions between landforms as opposed to examining an individual landform in isolation.

  18. Evolutionary Musicology Meets Embodied Cognition: Biocultural Coevolution and the Enactive Origins of Human Musicality

    Directory of Open Access Journals (Sweden)

    Dylan van der Schyff

    2017-09-01

    Full Text Available Despite evolutionary musicology's interdisciplinary nature, and the diverse methods it employs, the field has nevertheless tended to divide into two main positions. Some argue that music should be understood as a naturally selected adaptation, while others claim that music is a product of culture with little or no relevance for the survival of the species. We review these arguments, suggesting that while interesting and well-reasoned positions have been offered on both sides of the debate, the nature-or-culture (or adaptation vs. non-adaptation assumptions that have traditionally driven the discussion have resulted in a problematic either/or dichotomy. We then consider an alternative “biocultural” proposal that appears to offer a way forward. As we discuss, this approach draws on a range of research in theoretical biology, archeology, neuroscience, embodied and ecological cognition, and dynamical systems theory (DST, positing a more integrated model that sees biological and cultural dimensions as aspects of the same evolving system. Following this, we outline the enactive approach to cognition, discussing the ways it aligns with the biocultural perspective. Put simply, the enactive approach posits a deep continuity between mind and life, where cognitive processes are explored in terms of how self-organizing living systems enact relationships with the environment that are relevant to their survival and well-being. It highlights the embodied and ecologically situated nature of living agents, as well as the active role they play in their own developmental processes. Importantly, the enactive approach sees cognitive and evolutionary processes as driven by a range of interacting factors, including the socio-cultural forms of activity that characterize the lives of more complex creatures such as ourselves. We offer some suggestions for how this approach might enhance and extend the biocultural model. To conclude we briefly consider the implications of this approach for practical areas such as music education.

  19. Evolutionary Musicology Meets Embodied Cognition: Biocultural Coevolution and the Enactive Origins of Human Musicality.

    Science.gov (United States)

    van der Schyff, Dylan; Schiavio, Andrea

    2017-01-01

    Despite evolutionary musicology's interdisciplinary nature, and the diverse methods it employs, the field has nevertheless tended to divide into two main positions. Some argue that music should be understood as a naturally selected adaptation, while others claim that music is a product of culture with little or no relevance for the survival of the species. We review these arguments, suggesting that while interesting and well-reasoned positions have been offered on both sides of the debate, the nature-or-culture (or adaptation vs. non-adaptation) assumptions that have traditionally driven the discussion have resulted in a problematic either/or dichotomy. We then consider an alternative "biocultural" proposal that appears to offer a way forward. As we discuss, this approach draws on a range of research in theoretical biology, archeology, neuroscience, embodied and ecological cognition, and dynamical systems theory (DST), positing a more integrated model that sees biological and cultural dimensions as aspects of the same evolving system. Following this, we outline the enactive approach to cognition, discussing the ways it aligns with the biocultural perspective. Put simply, the enactive approach posits a deep continuity between mind and life, where cognitive processes are explored in terms of how self-organizing living systems enact relationships with the environment that are relevant to their survival and well-being. It highlights the embodied and ecologically situated nature of living agents, as well as the active role they play in their own developmental processes. Importantly, the enactive approach sees cognitive and evolutionary processes as driven by a range of interacting factors, including the socio-cultural forms of activity that characterize the lives of more complex creatures such as ourselves. We offer some suggestions for how this approach might enhance and extend the biocultural model. To conclude we briefly consider the implications of this approach for practical areas such as music education.

  20. Where Do New Organizational Forms Come From? Management Logics as a Source of Coevolution

    NARCIS (Netherlands)

    M.S. Dijksterhuis; F.A.J. van den Bosch (Frans); H.W. Volberda (Henk)

    1999-01-01

    textabstractMany scholars have described organization form as a management tool in the alignment of organization and environment. As the environment of many companies becomes more chaotic, the exploration of organization forms characterized by flexibility and adaptability has been intensifying. When

  1. Disentangling evolutionary signals: conservation, specificity determining positions and coevolution. Implication for catalytic residue prediction

    DEFF Research Database (Denmark)

    Teppa, Elin; Wilkins, Angela D.; Nielsen, Morten

    2012-01-01

    Background: A large panel of methods exists that aim to identify residues with critical impact on protein function based on evolutionary signals, sequence and structure information. However, it is not clear to what extent these different methods overlap, and if any of the methods have higher...... predictive potential compared to others when it comes to, in particular, the identification of catalytic residues (CR) in proteins. Using a large set of enzymatic protein families and measures based on different evolutionary signals, we sought to break up the different components of the information content......-value Evolutionary Trace (rvET) methods and conservation, another containing mutual information (MI) methods, and the last containing methods designed explicitly for the identification of specificity determining positions (SDPs): integer-value Evolutionary Trace (ivET), SDPfox, and XDET. In terms of prediction of CR...

  2. Co-Evolution of Friendship and Publishing in Online Blogging Social Networks

    OpenAIRE

    Zinoviev, Dmitry; Llewelyn, Sarah

    2014-01-01

    In the past decade, blogging web sites have become more sophisticated and influential than ever. Much of this sophistication and influence follows from their network organization. Blogging social networks (BSNs) allow individual bloggers to form contact lists, subscribe to other blogs, comment on blog posts, declare interests, and participate in collective blogs. Thus, a BSN is a bimodal venue, where users can engage in publishing (post) as well as in social (make friends) activities. In this...

  3. Co-evolution of affinity and stability of grafted amyloid-motif domain antibodies.

    Science.gov (United States)

    Julian, Mark C; Lee, Christine C; Tiller, Kathryn E; Rabia, Lilia A; Day, Evan K; Schick, Arthur J; Tessier, Peter M

    2015-10-01

    An attractive approach for designing lead antibody candidates is to mimic natural protein interactions by grafting peptide recognition motifs into the complementarity-determining regions (CDRs). We are using this approach to generate single-domain (VH) antibodies specific for amyloid-forming proteins such as the Alzheimer's Aβ peptide. Here, we use random mutagenesis and yeast surface display to improve the binding affinity of a lead VH domain grafted with Aβ residues 33-42 in CDR3. Interestingly, co-selection for improved Aβ binding and VH display on the surface of yeast yields antibody domains with improved affinity and reduced stability. The highest affinity VH domains were strongly destabilized on the surface of yeast as well as unfolded when isolated as autonomous domains. In contrast, stable VH domains with improved affinity were reliably identified using yeast surface display by replacing the display antibody that recognizes a linear epitope tag at the terminus of both folded and unfolded VH domains with a conformational ligand (Protein A) that recognizes a discontinuous epitope on the framework of folded VH domains. Importantly, we find that selection for improved stability using Protein A without simultaneous co-selection for improved Aβ binding leads to strong enrichment for stabilizing mutations that reduce antigen binding. Our findings highlight the importance of simultaneously optimizing affinity and stability to improve the rapid isolation of well-folded and specific antibody fragments. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  4. A Cooperative Coevolution Approach to Automate Pattern-based Software Architectural Synthesis

    NARCIS (Netherlands)

    Xu, Y.R.; Liang, P.

    2014-01-01

    To reuse successful experience in software architecture design, architects use architectural patterns as reusable architectural knowledge for architectural synthesis. However, it has been observed that the resulting architecture does not always conform to the initial architectural patterns employed.

  5. Industrial leadership in Science-based Industries. A co-evolution model

    OpenAIRE

    Fatas-Villafranca , Francisco; Jarne , Gloria; Sanchez-Choliz , Julio

    2009-01-01

    Abstract In this paper, we seek to analyse the role of national university systems in combination with technological and market factors as sources of industrial leadership and industry growth in sciencebased industries. We propose a model in which national university systems and their respective national firms and industries are considered as co-evolving. National firms compete on a worldwide level and they rely on the progress of science and the availability of scientists to innov...

  6. Artificial neuron-glia networks learning approach based on cooperative coevolution.

    Science.gov (United States)

    Mesejo, Pablo; Ibáñez, Oscar; Fernández-Blanco, Enrique; Cedrón, Francisco; Pazos, Alejandro; Porto-Pazos, Ana B

    2015-06-01

    Artificial Neuron-Glia Networks (ANGNs) are a novel bio-inspired machine learning approach. They extend classical Artificial Neural Networks (ANNs) by incorporating recent findings and suppositions about the way information is processed by neural and astrocytic networks in the most evolved living organisms. Although ANGNs are not a consolidated method, their performance against the traditional approach, i.e. without artificial astrocytes, was already demonstrated on classification problems. However, the corresponding learning algorithms developed so far strongly depends on a set of glial parameters which are manually tuned for each specific problem. As a consequence, previous experimental tests have to be done in order to determine an adequate set of values, making such manual parameter configuration time-consuming, error-prone, biased and problem dependent. Thus, in this paper, we propose a novel learning approach for ANGNs that fully automates the learning process, and gives the possibility of testing any kind of reasonable parameter configuration for each specific problem. This new learning algorithm, based on coevolutionary genetic algorithms, is able to properly learn all the ANGNs parameters. Its performance is tested on five classification problems achieving significantly better results than ANGN and competitive results with ANN approaches.

  7. Co-Evolution of Social Learning and Evolutionary Preparedness in Dangerous Environments.

    Science.gov (United States)

    Lindström, Björn; Selbing, Ida; Olsson, Andreas

    2016-01-01

    Danger is a fundamental aspect of the lives of most animals. Adaptive behavior therefore requires avoiding actions, objects, and environments associated with danger. Previous research has shown that humans and non-human animals can avoid such dangers through two types of behavioral adaptions, (i) genetic preparedness to avoid certain stimuli or actions, and (ii) social learning. These adaptive mechanisms reduce the fitness costs associated with danger but still allow flexible behavior. Despite the empirical prevalence and importance of both these mechanisms, it is unclear when they evolve and how they interact. We used evolutionary agent-based simulations, incorporating empirically based learning mechanisms, to clarify if preparedness and social learning typically both evolve in dangerous environments, and if these mechanisms generally interact synergistically or antagonistically. Our simulations showed that preparedness and social learning often co-evolve because they provide complimentary benefits: genetic preparedness reduced foraging efficiency, but resulted in a higher rate of survival in dangerous environments, while social learning generally came to dominate the population, especially when the environment was stochastic. However, even in this case, genetic preparedness reliably evolved. Broadly, our results indicate that the relationship between preparedness and social learning is important as it can result in trade-offs between behavioral flexibility and safety, which can lead to seemingly suboptimal behavior if the evolutionary environment of the organism is not taken into account.

  8. Anticipatory Interventions and the Co-Evolution of Nanotechnology and Society

    NARCIS (Netherlands)

    te Kulve, Haico

    2011-01-01

    In contrast with earlier emerging technologies, in the case of nanotechnology there is a lot of anticipation sourrounding how it might, or should, become embedded in society. These ‘anticipatory interventions’ not only affect ongoing processes in the present, but also provide directions for the

  9. Co-evolution of hydrological components under climate change scenarios in the Mediterranean area

    International Nuclear Information System (INIS)

    Viola, F.; Francipane, A.; Caracciolo, D.; Pumo, D.; La Loggia, G.; Noto, L.V.

    2016-01-01

    ABSTRACT: The Mediterranean area is historically characterized by high human pressure on water resources. Today, while climate is projected to be modified in the future, through precipitation decrease and temperature increase, that jointly and non-linearly may affect runoff, concerns about water availability are increasing. For these reasons, quantitative assessment of future modifications in the mean annual water availability are important; likewise, the description of the future interannual variability of some hydrological components such as runoff and evapotranspiration are highly wished for water management and ecosystems dynamics analyses. This study investigates at basin spatial scale future runoff and evapotranspiration, exploring their probability density functions and their interdependence as functions of climatic changes. In order to do that, a parsimonious conceptual lumped model is here used. The model is forced by different future climate scenarios, generated through a weather generator based on a stochastic downscaling of an ensemble of General Circulation Models (GCMs) realizations. The use of the adopted hydrological model, under reliable stochastic future climate scenarios, allows to project future values of evapotranspiration and runoff in a probabilistic framework and, at the same time, the evaluation of their bivariate frequency distributions for changes through the Multivariate Kernel Density Estimation method. As a case study, a benchmark Mediterranean watershed has been proposed (Imera Meridionale, Italy). Results suggest a radical shift and shape modification of the annual runoff and evapotranspiration probability density functions. Possible implications and impacts on water resources management are here addressed and discussed. - Highlights: • This study investigates at basin spatial scale future runoff and evapotranspiration. • A simple conceptual hydrological model and GCMs realizations have been coupled. • Radical shift and shape modification of the annual runoff and evapotranspiration pdf are foreseen. • Future evapotranspiration will lead to similar (same sign) and more marked modifications in runoff.

  10. Fossilized skin reveals coevolution with feathers and metabolism in feathered dinosaurs and early birds.

    Science.gov (United States)

    McNamara, Maria E; Zhang, Fucheng; Kearns, Stuart L; Orr, Patrick J; Toulouse, André; Foley, Tara; Hone, David W E; Rogers, Chris S; Benton, Michael J; Johnson, Diane; Xu, Xing; Zhou, Zhonghe

    2018-05-25

    Feathers are remarkable evolutionary innovations that are associated with complex adaptations of the skin in modern birds. Fossilised feathers in non-avian dinosaurs and basal birds provide insights into feather evolution, but how associated integumentary adaptations evolved is unclear. Here we report the discovery of fossil skin, preserved with remarkable nanoscale fidelity, in three non-avian maniraptoran dinosaurs and a basal bird from the Cretaceous Jehol biota (China). The skin comprises patches of desquamating epidermal corneocytes that preserve a cytoskeletal array of helically coiled α-keratin tonofibrils. This structure confirms that basal birds and non-avian dinosaurs shed small epidermal flakes as in modern mammals and birds, but structural differences imply that these Cretaceous taxa had lower body heat production than modern birds. Feathered epidermis acquired many, but not all, anatomically modern attributes close to the base of the Maniraptora by the Middle Jurassic.

  11. Stimulating diffusion of green products - Co-evolution between firms and consumers

    NARCIS (Netherlands)

    Janssen, MA; Jager, W

    This paper presents a model-based analysis of the introduction of green products, which are products with low environmental impacts. Both consumers and firms are simulated as populations of agents who differ in their behavioural characteristics. Model experiments illustrate the influence of

  12. Configuration management for models : generic methods for model comparison and model co-evolution

    NARCIS (Netherlands)

    Protic, Z.

    2011-01-01

    It is an undeniable fact that software plays an important role in our lives. We use the software to play our music, to check our e-mail, or even to help us drive our car. Thus, the quality of software directly influences the quality of our lives. However, the traditional Software Engineering

  13. The Co-evolution of Technologies and Markets - On Market Transparency in Nanotech Evolution

    DEFF Research Database (Denmark)

    Andersen, Maj Munch

    and the environment associated with nanotechnology. There are some early indications that firms are developing new nano strategies where nano activities increasingly are treated discretely. The paper investigates these trends using the flat glass industry as case based on bibliometric studies and other company......This paper suggests to look into the market formation processes related to emerging technologies, using nanotechnology as a case. This is in contrast to the usual focus on knowledge generation aspects when analyzing technology evolution in evolutionary economic research. Although nanotechnology...... communication as well as in depth case analyses. The paper concludes tentatively that while the market for nano products seems to approach commercialization it is becoming still less transparent. This may have important implications for the further commercialization of nanotechnology, which are discussed...

  14. FreeContact: fast and free software for protein contact prediction from residue co-evolution.

    Science.gov (United States)

    Kaján, László; Hopf, Thomas A; Kalaš, Matúš; Marks, Debora S; Rost, Burkhard

    2014-03-26

    20 years of improved technology and growing sequences now renders residue-residue contact constraints in large protein families through correlated mutations accurate enough to drive de novo predictions of protein three-dimensional structure. The method EVfold broke new ground using mean-field Direct Coupling Analysis (EVfold-mfDCA); the method PSICOV applied a related concept by estimating a sparse inverse covariance matrix. Both methods (EVfold-mfDCA and PSICOV) are publicly available, but both require too much CPU time for interactive applications. On top, EVfold-mfDCA depends on proprietary software. Here, we present FreeContact, a fast, open source implementation of EVfold-mfDCA and PSICOV. On a test set of 140 proteins, FreeContact was almost eight times faster than PSICOV without decreasing prediction performance. The EVfold-mfDCA implementation of FreeContact was over 220 times faster than PSICOV with negligible performance decrease. EVfold-mfDCA was unavailable for testing due to its dependency on proprietary software. FreeContact is implemented as the free C++ library "libfreecontact", complete with command line tool "freecontact", as well as Perl and Python modules. All components are available as Debian packages. FreeContact supports the BioXSD format for interoperability. FreeContact provides the opportunity to compute reliable contact predictions in any environment (desktop or cloud).

  15. Dutch identity in fashion: Co-evolution between brands and consumers

    NARCIS (Netherlands)

    Freiherr von Maltzahn, C.-F.

    2013-01-01

    We all like to think of ourselves as unique and creative personalities with their very own interpretation of fashion. Arguably, there are a number of individuals who stand out from the crowd with their clothing choices. But how many of us are actually part of that group? After all, one of fashion’s

  16. The role of local adaptation in shaping fish-mussel coevolution

    DEFF Research Database (Denmark)

    Douda, Karel; Liu, Huan-Zhang; Yu, Dan

    2017-01-01

    impact on the persistence of local populations. Bivalves of the order Unionida (freshwater mussels) are a functionally important but declining group of affiliate species, which are dependent on freshwater fish to host their parasitic larvae. The role of local adaptations and host fish resistance......1. The survival of affiliate (dependent) species in a changing environment is determined by the interactions between the affiliate species and their available hosts. However, the patterns of spatial and temporal changes in host compatibility are often unknown despite host shifts having direct...... associated bitterling fishes was low in its native range (with ancient sympatry). In areas of recent sympatry (non-native S.woodiana range in Europe), S.woodiana glochidia were demonstrated to readily parasitise local, evolutionarily naive bitterling species at high density.4. The results of a population...

  17. Predicting galaxy star formation rates via the co-evolution of galaxies and haloes

    Science.gov (United States)

    Watson, Douglas F.; Hearin, Andrew P.; Berlind, Andreas A.; Becker, Matthew R.; Behroozi, Peter S.; Skibba, Ramin A.; Reyes, Reinabelle; Zentner, Andrew R.; van den Bosch, Frank C.

    2015-01-01

    In this paper, we test the age matching hypothesis that the star formation rate (SFR) of a galaxy of fixed stellar mass is determined by its dark matter halo formation history, e.g. more quiescent galaxies reside in older haloes. We present new Sloan Digital Sky Survey measurements of the galaxy two-point correlation function and galaxy-galaxy lensing as a function of stellar mass and SFR, separated into quenched and star-forming galaxy samples to test this simple model. We find that our age matching model is in excellent agreement with these new measurements. We also find that our model is able to predict: (1) the relative SFRs of central and satellite galaxies, (2) the SFR dependence of the radial distribution of satellite galaxy populations within galaxy groups, rich groups, and clusters and their surrounding larger scale environments, and (3) the interesting feature that the satellite quenched fraction as a function of projected radial distance from the central galaxy exhibits an ˜r-.15 slope, independent of environment. These accurate predictions are intriguing given that we do not explicitly model satellite-specific processes after infall, and that in our model the virial radius does not mark a special transition region in the evolution of a satellite. The success of the model suggests that present-day galaxy SFR is strongly correlated with halo mass assembly history.

  18. Predicting Galaxy Star Formation Rates via the Co-evolution of Galaxies and Halos

    OpenAIRE

    Watson, Douglas F.; Hearin, Andrew P.; Berlind, Andreas A.; Becker, Matthew R.; Behroozi, Peter S.; Skibba, Ramin A.; Reyes, Reinabelle; Zentner, Andrew R.; Bosch, Frank C. van den

    2014-01-01

    In this paper, we test the age matching hypothesis that the star formation rate (SFR) of a galaxy of fixed stellar mass is determined by its dark matter halo formation history, and as such, that more quiescent galaxies reside in older halos. This simple model has been remarkably successful at predicting color-based galaxy statistics at low redshift as measured in the Sloan Digital Sky Survey (SDSS). To further test this method with observations, we present new SDSS measurements of the galaxy ...

  19. Black hole-galaxy co-evolution in the Mufasa simulations

    Science.gov (United States)

    Dave, Romeel; Angles-Alcazar, Daniel

    2017-08-01

    The Mufasa simulations are large-scale cosmological and zoom simulations of galaxy formation that employ novel state of the art modules for star formation and feedback physics, resulting in very good agreement with many key galaxy observables over most of cosmic time. We have recently included black hole growth and feedback using the torque-limited accretion model, which has several advantages over the commonly-used Bondi accretion. We also include AGN feedback using a BAL mode at high Eddington rates and low black hole masses, and a jet mode at low Eddington rates that successfully quenches galaxies. In this talk I will describe preliminary results of the AGN population and its evolution over cosmic time within our new simulations, including cosmological simulations of the general black hole population as well as zoom simulations targeting massive galaxies, with a focus on understanding the co-growth of black holes and galaxies as a function of mass, environment, and cosmic epoch. I will also discuss multi-wavelength approaches to testing and constraining our black hole model in particular using upcoming X-ray and radio facilities such as Lynx and the SKA.

  20. Does Society Need Altruists? Coevolution of General Trust and Social Intelligence

    OpenAIRE

    澁谷, 浩

    2013-01-01

    Most social scientists, especially economists, believe that altruists do not exist because they cannot survive exploitation by egoists. An agent-based model demonstrates, however, that altruists can survive natural selection if society comprises four types of individuals: altruists, reciprocal altruists, egoists and reciprocal egoists. These individuals are characterized by different combinations of two phenotypes: general trust and social intelligence. In a society of four types of individua...

  1. Cannabis use and psychotic-like experiences trajectories during early adolescence: the coevolution and potential mediators.

    Science.gov (United States)

    Bourque, Josiane; Afzali, Mohammad H; O'Leary-Barrett, Maeve; Conrod, Patricia

    2017-12-01

    The authors sought to model the different trajectories of psychotic-like experiences (PLE) during adolescence and to examine whether the longitudinal relationship between cannabis use and PLE is mediated by changes in cognitive development and/or change in anxiety or depression symptoms. A total of 2,566 youths were assessed every year for 4-years (from 13- to 16-years of age) on clinical, substance use and cognitive development outcomes. Latent class growth models identified three trajectories of PLE: low decreasing (83.9%), high decreasing (7.9%), and moderate increasing class (8.2%). We conducted logistic regressions to investigate whether baseline levels and growth in cannabis use were associated with PLE trajectory membership. Then, we examined the effects of potential mediators (growth in cognition and anxiety/depression) on the relationship between growth in cannabis use and PLE trajectory. A steeper growth in cannabis use from 13- to 16-years was associated with a higher likelihood of being assigned to the moderate increasing trajectory of PLE [odds ratio, 2.59; 95% confidence interval (CI), 1.11-6.03], when controlling for cumulative cigarette use. Growth in depression symptoms, not anxiety or change in cognitive functioning, mediated the relationship between growth in cannabis use and the PLE moderate increasing group (indirect effect: 0.07; 95% CI, 0.03-0.11). Depression symptoms partially mediated the longitudinal link between cannabis use and PLE in adolescents, suggesting that there may be a preventative effect to be gained from targeting depression symptoms, in addition to attempting to prevent cannabis use in youth presenting increasing psychotic experiences. © 2017 Association for Child and Adolescent Mental Health.

  2. Towards a Theory of Societal Co-Evolution: Individualism versus Collectivism

    OpenAIRE

    Ahuja, Kartik; Zhang, Simpson; van der Schaar, Mihaela

    2014-01-01

    Substantial empirical research has shown that the level of individualism vs. collectivism is one of the most critical and important determinants of societal traits, such as economic growth, economic institutions and health conditions. But the exact nature of this impact has thus far not been well understood in an analytical setting. In this work, we develop one of the first theoretical models that analytically studies the impact of individualism-collectivism on the society. We model the growt...

  3. Matching allele dynamics and coevolution in a minimal predator-prey replicator model

    International Nuclear Information System (INIS)

    Sardanyes, Josep; Sole, Ricard V.

    2008-01-01

    A minimal Lotka-Volterra type predator-prey model describing coevolutionary traits among entities with a strength of interaction influenced by a pair of haploid diallelic loci is studied with a deterministic time continuous model. We show a Hopf bifurcation governing the transition from evolutionary stasis to periodic Red Queen dynamics. If predator genotypes differ in their predation efficiency the more efficient genotype asymptotically achieves lower stationary concentrations

  4. Co-evolution of enzyme function in the attine ant-fungus symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    Introduction: Fungus-growing ants cultivate specialized fungi in the tribe Leucocoprineae (Lepiotaceae: Basidiomycota) inside their nests. The conspicuous leaf-cutting ants in the genus Atta build huge nests displacing several cubic meters of soil, whereas lower attine genera such as Cyphomyrmex ...... garden. This system can be viewed as ant induced crop optimization similar to human agricultural practices....... have small nests with a fungus garden the size of a table-tennis ball. Only the leaf-cutting ants are specialized on using fresh leaves as substrate for their fungus gardens, whereas the more basal attine genera use substrates such as dry plant material (leaf litter and small twigs) and also insect...... feces and insect carcasses. This diverse array of fungal substrates across the attine lineage implies that the symbiotic fungus needs different enzymes to break down the plant material that the ants provide or different efficiencies of enzyme function. Methods: (1.) We made a literature survey...

  5. Coevolution of hydrology and topography on a basalt landscape in the Oregon Cascade Range, USA

    Science.gov (United States)

    A. Jefferson; G.E. Grant; S.L. Lewis; S.T. Lancaster

    2010-01-01

    Young basalt terrains offer an exceptional opportunity to study landscape and hydrologic evolution through time, as the age of the landscape itself can be determined by dating lava flows. These constructional terrains are also highly permeable, allowing one to examine timescales and process of geomorphic evolution as they relate to the partitioning of hydrologic...

  6. Convergent coevolution in the domestication of coral mushrooms by fungus-growing ants

    DEFF Research Database (Denmark)

    Munkacsi, A B; Nees, Jan Pan; Villesen, Palle

    2004-01-01

    Comparisons of phylogenetic patterns between coevolving symbionts can reveal rich details about the evolutionary history of symbioses. The ancient symbiosis between fungus-growing ants, their fungal cultivars, antibiotic-producing bacteria and cultivar-infecting parasites is dominated by a patter...

  7. Coevolution in management fashion: an agent-based model of consultant-driven innovation.

    Science.gov (United States)

    Strang, David; David, Robert J; Akhlaghpour, Saeed

    2014-07-01

    The rise of management consultancy has been accompanied by increasingly marked faddish cycles in management techniques, but the mechanisms that underlie this relationship are not well understood. The authors develop a simple agent-based framework that models innovation adoption and abandonment on both the supply and demand sides. In opposition to conceptions of consultants as rhetorical wizards who engineer waves of management fashion, firms and consultants are treated as boundedly rational actors who chase the secrets of success by mimicking their highest-performing peers. Computational experiments demonstrate that consultant-driven versions of this dynamic in which the outcomes of firms are strongly conditioned by their choice of consultant are robustly faddish. The invasion of boom markets by low-quality consultants undercuts popular innovations while simultaneously restarting the fashion cycle by prompting the flight of high-quality consultants into less densely occupied niches. Computational experiments also indicate conditions involving consultant mobility, aspiration levels, mimic probabilities, and client-provider matching that attenuate faddishness.

