12,903 research outputs found

    Evolution as a language that speaks itself

    Get PDF
    The 'self-referential' character of evolutionary process noted by Goldenfeld and Woese (2010) can be restated through a 'language' model in which genes, gene expression, and environment are represented as interacting information sources. The larger, composite, source that characterizes the high probability evolutionary paths then becomes, in a real sense, a language that speaks itself. The approach represents a significant extension of nonequilibrium condensed matter formalism in which the asymptotic limit theorems of information theory beat back the mathematical thicket a full step, providing necessary, but not sufficient, conditions for punctuated evolutionary transitions that can themselves be expressed as highly structured large deviations having their own grammar and syntax

    Genome-driven evolutionary game theory helps understand the rise of metabolic interdependencies in microbial communities

    Get PDF
    Metabolite exchanges in microbial communities give rise to ecological interactions that govern ecosystem diversity and stability. It is unclear, however, how the rise of these interactions varies across metabolites and organisms. Here we address this question by integrating genome-scale models of metabolism with evolutionary game theory. Specifically, we use microbial fitness values estimated by metabolic models to infer evolutionarily stable interactions in multi-species microbial ā€œgamesā€. We first validate our approach using a well-characterized yeast cheater-cooperator system. We next perform over 80,000 in silico experiments to infer how metabolic interdependencies mediated by amino acid leakage in Escherichia coli vary across 189 amino acid pairs. While most pairs display shared patterns of inter-species interactions, multiple deviations are caused by pleiotropy and epistasis in metabolism. Furthermore, simulated invasion experiments reveal possible paths to obligate cross-feeding. Our study provides genomically driven insight into the rise of ecological interactions, with implications for microbiome research and synthetic ecology.We gratefully acknowledge funding from the Defense Advanced Research Projects Agency (Purchase Request No. HR0011515303, Contract No. HR0011-15-C-0091), the U.S. Department of Energy (Grants DE-SC0004962 and DE-SC0012627), the NIH (Grants 5R01DE024468 and R01GM121950), the national Science Foundation (Grants 1457695 and NSFOCE-BSF 1635070), MURI Grant W911NF-12-1-0390, the Human Frontiers Science Program (grant RGP0020/2016), and the Boston University Interdisciplinary Biomedical Research Office ARC grant on Systems Biology Approaches to Microbiome Research. We also thank Dr Kirill Korolev and members of the Segre Lab for their invaluable feedback on this work. (HR0011515303 - Defense Advanced Research Projects Agency; HR0011-15-C-0091 - Defense Advanced Research Projects Agency; DE-SC0004962 - U.S. Department of Energy; DE-SC0012627 - U.S. Department of Energy; 5R01DE024468 - NIH; R01GM121950 - NIH; 1457695 - national Science Foundation; NSFOCE-BSF 1635070 - national Science Foundation; W911NF-12-1-0390 - MURI; RGP0020/2016 - Human Frontiers Science Program; Boston University Interdisciplinary Biomedical Research Office ARC)Published versio

    Hunter-gatherers in a howling wilderness: Neoliberal capitalism as a language that speaks itself

    Get PDF
    The 'self-referential' character of evolutionary process noted by Goldenfeld and Woese (2010) can be restated in the context of a generalized Darwinian theory applied to economic process through a 'language' model: The underlying inherited and learned culture of the firm, the short-time cognitive response of the firm to patterns of threat and opportunity that is sculpted by that culture, and the embedding socioeconomic environment, are represented as interacting information sources constrained by the asymptotic limit theorems of information theory. If unregulated, the larger, compound, source that characterizes high probability evolutionary paths of this composite then becomes, literally, a self-dynamic language that speaks itself. Such a structure is, for those enmeshed in it, more akin to a primitive hunter-gatherer society at the mercy of internal ecological dynamics than to, say, a neolithic agricultural community in which a highly ordered, deliberately adapted, ecosystem is consciously farmed so as to match its productivity to human needs

    'Fat people and bombs':HPA axis cognition, structured stress, and the US obesity epidemic

    Get PDF
    We examine the accelerating 'obesity epidemic' in the US from the perspective of recently developed theory relating a cognitive hypothalamic-pituitary-adrenal axis to an embedding 'language' of structured psychosocial stress. Using a Rate Distortion argument, the obesity epidemic is found to represent the literal writing of an image of a ratcheting pathological social hierarchy onto the bodies of American adults and children. This process, while stratified by the usual divisions of class and ethnicity, is nonetheless relentlessly engulfing even affluent majority populations. Our perspective places the common explanation that 'obesity occurs when people eat too much and get too little exercise' in the same category as the remark by US President Calvin Coolidge on the eve of the Great Depression that 'unemployment occurs when large numbers of people are out of work'. Both statements ignore profound structural determinants of great population suffering which must be addressed by collective actions of equally great reform

    The cultural psychology of obesity: diffusion of pathological norms from Western to East Asian societies

    Get PDF
    We examine the accelerating worldwide obesity epidemic using a mathematical model relating a cognitive hypothalamic-pituitary-adrenal axis tuned by embedding cultural context to a signal of chronic, structured, psychosocial threat. The obesity epidemic emerges as a distorted physiological image of ratcheting social pathology involving massive, policy-driven, economic and social 'structural adjustment' causing increasing individual, family, and community insecurity. The resulting, broadly developmental, disorder, while stratified by expected divisions of class, ethnicity, and culture, is nonetheless relentlessly engulfing even affluent majority populations across the globe. The progression of analogous epidemics in affluent Western and East Asian socieities is particularly noteworthy since these enjoy markedly different cultural structures known to influence even such fundamental psychophysical phenomena as change blindness. Indeed, until recently population patterns of obesity were quite different for these cultures. We attribute the entrainment of East Asian societies into the obesity epidemic to the diffusion of Western socioeconomic practices whose imposed resource uncertainties and exacerbation of social and economic divisions constitute powerful threat signals. We find that individual-oriented 'therapeutic' interventions will be largely ineffective since the therapeutic process itself (e.g. relinace on drug treatments) embodies the very threats causing the epidemic
    • ā€¦
    corecore