  8. The role of local adaptation in shaping fish-mussel coevolution

    Czech Academy of Sciences Publication Activity Database

    Douda, K.; Liu, H.-Z.; Yu, D.; Rouchet, Romain; Liu, F.; Tang, Q.-Y.; Methling, Caroline; Smith, Carl; Reichard, Martin

    2017-01-01

    Roč. 62, č. 11 (2017), s. 1858-1868 ISSN 0046-5070 R&D Projects: GA ČR GA13-05872S Institutional support: RVO:68081766 Keywords : affiliate species * freshwater bivalves * glochidia * host relationships * Sinanodonta woodiana Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 3.255, year: 2016

  9. Coevolution within a transcriptional network by compensatory trans and cis mutations

    KAUST Repository

    Kuo, D.; Licon, K.; Bandyopadhyay, S.; Chuang, R.; Luo, C.; Catalana, J.; Ravasi, Timothy; Tan, K.; Ideker, T.

    2010-01-01

    Transcriptional networks have been shown to evolve very rapidly, prompting questions as to how such changes arise and are tolerated. Recent comparisons of transcriptional networks across species have implicated variations in the cis-acting DNA

  10. Convergent coevolution in the domestication of coral mushrooms by fungus-growing ants

    DEFF Research Database (Denmark)

    Munkacsi, A B; Pan, J J; Villesen, Palle

    2004-01-01

    -mushroom family Pterulaceae using phylogenetic reconstructions based on broad taxon sampling, including the first mushroom collected from the garden of an ant species in the A. pilosum group. The domestication of the pterulaceous cultivar is independent from the domestication of the gilled mushrooms cultivated......Comparisons of phylogenetic patterns between coevolving symbionts can reveal rich details about the evolutionary history of symbioses. The ancient symbiosis between fungus-growing ants, their fungal cultivars, antibiotic-producing bacteria and cultivar-infecting parasites is dominated by a pattern...

  11. The ecology of technology : the co-evolution of technology and organization

    NARCIS (Netherlands)

    Oord, van den A.J.

    2010-01-01

    In this day and age, arguing that technology is a powerful force that drives many economic processes is like preaching to the choir. Nevertheless, despite the widespread realization of the important role of technology in our modern day society, an intimate understanding of the process of

  12. Coevolution with bacteria drives the evolution of aerobic fermentation in Lachancea kluyveri.

    Directory of Open Access Journals (Sweden)

    Nerve Zhou

    Full Text Available The Crabtree positive yeasts, such as Saccharomyces cerevisiae, prefer fermentation to respiration, even under fully aerobic conditions. The selective pressures that drove the evolution of this trait remain controversial because of the low ATP yield of fermentation compared to respiration. Here we propagate experimental populations of the weak-Crabtree yeast Lachancea kluyveri, in competitive co-culture with bacteria. We find that L. kluyveri adapts by producing quantities of ethanol lethal to bacteria and evolves several of the defining characteristics of Crabtree positive yeasts. We use precise quantitative analysis to show that the rate advantage of fermentation over aerobic respiration is insufficient to provide an overall growth advantage. Thus, the rapid consumption of glucose and the utilization of ethanol are essential for the success of the aerobic fermentation strategy. These results corroborate that selection derived from competition with bacteria could have provided the impetus for the evolution of the Crabtree positive trait.

  13. Molecular diversity of entodiniomorphid ciliate Troglodytella abrassarti and its coevolution with chimpanzees

    Czech Academy of Sciences Publication Activity Database

    Vallo, Peter; Petrželková, Klára Judita; Profousová, Ilona; Petrášová, J.; Pomajbíková, K.; Leendertz, F.; Hashimoto, C.; Simmons, N.; Babweteera, F.; Machanda, Z.; Piel, A.; Robbins, M. M.; Boesch, C.; Sanz, C.; Morgan, D.; Sommer, V.; Furuichi, T.; Fujita, S.; Matsuzawa, T.; Kaur, T.; Huffman, M. A.; Modrý, David

    2012-01-01

    Roč. 148, č. 4 (2012), s. 525-533 ISSN 0002-9483 Institutional support: RVO:68081766 ; RVO:60077344 Keywords : SSU rDNA * ITS * entodiniomorphida * Troglodytellidae * Pan troglodytes Subject RIV: EG - Zoology Impact factor: 2.481, year: 2012

  14. Intestinal Microbiota and Celiac Disease: Cause, Consequence or Co-Evolution?

    Directory of Open Access Journals (Sweden)

    María Carmen Cenit

    2015-08-01

    Full Text Available It is widely recognized that the intestinal microbiota plays a role in the initiation and perpetuation of intestinal inflammation in numerous chronic conditions. Most studies report intestinal dysbiosis in celiac disease (CD patients, untreated and treated with a gluten-free diet (GFD, compared to healthy controls. CD patients with gastrointestinal symptoms are also known to have a different microbiota compared to patients with dermatitis herpetiformis and controls, suggesting that the microbiota is involved in disease manifestation. Furthermore, a dysbiotic microbiota seems to be associated with persistent gastrointestinal symptoms in treated CD patients, suggesting its pathogenic implication in these particular cases. GFD per se influences gut microbiota composition, and thus constitutes an inevitable confounding factor in studies conducted in CD patients. To improve our understanding of whether intestinal dysbiosis is the cause or consequence of disease, prospective studies in healthy infants at family risk of CD are underway. These studies have revealed that the CD host genotype selects for the early colonizers of the infant’s gut, which together with environmental factors (e.g., breast-feeding, antibiotics, etc. could influence the development of oral tolerance to gluten. Indeed, some CD genes and/or their altered expression play a role in bacterial colonization and sensing. In turn, intestinal dysbiosis could promote an abnormal response to gluten or other environmental CD-promoting factors (e.g., infections in predisposed individuals. Here, we review the current knowledge of host-microbe interactions and how host genetics/epigenetics and environmental factors shape gut microbiota and may influence disease risk. We also summarize the current knowledge about the potential mechanisms of action of the intestinal microbiota and specific components that affect CD pathogenesis.

  15. Victims, bullies, and their defenders : A longitudinal study of the coevolution of positive and negative networks

    NARCIS (Netherlands)

    Huitsing, Gijs; Snijders, Tom A.B.; Van Duijn, Marijtje A. J.; Veenstra, René

    The complex interplay between bullying/victimization and defending was examined using a longitudinal social network approach (stochastic actor-based models). The (co) evolution of these relations within three elementary schools (Grades 2-5 at Time 1, ages 8-11, N = 354 children) was investigated

  16. Co-evolution of Friendships and Antipathies: A Longitudinal Study of Preschool Peer Groups

    Directory of Open Access Journals (Sweden)

    João R. Daniel

    2016-10-01

    Full Text Available We used stochastic actor-based models to test whether the developmental dynamics of friendships and antipathies in preschool peer groups (followed throughout three school years were co-dependent. We combined choices from three sociometric tasks of 142 children to identify friendship and antipathy ties and used SIENA to model network dynamics. Our results show that different social processes drive the development of friendship and antipathy ties, and that they do not develop in association (i.e., friendship ties are not dependent on existing antipathies, and vice-versa. These results differ from those of older children (age range = 10-14 suggesting that the interplay of friendship and antipathy only plays a significant role in the peer group context in older children. We propose these differences to be likely related with preschool age children’s inaccurate perceptions of their classmates’ relationships, particularly of their antipathies, and/or with the absence of shared norms to deal with antipathetic relationships.

  17. Modelling the morphodynamics and co-evolution of coast and estuarine environments

    Science.gov (United States)

    Morris, Chloe; Coulthard, Tom; Parsons, Daniel R.; Manson, Susan; Barkwith, Andrew

    2017-04-01

    The morphodynamics of coast and estuarine environments are known to be sensitive to environmental change and sea-level rise. However, whilst these systems have received considerable individual research attention, how they interact and co-evolve is relatively understudied. These systems are intrinsically linked and it is therefore advantageous to study them holistically in order to build a more comprehensive understanding of their behaviour and to inform sustainable management over the long term. Complex environments such as these are often studied using numerical modelling techniques. Inherent from the limited research in this area, existing models are currently not capable of simulating dynamic coast-estuarine interactions. A new model is being developed through coupling the one-line Coastline Evolution Model (CEM) with CAESAR-Lisflood (C-L), a hydrodynamic Landscape Evolution Model. It is intended that the eventual model be used to advance the understanding of these systems and how they may evolve over the mid to long term in response to climate change. In the UK, the Holderness Coast, Humber Estuary and Spurn Point system offers a diverse and complex case study for this research. Holderness is one of the fastest eroding coastlines in Europe and research suggests that the large volumes of material removed from its cliffs are responsible for the formation of the Spurn Point feature and for the Holocene infilling of the Humber Estuary. Marine, fluvial and coastal processes are continually reshaping this system and over the next century, it is predicted that climate change could lead to increased erosion along the coast and supply of material to the Humber Estuary and Spurn Point. How this manifests will be hugely influential to the future morphology of these systems and the existence of Spurn Point. Progress to date includes a new version of the CEM that has been prepared for integration into C-L and includes an improved graphical user interface and more complex geomorphological processes. Preliminary results from simulations of the Holderness Coast and Spurn Point support findings of other authors, who suggest that changes to the wave climate influences sediment transport patterns in the nearshore zone. The angle of wave approach to the Holderness shows particular significance compared to the height of waves, with an optimum volume of material transported at 42 degrees. Further applications and results of this new model will be presented and discussed.

  18. Emerging search regimes: measuring co-evolutions among research, science, and society

    NARCIS (Netherlands)

    Heimeriks, G.; Leydesdorff, L.

    2012-01-01

    Scientometric data is used to investigate empirically the emergence of search regimes in biotechnology, genomics and nanotechnology. Complex regimes can emerge when three independent sources of variance interact. In our model, researchers can be considered as the nodes that carry the science system.

  19. Exploring the co-evolution of marine ecology and environment in silico

    Science.gov (United States)

    Ridgwell, A.

    2015-12-01

    Species do not live in isolation, but adapt and ultimately, evolve, in relationship with other species as well as with their chemical and physical environment. In the marine environment, this interaction is intimately two-way - the surface biogeochemical environment modulates the makeup of the pelagic ecosystem, yet at the same time, the ecosystem assemblage, by setting the strength of the biological pump and ultimately, in regulating the carbon and nutrient inventory of the ocean and atmospheric pCO2, influences the surface geochemical environment. Feedbacks, both negative and positive, must therefore exist between plankton ecology and global biogeochemical cycles. This has implications for understanding the geological record and particularly the response and recovery of marine ecosystems following major environmental perturbation, but also complicates making projections of future ocean changes. To address a coupled system such as this, new numerical tools are needed as traditional 'functional type' marine ecosystem models are generally incapable of accounting for short-term adaptation, let alone long-term evolution. What is needed is the combination of a plankton model able to simulate a highly diverse ecology plus 'genetic' mutation (changes in trait value(s)) and extinction, *and* an Earth system model capable of simulating long-term evolution of the climatology and geochemistry of the ocean. The Earth system model 'cGENIE' - http://mycgenie.seao2.org generally fills the second criteria, so for this presentation I will focus on the structure of the ecosystem model, the associated methodology, and numerical techniques for dealing with what will turn out to be an exceptionally large number of ocean tracers. If you are really lucky, there may even be some preliminary results :)

  20. Coevolution of Epidemics, Social Networks, and Individual Behavior: A Case Study

    Science.gov (United States)

    Chen, Jiangzhuo; Marathe, Achla; Marathe, Madhav

    This research shows how a limited supply of antivirals can be distributed optimally between the hospitals and the market so that the attack rate is minimized and enough revenue is generated to recover the cost of the antivirals. Results using an individual based model find that prevalence elastic demand behavior delays the epidemic and change in the social contact network induced by isolation reduces the peak of the epidemic significantly. A microeconomic analysis methodology combining behavioral economics and agent-based simulation is a major contribution of this work. In this paper we apply this methodology to analyze the fairness of the stockpile distribution, and the response of human behavior to disease prevalence level and its interaction with the market.

  1. Co-evolution of Vegetation, Sediment Transport and Infiltration on semi-arid hillslopes

    Science.gov (United States)

    Harman, C. J.; Troch, P. A.; Lohse, K. A.; Sivapalan, M.

    2011-12-01

    Soils in semi-arid landscapes can vary over very small distances, with a great deal of variation associated with 'resource islands' created and maintained by woody vegetation. The distinct physical and hydraulic properties that arise in these islands can lead to spatial patterns of infiltration that have been implicated in the maintenance of the vegetation populating the island. Less well understood are the roles that the small-scale variability in soils plays in determining the transport of sediments, water and sediment-bound carbon and nitrogen across hillslopes. Here we explore these relationships using a coupled field and modeling approach. Detailed field data from hillslopes underlain by both granite and schist parent materials in the Santa Catalina mountains (part of the JSC Critical Zone Observatory) suggest that soils under individual velvet mesquite (latin name) contain higher concentration of soil organic matter and have higher hydraulic conductivity and water holding capacity. Greater infiltration and increased roughness under the canopy appears to lead to the formation of mounds that alter overland flow lines around the area under the canopy, particularly in the finer schist soils. This diversion leads to a complex distribution of shear stresses across the hillslope, creating systematic patterns in the transport of carbon and nitrogen rich soils under the canopies. The relationship between the small scale mechanism and the emergent pattern dynamics in the temporal variability of materials delivered to the stream from the hillslope are also examined, and the implications of these results for the modeling of water, sediment and nutrient fluxes at hillslope scales will be discussed.

  2. Comparative modeling of coevolution in communities of unicellular organisms: adaptability and biodiversity.

    Science.gov (United States)

    Lashin, Sergey A; Suslov, Valentin V; Matushkin, Yuri G

    2010-06-01

    We propose an original program "Evolutionary constructor" that is capable of computationally efficient modeling of both population-genetic and ecological problems, combining these directions in one model of required detail level. We also present results of comparative modeling of stability, adaptability and biodiversity dynamics in populations of unicellular haploid organisms which form symbiotic ecosystems. The advantages and disadvantages of two evolutionary strategies of biota formation--a few generalists' taxa-based biota formation and biodiversity-based biota formation--are discussed.

  3. Effects of Climate on Co-evolution of Weathering Profiles and Hillscapes

    Science.gov (United States)

    Anderson, R. S.; Rajaram, H.; Anderson, S. P.

    2017-12-01

    Considerable debate revolves around the relative importance of rock type, tectonics, and climate in creating the architecture of the critical zone. It has recently been proposed that differences in the depths and patterns of weathering between landscapes in Colorado's Front Range and South Carolina's piedmont can be attributed to the state of stress in the rock imposed by the magnitude and orientation the regional stresses with respect to the ridgelines (St. Claire et al., 2016). We argue for the importance of the climate, and in particular, in temperate regions, the amount of recharge. We employ numerical models of hillslope evolution between bounding erosional channels, in which the degree of rock weathering governs the rate of transformation of rock to soil. As the water table drapes between the stream channels, fresh rock is brought into the weathering zone at a rate governed by the rate of incision of the channels. We track the chemical weathering of rock, represented by alteration of feldspar to clays, which in turn requires calculation of the concentration of reactive species in the water along hydrologic flow paths. We present results from analytic solutions to the flow field in which travel times can be efficiently assessed. Below the water table, flow paths are hyperbolic, taking on considerable lateral components as they veer toward the bounding channels that serve as drains to the hillslope. We find that if water is far from equilibrium with respect to weatherable minerals at the water table, as occurs in wet, slowly-eroding landscapes, deep weathering can occur well below the water table to levels approximating the base of the bounding channels. In dry climates, on the other hand, the weathering zone is limited to a shallow surface - parallel layer. These models capture the essence of the observed differences in depth to fresh rock in both wet and dry climates without appeal to the state of stress in the rock.

  4. Using analyses of amino Acid coevolution to understand protein structure and function.

    Science.gov (United States)

    Ashenberg, Orr; Laub, Michael T

    2013-01-01

    Determining which residues of a protein contribute to a specific function is a difficult problem. Analyses of amino acid covariation within a protein family can serve as a useful guide by identifying residues that are functionally coupled. Covariation analyses have been successfully used on several different protein families to identify residues that work together to promote folding, enable protein-protein interactions, or contribute to an enzymatic activity. Covariation is a statistical signal that can be measured in a multiple sequence alignment of homologous proteins. As sequence databases have expanded dramatically, covariation analyses have become easier and more powerful. In this chapter, we describe how functional covariation arises during the evolution of proteins and how this signal can be distinguished from various background signals. We discuss the basic methodology for performing amino acid covariation analysis, using bacterial two-component signal transduction proteins as an example. We provide practical suggestions for each step of the process including assembly of protein sequences, construction of a multiple sequence alignment, measurement of covariation, and analysis of results. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Why are there apes? Evidence for the co-evolution of ape and monkey ecomorphology.

    Science.gov (United States)

    Hunt, Kevin D

    2016-04-01

    Apes, members of the superfamily Hominoidea, possess a distinctive suite of anatomical and behavioral characters which appear to have evolved relatively late and relatively independently. The timing of paleontological events, extant cercopithecine and hominoid ecomorphology and other evidence suggests that many distinctive ape features evolved to facilitate harvesting ripe fruits among compliant terminal branches in tree edges. Precarious, unpredictably oriented, compliant supports in the canopy periphery require apes to maneuver using suspensory and non-sterotypical postures (i.e. postures with eccentric limb orientations or extreme joint excursions). Diet differences among extant species, extant species numbers and evidence of cercopithecoid diversification and expansion, in concert with a reciprocal decrease in hominoid species, suggest intense competition between monkeys and apes over the last 20 Ma. It may be that larger body masses allow great apes to succeed in contest competitions for highly desired food items, while the ability of monkeys to digest antifeedant-rich unripe fruits allows them to win scramble competitions. Evolutionary trends in morphology and inferred ecology suggest that as monkeys evolved to harvest fruit ever earlier in the fruiting cycle they broadened their niche to encompass first more fibrous, tannin- and toxin-rich unripe fruits and later, for some lineages, mature leaves. Early depletion of unripe fruit in the central core of the tree canopy by monkeys leaves a hollow sphere of ripening fruits, displacing antifeedant-intolerant, later-arriving apes to small-diameter, compliant terminal branches. Hylobatids, orangutans, Pan species, gorillas and the New World atelines may have each evolved suspensory behavior independently in response to local competition from an expanding population of monkeys. Genetic evidence of rapid evolution among chimpanzees suggests that adaptations to suspensory behavior, vertical climbing, knuckle-walking, consumption of terrestrial piths and intercommunity violence had not yet evolved or were still being refined when panins (chimpanzees and bonobos) and hominins diverged. © 2016 Anatomical Society.

  6. Modeling viral coevolution: HIV multi-clonal persistence and competition dynamics

    Science.gov (United States)

    Bagnoli, F.; Liò, P.; Sguanci, L.

    2006-07-01

    The coexistence of different viral strains (quasispecies) within the same host are nowadays observed for a growing number of viruses, most notably HIV, Marburg and Ebola, but the conditions for the formation and survival of new strains have not yet been understood. We present a model of HIV quasispecies competition, which describes the conditions of viral quasispecies coexistence under different immune system conditions. Our model incorporates both T and B cells responses, and we show that the role of B cells is important and additive to that of T cells. Simulations of coinfection (simultaneous infection) and superinfection (delayed secondary infection) scenarios in the early stages (days) and in the late stages of the infection (years) are in agreement with emerging molecular biology findings. The immune response induces a competition among similar phenotypes, leading to differentiation (quasispeciation), escape dynamics and complex oscillations of viral strain abundance. We found that the quasispecies dynamics after superinfection or coinfection has time scales of several months and becomes even slower when the immune system response is weak. Our model represents a general framework to study the speed and distribution of HIV quasispecies during disease progression, vaccination and therapy.

  7. Experimental evidence for the co-evolution of hominin tool-making teaching and language.

    Science.gov (United States)

    Morgan, T J H; Uomini, N T; Rendell, L E; Chouinard-Thuly, L; Street, S E; Lewis, H M; Cross, C P; Evans, C; Kearney, R; de la Torre, I; Whiten, A; Laland, K N

    2015-01-13

    Hominin reliance on Oldowan stone tools-which appear from 2.5 mya and are believed to have been socially transmitted-has been hypothesized to have led to the evolution of teaching and language. Here we present an experiment investigating the efficacy of transmission of Oldowan tool-making skills along chains of adult human participants (N=184) using five different transmission mechanisms. Across six measures, transmission improves with teaching, and particularly with language, but not with imitation or emulation. Our results support the hypothesis that hominin reliance on stone tool-making generated selection for teaching and language, and imply that (i) low-fidelity social transmission, such as imitation/emulation, may have contributed to the ~700,000 year stasis of the Oldowan technocomplex, and (ii) teaching or proto-language may have been pre-requisites for the appearance of Acheulean technology. This work supports a gradual evolution of language, with simple symbolic communication preceding behavioural modernity by hundreds of thousands of years.

  8. Evolutionary Musicology Meets Embodied Cognition: Biocultural Coevolution and the Enactive Origins of Human Musicality

    Science.gov (United States)

    van der Schyff, Dylan; Schiavio, Andrea

    2017-01-01

    Despite evolutionary musicology's interdisciplinary nature, and the diverse methods it employs, the field has nevertheless tended to divide into two main positions. Some argue that music should be understood as a naturally selected adaptation, while others claim that music is a product of culture with little or no relevance for the survival of the species. We review these arguments, suggesting that while interesting and well-reasoned positions have been offered on both sides of the debate, the nature-or-culture (or adaptation vs. non-adaptation) assumptions that have traditionally driven the discussion have resulted in a problematic either/or dichotomy. We then consider an alternative “biocultural” proposal that appears to offer a way forward. As we discuss, this approach draws on a range of research in theoretical biology, archeology, neuroscience, embodied and ecological cognition, and dynamical systems theory (DST), positing a more integrated model that sees biological and cultural dimensions as aspects of the same evolving system. Following this, we outline the enactive approach to cognition, discussing the ways it aligns with the biocultural perspective. Put simply, the enactive approach posits a deep continuity between mind and life, where cognitive processes are explored in terms of how self-organizing living systems enact relationships with the environment that are relevant to their survival and well-being. It highlights the embodied and ecologically situated nature of living agents, as well as the active role they play in their own developmental processes. Importantly, the enactive approach sees cognitive and evolutionary processes as driven by a range of interacting factors, including the socio-cultural forms of activity that characterize the lives of more complex creatures such as ourselves. We offer some suggestions for how this approach might enhance and extend the biocultural model. To conclude we briefly consider the implications of this approach for practical areas such as music education. PMID:29033780

  9. The Great Silk Alternative: Multiple Co-Evolution of Web Loss and Sticky Hairs in Spiders

    Science.gov (United States)

    Wolff, Jonas O.; Nentwig, Wolfgang; Gorb, Stanislav N.

    2013-01-01

    Spiders are the most important terrestrial predators among arthropods. Their ecological success is reflected by a high biodiversity and the conquest of nearly every terrestrial habitat. Spiders are closely associated with silk, a material, often seen to be responsible for their great ecological success and gaining high attention in life sciences. However, it is often overlooked that more than half of all Recent spider species have abandoned web building or never developed such an adaptation. These species must have found other, more economic solutions for prey capture and retention, compensating the higher energy costs of increased locomotion activity. Here we show that hairy adhesive pads (scopulae) are closely associated with the convergent evolution of a vagrant life style, resulting in highly diversified lineages of at least, equal importance as the derived web building taxa. Previous studies often highlighted the idea that scopulae have the primary function of assisting locomotion, neglecting the fact that only the distal most pads (claw tufts) are suitable for those purposes. The former observations, that scopulae are used in prey capture, are largely overlooked. Our results suggest the scopulae evolved as a substitute for silk in controlling prey and that the claw tufts are, in most cases, a secondary development. Evolutionary trends towards specialized claw tufts and their composition from a low number of enlarged setae to a dense array of slender ones, as well as the secondary loss of those pads are discussed further. Hypotheses about the origin of the adhesive setae and their diversification throughout evolution are provided. PMID:23650526

  10. Coevolution of female and male genital components to avoid genital size mismatches in sexually dimorphic spiders.

    Science.gov (United States)

    Lupše, Nik; Cheng, Ren-Chung; Kuntner, Matjaž

    2016-08-17

    In most animal groups, it is unclear how body size variation relates to genital size differences between the sexes. While most morphological features tend to scale with total somatic size, this does not necessarily hold for genitalia because divergent evolution in somatic size between the sexes would cause genital size mismatches. Theory predicts that the interplay of female-biased sexual size dimorphism (SSD) and sexual genital size dimorphism (SGD) should adhere to the 'positive genital divergence', the 'constant genital divergence', or the 'negative genital divergence' model, but these models remain largely untested. We test their validity in the spider family Nephilidae known for the highest degrees of SSD among terrestrial animals. Through comparative analyses of sex-specific somatic and genital sizes, we first demonstrate that 99 of the 351 pairs of traits are phylogenetically correlated. Through factor analyses we then group these traits for MCMCglmm analyses that test broader correlation patterns, and these reveal significant correlations in 10 out of the 36 pairwise comparisons. Both types of analyses agree that female somatic and internal genital sizes evolve independently. While sizes of non-intromittent male genital parts coevolve with male body size, the size of the intromittent male genital parts is independent of the male somatic size. Instead, male intromittent genital size coevolves with female (external and, in part, internal) genital size. All analyses also agree that SGD and SSD evolve independently. Internal dimensions of female genitalia evolve independently of female body size in nephilid spiders, and similarly, male intromittent genital size evolves independently of the male body size. The size of the male intromittent organ (the embolus) and the sizes of female internal and external genital components thus seem to respond to selection against genital size mismatches. In accord with these interpretations, we reject the validity of the existing theoretical models of genital and somatic size dimorphism in spiders.

  11. The coevolution of play and the cortico-cerebellar system in primates.

    Science.gov (United States)

    Kerney, Max; Smaers, Jeroen B; Schoenemann, P Thomas; Dunn, Jacob C

    2017-10-01

    Primates are some of the most playful animals in the natural world, yet the reason for this remains unclear. One hypothesis posits that primates are so playful because playful activity functions to help develop the sophisticated cognitive and behavioural abilities that they are also renowned for. If this hypothesis were true, then play might be expected to have coevolved with the neural substrates underlying these abilities in primates. Here, we tested this prediction by conducting phylogenetic comparative analyses to determine whether play has coevolved with the cortico-cerebellar system, a neural system known to be involved in complex cognition and the production of complex behaviour. We used phylogenetic generalised least squares analyses to compare the relative volume of the largest constituent parts of the primate cortico-cerebellar system (prefrontal cortex, non-prefrontal heteromodal cortical association areas, and posterior cerebellar hemispheres) to the mean percentage of time budget spent in play by a sample of primate species. Using a second categorical data set on play, we also used phylogenetic analysis of covariance to test for significant differences in the volume of the components of the cortico-cerebellar system among primate species exhibiting one of three different levels of adult-adult social play. Our results suggest that, in general, a positive association exists between the amount of play exhibited and the relative size of the main components of the cortico-cerebellar system in our sample of primate species. Although the explanatory power of this study is limited by the correlational nature of its analyses and by the quantity and quality of the data currently available, this finding nevertheless lends support to the hypothesis that play functions to aid the development of cognitive and behavioural abilities in primates.

  12. Coevolution of Siglec-11 and Siglec-16 via gene conversion in primates.

    Science.gov (United States)

    Hayakawa, Toshiyuki; Khedri, Zahra; Schwarz, Flavio; Landig, Corinna; Liang, Suh-Yuen; Yu, Hai; Chen, Xi; Fujito, Naoko T; Satta, Yoko; Varki, Ajit; Angata, Takashi

    2017-11-23

    Siglecs-11 and -16 are members of the sialic acid recognizing Ig-like lectin family, and expressed in same cells. Siglec-11 functions as an inhibitory receptor, whereas Siglec-16 exhibits activating properties. In humans, SIGLEC11 and SIGLEC16 gene sequences are extremely similar in the region encoding the extracellular domain due to gene conversions. Human SIGLEC11 was converted by the nonfunctional SIGLEC16P allele, and the converted SIGLEC11 allele became fixed in humans, possibly because it provides novel neuroprotective functions in brain microglia. However, the detailed evolutionary history of SIGLEC11 and SIGLEC16 in other primates remains unclear. We analyzed SIGLEC11 and SIGLEC16 gene sequences of multiple primate species, and examined glycan binding profiles of these Siglecs. The phylogenetic tree demonstrated that gene conversions between SIGLEC11 and SIGLEC16 occurred in the region including the exon encoding the sialic acid binding domain in every primate examined. Functional assays showed that glycan binding preference is similar between Siglec-11 and Siglec-16 in all analyzed hominid species. Taken together with the fact that Siglec-11 and Siglec-16 are expressed in the same cells, Siglec-11 and Siglec-16 are regarded as paired receptors that have maintained similar ligand binding preferences via gene conversions. Relaxed functional constraints were detected on the SIGLEC11 and SIGLEC16 exons that underwent gene conversions, possibly contributing to the evolutionary acceptance of repeated gene conversions. The frequency of nonfunctional SIGLEC16P alleles is much higher than that of SIGLEC16 alleles in every human population. Our findings indicate that Siglec-11 and Siglec-16 have been maintained as paired receptors by repeated gene conversions under relaxed functional constraints in the primate lineage. The high prevalence of the nonfunctional SIGLEC16P allele and the fixation of the converted SIGLEC11 imply that the loss of Siglec-16 and the gain of Siglec-11 in microglia might have been favored during the evolution of human lineage.

  13. Conflict vs Co-evolution: The Future of Sino-American Relations

    Science.gov (United States)

    2013-04-18

    to sustain industrialization.26 Today, estimates of 200 million migrant urban workers hold rural hukous, keeping families separated and limiting...politics, philosophy, human rights and other issues, economic interdependence will in the near term dissuade the possibility of any of those factors...modern history of humiliation that when a country loses sovereignty, its people lose dignity and status.6 The non-interference principle has

  14. Interpreting Sustainability through Co-Evolution: Evidence from Religious Accommodations in Rome

    Directory of Open Access Journals (Sweden)

    Paola M. A. Paniccia

    2017-12-01

    Full Text Available In recent decades, concepts such as sustainability, innovation, and competitiveness have become fundamental for the development of tourist destinations, and thus, particularly, for the generation of value co-creation processes. To understand the role of tourism firms in these processes, more theoretical and empirical research is required. This paper addresses this need by examining the increasing role played by religious accommodations, adopting a co-evolutionary approach to sustainability and the resulting value co-creation processes. The study focuses on the dynamics of the relationship between this new hospitality model, territories, and tourists, through the analysis of six case studies localized in the historic centre of Rome (Italy. Findings show that religious accommodations can be considered as a new sustainability-oriented hospitality model that, by creating effective multi-level co-evolutionary adaptations with its territory and tourists, positively affects sustainable development as well as the generation of value co-creation processes. The paper contributes significantly both to sustainability literature and to the study of new hospitality models. Thus, theoretical and managerial implications emerge, together with suggestions for future research.

  15. Complex coevolution of wing, tail, and vocal sounds of courting male bee hummingbirds.

    Science.gov (United States)

    Clark, Christopher J; McGuire, Jimmy A; Bonaccorso, Elisa; Berv, Jacob S; Prum, Richard O

    2018-03-01

    Phenotypic characters with a complex physical basis may have a correspondingly complex evolutionary history. Males in the "bee" hummingbird clade court females with sound from tail-feathers, which flutter during display dives. On a phylogeny of 35 species, flutter sound frequency evolves as a gradual, continuous character on most branches. But on at least six internal branches fall two types of major, saltational changes: mode of flutter changes, or the feather that is the sound source changes, causing frequency to jump from one discrete value to another. In addition to their tail "instruments," males also court females with sound from their syrinx and wing feathers, and may transfer or switch instruments over evolutionary time. In support of this, we found a negative phylogenetic correlation between presence of wing trills and singing. We hypothesize this transference occurs because wing trills and vocal songs serve similar functions and are thus redundant. There are also three independent origins of self-convergence of multiple signals, in which the same species produces both a vocal (sung) frequency sweep, and a highly similar nonvocal sound. Moreover, production of vocal, learned song has been lost repeatedly. Male bee hummingbirds court females with a diverse, coevolving array of acoustic traits. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

  16. Partner choice and fidelity stabilize coevolution in a Cretaceous-age defensive symbiosis

    Science.gov (United States)

    Kaltenpoth, Martin; Roeser-Mueller, Kerstin; Koehler, Sabrina; Peterson, Ashley; Nechitaylo, Taras Y.; Stubblefield, J. William; Herzner, Gudrun; Seger, Jon; Strohm, Erhard

    2014-01-01

    Many insects rely on symbiotic microbes for survival, growth, or reproduction. Over evolutionary timescales, the association with intracellular symbionts is stabilized by partner fidelity through strictly vertical symbiont transmission, resulting in congruent host and symbiont phylogenies. However, little is known about how symbioses with extracellular symbionts, representing the majority of insect-associated microorganisms, evolve and remain stable despite opportunities for horizontal exchange and de novo acquisition of symbionts from the environment. Here we demonstrate that host control over symbiont transmission (partner choice) reinforces partner fidelity between solitary wasps and antibiotic-producing bacteria and thereby stabilizes this Cretaceous-age defensive mutualism. Phylogenetic analyses show that three genera of beewolf wasps (Philanthus, Trachypus, and Philanthinus) cultivate a distinct clade of Streptomyces bacteria for protection against pathogenic fungi. The symbionts were acquired from a soil-dwelling ancestor at least 68 million years ago, and vertical transmission via the brood cell and the cocoon surface resulted in host–symbiont codiversification. However, the external mode of transmission also provides opportunities for horizontal transfer, and beewolf species have indeed exchanged symbiont strains, possibly through predation or nest reuse. Experimental infection with nonnative bacteria reveals that—despite successful colonization of the antennal gland reservoirs—transmission to the cocoon is selectively blocked. Thus, partner choice can play an important role even in predominantly vertically transmitted symbioses by stabilizing the cooperative association over evolutionary timescales. PMID:24733936

  17. Governance of sustainable development: co-evolution of corporate and political strategies

    International Nuclear Information System (INIS)

    Bleischwitz, R.; College of Europe, Bruges

    2004-01-01

    This article proposes a policy framework for analysing corporate governance toward sustainable development. The aim is to set up a framework for analysing market evolution toward sustainability. In the first section, the paper briefly refers to recent theories about both market and government failures that express scepticism about the way that framework conditions for market actors are set. For this reason, multi-layered governance structures seem advantageous if new solutions are to be developed in policy areas concerned with long-term change and stepwise internalisation of externalities. The paper introduces the principle of regulated self-regulation. With regard to corporate actors' interests, it presents recent insights from theories about the knowledge-based firm, where the creation of new knowledge is based on the absorption of societal views. The result is greater scope for the endogenous internalisation of externalities, which leads to a variety of new and different corporate strategies. Because governance has to set incentives for quite a diverse set of actors in their daily operations, the paper finally discusses innovation-inducing regulation. In both areas, regulated self-regulation and innovation-inducing regulation, corporate and political governance co-evolve. The paper concludes that these co-evolutionary mechanisms may assume some of the stabilising and orientating functions previously exercised by framing activities of the state. In such a view, the government's main function is to facilitate learning processes, thus departing from the state's function as known from welfare economics. (author)

  18. The co-evolution of networks and prisoner’s dilemma game by considering sensitivity and visibility

    Science.gov (United States)

    Li, Dandan; Ma, Jing; Han, Dun; Sun, Mei; Tian, Lixin; Stanley, H. Eugene

    2017-03-01

    Strategies adopted by individuals in a social network significantly impact the network, and they strongly affect relationships between individuals in the network. Links between individuals also heavily influence their levels of cooperation. Taking into account the evolution of each individual’s connection, we explore how sensitivity and visibility affect the prisoner’s dilemma game. The so-called ‘sensitivity’ and ‘visibility’ respectively present one’s self-protection consciousness and the ability of gaining information. We find that at moderate levels of player sensitivity cooperative behavior increases, but that at high levels it is inhibited. We also find that the heterogeneity of the weight of individuals at the end of the game is higher when sensitivity and visibility are increased, but that the successful-defection-payoff has less impact on the weight of individuals and on the relationship between the heterogeneity of the weight of individuals and the density of cooperators. This framework can be used to clarify the interaction mechanism between the micro-level of individual behavior and the macro-level of individual co-evolutionary processes.

  19. Coevolution Pattern and Functional Conservation or Divergence of miR167s and their targets across Diverse Plant Species.

    Science.gov (United States)

    Barik, Suvakanta; Kumar, Ashutosh; Sarkar Das, Shabari; Yadav, Sandeep; Gautam, Vibhav; Singh, Archita; Singh, Sharmila; Sarkar, Ananda K

    2015-10-13

    microRNAs (miRNAs), a class of endogenously produced small non-coding RNAs of 20-21 nt length, processed from precursor miRNAs, regulate many developmental processes by negatively regulating the target genes in both animals and plants. The coevolutionary pattern of a miRNA family and their targets underscores its functional conservation or diversification. The miR167 regulates various aspects of plant development in Arabidopsis by targeting ARF6 and ARF8. The evolutionary conservation or divergence of miR167s and their target genes are poorly understood till now. Here we show the evolutionary relationship among 153 MIR167 genes obtained from 33 diverse plant species. We found that out of the 153 of miR167 sequences retrieved from the "miRBase", 27 have been annotated to be processed from the 3' end, and have diverged distinctively from the other miR167s produced from 5' end. Our analysis reveals that gma-miR167h/i and mdm-miR167a are processed from 3' end and have evolved separately, diverged most resulting in novel targets other than their known ones, and thus led to functional diversification, especially in apple and soybean. We also show that mostly conserved miR167 sequences and their target AUXIN RESPONSE FACTORS (ARFs) have gone through parallel evolution leading to functional diversification among diverse plant species.

  20. Contributing towards a conceptual model of soil-landscape co-evolution: observations from historic mining sites in Alberta, Canada

    Science.gov (United States)

    Raab, Thomas; Naeth, Anne; Hirsch, Florian; Raab, Alexandra

    2016-04-01

    At the former Diplomat Mine near Forestburg, Alberta, Canada we find a diverse soil landscape which can help to conceptualize factors and processes controlling initial pedogenesis and soil distribution on very young landforms in prairie environments. Due to differing reclamation practices in the 1950s and landslides occurring after spoil dumping, four areas can be distinguished by GoogleMaps/LiDAR evaluation and onsite field survey: (i) not-mined, (ii) stock piled and unreclaimed, (iii) stock piled and reclaimed and (iv) affected by post-mining geomorphodynamics and quasi-natural redeposition. The parent material for areas (ii) to (iv) was initially dumped by spreaders but only (ii) didn't undergo further change. Landscape (iii) has seen levelling of the piles by heavy machinery. Features of landscape (iv) are formed by reshaping the originally dumped and levelled structures. This last landscape unit marks the rim of the former mine adjacent to the river valley. In practice, mining activities formed new valley slopes. In contrast to the naturally developed slopes the mine slopes were less stable. Vegetation, which could have hindered slope wash erosion, was missing after dumping the spoil slopes. Slopes were very steep (or practically undercut) and therefore, substrates were naturally re-located by mass movements such as sliding and slumping. Characteristic sliding and slumping structures can be identified in the close-ups of the LiDAR images. Both processes, mass movement and slope wash erosion, may have overlapped. Landscape (ii) is the most contrasting one. Dumped stock piles formed elongated, curved and steep ridges. These landforms do not have a natural analogue but clearly show their technological origin. Most interesting are differences in vegetation. South and southwest facing slopes are covered with grassland whereas north and northeast facing slopes are covered with aspen trees. Some of the ditches are filled with water and form small elongated ponds. The characteristic geomorphology of the prairie can be found in landscape (i). Distinct differences are found in properties and types of soils in these four landscapes. Natural soils and pile soils characteristically differ in parent material and soil horizons. No information is gathered yet for the reclaimed soils and the landslides soils due to prohibited access. However, based on what we find at the former Diplomat Mine we can conclude that distribution, development and properties of unreclaimed soils in historical open cast mines in Alberta are primarily controlled by parent material and topography. The geomorphological set-up is dominating the trajectory of vegetation development and post-mining geomorphodynamics. Contrasting slope aspects determine micro climatic conditions and lead to different vegetation types. This has likely had an effect on soil development and soil properties (especially carbon stocks). Further studies will be conducted to quantify these differing soil properties to refine this conceptual model of initial pedogenesis and soil distribution on very young landforms in the prairie landscapes.

  1. Socio-hydrologic perspectives of the co-evolution of humans and groundwater in Cangzhou, North China Plain

    Science.gov (United States)

    Han, S.; Tian, F.; Liu, Y.

    2017-12-01

    This study presents a historical analysis from socio-hydrologic perspectives of the coupled human-groundwater system of the Cangzhou region in the North China Plain. The history of the "pendulum swing" for water allocation between the economic development and aquifer environmental health of the system is divided into five eras (i.e., natural, exploitation, degradation and restoration, drought-triggered deterioration, and returning to the balance). The system evolution was interpreted using the Taiji-Tire model. Over-exploitation was considered as the main cause of aquifer depletion and the groundwater utilization pattern was affected by the varying groundwater table. The aquifer depletion enhanced the community sensitivity of humans toward environmental issues, and upgraded the social productive force for restoration. The evolution of the system was substantially impacted by two droughts. The drought in 1965 induced the system from natural condition to groundwater exploiting. The drought from 1997 to 2002 resulted a pulse in further groundwater abstraction and dramatic aquifer deterioration, and the community sensitivity increased rapidly and induced the social productive force to a tipping point. From then on, the system is returning the balance through new policies and water-saving technologies. Along with the establishment of a strict water resource management strategy and the launch of the South-to-North Water Diversion Project, further restorations of groundwater environment would be implemented. However, a comprehensive and coordinated drought management plan should be devised to avoid the irreversible change of the system.

  2. The Gentle Art of Coevolution: a complexity theory perspective on decision making over estuaries in Germany, Belgium and the Netherlands

    NARCIS (Netherlands)

    L.M. Gerrits (Lasse)

    2008-01-01

    textabstractSeaports in Europe are constantly engaged in fi erce competition over market share and one of the strategies utilised to survive this competition is to increase the capacity of the ports. Such a strategy can include the extension of quaysides, the building of new terminals and the

  3. "Conserving Marine Biodiversity in the Global Marine Commons: Co-evolution and Interaction with the Law of the Sea"

    Directory of Open Access Journals (Sweden)

    Robin Margaret Warner

    2014-05-01

    Full Text Available As global shipping intensifies and technological advances provide more opportunities to access the resources of the high seas and the deep seabed beyond national jurisdiction (ABNJ, the catalogue of threats to the marine environment and its biodiversity increase commensurately. Beyond these threats, new and emerging uses of ABNJ including more intrusive marine scientific research, bio-prospecting, deep seabed mining and environmental modification activities to mitigate the effects of climate change have the potential to harm the highly interconnected and sensitive ecosystems of the open ocean and the deep seabed if not sustainably managed now and into the future. Modern conservation norms such as environmental impact assessment, marine protected areas, marine spatial planning and development mechanisms such as technology transfer and capacity building are under developed in the legal and institutional framework for ABNJ. This article examines key normative features of the legal and institutional framework for ABNJ and their applicability to conservation of marine biodiversity, gaps and disconnects in that framework and ongoing global initiatives to develop more effective governance structures. It discusses some of the options being considered in the UN Ad Hoc Informal Open-ended Working Group to study issues related to the conservation and sustainable use of marine biodiversity in areas beyond national jurisdiction (BBNJ Working Group to evolve the legal and institutional framework for conservation and sustainable use of marine biodiversity in ABNJ and their current and future relevance for the law of the sea. It concludes that the discussions in the BBNJ Working Group and related initiatives in the Convention on Biological Diversity (CBD and at regional level have demonstrated that a more integrated legal and institutional structure is needed to address growing threats to marine biodiversity in ABNJ.

  4. Disentangling the Circularity in Sen's Capability Approach: An Analysis of the Co-Evolution of Functioning Achievement and Resources

    Science.gov (United States)

    Binder, Martin; Coad, Alex

    2011-01-01

    There is an ambiguity in Amartya Sen's capability approach as to what constitutes an individual's resources, conversion factors and valuable functionings. What we here call the "circularity problem" points to the fact that all three concepts seem to be mutually endogenous and interdependent. To econometrically account for this…

  5. Phylogenetic analysis of sarcocystis spp. of mammals and reptiles supports the coevolution of Sarcocystis spp. with their final hosts

    Czech Academy of Sciences Publication Activity Database

    Doležel, David; Koudela, Břetislav; Jirků, Milan; Hypša, Václav; Oborník, Miroslav; Votýpka, J.; Modrý, David; Šlapeta, J.; Lukeš, Julius

    1999-01-01

    Roč. 29, - (1999), s. 795-798 ISSN 0020-7519 R&D Projects: GA ČR GA508/95/0273; GA AV ČR IAA6022903; GA AV ČR KSK2022601 Subject RIV: fp - Other Medical Disciplines Impact factor: 1.900, year: 1999

  6. Coevolution of patients and hospitals: how changing epidemiology and technological advances create challenges and drive organizational innovation.

    Science.gov (United States)

    Lega, Federico; Calciolari, Stefano

    2012-01-01

    Over the last 20 years, hospitals have revised their organizational structures in response to new environmental pressures. Today, demographic and epidemiologic trends and recent technological advances call for new strategies to cope with ultra-elderly frail patients characterized by chronic conditions, high-severity health problems, and complex social situations. The main areas of change surround new ways of managing emerging clusters of patients whose needs are not efficiently or effectively met within traditional hospital organizations. Following the practitioner and academic literature, we first identify the most relevant clusters of new kinds of patients who represent an increasingly larger share of the hospital population in developed countries. Second, we propose a framework that synthesizes the major organizational innovations adopted by successful organizations around the world. We conclude by substantiating the trends of and the reasoning behind the prospective pattern of hospital organizational development.

  7. The Chlorella variabilis NC64A Genome Reveals Adaptation to Photosymbiosis, Coevolution with Viruses, and Cryptic Sex

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, Guillaume; Duncan, Garry A.; Agarakova, Irina; Borodovsky, Mark; Gurnon, James; Kuo, Alan; Lindquist, Erika; Lucas, Susan; Pangailinan, Jasmyn; Polle, Juergen; Salamov, Asaf; Terry, Astrid; Yamada, Takashi; Dunigan, David D.; Grigoriev, Igor V.; Claverie, Jean-Michel; Etten, James L. Van

    2010-05-06

    Chlorella variabilis NC64A, a unicellular photosynthetic green alga (Trebouxiophyceae), is an intracellular photobiont of Paramecium bursaria and a model system for studying virus/algal interactions. We sequenced its 46-Mb nuclear genome, revealing an expansion of protein families that could have participated in adaptation to symbiosis. NC64A exhibits variations in GC content across its genome that correlate with global expression level, average intron size, and codon usage bias. Although Chlorella species have been assumed to be asexual and nonmotile, the NC64A genome encodes all the known meiosis-specific proteins and a subset of proteins found in flagella. We hypothesize that Chlorella might have retained a flagella-derived structure that could be involved in sexual reproduction. Furthermore, a survey of phytohormone pathways in chlorophyte algae identified algal orthologs of Arabidopsis thaliana genes involved in hormone biosynthesis and signaling, suggesting that these functions were established prior to the evolution of land plants. We show that the ability of Chlorella to produce chitinous cell walls likely resulted from the capture of metabolic genes by horizontal gene transfer from algal viruses, prokaryotes, or fungi. Analysis of the NC64A genome substantially advances our understanding of the green lineage evolution, including the genomic interplay with viruses and symbiosis between eukaryotes.

  8. Effects of benefit-inspired network coevolution on spatial reciprocity in the prisoner’s dilemma game

    International Nuclear Information System (INIS)

    Wang, Lei; Wang, Juan; Guo, Baohong; Ding, Shuai; Li, Yukun; Xia, Chengyi

    2014-01-01

    Highlights: • A co-evolutionary prisoner’s dilemma game on regular lattice is proposed. • Each agent can have a chance to update its neighbors by pruning the connection with a defecting neighbor. • The structural properties of system structure display nontrivial transition. • The cooperation can be greatly promoted through the changing interaction topology. • The higher the cooperation level, the larger the probability to prune the defective link. - Abstract: How to interpret the emergence and ubiquity of cooperation between selfish agents has become a long-standing puzzle among the scientific communities. In this paper, we propose a co-evolutionary prisoner’s dilemma model to illustrate the evolution of cooperation, in which the model evolution can be divided into two basic steps: (i) strategy update: all agents play the game and perform the strategy update according to the Fermi rule; (ii) topology adjustment: each agent can have a chance to prune the connection with a defecting neighbor so as to decrease the potential benefit loss via an adjustment parameter (α). Large quantities of numerical simulations indicate that the cooperation level in the stationary state will be highly elevated, when compared to the traditional prisoner’s dilemma game on regular lattices. Meanwhile, we have also observed that the degree distribution of network will be broadened or more skewed and structural heterogeneities will also become higher when the dynamical adjustment of interaction topology is allowed during the system evolution. In addition, it is also proven that the tunable parameter α controls the link reconnection process, and even the node elimination and reproduction so that the whole cooperation level can be greatly influenced. Thus, the study points out a suitable way for the sustainability of cooperation in structured populations, and current findings are conducive to further understand the collective cooperation phenomenon within many biological, social, economic and even man-made systems

  9. Using Coevolution Genetic Algorithm with Pareto Principles to Solve Project Scheduling Problem under Duration and Cost Constraints

    Directory of Open Access Journals (Sweden)

    Alexandr Victorovich Budylskiy

    2014-06-01

    Full Text Available This article considers the multicriteria optimization approach using the modified genetic algorithm to solve the project-scheduling problem under duration and cost constraints. The work contains the list of choices for solving this problem. The multicriteria optimization approach is justified here. The study describes the Pareto principles, which are used in the modified genetic algorithm. We identify the mathematical model of the project-scheduling problem. We introduced the modified genetic algorithm, the ranking strategies, the elitism approaches. The article includes the example.

  10. Bacterial endosymbiosis in a chordate host: long-term co-evolution and conservation of secondary metabolism.

    Directory of Open Access Journals (Sweden)

    Jason C Kwan

    Full Text Available Intracellular symbiosis is known to be widespread in insects, but there are few described examples in other types of host. These symbionts carry out useful activities such as synthesizing nutrients and conferring resistance against adverse events such as parasitism. Such symbionts persist through host speciation events, being passed down through vertical transmission. Due to various evolutionary forces, symbionts go through a process of genome reduction, eventually resulting in tiny genomes where only those genes essential to immediate survival and those beneficial to the host remain. In the marine environment, invertebrates such as tunicates are known to harbor complex microbiomes implicated in the production of natural products that are toxic and probably serve a defensive function. Here, we show that the intracellular symbiont Candidatus Endolissoclinum faulkneri is a long-standing symbiont of the tunicate Lissoclinum patella, that has persisted through cryptic speciation of the host. In contrast to the known examples of insect symbionts, which tend to be either relatively recent or ancient relationships, the genome of Ca. E. faulkneri has a very low coding density but very few recognizable pseudogenes. The almost complete degradation of intergenic regions and stable gene inventory of extant strains of Ca. E. faulkneri show that further degradation and deletion is happening very slowly. This is a novel stage of genome reduction and provides insight into how tiny genomes are formed. The ptz pathway, which produces the defensive patellazoles, is shown to date to before the divergence of Ca. E. faulkneri strains, reinforcing its importance in this symbiotic relationship. Lastly, as in insects we show that stable symbionts can be lost, as we describe an L. patella animal where Ca. E. faulkneri is displaced by a likely intracellular pathogen. Our results suggest that intracellular symbionts may be an important source of ecologically significant natural products in animals.

  11. A Phylogenetic Comparative Study of Bantu Kinship Terminology Finds Limited Support for Its Co-Evolution with Social Organisation.

    Directory of Open Access Journals (Sweden)

    Myrtille Guillon

    Full Text Available The classification of kin into structured groups is a diverse phenomenon which is ubiquitous in human culture. For populations which are organized into large agropastoral groupings of sedentary residence but not governed within the context of a centralised state, such as our study sample of 83 historical Bantu-speaking groups of sub-Saharan Africa, cultural kinship norms guide all aspects of everyday life and social organization. Such rules operate in part through the use of differing terminological referential systems of familial organization. Although the cross-cultural study of kinship terminology was foundational in Anthropology, few modern studies have made use of statistical advances to further our sparse understanding of the structuring and diversification of terminological systems of kinship over time. In this study we use Bayesian Markov Chain Monte Carlo methods of phylogenetic comparison to investigate the evolution of Bantu kinship terminology and reconstruct the ancestral state and diversification of cousin terminology in this family of sub-Saharan ethnolinguistic groups. Using a phylogenetic tree of Bantu languages, we then test the prominent hypothesis that structured variation in systems of cousin terminology has co-evolved alongside adaptive change in patterns of descent organization, as well as rules of residence. We find limited support for this hypothesis, and argue that the shaping of systems of kinship terminology is a multifactorial process, concluding with possible avenues of future research.

  12. [Comigration of root nodule bacteria and bean plants to new habitats: coevolution mechanisms and practical importance (review)].

    Science.gov (United States)

    Provorov, N A; Zhukov, V A; Kurchak, O N; Onishchuk, O P; Andronov, E E; Borisov, A Iu; Chizhevskaia, E P; Naumkina, T S; Ovtsyna, A O; Vorob'ev, N I; Simarov, B V; Tikhonovich, I A

    2013-01-01

    The review summarizes the results of studies on the comigration of tubercular bacteria and bean plants to new habitats, which is often accompanied by a decrease in the symbiosis efficiency due to a loss of the diversity of genes responsible for the interaction. This migration may lead to a rise in new symbionts as a result of gene transfers from initial symbionts to local bacteria. It was demonstrated that typically new symbionts lack an ability for N2 fixation but are highly competitive, blocking the inoculation of bean cultures by industrial strains. The design of coadapted systems of recognition and signal interaction of partners is a perspective approach to ensure competitive advantages of efficient rhizobia strains introduced into agrocenoses, together with host plants, over inactive local strains.

  13. From road to lab to math: the co-evolution of technological, regulatory, and organizational innovations for automotive crash testing.

    Science.gov (United States)

    Leonardi, Paul M

    2010-04-01

    Today, in the midst of economic crisis, senior executives at US automakers and influential industry analysts frequently reflect on the progression that safety testing has taken from the crude trials done on the road, to controlled laboratory experiments, and to today's complex math-based simulation models. They use stories of this seemingly linear and natural sequence to justify further investment in simulation technologies. The analysis presented in this paper shows that change in the structures of automakers' organizations co-evolved with regulations specifying who was at fault in vehicle impacts, how vehicles should be built to withstand the force of an impact, and how testing should be done to assure that vehicles met those requirements. Changes in the regulatory environment were bolstered by new theories about crash test dynamics and changing technologies with which to test those theories. Thus, as new technological and regulatory innovations co-evolved with innovations in organizational structuring, ideas about how to best conduct crash tests shifted and catalyzed new cycles of technological, regulatory, and organizational innovation. However, this co-evolutionary story tells us that the move from road to lab to math was not natural or linear as today's managerial rhetoric would have us believe. Rather, the logic of math-based simulation was the result of technological, regulatory and organizational changes that created an industry-wide ideology that supported the move toward math while making it appear natural within the shifting structure of the industry.

  14. Co-evolution of land use changes, water quality deterioration and social conflicts in arid Northern Chile

    Science.gov (United States)

    Zang, Carina; Dame, Juliane

    2017-04-01

    Water scarcity concerns not only the limited availability of water but also water of inadequate quality in terms of its designated purposes. Arid regions, such as found in Northern Chile, are especially vulnerable to water contamination, owing to missing dilution. Additionally, the national government of Chile's goal to make the country a globally important food exporter has led to the widespread expansion of agricultural surfaces over the last 20 years, thereby increasing pressure on limited water resources and water quality. Mining, being one of the most important economic sectors in Chile, threatens both surface and groundwater quality. This scenario increases the potential for water use conflicts, which is further compounded by the demand for potable water provided by rivers and groundwater. In order to better understand the role of both physical and human dimensions of water quality, this research uses a socio-hydrological conceptual framework. This approach is used in order to broaden the scope of hydrology to include the anthropogenic impact on the environment. It therefore focuses on human and natural interactions and two-sided feedback loops, instead of purely hydrological cycles. Using the case study of the Rio Huasco watershed changes in water quality, which originate at the nexus of physical parameters, social conflicts and changing land use regimes in Northern Chile, are discussed. This region was chosen as an exemplary case for the development of Chile's arid regions: the valley is located at the southern edge of the Atacama Desert, where water scarcity is a major problem. At present, the watershed is predominantly used for agriculture. Many small farmers still practise strip cultivation, but are pressured to shift towards an international export-orientated future with monocultures. International companies are planning to mine the Pascua Lama Mine, one of the world's biggest gold reserves located in the headwaters of the Rio Huasco. Meanwhile, the problem of scarce water is complicated by the privatization of water rights in Chile. Within the watershed, the amount of sold water rights already exceeds the real water availability by far. An interdisciplinary set of methods was used, including measurements of the chemical and physical parameters of water quality, as well as semi-structured interviews. Water samples across spatial scales were analysed, with the results compared with local people's perceptions of water quality and how this affects their use decisions. The study showed that perceptions of water quality and fear of contamination were influenced by the social conflicts surrounding the controversial construction of the Pascua Lama Mine. The social conflicts were further aggravated by local mistrust towards the multilayered and so-perceived neoliberal and top-down governance structures of water resources in Chile.

  15. Socio-hydrological perspectives of the co-evolution of humans and groundwater in Cangzhou, North China Plain

    Science.gov (United States)

    Han, Songjun; Tian, Fuqiang; Liu, Ye; Duan, Xianhui

    2017-07-01

    This paper presents a historical analysis from socio-hydrological perspectives of the coupled human-groundwater system of the Cangzhou region in the North China Plain (NCP). The history of the pendulum swing for water allocation between the economic development and aquifer environmental health of the system is divided into five eras (i.e., natural, exploitation, degradation and restoration, drought-triggered deterioration, and returning to equilibrium). The system's evolution was interpreted using the Taiji-Tire model. Over-exploitation was considered as the main cause of aquifer depletion, and the groundwater utilization pattern was affected by the varying groundwater table. The aquifer depletion enhanced community sensitivity toward environmental issues, and upgraded the social productive force for restoration. The evolution of the system was substantially impacted by two droughts. The drought in 1965 induced the system from natural conditions to groundwater exploiting. The drought from 1997 to 2002 resulted in a surge in further groundwater abstraction and dramatic aquifer deterioration, and community sensitivity increased rapidly and induced the social productive force to a tipping point. From then on, the system returns to equilibrium through new policies and water-saving technologies. Along with the establishment of a strict water resource management strategy and the launch of the South-to-North Water Diversion Project, further restoration of groundwater environment was implemented. However, a comprehensive and coordinated drought management plan should be devised to avoid irreversible change in the system.

  16. Co-evolution of Riparian Vegetation and Channel Dynamics in an Aggrading Braided River System, Mount Pinatubo, Philippines

    Science.gov (United States)

    Gran, K. B.; Michal, T.

    2014-12-01

    Increased bank stability by riparian vegetation in braided rivers can decrease bed reworking rates and focus the flow. The magnitude of influence and resulting channel morphology are functions of vegetation strength vs. channel dynamics, a concept encapsulated in a dimensionless ratio between timescales for vegetation growth and channel reworking known as T*. We investigate this relationship in an aggrading braided river at Mount Pinatubo, Philippines, and compare results to numerical and physical models. Gradual reductions in post-eruption sediment loads have reduced bed reworking rates, allowing vegetation to persist year-round and impact channel dynamics on the Pasig-Potrero and Sacobia Rivers. From 2009-2011, we collected data detailing vegetation extent, type, density, and root strength. Incorporating these data into RipRoot and BSTEM models shows cohesion due to roots increased from zero in unvegetated conditions to >10.2 kPa in densely-growing grasses. Field-based parameters were incorporated into a cellular model comparing vegetation growth and sediment mobility effects on braided channel dynamics. The model shows that both low sediment mobility and high vegetation strength lead to less active systems, reflecting trends observed in the field. An estimated T* between 0.8 - 2.3 for the Pasig-Potrero River suggests channels were mobile enough to maintain the braidplain width clear of vegetation and even experience slight gains in area through annual removal of existing vegetation. However, persistent vegetation focused flow and thus aggradation over the unvegetated fraction of braidplain, leading to an aggradational imbalance and transition to a more avulsive state. While physical models predict continued narrowing of the active braidplain as T* declines, the future trajectory of channel-vegetation interactions at Pinatubo as sedimentation rates decline appears more complicated due to strong seasonal variability in precipitation and sediment loads. By 2011, seasonal incision in the dry season had started to occur, lowering the water-table, and impeding vegetation growth.

  17. Co-evolution of genomes and plasmids within Chlamydia trachomatis and the emergence in Sweden of a new variant strain

    Directory of Open Access Journals (Sweden)

    Skilton Rachel J

    2009-05-01

    Full Text Available Abstract Background Chlamydia trachomatis is the most common cause of sexually transmitted infections globally and the leading cause of preventable blindness in the developing world. There are two biovariants of C. trachomatis: 'trachoma', causing ocular and genital tract infections, and the invasive 'lymphogranuloma venereum' strains. Recently, a new variant of the genital tract C. trachomatis emerged in Sweden. This variant escaped routine diagnostic tests because it carries a plasmid with a deletion. Failure to detect this strain has meant it has spread rapidly across the country provoking a worldwide alert. In addition to being a key diagnostic target, the plasmid has been linked to chlamydial virulence. Analysis of chlamydial plasmids and their cognate chromosomes was undertaken to provide insights into the evolutionary relationship between chromosome and plasmid. This is essential knowledge if the plasmid is to be continued to be relied on as a key diagnostic marker, and for an understanding of the evolution of Chlamydia trachomatis. Results The genomes of two new C. trachomatis strains were sequenced, together with plasmids from six C. trachomatis isolates, including the new variant strain from Sweden. The plasmid from the new Swedish variant has a 377 bp deletion in the first predicted coding sequence, abolishing the site used for PCR detection, resulting in negative diagnosis. In addition, the variant plasmid has a 44 bp duplication downstream of the deletion. The region containing the second predicted coding sequence is the most highly conserved region of the plasmids investigated. Phylogenetic analysis of the plasmids and chromosomes are fully congruent. Moreover this analysis also shows that ocular and genital strains diverged from a common C. trachomatis progenitor. Conclusion The evolutionary pathways of the chlamydial genome and plasmid imply that inheritance of the plasmid is tightly linked with its cognate chromosome. These data suggest that the plasmid is not a highly mobile genetic element and does not transfer readily between isolates. Comparative analysis of the plasmid sequences has revealed the most conserved regions that should be used to design future plasmid based nucleic acid amplification tests, to avoid diagnostic failures.

  18. Co-evolution of three mega-trends nurtures un-captured GDP : Uber's ride-sharing revolution

    OpenAIRE

    Watanabe, Chihiro; Naveed, Kashif; Neittaanmäki, Pekka

    2016-01-01

    Uber used a disruptive business model driven by digital technology to trigger a ride-sharing revolution. The institution- al sources of the company’s platform ecosystem architecture were analyzed to explain this revolutionary change. Both an empirical analysis of a co-existing development trajectory with taxis and institutional enablers that helped to create Uber’s platform ecosystem were analyzed. The analysis identified a correspondence with the “two-faced” nature of ICT that nu...

  19. Co-evolution of soils and vegetation in the Aísa Valley Experimental Station (Central Pyrenees)

    Science.gov (United States)

    Serrano Muela, Maria Pilar; Nadal Romero, Estela; Lasanta, Teodoro; María García Ruiz, José

    2013-04-01

    Soils and vegetation tend to evolve jointly in relation to climate evolution and the impacts of human activity. This study analyzes soil and vegetation characteristics under various plant covers, using information from the Aísa Valley Experimental Station (AVES), Spanish Pyrenees, from 1991 to 2010. The land uses considered were: dense shrub cover, grazing meadow, abandoned field, cereal (barley), abandoned shifting agriculture, active shifting agriculture, burnt1 and burnt2 plots, and in-fallow plot. All the plots were installed on a field abandoned 45 years ago. Some of the plots did not change in plant cover through the study period (e.g., the meadow, cereal and shifting agriculture plots), but others underwent changes in density and composition, such as: (i) The dense shrub cover plot represents the natural evolution of the abandoned field. When the AVES was equipped, this plot was completely dominated by Genista scorpius, with a few stands of Rosa gr. Canina. Twenty years later, Genista scorpius is affected of senescence and shows almost no regeneration capacity. (ii) The abandoned field had previously been cultivated with cereals until 1993. Once abandoned, the progression of plant colonization was very rapid. Firstly with grasses and, 10 years later, with Genista scorpius. At present, this latter occupies more than 50% of the plot. (iii) The evolution of plant colonization in the abandoned shifting agriculture plot was slower than that in the 'normal' abandoned field, mainly because of the differences in fertilization when they were cultivated. (iv) One of the burnt plots evolved from 0% to a coverage of almost 100% in a shot period, whereas the other plot remained with a shrub density of about 60% several years after the fire. Soil samples (superficial and depth) were analyzed to obtain physical and chemical properties: structure, texture, pH, CaCO3, Organic Matter and various anions and cations. The main purpose was to detect differences in the soil properties as a consequence of land cover/land uses.

  20. Has substrate-dependent co-evolution of enzyme function occured in the attine ant-fungus symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    The conspicuous leaf-cutter ants in the genus Atta build huge nests displacing several cubic meters of soil, whereas lower attine genera such as Cyphomyrmex have small nests with a fungus garden the size of a table-tennis ball. Only the leaf-cutter ants are specialized on using fresh leaves as su...

  1. Role of horizontal gene transfer as a control on the coevolution of ribosomal proteins and the genetic code

    Energy Technology Data Exchange (ETDEWEB)

    Woese, Carl R.; Goldenfeld, Nigel; Luthey-Schulten, Zaida

    2011-03-31

    Our main goal is to develop the conceptual and computational tools necessary to understand the evolution of the universal processes of translation and replication and to identify events of horizontal gene transfer that occurred within the components. We will attempt to uncover the major evolutionary transitions that accompanied the development of protein synthesis by the ribosome and associated components of the translation apparatus. Our project goes beyond standard genomic approaches to explore homologs that are represented at both the structure and sequence level. Accordingly, use of structural phylogenetic analysis allows us to probe further back into deep evolutionary time than competing approaches, permitting greater resolution of primitive folds and structures. Specifically, our work focuses on the elements of translation, ranging from the emergence of the canonical genetic code to the evolution of specific protein folds, mediated by the predominance of horizontal gene transfer in early life. A unique element of this study is the explicit accounting for the impact of phenotype selection on translation, through a coevolutionary control mechanism. Our work contributes to DOE mission objectives through: (1) sophisticated computer simulation of protein dynamics and evolution, and the further refinement of techniques for structural phylogeny, which complement sequence information, leading to improved annotation of genomic databases; (2) development of evolutionary approaches to exploring cellular function and machinery in an integrated way; and (3) documentation of the phenotype interaction with translation over evolutionary time, reflecting the system response to changing selection pressures through horizontal gene transfer.

  2. Hydrologic Synthesis Across the Critical Zone Observatory Network: A Step Towards Understanding the Coevolution of Critical Zone Function and Structure

    Science.gov (United States)

    Wlostowski, A. N.; Harman, C. J.; Molotch, N. P.

    2017-12-01

    The physical and biological architecture of the Earth's Critical Zone controls hydrologic partitioning, storage, and chemical evolution of precipitated water. The Critical Zone Observatory (CZO) Network provides an ideal platform to explore linkages between catchment structure and hydrologic function across a gradient of geologic and climatic settings. A legacy of hypothesis-motivated research at each site has generated a wealth of data characterizing the architecture and hydrologic function of the critical zone. We will present a synthesis of this data that aims to elucidate and explain (in the sense of making mutually intelligible) variations in hydrologic function across the CZO network. Top-down quantitative signatures of the storage and partitioning of water at catchment scales extracted from precipitation, streamflow, and meteorological data will be compared with each other, and provide quantitative benchmarks to assess differences in perceptual models of hydrologic function at each CZO site. Annual water balance analyses show that CZO sites span a wide gradient of aridity and evaporative partitioning. The aridity index (PET/P) ranges from 0.3 at Luquillo to 4.3 at Reynolds Creek, while the evaporative index (E/P) ranges from 0.3 at Luquillo (Rio Mamayes) to 0.9 at Reynolds Creek (Reynolds Creek Outlet). Snow depth and SWE observations reveal that snowpack is an important seasonal storage reservoir at three sites: Boulder, Jemez, Reynolds Creek and Southern Sierra. Simple dynamical models are also used to infer seasonal patterns of subsurface catchment storage. A root-zone water balance model reveals unique seasonal variations in plant-available water storage. Seasonal patterns of plant-available storage are driven by the asynchronicity of seasonal precipitation and evaporation cycles. Catchment sensitivity functions are derived at each site to infer relative changes in hydraulic storage (the apparent storage reservoir responsible for modulating streamflow generation). Storage-discharge relationships vary widely across the Network, and may be associated with inter-site differences in sub-surface architecture. Moving forward, we seek to reconcile top-down analysis results against the bottom-up understanding of critical zone structure and hydrologic function at each CZO site.

  3. Co-evolution of transportation and land use : modeling historical dependencies in land use and transportation decision making.

    Science.gov (United States)

    2009-11-01

    The interaction between land use and transportation has long been the central issue in urban and regional planning. Models of such : interactions provide vital information to support many public policy decisions, such as land supply, infrastructure p...

  4. The spider Harpactea sadistica: co-evolution of traumatic insemination and complex female genital morphology in spiders.

    Science.gov (United States)

    Rezác, Milan

    2009-08-07

    The males of invertebrates from a few phyla, including arthropods, have been reported to practise traumatic insemination (TI; i.e. injecting sperm by using the copulatory organ to penetrate the female's body wall). As all previously reported arthropod examples have been insects, there is considerable interest in whether TI might have evolved independently in other arthropods. The research reported here demonstrates the first case of TI in the arthropod subphylum Chelicerata, in particular how the genital morphology and mating behaviour of Harpactea sadistica (Rezác 2008), a spider from Israel, has become adapted specifically for reproduction based on TI. Males have needle-like intromittent organs and females have atrophied spermathecae. In other spiders, eggs are fertilized simultaneously with oviposition, but the eggs of H. sadistica are fertilized in the ovaries (internal fertilization) and develop as embryos before being laid. Sperm-storage organs of phylogenetically basal groups to H. sadistica provide males with last male sperm priority and allow removal of sperm by males that mate later, suggesting that TI might have evolved as an adaptive strategy to circumvent an unfavourable structure of the sperm-storage organs, allowing the first male to mate with paternity advantage. Understanding the functional significance of TI gives us insight into factors underlying the evolution of the genital and sperm-storage morphology in spiders.

  5. Coevolution of aah: A dps-Like Gene with the Host Bacterium Revealed by Comparative Genomic Analysis

    Directory of Open Access Journals (Sweden)

    Liyan Ping

    2012-01-01

    Full Text Available A protein named AAH was isolated from the bacterium Microbacterium arborescens SE14, a gut commensal of the lepidopteran larvae. It showed not only a high sequence similarity to Dps-like proteins (DNA-binding proteins from starved cell but also reversible hydrolase activity. A comparative genomic analysis was performed to gain more insights into its evolution. The GC profile of the aah gene indicated that it was evolved from a low GC ancestor. Its stop codon usage was also different from the general pattern of Actinobacterial genomes. The phylogeny of dps-like proteins showed strong correlation with the phylogeny of host bacteria. A conserved genomic synteny was identified in some taxonomically related Actinobacteria, suggesting that the ancestor genes had incorporated into the genome before the divergence of Micrococcineae from other families. The aah gene had evolved new function but still retained the typical dodecameric structure.

  6. Socio-cognitive evolution and co-evolution in competing technical trajectories : biogas development in Denmark (1970-2002)

    NARCIS (Netherlands)

    Geels, F.W.; Raven, R.P.J.M.

    2007-01-01

    This article makes two fundamental contributions to evolutionary theories of technological changes. First, a socio-cognitive evolutionary perspective is developed that conceptualises the emergence of new technologies in the pre-market phase. This topic is underdeveloped in evolutionary economics,

  7. The dominantly expressed class I molecule of the chicken MHC is explained by coevolution with the polymorphic peptide transporter (TAP) genes

    DEFF Research Database (Denmark)

    Walker, Brian A; Hunt, Lawrence G; Sowa, Anna K

    2011-01-01

    In most mammals, the MHC class I molecules are polymorphic and determine the specificity of peptide presentation, whereas the transporter associated with antigen presentation (TAP) heterodimers are functionally monomorphic. In chickens, there are two classical class I genes but only one is expres...

  8. Molecular Determinants Underlying Binding Specificities of the ABL Kinase Inhibitors: Combining Alanine Scanning of Binding Hot Spots with Network Analysis of Residue Interactions and Coevolution.

    Directory of Open Access Journals (Sweden)

    Amanda Tse

    Full Text Available Quantifying binding specificity and drug resistance of protein kinase inhibitors is of fundamental importance and remains highly challenging due to complex interplay of structural and thermodynamic factors. In this work, molecular simulations and computational alanine scanning are combined with the network-based approaches to characterize molecular determinants underlying binding specificities of the ABL kinase inhibitors. The proposed theoretical framework unveiled a relationship between ligand binding and inhibitor-mediated changes in the residue interaction networks. By using topological parameters, we have described the organization of the residue interaction networks and networks of coevolving residues in the ABL kinase structures. This analysis has shown that functionally critical regulatory residues can simultaneously embody strong coevolutionary signal and high network centrality with a propensity to be energetic hot spots for drug binding. We have found that selective (Nilotinib and promiscuous (Bosutinib, Dasatinib kinase inhibitors can use their energetic hot spots to differentially modulate stability of the residue interaction networks, thus inhibiting or promoting conformational equilibrium between inactive and active states. According to our results, Nilotinib binding may induce a significant network-bridging effect and enhance centrality of the hot spot residues that stabilize structural environment favored by the specific kinase form. In contrast, Bosutinib and Dasatinib can incur modest changes in the residue interaction network in which ligand binding is primarily coupled only with the identity of the gate-keeper residue. These factors may promote structural adaptability of the active kinase states in binding with these promiscuous inhibitors. Our results have related ligand-induced changes in the residue interaction networks with drug resistance effects, showing that network robustness may be compromised by targeted mutations of key mediating residues. This study has outlined mechanisms by which inhibitor binding could modulate resilience and efficiency of allosteric interactions in the kinase structures, while preserving structural topology required for catalytic activity and regulation.

  9. The Making of the Indian National Innovation Systems: Lessons on the specific characteristics of the domestic and the external co-evolutions of technologies, institutions and incentives

    DEFF Research Database (Denmark)

    Muchie, Mammo; Baskaran, Angathevar

    is growing at a nearly 8 % of GDP and is seen as an emerging economy on a par with China. The policy makers in India have asked: can India become a developed country by 2020? (see Kalam, 1998).  India has tried to apply science and technology to industrialise agriculture and build a modern economy......India is one of the few large economies that have functioning national systems of innovation. It has followed largely a period when self-reliance and selective and guided intervention in the world economy prevailed until the early 1990s when liberalisation of the economy took off. Its economy now....... To this day despite the splendid achievements, India has not escaped from underdevelopment, poverty and inequalities. The specification of the peculiarities and characteristics of India's system of innovation by taking various indicators is critical to undertake. India's strategy for building its national...

  10. How the Cobra Got Its Flesh-Eating Venom: Cytotoxicity as a Defensive Innovation and Its Co-Evolution with Hooding, Aposematic Marking, and Spitting.

    Science.gov (United States)

    Panagides, Nadya; Jackson, Timothy N W; Ikonomopoulou, Maria P; Arbuckle, Kevin; Pretzler, Rudolf; Yang, Daryl C; Ali, Syed A; Koludarov, Ivan; Dobson, James; Sanker, Brittany; Asselin, Angelique; Santana, Renan C; Hendrikx, Iwan; van der Ploeg, Harold; Tai-A-Pin, Jeremie; van den Bergh, Romilly; Kerkkamp, Harald M I; Vonk, Freek J; Naude, Arno; Strydom, Morné A; Jacobsz, Louis; Dunstan, Nathan; Jaeger, Marc; Hodgson, Wayne C; Miles, John; Fry, Bryan G

    2017-03-13

    The cytotoxicity of the venom of 25 species of Old World elapid snake was tested and compared with the morphological and behavioural adaptations of hooding and spitting. We determined that, contrary to previous assumptions, the venoms of spitting species are not consistently more cytotoxic than those of closely related non-spitting species. While this correlation between spitting and non-spitting was found among African cobras, it was not present among Asian cobras. On the other hand, a consistent positive correlation was observed between cytotoxicity and utilisation of the defensive hooding display that cobras are famous for. Hooding and spitting are widely regarded as defensive adaptations, but it has hitherto been uncertain whether cytotoxicity serves a defensive purpose or is somehow useful in prey subjugation. The results of this study suggest that cytotoxicity evolved primarily as a defensive innovation and that it has co-evolved twice alongside hooding behavior: once in the Hemachatus + Naja and again independently in the king cobras ( Ophiophagus ). There was a significant increase of cytotoxicity in the Asian Naja linked to the evolution of bold aposematic hood markings, reinforcing the link between hooding and the evolution of defensive cytotoxic venoms. In parallel, lineages with increased cytotoxicity but lacking bold hood patterns evolved aposematic markers in the form of high contrast body banding. The results also indicate that, secondary to the evolution of venom rich in cytotoxins, spitting has evolved three times independently: once within the African Naja , once within the Asian Naja , and once in the Hemachatus genus. The evolution of cytotoxic venom thus appears to facilitate the evolution of defensive spitting behaviour. In contrast, a secondary loss of cytotoxicity and reduction of the hood occurred in the water cobra Naja annulata , which possesses streamlined neurotoxic venom similar to that of other aquatic elapid snakes (e.g., hydrophiine sea snakes). The results of this study make an important contribution to our growing understanding of the selection pressures shaping the evolution of snake venom and its constituent toxins. The data also aid in elucidating the relationship between these selection pressures and the medical impact of human snakebite in the developing world, as cytotoxic cobras cause considerable morbidity including loss-of-function injuries that result in economic and social burdens in the tropics of Asia and sub-Saharan Africa.

  11. How the Cobra Got Its Flesh-Eating Venom: Cytotoxicity as a Defensive Innovation and Its Co-Evolution with Hooding, Aposematic Marking, and Spitting

    Directory of Open Access Journals (Sweden)

    Nadya Panagides

    2017-03-01

    Full Text Available The cytotoxicity of the venom of 25 species of Old World elapid snake was tested and compared with the morphological and behavioural adaptations of hooding and spitting. We determined that, contrary to previous assumptions, the venoms of spitting species are not consistently more cytotoxic than those of closely related non-spitting species. While this correlation between spitting and non-spitting was found among African cobras, it was not present among Asian cobras. On the other hand, a consistent positive correlation was observed between cytotoxicity and utilisation of the defensive hooding display that cobras are famous for. Hooding and spitting are widely regarded as defensive adaptations, but it has hitherto been uncertain whether cytotoxicity serves a defensive purpose or is somehow useful in prey subjugation. The results of this study suggest that cytotoxicity evolved primarily as a defensive innovation and that it has co-evolved twice alongside hooding behavior: once in the Hemachatus + Naja and again independently in the king cobras (Ophiophagus. There was a significant increase of cytotoxicity in the Asian Naja linked to the evolution of bold aposematic hood markings, reinforcing the link between hooding and the evolution of defensive cytotoxic venoms. In parallel, lineages with increased cytotoxicity but lacking bold hood patterns evolved aposematic markers in the form of high contrast body banding. The results also indicate that, secondary to the evolution of venom rich in cytotoxins, spitting has evolved three times independently: once within the African Naja, once within the Asian Naja, and once in the Hemachatus genus. The evolution of cytotoxic venom thus appears to facilitate the evolution of defensive spitting behaviour. In contrast, a secondary loss of cytotoxicity and reduction of the hood occurred in the water cobra Naja annulata, which possesses streamlined neurotoxic venom similar to that of other aquatic elapid snakes (e.g., hydrophiine sea snakes. The results of this study make an important contribution to our growing understanding of the selection pressures shaping the evolution of snake venom and its constituent toxins. The data also aid in elucidating the relationship between these selection pressures and the medical impact of human snakebite in the developing world, as cytotoxic cobras cause considerable morbidity including loss-of-function injuries that result in economic and social burdens in the tropics of Asia and sub-Saharan Africa.

  12. Hypothesis and Theory: Revisiting Views on the Co-evolution of the Melanocortin Receptors and the Accessory Proteins, MRAP1 and MRAP2.

    Science.gov (United States)

    Dores, Robert M

    2016-01-01

    The evolution of the melanocortin receptors (MCRs) is closely associated with the evolution of the melanocortin-2 receptor accessory proteins (MRAPs). Recent annotation of the elephant shark genome project revealed the sequence of a putative MRAP1 ortholog. The presence of this sequence in the genome of a cartilaginous fish raises the possibility that the mrap1 and mrap2 genes in the genomes of gnathostome vertebrates were the result of the chordate 2R genome duplication event. The presence of a putative MRAP1 ortholog in a cartilaginous fish genome is perplexing. Recent studies on melanocortin-2 receptor (MC2R) in the genomes of the elephant shark and the Japanese stingray indicate that these MC2R orthologs can be functionally expressed in CHO cells without co-expression of an exogenous mrap1 cDNA. The novel ligand selectivity of these cartilaginous fish MC2R orthologs is discussed. Finally, the origin of the mc2r and mc5r genes is reevaluated. The distinctive primary sequence conservation of MC2R and MC5R is discussed in light of the physiological roles of these two MCR paralogs.

  13. Co-evolution in relation to small cars and sustainability in China : interactions between central and local governments, and with business

    NARCIS (Netherlands)

    Kolk, A.; Tsang, S.

    2017-01-01

    This article explores how the institutional context, including central and local governments, has co-evolved with business in relation to small cars and sustainability. This is a very relevant issue for business and society in view of the environmental implications of the rapidly growing vehicle

  14. Impacts of Vegetation Growth on Reach-scale Flood Hydraulics in a Sand-bed River and the Implications for Vegetation-morphology Coevolution

    Science.gov (United States)

    Box, S.; Wilcox, A. C.

    2017-12-01

    Vegetation alters flood hydraulics and geomorphic response, yet quantifying and predicting such responses across spatial and temporal scales remains challenging. Plant- and patch-scale studies consistently show that vegetation increases local hydraulic variability, yet reach-scale hydrodynamic models often assume vegetation has a spatially homogeneous effect on hydraulics. Using Nays2DH in iRIC (International River Interface Cooperative), we model the effect of spatially heterogeneous vegetation on a series of floods with varying antecedent vegetation conditions in a sand-bed river in western Arizona, taking advantage of over a decade of data on a system that experienced substantial geomorphic, hydrologic, and ecosystem changes. We show that pioneer woody seedlings (Tamarix, Populus, Salix) and cattail (Typha) increase local hydraulic variability, including velocity and bed shear stress, along individual cross sections, predominantly by decreasing velocity in zones of vegetation establishment and growth and increasing velocity in unvegetated areas, with analogous effects on shear stress. This was especially prominent in a study reach where vegetation growth contributed to thalweg incision relative to a vegetated bar. Evaluation of these results in the context of observed geomorphic response to floods elucidates mechanisms by which vegetation and channel morphology coevolve at a reach scale. By quantifying the influence of spatially heterogeneous vegetation on reach-scale hydraulics, we demonstrate that plant- and patch-scale research on vegetation hydraulics is applicable to ecogeomorphology at the reach scale.

  15. Molecular variants of human papillomavirus type 16 from four continents suggest ancient pandemic spread of the virus and its coevolution with humankind.

    Science.gov (United States)

    Chan, S Y; Ho, L; Ong, C K; Chow, V; Drescher, B; Dürst, M; ter Meulen, J; Villa, L; Luande, J; Mgaya, H N

    1992-04-01

    We have amplified by the polymerase chain reaction, cloned, and sequenced genomic segments of 118 human papillomavirus type 16 (HPV-16) isolates from 76 cervical biopsy, 14 cervical smear, 3 vulval biopsy, 2 penile biopsy, 2 anal biopsy, and 1 vaginal biopsy sample and two cell lines. The specimens were taken from patients in four countries--Singapore, Brazil, Tanzania, and Germany. The sequence of a 364-bp fragment of the long control region of the virus revealed 38 variants, most of which differed by one or several point mutations. Phylogenetic trees were constructed by distance matrix methods and a transformation series approach. The trees based on the long control region were supported by another set based on the complete E5 protein-coding region. Both sets had two main branches. Nearly all of the variants from Tanzania were assigned to one (African) branch, and all of the German and most of the Singaporean variants were assigned to the other (Eurasian) branch. While some German and Singaporean variants were identical, each group also contained variants that formed unique branches. In contrast to the group-internal homogeneity of the Singaporean, German, and Tanzanian variants, the Brazilian variants were clearly divided between the two branches. Exceptions to this were the seven Singaporean isolates with mutational patterns typical of the Tanzanian isolates. The data suggest that HPV-16 evolved separately for a long period in Africa and Eurasia. Representatives of both branches may have been transferred to Brazil via past colonial immigration. The comparable efficiencies of transfer of the African and the Eurasian variants to the New World suggest pandemic spread of HPV-16 in past centuries. Representatives of the African branch were possibly transferred to the Far East along old Arab and Indonesian sailing routes. Our data also support the view that HPV-16 is a well-defined virus type, since the variants show only a maximal genomic divergence of about 5%. The small amount of divergence in any one geographic location and the lack of marked divergence between the Tanzanian and Brazilian African genome variants two centuries after their likely introduction into the New World suggest a very slow rate of viral evolution. The phylogenetic tree therefore probably represents a minimum of several centuries of evolution, if not an age equal to that of the respective human races.

  16. MAIT, MR1, microbes and riboflavin: a paradigm for the co-evolution of invariant TCRs and restricting MHCI-like molecules?

    Science.gov (United States)

    Mondot, Stanislas; Boudinot, Pierre; Lantz, Olivier

    2016-08-01

    MAIT cells express an invariant TCR that recognizes non-peptidic microbial antigens presented by the non-polymorphic MHCI-like molecule, MR1. We briefly describe how the antigens recognized by MAIT cells are generated from an unstable precursor of the riboflavin (Vitamin B2) biosynthesis pathway, as well as the main features of MAIT cells in comparison with other related T cell subsets. In silico analysis of bacterial genomes shows that the riboflavin biosynthesis pathway is highly prevalent in all groups of Prokaryotes with, however, notable exceptions. We discuss the putative functions and the evolution of the MAIT/MR1 couple: it appeared in the ancestors of mammals and is highly conserved across this group, but was independently lost in three orders. We describe the four instances of known invariant TCR and MHC-I-like molecules encountered in Vertebrates. Both T cells bearing semi-invariant TCR and the associated, evolutionarily conserved MHC-I related molecules have been found in mammals or in amphibians, which suggests that other MHC1-like/invariant TCR couples might be present in other classes of Vertebrates to detect generic microbial compounds. This allows us to discuss how the recognition of riboflavin precursor derivatives by the MAIT TCR may be a way to detect invasive microbes in specific organs, and may epitomize other invariant T cell systems across vertebrates.

  17. Co-evolution in a landrace meta-population: two closely related pathogens interacting with the same host can lead to different adaptive outcomes.

    Science.gov (United States)

    Rau, Domenico; Rodriguez, Monica; Leonarda Murgia, Maria; Balmas, Virgilio; Bitocchi, Elena; Bellucci, Elisa; Nanni, Laura; Attene, Giovanna; Papa, Roberto

    2015-08-07

    We examined the local adaptation patterns in a system comprising several interconnected heterogeneous plant populations from which populations of two phylogenetically closely related pathogens were also sampled. The host is Hordeum vulgare (cultivated barley); the pathogens are Pyrenophora teres f. teres (net form) and Pyrenophora teres f. maculata (spot form), the causal agents of barley net blotch. We integrated two approaches, the comparison between the population structures of the host and the pathogens, and a cross-inoculation test. We demonstrated that two closely related pathogens with very similar niche specialisation and life-styles can give rise to different co-evolutionary outcomes on the same host. Indeed, we detected local adaptation for the net form of the pathogen but not for the spot form. We also provided evidence that an a-priori well-known resistance quantitative-trait-locus on barley chromosome 6H is involved in the co-evolutionary 'arms race' between the plant and the net-form pathogen. Moreover, data suggested latitudinal clines of host resistance and that different ecological conditions can result in differential selective pressures at different sites. Our data are of interest for on-farm conservation of plant genetic resources, as also in establishing efficient breeding programs and strategies for deployment of resistance genes of P. teres.

  18. Coevolution of the Ile1,016 and Cys1,534 Mutations in the Voltage Gated Sodium Channel Gene of Aedes aegypti in Mexico.

    Directory of Open Access Journals (Sweden)

    Farah Z Vera-Maloof

    2015-12-01

    Full Text Available Worldwide the mosquito Aedes aegypti (L. is the principal urban vector of dengue viruses. Currently 2.5 billion people are at risk for infection and reduction of Ae. aegypti populations is the most effective means to reduce the risk of transmission. Pyrethroids are used extensively for adult mosquito control, especially during dengue outbreaks. Pyrethroids promote activation and prolong the activation of the voltage gated sodium channel protein (VGSC by interacting with two distinct pyrethroid receptor sites [1], formed by the interfaces of the transmembrane helix subunit 6 (S6 of domains II and III. Mutations of S6 in domains II and III synergize so that double mutants have higher pyrethroid resistance than mutants in either domain alone. Computer models predict an allosteric interaction between mutations in the two domains. In Ae. aegypti, a Ile1,016 mutation in the S6 of domain II was discovered in 2006 and found to be associated with pyrethroid resistance in field populations in Mexico. In 2010 a second mutation, Cys1,534 in the S6 of domain III was discovered and also found to be associated with pyrethroid resistance and correlated with the frequency of Ile1,016.A linkage disequilibrium analysis was performed on Ile1,016 and Cys1,534 in Ae. aegypti collected in Mexico from 2000-2012 to test for statistical associations between S6 in domains II and III in natural populations. We estimated the frequency of the four dilocus haplotypes in 1,016 and 1,534: Val1,016/Phe1,534 (susceptible, Val1,016/Cys1,534, Ile1,016/Phe1,534, and Ile1,016/Cys1,534 (resistant. The susceptible Val1,016/Phe1,534 haplotype went from near fixation to extinction and the resistant Ile1,016/Cys1,534 haplotype increased in all collections from a frequency close to zero to frequencies ranging from 0.5-0.9. The Val1,016/Cys1,534 haplotype increased in all collections until 2008 after which it began to decline as Ile1,016/Cys1,534 increased. However, the Ile1,016/Phe1,534 haplotype was rarely detected; it reached a frequency of only 0.09 in one collection and subsequently declined.Pyrethroid resistance in the vgsc gene requires the sequential evolution of two mutations. The Ile1,016/Phe1,534 haplotype appears to have low fitness suggesting that Ile1,016 was unlikely to have evolved independently. Instead the Cys1,534 mutation evolved first but conferred only a low level of resistance. Ile1,016 in S6 of domain II then arose from the Val1,016/Cys1,534 haplotype and was rapidly selected because double mutants confer higher pyrethroid resistance. This pattern suggests that knowledge of the frequencies of mutations in both S6 in domains II and III are important to predict the potential of a population to evolve kdr. Susceptible populations with high Val1,016/Cys1,534 frequencies are at high risk for kdr evolution, whereas susceptible populations without either mutation are less likely to evolve high levels of kdr, at least over a 10 year period.

  19. The soils of Champaign are still alive. An assessment of socio-ecological co-evolution in viticulture using DPSIR framework.

    Science.gov (United States)

    Nicolai, Annegret; Cluzeau, Daniel; Descotes, Arnaud; Georget, Cédric; Chaussod, Rémi; Nouaim-Chaussod, Rachida; Peres, Guénola; Guernion, Muriel; Cylly, Daniel; Rougé, Laurence; Garcia, Olivier; Panigai, Laurent; Moncomble, Dominique

    2016-04-01

    Conventional agricultural practices have lead to a loss of ecosystem services, such as soil fertility and soil integrity, water quality, and carbon storage. The importance of soil health to sustain agriculture in the future has raised sociological and political awareness. Wine growers in the Champaign have been the top one users of pesticides in France, and soils were declared by media "being dead" in the 1980ies. Using the DPSIR framework (Driving forces, Pressure, State, Impact, Response circle) we show the mechanism for the evolution of practices in viticulture between 1990 and 2010 in this region. The observed change from 90% to 33% conventional pesticide use is the result of the interaction between scientists and stakeholders via impact studies and technical advices, thereby modulating socio-economic driving forces. Until 1995, 100% of newly planted vineyard were subjected to fumigation by nematicides which represented the highest pressure in Champaign observed through the negative impact on Lombricidae biomass and diversity as well as on aging of vine. In response, a first warning message was published in 1993 in the Professional Technical Guide for Champaign's Viticulture followed by systematic yearly recommendation of alternative practices, such as 3 years of fallow before plantation. The increased fear of economic losses for vine farmers drove the nematicide treatment gradually down to 1% in 2010. The restoration of the soil's biological activities was observed progressively since 2000, associated to an improvement in ecosystem services. The assessment of Champaign's viticulture show, how studying and communicating indicators within a DPSIR framework at a regional scale allow for a directed evolution of management measures in socio-ecosystems.

  20. Co-evolution between streaming and live music leads a way to the sustainable growth of music industry : Lessons from the US experiences

    OpenAIRE

    Naveed, Kashif; Watanabe, Chihiro; Neittaanmäki, Pekka

    2017-01-01

    While digitization of music, particularly streaming services, has gained increasing popularity, it has also led to a steady decline in the revenues of recorded music industry. This is causing strong concern regarding a potential collapse of the music industry comparable to other print media industries such as newspaper and book publishing. However, recent changes in the music industry initiated by a resurgence of the live music industry are giving rise to some expectations for the surviva...

  1. Comparative ribotyping of Staphylococcus intermedius isolated from members of the Canoidea gives possible evidence for host-specificity and co-evolution of bacteria and hosts

    DEFF Research Database (Denmark)

    Aarestrup, Frank Møller

    2001-01-01

    A total of 41 Staphylococcus intermedius isolates were isolated from skin of healthy members of six phylogenetic groups within the Canoidea (the dog family, skunk subfamily, weasel subfamily, racoon family, red panda and bear family) of different geographical origin and compared by EcoRI ribotyping...

  2. The co-evolution of alternative fuel infrastructure and vehicles. A study of the experience of Argentina with compressed natural gas

    International Nuclear Information System (INIS)

    Collantes, Gustavo; Melaina, Marc W.

    2011-01-01

    In a quest for strategic and environmental benefits, the developed countries have been trying for many years to increase the share of alternative fuels in their transportation fuel mixes. They have met very little success though. In this paper, we examine the experience of Argentina with compressed natural gas. We conducted interviews with a wide range of stakeholders and analyzed econometrically data collected in Argentina to investigate the factors, economic, political, and others that determined the high rate of adoption of this fuel. A central objective of this research was to identify lessons that could be useful to developed countries in their efforts to deploy alternative fuel vehicles. We find that fuel price regulation was a significant determinant of the adoption of compressed natural gas, while, contrary to expectations, government financing of refueling infrastructure was minimal. (author)

  3. Co-evolution of soil and water conservation policy and human-environment linkages in the Yellow River Basin since 1949

    NARCIS (Netherlands)

    Wang, F.; Mu, X.; Li, R.; Fleskens, L.; Stringer, L.C.; Ritsema, C.J.

    2015-01-01

    Policy plays a very important role in natural resource management as it lays out a government framework for guiding long-term decisions, and evolves in light of the interactions between human and environment. This paper focuses on soil and water conservation (SWC) policy in the Yellow River Basin

  4. Co-evolution of soil and water conservation policy and human-environment linkages in the Yellow River Basin since 1949.

    Science.gov (United States)

    Wang, Fei; Mu, Xingmin; Li, Rui; Fleskens, Luuk; Stringer, Lindsay C; Ritsema, Coen J

    2015-03-01

    Policy plays a very important role in natural resource management as it lays out a government framework for guiding long-term decisions, and evolves in light of the interactions between human and environment. This paper focuses on soil and water conservation (SWC) policy in the Yellow River Basin (YRB), China. The problems, rural poverty, severe soil erosion, great sediment loads and high flood risks, are analyzed over the period of 1949-present using the Driving force-Pressure-State-Impact-Response (DPSIR) framework as a way to organize analysis of the evolution of SWC policy. Three stages are identified in which SWC policy interacts differently with institutional, financial and technology support. In Stage 1 (1949-1979), SWC policy focused on rural development in eroded areas and on reducing sediment loads. Local farmers were mainly responsible for SWC. The aim of Stage 2 (1980-1990) was the overall development of rural industry and SWC. A more integrated management perspective was implemented taking a small watershed as a geographic interactional unit. This approach greatly improved the efficiency of SWC activities. In Stage 3 (1991 till now), SWC has been treated as the main measure for natural resource conservation, environmental protection, disaster mitigation and agriculture development. Prevention of new degradation became a priority. The government began to be responsible for SWC, using administrative, legal and financial approaches and various technologies that made large-scale SWC engineering possible. Over the historical period considered, with the implementation of the various SWC policies, the rural economic and ecological system improved continuously while the sediment load and flood risk decreased dramatically. The findings assist in providing a historical perspective that could inform more rational, scientific and effective natural resource management going forward. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Smallholder participation in high value agro-export chains in Peru. A study of the co-evolution of technology and institutions

    NARCIS (Netherlands)

    A.H.J. Helmsing (Bert)

    2009-01-01

    textabstract[Introduction] In essence poverty is not only about lack of resources but also about the lack of opportunities. High value, tradable crops may provide opportunities to escape from what Dorward et al (2005) call a ‘low level equilibrium trap’ but as they observe there are important

  6. Molecular Determinants Underlying Binding Specificities of the ABL Kinase Inhibitors: Combining Alanine Scanning of Binding Hot Spots with Network Analysis of Residue Interactions and Coevolution

    Science.gov (United States)

    Tse, Amanda; Verkhivker, Gennady M.

    2015-01-01

    Quantifying binding specificity and drug resistance of protein kinase inhibitors is of fundamental importance and remains highly challenging due to complex interplay of structural and thermodynamic factors. In this work, molecular simulations and computational alanine scanning are combined with the network-based approaches to characterize molecular determinants underlying binding specificities of the ABL kinase inhibitors. The proposed theoretical framework unveiled a relationship between ligand binding and inhibitor-mediated changes in the residue interaction networks. By using topological parameters, we have described the organization of the residue interaction networks and networks of coevolving residues in the ABL kinase structures. This analysis has shown that functionally critical regulatory residues can simultaneously embody strong coevolutionary signal and high network centrality with a propensity to be energetic hot spots for drug binding. We have found that selective (Nilotinib) and promiscuous (Bosutinib, Dasatinib) kinase inhibitors can use their energetic hot spots to differentially modulate stability of the residue interaction networks, thus inhibiting or promoting conformational equilibrium between inactive and active states. According to our results, Nilotinib binding may induce a significant network-bridging effect and enhance centrality of the hot spot residues that stabilize structural environment favored by the specific kinase form. In contrast, Bosutinib and Dasatinib can incur modest changes in the residue interaction network in which ligand binding is primarily coupled only with the identity of the gate-keeper residue. These factors may promote structural adaptability of the active kinase states in binding with these promiscuous inhibitors. Our results have related ligand-induced changes in the residue interaction networks with drug resistance effects, showing that network robustness may be compromised by targeted mutations of key mediating residues. This study has outlined mechanisms by which inhibitor binding could modulate resilience and efficiency of allosteric interactions in the kinase structures, while preserving structural topology required for catalytic activity and regulation. PMID:26075886

  7. The Co-Evolution between Product Form Design and Product CategoriesThe Renaissance of the Behind-the-ear Hearing Aid

    DEFF Research Database (Denmark)

    Krabbe, Anders Dahl

    in the hearing aid industry in the period 2003-2010. Data for the study include interviews, archival material, industry statistics, and hearing care trade journals. The study contributes to theory with the following results: Co-evolutionary dynamics found in the case of technological designs were also observed...

  8. A suture delta: the co-evolution of tectonics and sedimentology as a remnant ocean basin closes; the Indo Burman ranges, northeast India and Bangladesh

    Science.gov (United States)

    Sincavage, R.; Betka, P. M.; Seeber, L.; Steckler, M. S.; Zoramthara, C.

    2017-12-01

    The closure of an ocean basin involves the interplay of tectonics and sedimentology, whereby thick successions of fluvio-deltaic and shallow marine sediment accumulate in the closing gap between the subduction zone and passive margin. The transition from subduction to collision involves processes that are inherently time-transgressive and co-evolve to influence the nature of the developing tectonic wedge. The Indo-Burman Ranges (IBR) of eastern India present a unique opportunity to examine this scenario on a variety of spatial (10-2­­­-105 m2) and temporal (1 a-10 Ma) scales. Recent field mapping campaigns in the IBR have illuminated analogous depositional environments expressed in the Neogene outcrops of the IBR and the Holocene sediment archive of the Ganges-Brahmaputra-Meghna delta (GBMD). Six distinct lithofacies are present in shallow-marine to fluvial strata of the IBR, containing sedimentary structures that reflect depositional environments correlative with the modern delta. Cyclical alternations of fine sands and silts in packages on the order of 15-20 cm thick define part of the shallow-marine section (M2 facies) that we interpret to represent the foreset beds of the ancient subaqueous delta. The overall scale and sedimentary structures of M2 compare favorably with modern foreset deposits in the Bay of Bengal. Tan-orange medium-grained, well sorted fluvial sandstone that contain large scale (1-10 m) tabular and trough cross bedding represent large-river channel deposits (F2 facies) that overlie the shallow marine strata. F2 deposits bear a striking resemblance in scale and character to bar deposits along the modern Jamuna River. Preliminary grain size analyses on the F2 facies yield grain size distributions that are remarkably consistent with Brahmaputra-sourced mid-Holocene sediments from Sylhet basin within the GBMD. Current research on the GBMD has revealed quantifiable trends in bed thicknesses, downstream fining, and grain size within fluvial deposits. These data will be coupled with ongoing structural and geo- and thermochronology field studies of the IBR that aim to continue to reveal the structural and stratigraphic evolution of this geologically active and densely populated region.

  9. Coevolution of nonlinear trends in vegetation, soils, and topography with elevation and slope aspect: A case study in the sky islands of southern Arizona

    Science.gov (United States)

    Pelletier, Jon D.; Barron-Gafford, Greg A.; Breshears, David D.; Brooks, Paul D.; Chorover, Jon; Durcik, Matej; Harman, Ciaran J.; Huxman, Travis E.; Lohse, Kathleen A.; Lybrand, Rebecca; Meixner, Tom; McIntosh, Jennifer C.; Papuga, Shirley A.; Rasmussen, Craig; Schaap, Marcel; Swetnam, Tyson L.; Troch, Peter A.

    2013-06-01

    among vegetation dynamics, pedogenesis, and topographic development affect the "critical zone"—the living filter for Earth's hydrologic, biogeochemical, and rock/sediment cycles. Assessing the importance of such feedbacks, which may be particularly pronounced in water-limited systems, remains a fundamental interdisciplinary challenge. The sky islands of southern Arizona offer an unusually well-defined natural experiment involving such feedbacks because mean annual precipitation varies by a factor of five over distances of approximately 10 km in areas of similar rock type (granite) and tectonic history. Here we compile high-resolution, spatially distributed data for Effective Energy and Mass Transfer (EEMT: the energy available to drive bedrock weathering), above-ground biomass, soil thickness, hillslope-scale topographic relief, and drainage density in two such mountain ranges (Santa Catalina: SCM; Pinaleño: PM). Strong correlations exist among vegetation-soil-topography variables, which vary nonlinearly with elevation, such that warm, dry, low-elevation portions of these ranges are characterized by relatively low above-ground biomass, thin soils, minimal soil organic matter, steep slopes, and high drainage densities; conversely, cooler, wetter, higher elevations have systematically higher biomass, thicker organic-rich soils, gentler slopes, and lower drainage densities. To test if eco-pedo-geomorphic feedbacks drive this pattern, we developed a landscape evolution model that couples pedogenesis and topographic development over geologic time scales, with rates explicitly dependent on vegetation density. The model self-organizes into states similar to those observed in SCM and PM. Our results highlight the potential importance of eco-pedo-geomorphic feedbacks, mediated by soil thickness, in water-limited systems.

  10. The co-evolution of cultures, social network communities, and agent locations in an extension of Axelrod’s model of cultural dissemination

    Science.gov (United States)

    Pfau, Jens; Kirley, Michael; Kashima, Yoshihisa

    2013-01-01

    We introduce a variant of the Axelrod model of cultural dissemination in which agents change their physical locations, social links, and cultures. Numerical simulations are used to investigate the evolution of social network communities and the cultural diversity within and between these communities. An analysis of the simulation results shows that an initial peak in the cultural diversity within network communities is evident before agents segregate into a final configuration of culturally homogeneous communities. Larger long-range interaction probabilities facilitate the initial emergence of culturally diverse network communities, which leads to a more pronounced initial peak in cultural diversity within communities. At equilibrium, the number of communities, and hence cultures, increases when the initial cultural diversity increases. However, the number of communities decreases when the lattice size or population density increases. A phase transition between two regimes of initial cultural diversity is evident. For initial diversities below a critical value, a single network community and culture emerges that dominates the population. For initial diversities above the critical value, multiple culturally homogeneous communities emerge. The critical value of initial diversity at which this transition occurs increases with increasing lattice size and population density and generally with increasing absolute population size. We conclude that larger initial diversities promote cultural heterogenization, while larger lattice sizes, population densities, and in fact absolute population sizes promote homogenization.

  11. COEVOLUTION BETWEEN SUPERMASSIVE BLACK HOLES AND BULGES IS NOT VIA INTERNAL FEEDBACK REGULATION BUT BY RATIONED GAS SUPPLY DUE TO ANGULAR MOMENTUM DISTRIBUTION

    Energy Technology Data Exchange (ETDEWEB)

    Cen, Renyue, E-mail: cen@astro.princeton.edu [Princeton University Observatory, Princeton, NJ 08544 (United States)

    2015-05-20

    We reason that without physical fine-tuning, neither the supermassive black holes (SMBHs) nor the stellar bulges can self-regulate or inter-regulate by driving away already fallen cold gas to produce the observed correlation between them. We suggest an alternative scenario where the observed mass ratios of the SMBHs to bulges reflect the angular momentum distribution of infallen gas such that the mass reaching the stable accretion disk is a small fraction of that reaching the bulge region, averaged over the cosmological timescales. We test this scenario using high-resolution, large-scale cosmological hydrodynamic simulations, without active galactic nucleus (AGN) feedback, assuming the angular momentum distribution of gas landing in the bulge region yields a Mestel disk that is supported by independent simulations resolving the Bondi radii of SMBHs. A mass ratio of 0.1%–0.3% between the very low angular momentum gas that free falls to the subparsec region to accrete to the SMBH and the overall star formation rate is found. This ratio is found to increase with increasing redshift to within a factor of ∼2, suggesting that the SMBH-to-bulge ratio is nearly redshift independent, with a modest increase with redshift, which is a testable prediction. Furthermore, the duty cycle of AGNs with high Eddington ratios is expected to increase significantly with redshift. Finally, while SMBHs and bulges are found to coevolve on ∼30–150 Myr timescales or longer, there is indication that on still smaller timescales, the SMBH accretion and star formation may be less correlated.

  12. Knowledge-Driven Creative Destruction, or Leveraging Knowledge for Competitive Advantage: Strategic Knowledge Arbitrage and Serendipity as Real Options Drivers Triggered by Co-Opetition, Co-Evolution and Co-Specialization

    Science.gov (United States)

    Carayannis, Elias G.

    2008-01-01

    In today's globalizing and hypercompetitive marketplace, knowledge and learning are the only capabilities that can provide sustained competitive advantage. "Knowledge" is the content of learning, and a firm gains competitive superiority either by knowing something that its competitors do not know or by having a certain type of knowledge that…

  13. Seed dispersal in limber and southwestern white pine: Comparing core and peripheral populations

    Science.gov (United States)

    Diana F. Tomback; Sheridan Samano; Elizabeth L. Pruett; Anna W. Schoettle

    2011-01-01

    According to the geographic mosaic theory of coevolution (Thompson 2005), the potential for coevolutionary relationships between interacting species varies with the presence of other species within a community. This implies that the strength of coevolution between two species may vary geographically. In this study, we ask whether there is a shift in vertebrate seed...

  14. Discovering local patterns of co - evolution: computational aspects and biological examples

    Directory of Open Access Journals (Sweden)

    Tuller Tamir

    2010-01-01

    Full Text Available Abstract Background Co-evolution is the process in which two (or more sets of orthologs exhibit a similar or correlative pattern of evolution. Co-evolution is a powerful way to learn about the functional interdependencies between sets of genes and cellular functions and to predict physical interactions. More generally, it can be used for answering fundamental questions about the evolution of biological systems. Orthologs that exhibit a strong signal of co-evolution in a certain part of the evolutionary tree may show a mild signal of co-evolution in other branches of the tree. The major reasons for this phenomenon are noise in the biological input, genes that gain or lose functions, and the fact that some measures of co-evolution relate to rare events such as positive selection. Previous publications in the field dealt with the problem of finding sets of genes that co-evolved along an entire underlying phylogenetic tree, without considering the fact that often co-evolution is local. Results In this work, we describe a new set of biological problems that are related to finding patterns of local co-evolution. We discuss their computational complexity and design algorithms for solving them. These algorithms outperform other bi-clustering methods as they are designed specifically for solving the set of problems mentioned above. We use our approach to trace the co-evolution of fungal, eukaryotic, and mammalian genes at high resolution across the different parts of the corresponding phylogenetic trees. Specifically, we discover regions in the fungi tree that are enriched with positive evolution. We show that metabolic genes exhibit a remarkable level of co-evolution and different patterns of co-evolution in various biological datasets. In addition, we find that protein complexes that are related to gene expression exhibit non-homogenous levels of co-evolution across different parts of the fungi evolutionary line. In the case of mammalian evolution

  15. [Book review] Cowbirds and Other Brood Parasites by Catherine Ortega. Tucson, Arizona: University of Arizona Press (1998). The Avian Brood Parasites: Deception at the Nest by Paul A. Johnsgard. New York: Oxford University Press (1997) Parasitic Birds and their Hosts: Studies in Coevolution edited by S.I. Rothstein & S.K. Robinson. New York: Oxford University Press (1998)

    Science.gov (United States)

    Hahn, D.C.

    1999-01-01

    We are in a golden age for the study of brood parasitism, judging from both the quantity and quality of recent scientific publications on cuckoos, cowbirds and parasitic finches by investigators working in Europe, the Americas, Africa and Asia. As Johnsgard (1997) remarks in his preface, the evolutionary, ecological, and behavioural questions posed by obligate brood parasites are among the most intriguing contemporary ornithological topics. Rothstein & Robinson (1998) explain that brood parasites make ideal subjects for testing the generality of models for the evolution of social and mating behaviour, foraging behaviour, spatial distribution, and vocal development, because the strategy of providing no parental care removes constraints imposed on other birds. Since Aristotle, people have been fascinated by brood parasites, but only in the past two decades has the number of investigators working on this topic reached a critical mass and created momentum that promises many breakthroughs. New studies are being completed so rapidly that a general book is inevitably out of date on some topics by the time it is published. A complete library on brood parasitism should add two recent volumes (Morrison et al. 1999; Smith et al., in press).to the three reviewed here.

  16. Analysis of Claviceps africana and C. sorghi from India using AFLPs, EF-1alfa gene intron 4, and Beta-tubulin gene intron 3

    Czech Academy of Sciences Publication Activity Database

    Tooley, P. W.; Bandyopadhyay, R.; Carras, M. M.; Pažoutová, Sylvie

    2006-01-01

    Roč. 101, č. 4 (2006), s. 441-451 ISSN 0953-7562 Institutional research plan: CEZ:AV0Z50200510 Keywords : clavicipitaceae * coevolution * ergot Subject RIV: EE - Microbiology, Virology Impact factor: 1.860, year: 2006

  17. Inequality and Development Challenges | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2013-08-30

    Aug 30, 2013 ... This book analyses the co-evolution of inequality and NSI across the BRICS ... knowledge, race, gender, ethnicity, and geographic location) that go beyond ... water management: Innovative solutions from the Global South”.

  18. Dual transcriptomics reveals co-evolutionary mechanisms of intestinal parasite infections in blue mussels Mytilus edulis

    NARCIS (Netherlands)

    Feis, M.E.; John, U.; Lokmer, A.; Luttikhuizen, P.C.; Wegner, K.M.

    2018-01-01

    On theoretical grounds, antagonistic co-evolution between hosts and their parasitesshould be a widespread phenomenon but only received little empirical support sofar. Consequently, the underlying molecular mechanisms and evolutionary stepsremain elusive, especially in nonmodel systems. Here, we

  19. Community structure of insect herbivores is driven by conservatism, escalation and divergence of defensive traits in Ficus

    Czech Academy of Sciences Publication Activity Database

    Volf, M.; Segar, S. T.; Miller, S. E.; Isua, B.; Sisol, M.; Aubona, G.; Šimek, P.; Moos, M.; Laitila, J.; Kim, J.; Zima, Jan; Rota, J.; Weiblen, G. D.; Wossa, S.; Salminen, J.-P.; Basset, Y.; Novotný, V.

    2018-01-01

    Roč. 21, č. 1 (2018), s. 83-92 ISSN 1461-023X Institutional support: RVO:67985939 Keywords : alcaloids * coevolution * herbivore Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 9.449, year: 2016

  20. Exploration of hitherto-uncultured bacteria from the rhizosphere

    NARCIS (Netherlands)

    Rocha, da U.N.; Overbeek, van L.S.; Elsas, van J.D.

    2009-01-01

    The rhizosphere environment selects a particular microbial community that arises from the one present in bulk soil due to the release of particular compounds in exudates and different opportunities for microbial colonization. During plant-microorganism coevolution, microbial functions supporting

  1. Exploration of hitherto-uncultured bacteria from the rhizosphere

    NARCIS (Netherlands)

    da Rocha, Ulisses Nunes; van Overbeek, Leo; van Elsas, Jan Dirk

    The rhizosphere environment selects a particular microbial community that arises from the one present in bulk soil due to the release of particular compounds in exudates and different opportunities for microbial colonization. During plant-microorganism coevolution, microbial functions supporting

  2. Evaluation of total phenolics, anthocyanins and antioxidant capacity ...

    African Journals Online (AJOL)

    TUOYO

    2010-08-09

    Aug 9, 2010 ... whose fruits, especially green color, are consumed in different regions of ... chemicals present in this nutritious vegetable. Thus, the ... gallic acid (Sigma Chemical Co.) .... The origin of autumn colours by coevolution. J. Theor.

  3. Mammals of Malawi An annotated check list and atlas

    African Journals Online (AJOL)

    co-evolution between plants and animals is downplayed. This interaction can be counteracted in many ways by ... pollination and breeding systems, seed germination requirements .... history framework and that the ecological consequences.

  4. The co-optimization of floral display and nectar reward

    Indian Academy of Sciences (India)

    Prakash

    2009-12-10

    Dec 10, 2009 ... Flowers may lure pollinators by making large floral displays. (Ohashi and ... Pollination biology; plant–animal interaction; co-evolution; cheater; pollinator learning ..... cheater flowers optimized according to the local ecological.

  5. Interference competition between sunbirds and carpenter bees for ...

    African Journals Online (AJOL)

    Interference competition between sunbirds and carpenter bees for the nectar of ... the nectar plant Hypoestes aristata against carpenter bees (Xylocopa caffra and ... co-evolution, nectar, interspecific competition, pollination biology, pollinators, ...

  6. Some Insights on the Changing Architecture of the World’s Top 100 Multinationals

    Directory of Open Access Journals (Sweden)

    Ogrean Claudia

    2016-12-01

    Full Text Available Premise: globalization represents both the fertile background and the accountable foreground that accompanies the evolution of TNCs/MNEs, within a self-enforcing spiral of co-evolution which gratifies the winners and discards the losers.

  7. Co-evolutionary and multi-level dynamics in transitions: The transformation of aviation systems and the shift from propeller to turbojet (1930-1970)

    OpenAIRE

    Geels, F. W.

    2006-01-01

    This article deals with system innovation in Freeman and Perez's innovation typology (incremental, radical, system, techno-economic paradigm). This article conceptualises these changes as transitions from one socio-technical system to another. These transitions are co-evolution processes that are not only about technological discontinuities, but also about markets, user practices, regulation, culture, infrastructure and science. In a critical discussion of co-evolution literatures, the articl...

  8. The interplay between social networks and culture: theoretically and among whales and dolphins

    OpenAIRE

    Cantor, Mauricio; Whitehead, Hal

    2013-01-01

    Culture is increasingly being understood as a driver of mammalian phenotypes. Defined as group-specific behaviour transmitted by social learning, culture is shaped by social structure. However, culture can itself affect social structure if individuals preferentially interact with others whose behaviour is similar, or cultural symbols are used to mark groups. Using network formalism, this interplay can be depicted by the coevolution of nodes and edges together with the coevolution of network t...

  9. Connecting functional and statistical definitions of genotype by genotype interactions in coevolutionary studies

    Directory of Open Access Journals (Sweden)

    Katy Denise Heath

    2014-04-01

    Full Text Available Predicting how species interactions evolve requires that we understand the mechanistic basis of coevolution, and thus the functional genotype-by-genotype interactions (G × G that drive reciprocal natural selection. Theory on host-parasite coevolution provides testable hypotheses for empiricists, but depends upon models of functional G × G that remain loosely tethered to the molecular details of any particular system. In practice, reciprocal cross-infection studies are often used to partition the variation in infection or fitness in a population that is attributable to G × G (statistical G × G. Here we use simulations to demonstrate that within-population statistical G × G likely tells us little about the existence of coevolution, its strength, or the genetic basis of functional G × G. Combined with studies of multiple populations or points in time, mapping and molecular techniques can bridge the gap between natural variation and mechanistic models of coevolution, while model-based statistics can formally confront coevolutionary models with cross-infection data. Together these approaches provide a robust framework for inferring the infection genetics underlying statistical G × G, helping unravel the genetic basis of coevolution.

  10. Structure-based Markov random field model for representing evolutionary constraints on functional sites.

    Science.gov (United States)

    Jeong, Chan-Seok; Kim, Dongsup

    2016-02-24

    Elucidating the cooperative mechanism of interconnected residues is an important component toward understanding the biological function of a protein. Coevolution analysis has been developed to model the coevolutionary information reflecting structural and functional constraints. Recently, several methods have been developed based on a probabilistic graphical model called the Markov random field (MRF), which have led to significant improvements for coevolution analysis; however, thus far, the performance of these models has mainly been assessed by focusing on the aspect of protein structure. In this study, we built an MRF model whose graphical topology is determined by the residue proximity in the protein structure, and derived a novel positional coevolution estimate utilizing the node weight of the MRF model. This structure-based MRF method was evaluated for three data sets, each of which annotates catalytic site, allosteric site, and comprehensively determined functional site information. We demonstrate that the structure-based MRF architecture can encode the evolutionary information associated with biological function. Furthermore, we show that the node weight can more accurately represent positional coevolution information compared to the edge weight. Lastly, we demonstrate that the structure-based MRF model can be reliably built with only a few aligned sequences in linear time. The results show that adoption of a structure-based architecture could be an acceptable approximation for coevolution modeling with efficient computation complexity.

  11. Coordinated rates of evolution between interacting plastid and nuclear genes in Geraniaceae.

    Science.gov (United States)

    Zhang, Jin; Ruhlman, Tracey A; Sabir, Jamal; Blazier, J Chris; Jansen, Robert K

    2015-03-01

    Although gene coevolution has been widely observed within individuals and between different organisms, rarely has this phenomenon been investigated within a phylogenetic framework. The Geraniaceae is an attractive system in which to study plastid-nuclear genome coevolution due to the highly elevated evolutionary rates in plastid genomes. In plants, the plastid-encoded RNA polymerase (PEP) is a protein complex composed of subunits encoded by both plastid (rpoA, rpoB, rpoC1, and rpoC2) and nuclear genes (sig1-6). We used transcriptome and genomic data for 27 species of Geraniales in a systematic evaluation of coevolution between genes encoding subunits of the PEP holoenzyme. We detected strong correlations of dN (nonsynonymous substitutions) but not dS (synonymous substitutions) within rpoB/sig1 and rpoC2/sig2, but not for other plastid/nuclear gene pairs, and identified the correlation of dN/dS ratio between rpoB/C1/C2 and sig1/5/6, rpoC1/C2 and sig2, and rpoB/C2 and sig3 genes. Correlated rates between interacting plastid and nuclear sequences across the Geraniales could result from plastid-nuclear genome coevolution. Analyses of coevolved amino acid positions suggest that structurally mediated coevolution is not the major driver of plastid-nuclear coevolution. The detection of strong correlation of evolutionary rates between SIG and RNAP genes suggests a plausible explanation for plastome-genome incompatibility in Geraniaceae. © 2015 American Society of Plant Biologists. All rights reserved.

  12. Magnetic Fields In NGC 6946 Using Wide-Band Radio Polarimetry

    NARCIS (Netherlands)

    Williams, Anna; Heald, George; Wilcots, Eric M.; Gould Zweibel, Ellen

    Magnetic fields are important ingredients in the interstellar medium of galaxies. They accelerate cosmic rays, affect star formation, and regulate the redistribution of matter and energy. Despite their ubiquitous presence, the growth and coevolution of magnetic fields with galactic processes are not

  13. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing discriminat...

  14. Human and Machine Entanglement in the Digital Archive: Academic Libraries and Socio-Technical Change

    Science.gov (United States)

    Manoff, Marlene

    2015-01-01

    This essay urges a broadening of the discourse of library and information science (LIS) to address the convergence of forces shaping the information environment. It proposes adopting a model from the field of science studies that acknowledges the interdependence and coevolution of social, cultural, and material phenomena. Digital archives and…

  15. Gradual adaptation of HIV to human host populations: good or bad news?

    Science.gov (United States)

    Brander, Christian; Walker, Bruce D

    2003-11-01

    The continuous evolution and adaptation of HIV to its host has produced extensive global viral diversity. Understanding the kinetics and directions of this continuing adaptation and its impact on viral fitness, immunogenicity and pathogenicity will be crucial to the successful design of effective HIV vaccines. Here we discuss some potential scenarios of viral and host coevolution.

  16. A review of the latest concepts in molecular plant pathology and applications to potato breeding

    Science.gov (United States)

    Co-evolution between pathogens and plants has led to the development of a range of constitutive and inducible resistance mechanisms that help plants survive pathogen attack. Different models have been proposed to describe the plant immune system. The most popular current model indicates that plants ...

  17. Molecular evidence for polyphyletic origin of the primary symbionts of sucking lice (Phthiraptera, Anoplura)

    Czech Academy of Sciences Publication Activity Database

    Hypša, Václav; Křížek, J.

    2007-01-01

    Roč. 54, č. 2 (2007), s. 242-251 ISSN 0095-3628 Grant - others:GA ČR(CZ) GA206/04/0520 Institutional research plan: CEZ:AV0Z60220518 Keywords : Anoplura * endosymbionts * coevolution * molecular phylogeny Subject RIV: EE - Microbiology, Virology Impact factor: 2.558, year: 2007

  18. The Collective Knowledge of Social Tags: Direct and Indirect Influences on Navigation, Learning, and Information Processing

    Science.gov (United States)

    Cress, Ulrike; Held, Christoph; Kimmerle, Joachim

    2013-01-01

    Tag clouds generated in social tagging systems can capture the collective knowledge of communities. Using as a basis spreading activation theories, information foraging theory, and the co-evolution model of cognitive and social systems, we present here a model for an "extended information scent," which proposes that both collective and individual…

  19. Dynamics of adolescent friendship networks and smoking behavior : Social network analyses in six European countries

    NARCIS (Netherlands)

    Mercken, Liesbeth; Snijders, Tom A. B.; Steglich, Christian; de Vries, H.

    The co-evolution of adolescents' friendship networks and their smoking behavior is examined in a large sample across six European countries. Selection and influence processes are disentangled using new methods of social network analysis that enable alternative selection mechanisms to be controlled

  20. Identification and functional comparison of seven-transmembrane G-protein-coupled BILF1 receptors in recently discovered nonhuman primate lymphocryptoviruses

    DEFF Research Database (Denmark)

    Spiess, Katja; Fares, Suzan; Sparre-Ulrich, Alexander H

    2015-01-01

    Coevolution of herpesviruses with their respective host has resulted in a delicate balance between virus-encoded immune evasion mechanisms and host antiviral immunity. BILF1 encoded by human Epstein-Barr virus (EBV) is a 7-transmembrane (7TM) G-protein-coupled receptor (GPCR) with multiple immuno...

  1. Functional properties of Virus-Encoded and Virus-Regulated 7TM Receptors

    DEFF Research Database (Denmark)

    Spiess, Katja; Rosenkilde, Mette Marie

    2014-01-01

    During co-evolution with their hosts, viruses have developed several survival strategies that involve exploitation of 7TM receptors. These include virus-encoded 7TM receptors and ligands and viral regulation of endogenous receptors. Many functional properties have been ascribed to virus-exploited...

  2. Vectors, viscin, and Viscaceae: mistletoes as parasites, mutualists, and resources.

    Science.gov (United States)

    Juliann E. Aukema

    2003-01-01

    Mistletoes are aerial, hemiparasitic plants found on trees throughout the world. They have unique ecological arrangements with the host plants they parasitize and the birds that disperse their seeds. Similar in many respects to vector-borne macroparasites, mistletoes are often detrimental to their hosts, and can even kill them. Coevolution has led to resistance...

  3. A parameter-adaptive dynamic programming approach for inferring cophylogenies

    DEFF Research Database (Denmark)

    Merkle, Daniel; Middendorf, Martin; Wieseke, Nicolas

    2010-01-01

    Background: Coevolutionary systems like hosts and their parasites are commonly used model systems for evolutionary studies. Inferring the coevolutionary history based on given phylogenies of both groups is often done by employing a set of possible types of events that happened during coevolution....

  4. What is freedom--and does wealth cause it?

    Science.gov (United States)

    Iyer, Ravi; Motyl, Matt; Graham, Jesse

    2013-10-01

    The target article's climato-economic theory will benefit by allowing for bidirectional effects and the heterogeneity of types of freedom, in order to more fully capture the coevolution of societal wealth and freedom. We also suggest alternative methods of testing climato-economic theory, such as longitudinal analyses of these countries' histories and micro-level experiments of each of the theory's hypotheses.

  5. Ability of phages to infect Acinetobacter calcoaceticus-Acinetobacter baumannii complex species through acquisition of different pectate lyase depolymerase domains

    NARCIS (Netherlands)

    Oliveira, Hugo; Costa, Ana R.; Konstantinides, Nico; Ferreira, Alice; Akturk, Ergun; Sillankorva, Sanna; Nemec, Alexandr; Shneider, Mikhail; Dötsch, Andreas; Azeredo, Joana

    2017-01-01

    Bacteriophages are ubiquitous in nature and represent a vast repository of genetic diversity, which is driven by the endless coevolution cycle with a diversified group of bacterial hosts. Studying phage-host interactions is important to gain novel insights into their dynamic adaptation. In this

  6. Interfacing Network Simulations and Empirical Data

    Science.gov (United States)

    2009-05-01

    contraceptive innovations in the Cameroon. He found that real-world adoption rates did not follow simulation models when the network relationships were...Analysis of the Coevolution of Adolescents ’ Friendship Networks, Taste in Music, and Alcohol Consumption. Methodology, 2: 48-56. Tichy, N.M., Tushman

  7. The costs and benefits in an unusual symbiosis: experimental evidence that bitterling fish (Rhodeus sericeus) are parasites of unionid mussels in Europe

    Czech Academy of Sciences Publication Activity Database

    Reichard, Martin; Ondračková, Markéta; Przybylski, M.; Liu, H.; Smith, C.

    2006-01-01

    Roč. 19, č. 3 (2006), s. 788-796 ISSN 1010-061X Grant - others:NSFC(CN) 30470237 Institutional research plan: CEZ:AV0Z60930519 Keywords : brood parasitism * coevolution * glochidia Subject RIV: EG - Zoology Impact factor: 2.970, year: 2006

  8. The co-evolutionary relationship between bitterling fishes and freshwater mussels: insights from interspecific comparisons

    Czech Academy of Sciences Publication Activity Database

    Reichard, Martin; Liu, H.; Smith, C.

    2007-01-01

    Roč. 9, č. 2 (2007), s. 239-259 ISSN 1522-0613 Grant - others:NSFC(CN) 30470237 Institutional research plan: CEZ:AV0Z60930519 Keywords : brood parasitism * co-evolution * egg ejection * host-parasite relationship * mutualism * oviposition Subject RIV: EG - Zoology Impact factor: 1.409, year: 2007

  9. Diversity of Trypanosomatids (Kinetoplastea: Trypanosomatidae) Parasitizing Fleas (Insecta: Siphonaptera) and Description of a New Genus Blechomonas gen. n

    Czech Academy of Sciences Publication Activity Database

    Votýpka, Jan; Suková, E.; Kraeva, N.; Ishemgulova, A.; Duží, I.; Lukeš, Julius; Yurchenko, V.

    2013-01-01

    Roč. 164, NOV 2013 (2013), s. 763-781 ISSN 1434-4610 R&D Projects: GA ČR GA13-24983S Institutional support: RVO:60077344 Keywords : Trypanomatidae * phylogeny * Siphonaptera * Blechomonas * host specificty * co-evolution Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.558, year: 2013

  10. Common cuckoo females are not choosy when removing an egg during parasitism

    Czech Academy of Sciences Publication Activity Database

    Šulc, Michal; Procházka, Petr; Čapek, Miroslav; Honza, Marcel

    2016-01-01

    Roč. 27, č. 6 (2016), s. 1642-1649 ISSN 1045-2249 R&D Projects: GA ČR(CZ) GAP506/12/2404 Institutional support: RVO:68081766 Keywords : brood parasitism * coevolution * egg removal * great reed warbler * host and parasite * mimicry * reflectance * spotting pattern Subject RIV: EG - Zoology Impact factor: 3.311, year: 2016

  11. Dynamic egg color mimicry

    Czech Academy of Sciences Publication Activity Database

    Hanley, D.; Šulc, Michal; Brennan, P. L. R.; Hauber, M. E.; Grim, T.; Honza, Marcel

    2016-01-01

    Roč. 6, č. 12 (2016), s. 4192-4202 ISSN 2045-7758 R&D Projects: GA ČR(CZ) GAP506/12/2404; GA AV ČR IAA600930903 Institutional support: RVO:68081766 Keywords : avian vision * brood parasitism * coevolution * common cuckoo * mimicry * pigments Subject RIV: EG - Zoology Impact factor: 2.440, year: 2016

  12. How to hatch from the Common Cuckoo (Cuculus canorus) egg: implications of strong eggshells for the hatching muscle (musculus complexus)

    Czech Academy of Sciences Publication Activity Database

    Honza, Marcel; Feikusová, Kateřina; Procházka, Petr; Picman, J.

    2015-01-01

    Roč. 156, č. 3 (2015), s. 679-685 ISSN 0021-8375 R&D Projects: GA ČR(CZ) GAP506/12/2404; GA AV ČR IAA6093203 Institutional support: RVO:68081766 Keywords : Brood parasitism * Common Cuckoo * Coevolution * Adaptations * Hatching muscle * Hatching Subject RIV: EG - Zoology Impact factor: 1.419, year: 2015

  13. Caste-specific symbiont policing by workers of Acromyrmex fungus-growing ants

    NARCIS (Netherlands)

    Ivens, Aniek B. F.; Nash, David R.; Poulsen, Michael; Boomsma, Jacobus J.

    2009-01-01

    The interaction between leaf-cutting ants and their fungus garden mutualists is ideal for studying the evolutionary stability of interspecific cooperation. Although the mutualism has a long history of diffuse coevolution, there is ample potential for conflicts between the partners over the mixing

  14. Novel Phialophora species from leaf-cutting ants (tribe Attini)

    NARCIS (Netherlands)

    Attili-Angelis, D.; Duarte, A.P.M.; Pagnocca, F.C.; Nagamoto, N.S.; de Vries, M.; Stielow, J.B.; de Hoog, G.S.

    2014-01-01

    Ants in the tribe Attini (Hymenoptera, Formicidae) maintain a 50 million-year-old lifestyle of co-evolution with symbiotic basidiomycetous fungi which they cultivate as essential source of nutrition. However, other microorganisms have been reported from ant habitats indicating a higher diversity of

  15. Ecological turmoil in evolutionary dynamics of plant-insect interactions: defense to offence

    Czech Academy of Sciences Publication Activity Database

    Mishra, Manasi; Lomate, P. R.; Joshi, R. S.; Punekar, S. A.; Gupta, V. S.; Giri, A. P.

    2015-01-01

    Roč. 242, č. 4 (2015), s. 761-771 ISSN 0032-0935 Institutional support: RVO:61388963 Keywords : plant-insect interaction * co-evolution * human interference * ecosystem * climatic change Subject RIV: CE - Biochemistry Impact factor: 3.239, year: 2015

  16. How many species of arthropods visit flowers?

    Czech Academy of Sciences Publication Activity Database

    Wardhaugh, Carl W.

    2015-01-01

    Roč. 9, č. 6 (2015), s. 547-565 ISSN 1872-8855 R&D Projects: GA ČR GB14-36098G Institutional support: RVO:60077344 Keywords : cantharophily * coevolution * florivory Subject RIV: EH - Ecology, Behaviour Impact factor: 1.448, year: 2015 http://link.springer.com/article/10.1007%2Fs11829-015-9398-4

  17. Convergent evolution of sunbird pollination systems of Impatiens species in tropical Africa and hummingbird systems of the New World

    Czech Academy of Sciences Publication Activity Database

    Janeček, Štěpán; Bartoš, Michael; Njabo, K. Y.

    2015-01-01

    Roč. 115, č. 1 (2015), s. 127-133 ISSN 0024-4066 R&D Projects: GA ČR(CZ) GAP505/11/1617 Institutional support: RVO:67985939 Keywords : Cameroon * co-evolution * pollination Subject RIV: EF - Botanics Impact factor: 1.984, year: 2015

  18. Citation algorithms for identifying research milestones driving biomedical innovation

    NARCIS (Netherlands)

    Comins, J.A.; Leydesdorff, L.

    Scientific activity plays a major role in innovation for biomedicine and healthcare. For instance, fundamental research on disease pathologies and mechanisms can generate potential targets for drug therapy. This co-evolution is punctuated by papers which provide new perspectives and open new

  19. Intronic deletions that disrupt mRNA splicing of the tva receptor gene result in decreased susceptibility to infection by avian sarcoma and leukosis virus subgroup A

    Czech Academy of Sciences Publication Activity Database

    Reinišová, Markéta; Plachý, Jiří; Trejbalová, Kateřina; Šenigl, Filip; Kučerová, Dana; Geryk, Josef; Svoboda, Jan; Hejnar, Jiří

    2012-01-01

    Roč. 86, č. 4 (2012), s. 2021-2030 ISSN 1098-5514 R&D Projects: GA ČR GAP502/10/1651 Institutional research plan: CEZ:AV0Z50520514 Keywords : avian sarcoma and leukosis virus * virus-host coevolution * resistance to retroviruses Subject RIV: EB - Genetics ; Molecular Biology

  20. "Neem het dier serieus als individu"

    NARCIS (Netherlands)

    Kleis, R.; Driessen, C.P.G.

    2014-01-01

    Ethiek op de boerderij komt het beste uit de verf door samen met dieren nieuwe technologie te ontwikkelen. Filosoof Clemens Driessen, de man van het varkensspel Pig Chase, promoveerde afgelopen week cum laude op Animal deliberation, the co-evolution of technology and ethics on the farm. Resource

  1. Demographically idiosyncratic responses to climate change and rapid Pleistocene diversification of the walnut genus Juglans (Juglandaceae) revealed by whole-genome sequences

    Science.gov (United States)

    Wei-Ning Bai; Peng-Cheng Yan; Bo-Wen Zhang; Keith E. Woeste; Kui Lin; Da-Yong. Zhang

    2018-01-01

    Whether species demography and diversification are driven primarily by extrinsic environmental changes such as climatic oscillations in the Quaternary or by intrinsic biological interactions like coevolution between antagonists is a matter of active debate. In fact, their relative importance can be assessed by tracking past population fluctuations over considerable...

  2. Cross-linked structure of network evolution

    Energy Technology Data Exchange (ETDEWEB)

    Bassett, Danielle S., E-mail: dsb@seas.upenn.edu [Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Department of Physics, University of California, Santa Barbara, California 93106 (United States); Sage Center for the Study of the Mind, University of California, Santa Barbara, California 93106 (United States); Wymbs, Nicholas F.; Grafton, Scott T. [Department of Psychology and UCSB Brain Imaging Center, University of California, Santa Barbara, California 93106 (United States); Porter, Mason A. [Oxford Centre for Industrial and Applied Mathematics, Mathematical Institute, University of Oxford, Oxford OX2 6GG (United Kingdom); CABDyN Complexity Centre, University of Oxford, Oxford, OX1 1HP (United Kingdom); Mucha, Peter J. [Carolina Center for Interdisciplinary Applied Mathematics, Department of Mathematics, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)

    2014-03-15

    We study the temporal co-variation of network co-evolution via the cross-link structure of networks, for which we take advantage of the formalism of hypergraphs to map cross-link structures back to network nodes. We investigate two sets of temporal network data in detail. In a network of coupled nonlinear oscillators, hyperedges that consist of network edges with temporally co-varying weights uncover the driving co-evolution patterns of edge weight dynamics both within and between oscillator communities. In the human brain, networks that represent temporal changes in brain activity during learning exhibit early co-evolution that then settles down with practice. Subsequent decreases in hyperedge size are consistent with emergence of an autonomous subgraph whose dynamics no longer depends on other parts of the network. Our results on real and synthetic networks give a poignant demonstration of the ability of cross-link structure to uncover unexpected co-evolution attributes in both real and synthetic dynamical systems. This, in turn, illustrates the utility of analyzing cross-links for investigating the structure of temporal networks.

  3. Intronic deletions that disrupt mRNA splicing of the tva receptor gene result in decreased susceptibility to infection by avian sarcoma and leukosis virus subgroup A

    Czech Academy of Sciences Publication Activity Database

    Reinišová, Markéta; Plachý, Jiří; Trejbalová, Kateřina; Šenigl, Filip; Kučerová, Dana; Geryk, Josef; Svoboda, Jan; Hejnar, Jiří

    2012-01-01

    Roč. 86, č. 4 (2012), s. 2021-2030 ISSN 1098-5514 R&D Projects: GA ČR GAP502/10/1651 Institutional research plan: CEZ:AV0Z50520514 Keywords : avian sarcoma and leukosis virus * virus- host coevolution * resistance to retroviruses Subject RIV: EB - Genetics ; Molecular Biology

  4. Regulation under Uncertainty

    DEFF Research Database (Denmark)

    Sabel, Charles; Herrigel, Gary; Hull Kristensen, Peer

    2017-01-01

    generation of the implicated components or installations are updated accordingly. In this essay we develop these arguments and look closely at changes in the Norwegian offshore oil and gas industry and its regulator, the Petroleum Safety Authority to better understand the coevolution of vertically...

  5. Genetic signatures of variation in population size in a native fungal pathogen after the recent intensive plantation of its host tree

    NARCIS (Netherlands)

    Labbé, Frédéric; Fontaine, Michael Christophe; Robin, Cécile; Dutech, Cyril

    2017-01-01

    Historical fluctuations in forests’ distribution driven by past climate changes and anthropogenic activities can have large impacts on the demographic history of pathogens that have a long co-evolution history with these host trees. Using a population genetic approach, we investigated that

  6. Genotype specificity among hosts, pathogens, and beneficial microbes influences the strength of symbiont-mediated protection

    Czech Academy of Sciences Publication Activity Database

    Parker, B. J.; Hrček, Jan; McLean, A. H. C.; Godfray, H. C. J.

    2017-01-01

    Roč. 71, č. 5 (2017), s. 1222-1231 ISSN 0014-3820 Institutional support: RVO:60077344 Keywords : coevolution * endosymbiont * fungal pathogens Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.201, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/evo.13216/full

  7. Autonomous Learning for English Acquisition in Blended e-Studies for Adults within the Context of Sustainable Development

    Science.gov (United States)

    Bojare, Inara

    2016-01-01

    Personality integration and self-realisation in the global economy and coevolution with multilingual cultural environment of sustainable learning society by means of technologies actualise the paradigm shift in science, and create the necessity for transdisciplinary research to resolve the problem of transformation of the system of values in the…

  8. Cross-linked structure of network evolution

    International Nuclear Information System (INIS)

    Bassett, Danielle S.; Wymbs, Nicholas F.; Grafton, Scott T.; Porter, Mason A.; Mucha, Peter J.

    2014-01-01

    We study the temporal co-variation of network co-evolution via the cross-link structure of networks, for which we take advantage of the formalism of hypergraphs to map cross-link structures back to network nodes. We investigate two sets of temporal network data in detail. In a network of coupled nonlinear oscillators, hyperedges that consist of network edges with temporally co-varying weights uncover the driving co-evolution patterns of edge weight dynamics both within and between oscillator communities. In the human brain, networks that represent temporal changes in brain activity during learning exhibit early co-evolution that then settles down with practice. Subsequent decreases in hyperedge size are consistent with emergence of an autonomous subgraph whose dynamics no longer depends on other parts of the network. Our results on real and synthetic networks give a poignant demonstration of the ability of cross-link structure to uncover unexpected co-evolution attributes in both real and synthetic dynamical systems. This, in turn, illustrates the utility of analyzing cross-links for investigating the structure of temporal networks

  9. Discovery of a novel insect neuropeptide signaling system closely related to the insect adipokinetic hormone and corazonin hormonal systems

    DEFF Research Database (Denmark)

    Hansen, Karina Kiilerich; Stafflinger, Elisabeth; Schneider, Martina

    2010-01-01

    receptors, this is a prominent example of receptor/ligand co-evolution, probably originating from receptor and ligand gene duplications followed by mutations and evolutionary selection, thereby yielding three independent hormonal systems. The ACP signaling system occurs in the mosquitoes A. gambiae, Aedes...

  10. Constraints on host choice: why do parasitic birds rarely exploit some common potential hosts?

    Czech Academy of Sciences Publication Activity Database

    Grim, T.; Samaš, P.; Moskát, C.; Kleven, O.; Honza, Marcel; Moksnes, A.; Roskaft, E.; Stokke, B. G.

    2011-01-01

    Roč. 80, č. 3 (2011), s. 508-518 ISSN 0021-8790 R&D Projects: GA AV ČR IAA600930605 Institutional research plan: CEZ:AV0Z60930519 Keywords : antiparasite defence * co-evolution * host selection * interactive effects * parasite avoidance Subject RIV: EG - Zoology Impact factor: 4.937, year: 2011

  11. Infection dynamics of the monogenean parasite Gyrodactylus gasterostei on sympatric and allopatric populations of the three-spined stickleback Gasterosteus aculeatus.

    Science.gov (United States)

    Raeymaekers, Joost A M; Wegner, K Mathias; Huyset, Tine; Volckaert, Filip A M

    2011-03-01

    Parasites with high host specificity maximally depend on their hosts, which should increase the likelihood of coevolution. However, coevolution requires reciprocal selection exerted by the host and the parasite, and thus a considerable level of parasite virulence. In species of the monogenean ectoparasite genus Gyrodactylus consecutive generations are confronted with a single host, which may constrain the evolution of virulence. Transmission, which is often important in the ecology of Gyrodactylus species, may have the opposite effect, but may also lead to the avoidance of coevolutionary arms races. We investigated the potential outcome of coevolution between Gyrodactylus gasterostei Gläser, 1974 and its host, the three-spined stickleback (Gasterosteus aculeatus L.) by determining the strength of genotype by genotype (GxG) interactions on two levels: within and between sympatric and allopatric host populations. To do so, we compared the parasite's infection dynamics on laboratory-reared sympatric (Belgian) and allopatric (German) hosts. We found that a parasite line successfully infected a range of sympatric host genotypes (represented by families), while it failed to establish on allopatric hosts. Phylogeographic studies suggest that neutral genetic divergence between the host populations cannot explain this dramatic difference. Provided that this result can be generalised towards other parasite lines, we conclude that coevolution in this host-parasite system is more likely to lead to local adaptation on the population level than to GxG interactions within populations.

  12. Quasar feedback in the early Universe : The case of SDSS J1148+5251

    NARCIS (Netherlands)

    Valiante, Rosa; Schneider, Raffaella; Maiolino, Roberto; Salvadori, Stefania; Bianchi, Simone

    2012-01-01

    Galaxy-scale gas outflows triggered by active galactic nuclei have been proposed as a key physical process to regulate the co-evolution of nuclear black holes and their host galaxies. The recent detection of a massive gas outflow in one of the most distant quasars, SDSS J1148+5251 at z = 6.4,

  13. Quasar feedback in the early Universe: the case of SDSS J1148+5251

    NARCIS (Netherlands)

    Valiante, Rosa; Schneider, Raffaella; Maiolino, Roberto; Salvadori, Stefania; Bianchi, Simone

    2012-01-01

    Galaxy-scale gas outflows triggered by active galactic nuclei have been proposed as a key physical process to regulate the co-evolution of nuclear black holes and their host galaxies. The recent detection of a massive gas outflow in one of the most distant quasars, SDSS J1148+5251 at z= 6.4,

  14. Framing Behaviours in Novice Interaction Designers

    Science.gov (United States)

    Lotz, Nicole; Sharp, Helen; Woodroffe, Mark; Blyth, Richard; Rajah, Dino; Ranganai, Turugare

    2015-01-01

    Framing design problems and solutions has been recognised in design studies as a central designerly activity. Some recent findings with expert designers relate framing practices to problem-solution co-evolution and analogy use, two further widely recognised design strategies. We wanted to understand if interaction design novices also use…

  15. Joint determination of biological encephalization and economic specialization

    NARCIS (Netherlands)

    Horan, R.D.; Shogren, J.F.; Bulte, E.H.

    2011-01-01

    In this paper, we develop a paleoeconomic model of the co-evolution of economic specialization and encephalization—the common physiological measure of intelligence as reflected by brain mass relative to total body mass. Our economic analysis links ecological and social intelligence theories of

  16. Joint determination of biological encephalization, economic specialization

    NARCIS (Netherlands)

    Horan, R.D.; Shogren, J.F.; Bulte, E.H.

    2011-01-01

    In this paper, we develop a paleoeconomic model of the co-evolution of economic specialization and encephalization-the common physiological measure of intelligence as reflected by brain mass relative to total body mass. Our economic analysis links ecological and social intelligence theories of

  17. Homophily and assimilation among sportactive adolescent substance users

    NARCIS (Netherlands)

    Pearson, M; Steglich, Ch.; Snijders, T.A.B.

    2006-01-01

    We analyse the co-evolution of social networks and substance use behaviour of adolescents and address the problem of separating the effects of homophily and assimilation. Adolescents who prefer friends with the same substance-use behaviour exhibit the homophily principle. Adolescents who adapt their

  18. An invasive species reverses the roles in a host–parasite relationship between bitterling fish and unionid mussels

    Czech Academy of Sciences Publication Activity Database

    Reichard, Martin; Vrtílek, Milan; Douda, K.; Smith, C.

    2012-01-01

    Roč. 8, č. 4 (2012), s. 601-604 ISSN 1744-9561 R&D Projects: GA ČR GA206/09/1163 Institutional research plan: CEZ:AV0Z60930519 Institutional support: RVO:68081766 Keywords : species interaction * coevolution * interspecific relationship * parasitism Subject RIV: EG - Zoology Impact factor: 3.348, year: 2012

  19. Individual female common cuckoos Cuculus canorus lay constant egg types but egg appearance cannot be used to assign eggs to females

    Czech Academy of Sciences Publication Activity Database

    Moksnes, A.; Roskaft, E.; Rudolfsen, G.; Skjelseth, S.; Stokke, B. G.; Kleven, O.; Gibbs, H. L.; Honza, Marcel; Taborsky, B.; Teuschl, Y.; Vogl, W.; Taborsky, M.

    2008-01-01

    Roč. 39, č. 2 (2008), s. 238-241 ISSN 0908-8857 Institutional research plan: CEZ:AV0Z60930519 Keywords : host preference * co-evolution * parasitism Subject RIV: EG - Zoology Impact factor: 2.327, year: 2008

  20. Selection on the Major Color Gene Melanocortin-1-Receptor Shaped the Evolution of the Melanocortin System Genes

    Directory of Open Access Journals (Sweden)

    Linda Dib

    2017-12-01

    Full Text Available Modular genetic systems and networks have complex evolutionary histories shaped by selection acting on single genes as well as on their integrated function within the network. However, uncovering molecular coevolution requires the detection of coevolving sites in sequences. Detailed knowledge of the functions of each gene in the system is also necessary to identify the selective agents driving coevolution. Using recently developed computational tools, we investigated the effect of positive selection on the coevolution of ten major genes in the melanocortin system, responsible for multiple physiological functions and human diseases. Substitutions driven by positive selection at the melanocortin-1-receptor (MC1R induced more coevolutionary changes on the system than positive selection on other genes in the system. Contrarily, selection on the highly pleiotropic POMC gene, which orchestrates the activation of the different melanocortin receptors, had the lowest coevolutionary influence. MC1R and possibly its main function, melanin pigmentation, seems to have influenced the evolution of the melanocortin system more than functions regulated by MC2-5Rs such as energy homeostasis, glucocorticoid-dependent stress and anti-inflammatory responses. Although replication in other regulatory systems is needed, this suggests that single functional aspects of a genetic network or system can be of higher importance than others in shaping coevolution among the genes that integrate it.

  1. Multi-objective based on parallel vector evaluated particle swarm optimization for optimal steady-state performance of power systems

    DEFF Research Database (Denmark)

    Vlachogiannis, Ioannis (John); Lee, K Y

    2009-01-01

    In this paper the state-of-the-art extended particle swarm optimization (PSO) methods for solving multi-objective optimization problems are represented. We emphasize in those, the co-evolution technique of the parallel vector evaluated PSO (VEPSO), analysed and applied in a multi-objective problem...

  2. Bayesian inference supports the host selection hypothesis in explaining adaptive host specificity by European bitterling

    Czech Academy of Sciences Publication Activity Database

    Smith, Carl

    2017-01-01

    Roč. 183, č. 2 (2017), s. 379-389 ISSN 0029-8549 R&D Projects: GA ČR GA13-05872S Institutional support: RVO:68081766 Keywords : Brood parasite * Host–parasite co-evolution * Oviposition * Spawning site * Superparasitism Subject RIV: EG - Zoology OBOR OECD: Ecology Impact factor: 3.130, year: 2016

  3. Characterisation of microsatellite loci in two species of lice, Polyplax serrata (Phthiraptera: Anoplura: Polyplacidae) and/nMyrsidea nesomimi (Phthiraptera: Amblycera: Menoponidae)

    Czech Academy of Sciences Publication Activity Database

    Martinů, Jana; Roubová, V.; Nováková, M.; Smith, V. S.; Hypša, Václav; Štefka, Jan

    2015-01-01

    Roč. 62, FEB 13 2015 (2015), 016 ISSN 1803-6465 R&D Projects: GA ČR GPP506/12/P529 Institutional support: RVO:60077344 Keywords : ectoparasite * population genetics * coevolution * Polypax * Myrsidea * evolution * Europe * Galapagos Subject RIV: EG - Zoology Impact factor: 1.271, year: 2015

  4. Phylogeny, evolution and host-parasite relationships of the order Proteocephalidea (Eucestoda) as revealed by combined analysis and secondary structure characters

    Czech Academy of Sciences Publication Activity Database

    Hypša, Václav; Škeříková, Andrea; Scholz, Tomáš

    2005-01-01

    Roč. 130, č. 3 (2005), s. 359-371 ISSN 0031-1820 R&D Projects: GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z60220518 Keywords : phylogeny * co-evolution * Proteocephalidea Subject RIV: EG - Zoology Impact factor: 1.703, year: 2005

  5. Population structure of a microparasite infecting Daphnia: spatio-temporal dynamics

    Czech Academy of Sciences Publication Activity Database

    Wolinska, J.; Petrusek, A.; Yin, M.; Koerner, H.; Seďa, Jaromír; Giessler, S.

    2014-01-01

    Roč. 14, DEC 4 (2014), s. 1-11 ISSN 1471-2148 R&D Projects: GA AV ČR(CZ) IAA600960901 Institutional support: RVO:60077344 Keywords : Caullerya mesnili * host − parasite coevolution * ITS region Subject RIV: DA - Hydrology ; Limnology Impact factor: 3.368, year: 2014

  6. Coevolving parasites and population size shape the evolution of mating behaviour

    Directory of Open Access Journals (Sweden)

    Kerstes Niels AG

    2013-02-01

    Full Text Available Abstract Background Coevolution with parasites and population size are both expected to influence the evolution of mating rates. To gain insights into the interaction between these dual selective factors, we used populations from a coevolution experiment with the red flour beetle, Tribolium castaneum, and its microsporidian parasite, Nosema whitei. We maintained each experimental population at two different population sizes. We assayed the mating behaviour of both males and females from coevolved and paired non-coevolved control populations after 24 generations of coevolution with parasites. Results Males from large, coevolved populations (i.e. ancestors were exposed to parasites showed a reduced eagerness to mate compared to males from large, non-coevolved populations. But in small populations, coevolution did not lead to decreased male mating rates. Coevolved females from both large and small populations appeared to be more willing to accept mating than non-coevolved females. Conclusions This study provides unique, experimental insights into the combined roles of coevolving parasites and population size on the evolution of mating rate. Furthermore, we find that males and females respond differently to the same environmental conditions. Our results show that parasites can be key determinants of the sexual behaviour of their hosts.

  7. Relation between phylogeny of African green monkey CD4 genes and their respective simian immunodeficiency virus genes

    DEFF Research Database (Denmark)

    Fomsgaard, Anders; Müller-Trutwin, Michaela C.; Diop, Ousmane

    1997-01-01

    An apparent species-specific relatedness of SIVagm suggests a coevolution with their natural hosts. However, the exact species or subspecies classification of African green monkeys, AGM, is uncertain because current classification schemes rely on phenotype markers, while more definitive genetic d...

  8. The common cuckoo Cuculus canorus is not locally adapted to its reed warbler Acrocephalus scirpaceus host

    Czech Academy of Sciences Publication Activity Database

    Avilés, J. M.; Vikan, J. R.; Fossoy, F.; Antonov, A.; Moksnes, A.; Roskaft, E.; Shykoff, J.A.; Moller, A. P.; Jensen, H.; Procházka, Petr; Stokke, B. G.

    2011-01-01

    Roč. 24, č. 2 (2011), s. 314-325 ISSN 1010-061X Institutional research plan: CEZ:AV0Z60930519 Keywords : coevolution * geographical mosaic * local adaptation * mimicry * specialization Subject RIV: EG - Zoology Impact factor: 3.276, year: 2011

  9. Review of Cytoskeleton Research in Cell Differentiation and Development.

    Science.gov (United States)

    1987-09-10

    tetrameric mol- molecule and the corresponding site on ecule of dumbbell-like structure. Plec - ,MAP’s underwent molecular coevolution and tin’s globular...coworkers as plectin’s interaction by dlffe~ent MAP’s. Limited proteolysis partners. Thus, Wiche suggests that plec - of tubulin and MAP’s to analyze the

  10. Inequality and Development Challenges | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    30 août 2013 ... This is the second volume in a series of five books bringing together the results of intensive research on the national systems of innovation (NSI) in the BRICS countries – Brazil, Russia, India, China, and South Africa. This book analyses the co-evolution of inequality and NSI across the BRICS economies.

  11. An indirect effect of biological invasions: the effect of zebra mussel fouling on parasitisation of unionid mussels by bitterling fish

    Czech Academy of Sciences Publication Activity Database

    Vrtílek, Milan; Reichard, Martin

    2012-01-01

    Roč. 696, č. 1 (2012), s. 205-214 ISSN 0018-8158 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Non-native species * Coevolution * Invasional meltdown * Host-parasite relationship * Aquatic ecosystems Subject RIV: EG - Zoology Impact factor: 1.985, year: 2012

  12. Regulatory RNAs derived from transfer RNA?

    Science.gov (United States)

    Pederson, Thoru

    2010-10-01

    Four recent studies suggest that cleavages of transfer RNAs generate products with microRNA-like features, with some evidence of function. If their regulatory functions were to be confirmed, these newly revealed RNAs would add to the expanding repertoire of small noncoding RNAs and would also provide new perspectives on the coevolution of transfer RNA and messenger RNA.

  13. Training with O (Observing) and T (Treatment) Teams in Live Supervision: Reflections in the Looking Glass.

    Science.gov (United States)

    Roberts, Janine; And Others

    1989-01-01

    Describes process that six counselor trainees and two supervisors used with treatment and observation teams to examine their own coevolution as a therapeutic system using the Milan model of family therapy and Ericksonian hypnotherapy. Concludes with a discussion of advantages and pitfalls of this type of dual supervision. (Author/ABL)

  14. Bipteria vetusta n. sp. – an old parasite in an old host: tracing the origin of myxosporean parasitism in vertebrates

    Czech Academy of Sciences Publication Activity Database

    Kodádková, Alena; Bartošová-Sojková, Pavla; Holzer, Astrid S.; Fiala, Ivan

    2015-01-01

    Roč. 45, č. 4 (2015), s. 269-276 ISSN 0020-7519 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Myxosporean evolution * Molecular clock * Bipteria * Holocephali * Vertebrate host * Cartilaginous fish * Phylogeny * Co-evolution Subject RIV: EG - Zoology Impact factor: 4.242, year: 2015

  15. The Evolutionary Strategy of Mimcry

    Science.gov (United States)

    Lane, Patricia A.

    1977-01-01

    Describes methods and materials for an innovative laboratory exercise that centers on the concept of mimicry and illustrates the importance of adaptation, natural selection and coevolution. Students are used as predators and raisins as prey. Included are directions for preparation of unpalatable raisins using alum dissolved in reconstituted lemon…

  16. Life cycles, molecular phylogeny and historical biogeography of the ‘pygmaeus’ microphallids (Digenea: Microphallidae): widespread parasites of marine and coastal birds in the Holarctic

    Czech Academy of Sciences Publication Activity Database

    Galaktionov, K.V.; Blasco-Costa, Maria Isabel; Olson, P. D.

    2012-01-01

    Roč. 139, č. 10 (2012), s. 1346-1360 ISSN 0031-1820 Institutional support: RVO:60077344 Keywords : marine parasites * trematode * Microphallus * parasite speciation * parasite transmission * host-parasite co-evolution * host switching * host-parasite assemblages Subject RIV: EH - Ecology, Behaviour; EB - Genetics ; Molecular Biology (BC-A) Impact factor: 2.355, year: 2012

  17. Constructive Technology Assessmentand Technology Dynamics. The Case of Clean Technologies

    NARCIS (Netherlands)

    Schot, Johan

    1992-01-01

    A synthesis of neo-Schumpeterian evolutionary, sociological, and historical coevolution ary models could be used for constructive technology assessment, aimed at the active management of the process of technological change. This article proposes a synthetic quasi-evolutionary model, in which

  18. Assessing host-virus codivergence for close relatives of Merkel cell polyomavirus infecting African great apes

    Czech Academy of Sciences Publication Activity Database

    Madinda, N. F.; Ehlers, B.; Wertheim, J. O.; Akoua-Koffi, C.; Bergl, R. A.; Boesch, C.; Akonkwa, D. B. M.; Eckardt, W.; Fruth, B.; Gillespie, T. R.; Gray, M.; Hohmann, G.; Karhemere, S.; Kujirakwinja, D.; Langergraber, K.; Muyembe, J.-J.; Nishuli, R.; Pauly, M.; Petrželková, Klára Judita; Robbins, M. M.; Todd, A.; Schubert, G.; Stoinski, T. S.; Wittig, R. M.; Zuberbühler, K.; Peeters, M.; Leendertz, F. H.; Calvignac-Spencer, S.

    2016-01-01

    Roč. 90, č. 19 (2016), s. 8531-8541 ISSN 0022-538X R&D Projects: GA ČR GA206/09/0927 Institutional support: RVO:68081766 Keywords : JC virus * divergence times * evolution * phylogenies * selection * bats * coevolution * population * chimpanzee * diversity Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 4.663, year: 2016

  19. Assessing Host-Virus Codivergence for Close Relatives of Merkel Cell Polyomavirus Infecting African Great Apes

    Czech Academy of Sciences Publication Activity Database

    Madinda, N. F.; Ehlers, B.; Wertheim, J. O.; Akoua-Koffi, C.; Bergl, R. A.; Boesch, C.; Akonkwa, D. B. M.; Eckardt, W.; Fruth, B.; Gillespie, T. R.; Gray, M.; Hohmann, G.; Karhemere, S.; Kujirakwinja, D.; Langergraber, K.; Muyembe, J.-J.; Nishuli, R.; Pauly, M.; Petrželková, Klára Judita; Robbins, M. M.; Todd, A.; Schubert, G.; Stoinski, T. S.; Wittig, R. M.; Zuberbühler, K.; Peeters, M.; Leendertz, F. H.; Calvignac-Spencer, S.

    2016-01-01

    Roč. 90, č. 19 (2016), s. 8531-8541 ISSN 0022-538X Institutional support: RVO:60077344 Keywords : JC virus * divergence times * evolution * phylogenies * selection * bats * coevolution * population * chimpanzee * diversity Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 4.663, year: 2016

  20. No evidence for host specialization or host-race formation in the European bitterling (Rhodeus amarus), a fish that parasitizes freshwater mussels

    Czech Academy of Sciences Publication Activity Database

    Reichard, Martin; Bryja, Josef; Polačik, Matej; Smith, C.

    2011-01-01

    Roč. 20, č. 17 (2011), s. 3631-3643 ISSN 0962-1083 R&D Projects: GA AV ČR KJB600930802; GA ČR GA206/09/1163 Institutional research plan: CEZ:AV0Z60930519 Keywords : coevolution * cuckoo * host–parasite relationship * speciation * symbiosis Subject RIV: EG - Zoology Impact factor: 5.522, year: 2011

  1. In love and war: altruism, norm formation, and two different types of group selection

    NARCIS (Netherlands)

    van Veelen, C.M.; Hopfensitz, A.

    2007-01-01

    We analyse simulations reported in "The co-evolution of individual behaviors and social institutions" by Bowles et al., 2003 in the Journal of Theoretical Biology 223, 135-147, and begin with distinguishing two types of group selection models. The literature does not provide different names for

  2. ComplexContact: a web server for inter-protein contact prediction using deep learning

    KAUST Repository

    Zeng, Hong; Wang, Sheng; Zhou, Tianming; Zhao, Feifeng; Li, Xiufeng; Wu, Qing; Xu, Jinbo

    2018-01-01

    ComplexContact (http://raptorx2.uchicago.edu/ComplexContact/) is a web server for sequence-based interfacial residue-residue contact prediction of a putative protein complex. Interfacial residue-residue contacts are critical for understanding how proteins form complex and interact at residue level. When receiving a pair of protein sequences, ComplexContact first searches for their sequence homologs and builds two paired multiple sequence alignments (MSA), then it applies co-evolution analysis and a CASP-winning deep learning (DL) method to predict interfacial contacts from paired MSAs and visualizes the prediction as an image. The DL method was originally developed for intra-protein contact prediction and performed the best in CASP12. Our large-scale experimental test further shows that ComplexContact greatly outperforms pure co-evolution methods for inter-protein contact prediction, regardless of the species.

  3. Irreducible Vagueness

    DEFF Research Database (Denmark)

    Ekman, Ulrik

    2009-01-01

    This article argues that Blur Building, Diller & Scofidio's architectural project for the Swiss Expo 2002, demonstrated performatively and interactively how contemporary worldmaking involves cultural and technological invention and construction both, implying our cultural co-evolution with ubiqui......This article argues that Blur Building, Diller & Scofidio's architectural project for the Swiss Expo 2002, demonstrated performatively and interactively how contemporary worldmaking involves cultural and technological invention and construction both, implying our cultural co......-evolution with ubiquitous computing and media such that "worlding" must today be approached and approximated as a question of realities that mix virtuality and actuality. This article not only touches upon the actual inventions produced in this project--with its atmospheric architecture of tensegrity structures, its vast...

  4. Older partner selection promotes the prevalence of cooperation in evolutionary games.

    Science.gov (United States)

    Yang, Guoli; Huang, Jincai; Zhang, Weiming

    2014-10-21

    Evolutionary games typically come with the interplays between evolution of individual strategy and adaptation to network structure. How these dynamics in the co-evolution promote (or obstruct) the cooperation is regarded as an important topic in social, economic, and biological fields. Combining spatial selection with partner choice, the focus of this paper is to identify which neighbour should be selected as a role to imitate during the process of co-evolution. Age, an internal attribute and kind of local piece of information regarding the survivability of the agent, is a significant consideration for the selection strategy. The analysis and simulations presented, demonstrate that older partner selection for strategy imitation could foster the evolution of cooperation. The younger partner selection, however, may decrease the level of cooperation. Our model highlights the importance of agent׳s age on the promotion of cooperation in evolutionary games, both efficiently and effectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Next step in the ongoing arms race between myxoma virus and wild rabbits in Australia is a novel disease phenotype

    Science.gov (United States)

    Kerr, Peter J.; Cattadori, Isabella M.; Liu, June; Sim, Derek G.; Dodds, Jeff W.; Brooks, Jason W.; Kennett, Mary J.; Holmes, Edward C.

    2017-01-01

    In host–pathogen arms races, increases in host resistance prompt counteradaptation by pathogens, but the nature of that counteradaptation is seldom directly observed outside of laboratory models. The best-documented field example is the coevolution of myxoma virus (MYXV) in European rabbits. To understand how MYXV in Australia has continued to evolve in wild rabbits under intense selection for genetic resistance to myxomatosis, we compared the phenotypes of the progenitor MYXV and viral isolates from the 1950s and the 1990s in laboratory rabbits with no resistance. Strikingly, and unlike their 1950s counterparts, most virus isolates from the 1990s induced a highly lethal immune collapse syndrome similar to septic shock. Thus, the next step in this canonical case of coevolution after a species jump has been further escalation by the virus in the face of widespread host resistance. PMID:28808019

  6. Costly advertising and the evolution of cooperation.

    Directory of Open Access Journals (Sweden)

    Markus Brede

    Full Text Available In this paper, I investigate the co-evolution of fast and slow strategy spread and game strategies in populations of spatially distributed agents engaged in a one off evolutionary dilemma game. Agents are characterized by a pair of traits, a game strategy (cooperate or defect and a binary 'advertising' strategy (advertise or don't advertise. Advertising, which comes at a cost [Formula: see text], allows investment into faster propagation of the agents' traits to adjacent individuals. Importantly, game strategy and advertising strategy are subject to the same evolutionary mechanism. Via analytical reasoning and numerical simulations I demonstrate that a range of advertising costs exists, such that the prevalence of cooperation is significantly enhanced through co-evolution. Linking costly replication to the success of cooperators exposes a novel co-evolutionary mechanism that might contribute towards a better understanding of the origins of cooperation-supporting heterogeneity in agent populations.

  7. Testing for coevolutionary diversification: linking pattern with process.

    Science.gov (United States)

    Althoff, David M; Segraves, Kari A; Johnson, Marc T J

    2014-02-01

    Coevolutionary diversification is cited as a major mechanism driving the evolution of diversity, particularly in plants and insects. However, tests of coevolutionary diversification have focused on elucidating macroevolutionary patterns rather than the processes giving rise to such patterns. Hence, there is weak evidence that coevolution promotes diversification. This is in part due to a lack of understanding about the mechanisms by which coevolution can cause speciation and the difficulty of integrating results across micro- and macroevolutionary scales. In this review, we highlight potential mechanisms of coevolutionary diversification, outline approaches to examine this process across temporal scales, and propose a set of minimal requirements for demonstrating coevolutionary diversification. Our aim is to stimulate research that tests more rigorously for coevolutionary diversification. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. ComplexContact: a web server for inter-protein contact prediction using deep learning

    KAUST Repository

    Zeng, Hong

    2018-05-20

    ComplexContact (http://raptorx2.uchicago.edu/ComplexContact/) is a web server for sequence-based interfacial residue-residue contact prediction of a putative protein complex. Interfacial residue-residue contacts are critical for understanding how proteins form complex and interact at residue level. When receiving a pair of protein sequences, ComplexContact first searches for their sequence homologs and builds two paired multiple sequence alignments (MSA), then it applies co-evolution analysis and a CASP-winning deep learning (DL) method to predict interfacial contacts from paired MSAs and visualizes the prediction as an image. The DL method was originally developed for intra-protein contact prediction and performed the best in CASP12. Our large-scale experimental test further shows that ComplexContact greatly outperforms pure co-evolution methods for inter-protein contact prediction, regardless of the species.

  9. Physical model of the immune response of bacteria against bacteriophage through the adaptive CRISPR-Cas immune system

    Energy Technology Data Exchange (ETDEWEB)

    Han, Pu; Niestemski, Liang Ren; Deem, Michael W [Department of Physics and Astronomy, Rice University, Houston, TX 77005 (United States); Barrick, Jeffrey E, E-mail: mwdeem@rice.edu [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, TX 78712 (United States)

    2013-04-15

    Bacteria and archaea have evolved an adaptive, heritable immune system that recognizes and protects against viruses or plasmids. This system, known as the CRISPR-Cas system, allows the host to recognize and incorporate short foreign DNA or RNA sequences, called 'spacers' into its CRISPR system. Spacers in the CRISPR system provide a record of the history of bacteria and phage coevolution. We use a physical model to study the dynamics of this coevolution as it evolves stochastically over time. We focus on the impact of mutation and recombination on bacteria and phage evolution and evasion. We discuss the effect of different spacer deletion mechanisms on the coevolutionary dynamics. We make predictions about bacteria and phage population growth, spacer diversity within the CRISPR locus, and spacer protection against the phage population. (paper)

  10. Collective evolution of cyanobacteria and cyanophages mediated by horizontal gene transfer

    Science.gov (United States)

    Shih, Hong-Yan; Rogers, Tim; Goldenfeld, Nigel

    We describe a model for how antagonistic predator-prey coevolution can lead to mutualistic adaptation to an environment, as a result of horizontal gene transfer. Our model is a simple description of ecosystems such as marine cyanobacteria and their predator cyanophages, which carry photosynthesis genes. These genes evolve more rapidly in the virosphere than the bacterial pan-genome, and thus the bacterial population could potentially benefit from phage predation. By modeling both the barrier to predation and horizontal gene transfer, we study this balance between individual sacrifice and collective benefits. The outcome is an emergent mutualistic coevolution of improved photosynthesis capability, benefiting both bacteria and phage. This form of multi-level selection can contribute to niche stratification in the cyanobacteria-phage ecosystem. This work is supported in part by a cooperative agreement with NASA, Grant NNA13AA91A/A0018.

  11. Mating with an allopatric male triggers immune response and decreases longevity of ant queens.

    Science.gov (United States)

    Schrempf, A; von Wyschetzki, K; Klein, A; Schrader, L; Oettler, J; Heinze, J

    2015-07-01

    In species with lifelong pair bonding, the reproductive interests of the mating partners are aligned, and males and females are expected to jointly maximize their reproductive success. Mating increases both longevity and fecundity of female reproductives (queens) of the ant Cardiocondyla obscurior, indicating a tight co-evolution of mating partners. Here, we show that mating with a male from their own population increases lifespan and reproductive success of queens more than mating with a male from a different population, with whom they could not co-evolve. A comparison of transcriptomes revealed an increased expression of genes involved in immunity processes in queens, which mated with males from a different population. Increased immune response might be proximately associated with decreased lifespan. Our study suggests a synergistic co-evolution between the sexes and sheds light on the proximate mechanisms underlying the decreased fitness of allopatrically mated queens. © 2015 John Wiley & Sons Ltd.

  12. Re-imagining the Growth Process

    DEFF Research Database (Denmark)

    Clarke, Jean; Holt, Robin; Blundel, Richard

    2014-01-01

    We investigate the role and influence of the biological metaphor 'growth' in studies of organizations, specifically in entrepreneurial settings. We argue that we need to reconsider metaphorical expressions of growth processes in entrepreneurship studies in order to better understand growth...... in the light of contemporary challenges, such as environmental concerns. Our argument is developed in two stages: first, we review the role of metaphor in organization and entrepreneurship studies. Second, we reflect critically on three conceptualizations of growth that have drawn on biological metaphors......: the growing organism, natural selection and co-evolution. We find the metaphor of co-evolution heuristically valuable but under-used and in need of further refinement. We propose three characteristics of the co-evolutionary metaphor that might enrich our understanding of entrepreneurial growth: relational...

  13. Costly Advertising and the Evolution of Cooperation

    Science.gov (United States)

    Brede, Markus

    2013-01-01

    In this paper, I investigate the co-evolution of fast and slow strategy spread and game strategies in populations of spatially distributed agents engaged in a one off evolutionary dilemma game. Agents are characterized by a pair of traits, a game strategy (cooperate or defect) and a binary ‘advertising’ strategy (advertise or don’t advertise). Advertising, which comes at a cost , allows investment into faster propagation of the agents’ traits to adjacent individuals. Importantly, game strategy and advertising strategy are subject to the same evolutionary mechanism. Via analytical reasoning and numerical simulations I demonstrate that a range of advertising costs exists, such that the prevalence of cooperation is significantly enhanced through co-evolution. Linking costly replication to the success of cooperators exposes a novel co-evolutionary mechanism that might contribute towards a better understanding of the origins of cooperation-supporting heterogeneity in agent populations. PMID:23861752

  14. Costly advertising and the evolution of cooperation.

    Science.gov (United States)

    Brede, Markus

    2013-01-01

    In this paper, I investigate the co-evolution of fast and slow strategy spread and game strategies in populations of spatially distributed agents engaged in a one off evolutionary dilemma game. Agents are characterized by a pair of traits, a game strategy (cooperate or defect) and a binary 'advertising' strategy (advertise or don't advertise). Advertising, which comes at a cost [Formula: see text], allows investment into faster propagation of the agents' traits to adjacent individuals. Importantly, game strategy and advertising strategy are subject to the same evolutionary mechanism. Via analytical reasoning and numerical simulations I demonstrate that a range of advertising costs exists, such that the prevalence of cooperation is significantly enhanced through co-evolution. Linking costly replication to the success of cooperators exposes a novel co-evolutionary mechanism that might contribute towards a better understanding of the origins of cooperation-supporting heterogeneity in agent populations.

  15. Physical model of the immune response of bacteria against bacteriophage through the adaptive CRISPR-Cas immune system

    Science.gov (United States)

    Han, Pu; Niestemski, Liang Ren; Barrick, Jeffrey E.; Deem, Michael W.

    2013-04-01

    Bacteria and archaea have evolved an adaptive, heritable immune system that recognizes and protects against viruses or plasmids. This system, known as the CRISPR-Cas system, allows the host to recognize and incorporate short foreign DNA or RNA sequences, called ‘spacers’ into its CRISPR system. Spacers in the CRISPR system provide a record of the history of bacteria and phage coevolution. We use a physical model to study the dynamics of this coevolution as it evolves stochastically over time. We focus on the impact of mutation and recombination on bacteria and phage evolution and evasion. We discuss the effect of different spacer deletion mechanisms on the coevolutionary dynamics. We make predictions about bacteria and phage population growth, spacer diversity within the CRISPR locus, and spacer protection against the phage population.

  16. Physical model of the immune response of bacteria against bacteriophage through the adaptive CRISPR-Cas immune system

    International Nuclear Information System (INIS)

    Han, Pu; Niestemski, Liang Ren; Deem, Michael W; Barrick, Jeffrey E

    2013-01-01

    Bacteria and archaea have evolved an adaptive, heritable immune system that recognizes and protects against viruses or plasmids. This system, known as the CRISPR-Cas system, allows the host to recognize and incorporate short foreign DNA or RNA sequences, called ‘spacers’ into its CRISPR system. Spacers in the CRISPR system provide a record of the history of bacteria and phage coevolution. We use a physical model to study the dynamics of this coevolution as it evolves stochastically over time. We focus on the impact of mutation and recombination on bacteria and phage evolution and evasion. We discuss the effect of different spacer deletion mechanisms on the coevolutionary dynamics. We make predictions about bacteria and phage population growth, spacer diversity within the CRISPR locus, and spacer protection against the phage population. (paper)

  17. ComplexContact: a web server for inter-protein contact prediction using deep learning.

    Science.gov (United States)

    Zeng, Hong; Wang, Sheng; Zhou, Tianming; Zhao, Feifeng; Li, Xiufeng; Wu, Qing; Xu, Jinbo

    2018-05-22

    ComplexContact (http://raptorx2.uchicago.edu/ComplexContact/) is a web server for sequence-based interfacial residue-residue contact prediction of a putative protein complex. Interfacial residue-residue contacts are critical for understanding how proteins form complex and interact at residue level. When receiving a pair of protein sequences, ComplexContact first searches for their sequence homologs and builds two paired multiple sequence alignments (MSA), then it applies co-evolution analysis and a CASP-winning deep learning (DL) method to predict interfacial contacts from paired MSAs and visualizes the prediction as an image. The DL method was originally developed for intra-protein contact prediction and performed the best in CASP12. Our large-scale experimental test further shows that ComplexContact greatly outperforms pure co-evolution methods for inter-protein contact prediction, regardless of the species.

  18. Indirect reciprocity and the evolution of "moral signals"

    Science.gov (United States)

    Smead, Rory

    2010-01-01

    Signals regarding the behavior of others are an essential element of human moral systems and there are important evolutionary connections between language and large-scale cooperation. In particular, social communication may be required for the reputation tracking needed to stabilize indirect reciprocity. Additionally, scholars have suggested that the benefits of indirect reciprocity may have been important for the evolution of language and that social signals may have coevolved with large-scale cooperation. This paper investigates the possibility of such a coevolution. Using the tools of evolutionary game theory, we present a model that incorporates primitive "moral signaling" into a simple setting of indirect reciprocity. This model reveals some potential difficulties for the evolution of "moral signals." We find that it is possible for "moral signals" to evolve alongside indirect reciprocity, but without some external pressure aiding the evolution of a signaling system, such a coevolution is unlikely.

  19. Smart health community: the hidden value of health information exchange.

    Science.gov (United States)

    Ciriello, James N; Kulatilaka, Nalin

    2010-12-01

    Investments in health information technology are accelerating the digitization of medicine. The value from these investments, however, can grow beyond efficiencies by filling the information gaps between the various stakeholders. New work processes, governance structures, and relationships are needed for the coevolution of healthcare markets and business models. But coevolution is slow, hindered by the scarcity of incentives for legacy delivery systems and constrained by the prevailing patient-healthcare paradigm. The greater opportunity lies in wellness for individuals, families, communities, and society at large: a consumer-community paradigm. Capturing new value from this opportunity can start with investment in health information exchange and the creation of Smart Health Communities. By shifting the focus of exchange from public servant to value-added service provider, these communities can serve as a platform for a wider array of wellness services from consumer care, traditional healthcare, and research.

  20. The Relevance of Rabies to Today’s Military

    Science.gov (United States)

    2012-01-01

    April 26, 2012. Heithaus ER, Opler PA, Baker HG. Bat activity and 20. pollination of Bauhinia Pauletia: plant- pollinator coevolution. Ecology ...canine. This is especially true in urban centers of the developing world. It should be understood, however, that any mammal can become infected by the...the feeding on vast numbers of insects, while many plants depend on the pollinating activities of fruit bats.20 BAT RABIES IN THE UNITED STATES Bat

  1. Impact of two specialist insect herbivores on reproduction of horse nettle, Solanum carolinense.

    Science.gov (United States)

    Wise, Michael J; Sacchi, Christopher F

    1996-10-01

    The frequency of coevolution as a process of strong mutual interaction between a single plant and herbivore species has been questioned in light of more commonly observed, complex relationships between a plant and a suite of herbivore species. Despite recognition of the possibility of diffuse coevolution, relatively few studies have examined ecological responses of plants to herbivores in complex associations. We studied the impact of two specialist herbivores, the horse nettle beetle, Leptinotarsa juncta, and the eggplant flea beetle, Epitrix fuscula, on reproduction of their host, Solanum carolinense. Our study involved field and controlled-environment experimental tests of the impact on sexual and potential asexual reproduction of attack by individuals of the two herbivore species, individually and in combination. Field tests demonstrated that under normal levels of phytophagous insect attack, horse nettle plants experienced a reduction in fruit production of more than 75% compared with plants from which insects were excluded. In controlled-environment experiments using enclosure-exclosure cages, the horse nettle's two principal herbivores, the flea beetle and the horse nettle beetle, caused decreases in sexual reproduction similar to those observed in the field, and a reduction in potential asexual reproduction, represented by root biomass. Attack by each herbivore reduced the numbers of fruits produced, and root growth, when feeding in isolation. When both species were feeding together, fruit production, but not root growth, was lower than when either beetle species fed alone. Ecological interactions between horse nettle and its two primary herbivores necessary for diffuse coevolution to occur were evident from an overall analysis of the statistical interactions between the two herbivores for combined assessment of fruit and vegetative traits. For either of these traits alone, the interactions necessary to promote diffuse coevolution apparently were lacking.

  2. Development of Geo-Marketing

    OpenAIRE

    Tatiana Ozhereleva

    2014-01-01

    This article analyzes the state and development of geo-marketing. The author illustrates the multi-aspectedness of geo-marketing: applied technology and management technology. The article demonstrates that geo-marketing can be viewed as a reflection of the processes of co-evolution in society. The author brings to light the specifics of geo-marketing research and situational analysis in geo-marketing. The article describes applications of geo-marketing

  3. Development of Geo-Marketing

    Directory of Open Access Journals (Sweden)

    Tatiana Ozhereleva

    2014-10-01

    Full Text Available This article analyzes the state and development of geo-marketing. The author illustrates the multi-aspectedness of geo-marketing: applied technology and management technology. The article demonstrates that geo-marketing can be viewed as a reflection of the processes of co-evolution in society. The author brings to light the specifics of geo-marketing research and situational analysis in geo-marketing. The article describes applications of geo-marketing

  4. AN INVESTIGATION INTO FACTORS INFLUENCING INTERNATIONAL STRATEGIC ALLIANCE PROCESS

    OpenAIRE

    Sari Wahyuni; Theo J.B.M. Postma

    2003-01-01

    Empirical research indicates that strategic alliances, like other organizational forms, emerge as an adaptive mechanism to market uncertainty, and their developments over time reflect the co-evolution of distinctive firm capabilities and of industry and market activities. Interestingly, most strategic alliances go through similar revolutionary cycles in terms of their motives and capabilities toward the cooperative relationship. Studies in this areas how that alliance failure is an outcome of...

  5.  Molecular evolution and positive selection of the symbiotic gene NORK in Medicago truncatula

    DEFF Research Database (Denmark)

    De Mita, Stephane; Santoni, Sylvain; Hochu, Isabelle

    2006-01-01

     Understanding the selective constraints of partner specificity in mutually beneficial symbiosis is a significant, yet largely unexplored, prospect of evolutionary biology. These selective constraints can be explored through the study of nucleotide polymorphism at loci controlling specificity...... domain of the protein, evolved under the regime of positive selection. Further research should focus on the rate and direction of molecular coevolution between microorganisms' signaling molecules and legumes' receptors....

  6. Geography and host specificity: Two forces behind the genetic structure of the freshwater fish parasite Ligula intestinalis (Cestoda: Diphyllobothriidae)

    Czech Academy of Sciences Publication Activity Database

    Bouzid, W.; Štefka, Jan; Hypša, Václav; Lek, S.; Scholz, Tomáš; Legal, L.; Ben Hassine, O. K.; Loot, G.

    2008-01-01

    Roč. 38, č. 12 (2008), s. 1465-1479 ISSN 0020-7519 R&D Projects: GA MŠk LC522; GA ČR GA524/04/0342; GA MŠk LC06073 Grant - others:GA ČR(CZ) GA206/08/1019 Institutional research plan: CEZ:AV0Z60220518 Keywords : genealogy * coevolution * genetic structure * tapeworms Subject RIV: EG - Zoology Impact factor: 3.752, year: 2008

  7. The Emergence of Governance and the Function of Law

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2015-01-01

    such orders are made possible. They structure the transposition of condensed social components such as economic products and capital, political decisions, legal judgments, scientific knowledge, and religious acts of salvation from one order to another, thereby allowing coevolution to unfold. In this context......, law and legal instruments gain a central role since legal formalization is the central element that enables successful transfers to take place....

  8. Politics-business interaction paths

    OpenAIRE

    Belloc, Marianna; Pagano, Ugo

    2009-01-01

    Most pre-crisis explanations of the various corporate governance systems have considered the separation between ownership and control to be an advantage of the Anglo-American economies. They have also attributed the failure of other countries to achieve these efficient arrangements to their different legal and/or electoral systems. In this paper we compare this view with the co-evolution approach based on the hypothesis that politics and corporate governance influence each other, generating c...

  9. Hovering sunbirds in the Old World: occasional behaviour or evolutionary trend?

    Czech Academy of Sciences Publication Activity Database

    Janeček, Štěpán; Patáčová, Eliška; Bartoš, Michael; Padyšáková, Eliška; Spitzer, Lukáš; Tropek, Robert

    2011-01-01

    Roč. 120, č. 2 (2011), s. 178-183 ISSN 0030-1299 R&D Projects: GA AV ČR IAA601410709; GA AV ČR KJB601110703; GA ČR GD206/08/H044 Institutional research plan: CEZ:AV0Z60050516; CEZ:AV0Z50070508 Keywords : coevolution * sunbirds * hovering Subject RIV: EF - Botanics Impact factor: 3.061, year: 2011

  10. Adaptation of water resources systems to changing society and environment: a statement by the International Association of Hydrological Sciences

    OpenAIRE

    Serena Ceola; Alberto Montanari; Tobias Krueger; Fiona Dyer; H. Kreibich; Ida Westerberg; Gemma Carr; Christophe Cudennec; Amin Elshorbagy; Hubert Savenije; Pieter van der Zaag; Dan Rosbjerg; Hafzullah Aksoy; Francesco Viola; Guido Petrucci

    2016-01-01

    We explore how to address the challenges of adaptation of water resources systems under changing conditions by supporting flexible, resilient and low-regret solutions, coupled with on-going monitoring and evaluation. This will require improved understanding of the linkages between biophysical and social aspects in order to better anticipate the possible future co-evolution of water systems and society. We also present a call to enhance the dialogue and foster the actions of governments, the i...

  11. Black hole feedback in the luminous quasar PDS 456

    DEFF Research Database (Denmark)

    Nardini, E.; Reeves, J. N.; Gofford, J.

    2015-01-01

    The evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. Over five different...... gas. The outflow’s kinetic power larger than 1046 ergs per second is enough to provide the feedback required by models of black hole and host galaxy coevolution....

  12. Transcriptome and target DNA enrichment sequence data provide new insights into the phylogeny of vespid wasps (Hymenoptera: Aculeata: Vespidae)

    DEFF Research Database (Denmark)

    Bank, Sarah; Sann, Manuela; Mayer, Christoph

    2017-01-01

    The wasp family Vespidae comprises more than 5000 described species which represent life history strategies ranging from solitary and presocial to eusocial and socially parasitic. The phylogenetic relationships of the major vespid wasp lineages (i.e., subfamilies and tribes) have been investigate...... studies on species of the family Vespidae, including their genomes, life styles, evolution of sociality, and co-evolution with other organisms....

  13. FuturICT

    OpenAIRE

    Helbing, Dirk; Bishop, Steven; Lukowicz, Paul; Consortium, the FuturICT

    2012-01-01

    FuturlCT is a FET Flagship project using collective, participatory research, integrated across ICT, the social sciences and complexity science, to design socio-inspired technology and develop a science of global, socially interactive systems. The project will bring together, on a global level, Big Data, new modelling techniques and new forms of interaction, leading to a new understanding of society and its coevolution with technology. It aims to understand, explore and manage our complex, con...

  14. An effect of 16S rRNA intercistronic variability on coevolutionary analysis in symbiotic bacteria: Molecular phylogeny of Arsenophonus triatominarum

    Czech Academy of Sciences Publication Activity Database

    Šorfová, Pavlína; Škeříková, Andrea; Hypša, Václav

    2008-01-01

    Roč. 31, č. 2 (2008), s. 88-100 ISSN 0723-2020 R&D Projects: GA ČR GA206/04/0520; GA AV ČR IAA601410708 Institutional research plan: CEZ:AV0Z60220518 Keywords : intragenomic heterogeneity * 16S rRNA * coevolution * insect symbionts * molecular phylogeny Subject RIV: EE - Microbiology, Virology Impact factor: 2.582, year: 2008

  15. Identifying Cytochrome P450 Functional Networks and Their Allosteric Regulatory Elements

    Science.gov (United States)

    2013-12-03

    based on physiochemical features not captured by residue co-evolution. In all the networks we characterized, it was evident that some residues were...corresponding iron and sulphur related parameters, were obtained from Bathelt et al. [46]. These parameters are based on QM/MM calculations and have been...2007) Adaptations for the oxidation of polycyclic aromatic hydrocarbons exhibited by the structure of human P450 1A2. J Biol Chem 282: 14348-14355. doi

  16. 454 pyrosequencing based transcriptome analysis of Zygaena filipendulae with focus on genes involved in biosynthesis of cyanogenic glucosides

    OpenAIRE

    Zagrobelny, Mika; Scheibye-Alsing, Karsten; Jensen, Niels Bjerg; Møller, Birger Lindberg; Gorodkin, Jan; Bak, Søren

    2009-01-01

    Abstract Background An essential driving component in the co-evolution of plants and insects is the ability to produce and handle bioactive compounds. Plants produce bioactive natural products for defense, but some insects detoxify and/or sequester the compounds, opening up for new niches with fewer competitors. To study the molecular mechanism behind the co-adaption in plant-insect interactions, we have investigated the interactions between Lotus corniculatus and Zygaena filipendulae. They b...

  17. The antibiotic resistance ?mobilome?: searching for the link between environment and clinic

    OpenAIRE

    Perry, Julie A.; Wright, Gerard D.

    2013-01-01

    Antibiotic resistance is an ancient problem, owing to the co-evolution of antibiotic-producing and target organisms in the soil and other environments over millennia. The environmental “resistome” is the collection of all genes that directly or indirectly contribute to antibiotic resistance. Many of these resistance determinants originate in antibiotic-producing organisms (where they serve to mediate self-immunity), while others become resistance determinants only when mobilized and over-expr...

  18. Schumpeter's core works revisited

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    2012-01-01

    This paper organises Schumpeter’s core books in three groups: the programmatic duology,the evolutionaryeconomic duology,and the socioeconomic synthesis. By analysing these groups and their interconnections from the viewpoint of modern evolutionaryeconomics,the paper summarises resolved problems a...... and points at remaining challenges. Its analyses are based on distinctions between microevolution and macroevolution, between economic evolution and socioeconomic coevolution, and between Schumpeter’s three major evolutionary models (called Mark I, Mark II and Mark III)....

  19. Patrilocal Exogamy as a Monitoring Mechanism : How Inheritance and Residence Patterns Co-evolve

    OpenAIRE

    Brishti Guha

    2010-01-01

    Economists have modeled inheritance norms assuming the pattern of post-marital residence is exogenous. We model the co-evolution of these two institutions, examining how patrilineal inheritance and patrilocal exogamy reinforced each other in a patrilineal-patrilocal equilibrium. We also derive conditions for a matrilineal-matrilocal equilibrium. The endogenous choice of the old to monitor the sexual behavior of the young women who reside with them, thereby affecting the paternity confidence o...

  20. Evidence of host specificity and congruence between phylogenies of bitterling and freshwater mussels

    Czech Academy of Sciences Publication Activity Database

    Liu, H.-Z.; Zhu, Y.-R.; Smith, C.; Reichard, Martin

    2006-01-01

    Roč. 45, č. 3 (2006), s. 428-434 ISSN 1021-5506 Grant - others:NSFC(CN) 30470237; NSFC(CN) 40432003; Innovation Program of the Chinese Academy of Sciences(CN) KZCX3-SW-126 Institutional research plan: CEZ:AV0Z60930519 Keywords : bitterling * host specificity * coevolution * phylogeny Subject RIV: EG - Zoology Impact factor: 0.943, year: 2006 http://zoolstud.sinica.edu.tw/Journals/45.3/428.pdf