Como a maior parte das pessoas, aliás, não representaria ela, na vida, o mesmo que, nas florestas... more Como a maior parte das pessoas, aliás, não representaria ela, na vida, o mesmo que, nas florestas, as clareiras em forma de estrela para onde convergem, de pontos diversos, tantas veredas? Eram numerosas, em meu caso, as que se dirigiam para a Srta. de Saint-Loup, ou de seu derredor irradiavam. E, antes de tudo, a ela conduziam os dois grandes "caminhos" de meus passeios e dos sonhos -por seu pai Robert, o de Guermantes, por Gilberte, sua mãe, o de Méséglise, que era o de Swann. M. Proust (1995, p.276-277). ▪ RESUMO: Mesmo se, recentemente, parte da crítica literária tem demonstrado interesse na aproximação com as ciências "duras", a resistência a essa aproximação, dentro do âmbito da própria crítica, é ainda bastante presente. Neste artigo, através da revisitação da história da ciência no século vinte, tentamos mostrar como parece ser possível criar algumas transversais entre esses dois caminhos. ▪ PALAVRAS-CHAVE: Crítica literária. Ciência. Duas culturas. Complexidade. Emergentismo.
Abstract: The ways in which natural selection can allow the proliferation of cooperative behavior... more Abstract: The ways in which natural selection can allow the proliferation of cooperative behavior have long been seen as a central problem in evolutionary biology. Most of the literature has focused on interactions between pairs of individuals and on linear public goods games. This emphasis led to the conclusion that even modest levels of migration would pose a serious problem to the spread of altruism in group structured populations.
Abstract: Stable mixtures of cooperators and defectors are often seen in nature. This fact is at ... more Abstract: Stable mixtures of cooperators and defectors are often seen in nature. This fact is at odds with predictions based on linear public goods games under weak selection. That model implies fixation either of cooperators or of defectors, and the former scenario requires a level of group relatedness larger than the cost/benefit ratio, being therefore expected only if there is either kin recognition or a very low cost/benefit ratio, or else under stringent conditions with low gene flow.
Abstract: The Taylor-Frank method for making kin selection models when fitness is a nonlinear fun... more Abstract: The Taylor-Frank method for making kin selection models when fitness is a nonlinear function of a continuous phenotype requires this function to be differentiable. This assumption sometimes fails for biologically important fitness functions, for instance in microbial data and the theory of repeated n-person games, even when fitness functions are smooth and continuous.
A framework for the mathematical modeling of evolution in group structured populations is introdu... more A framework for the mathematical modeling of evolution in group structured populations is introduced. The population is divided into a fixed large number of groups of fixed size. From generation to generation, new groups are formed that descend from previous groups, through a two-level Fisher-Wright process, with selection between groups and within groups and with migration between groups at rate $m$. When $m=1$, the framework reduces to the often used trait-group framework, so that our setting can be seen as an extension of that approach. Our framework allows the analysis of previously introduced models in which altruists and non-altruists compete, and provides new insights into these models. We focus on the situation in which initially there is a single altruistic allele in the population, and no further mutations occur. The main questions are conditions for the viability of that altruistic allele to spread, and the fashion in which it spreads when it does. Because our results and methods are rigorous, we see them as shedding light on various controversial issues in this field, including the role of Hamilton's rule, and of the Price equation, the relevance of linearity in fitness functions and the need to only consider pairwise interactions, or weak selection. In this paper we analyze the early stages of the evolution, during which the number of altruists is small compared to the size of the population. We show that during this stage the evolution is well described by a multitype branching process. The driving matrix for this process can be obtained, reducing the problem of determining when the altruistic gene is viable to a comparison between the leading eigenvalue of that matrix, and the fitness of the non-altruists before the altruistic gene appeared. This leads to a generalization of Hamilton's condition for the viability of a mutant gene.
Moral Foundation Theory states that groups of different observers may rely on partially dissimila... more Moral Foundation Theory states that groups of different observers may rely on partially dissimilar sets of moral foundations, thereby reaching different moral valuations. The use of functional imaging techniques has revealed a spectrum of cognitive styles with respect to the differential handling of novel or corroborating information that is correlated to political affiliation. Here we characterize the collective behavior of an agent-based model whose inter individual interactions due to information exchange in the form of opinions are in qualitative agreement with data. The main conclusion derived connects the existence of diversity in the cognitive strategies and statistics of the sets of moral foundations and suggests that this connection arises from interactions between agents. Thus a simple interacting agent model, whose interactions are in accord with empirical data on conformity and learning processes, presents statistical signatures consistent with those that characterize moral judgment patterns of conservatives and liberals.
We employ the Bayesian framework to define a cointegration measure aimed to represent long term r... more We employ the Bayesian framework to define a cointegration measure aimed to represent long term relationships between time series. For visualization of these relationships we introduce a dissimilarity matrix and a map based on the sorting points into neighborhoods (SPIN) technique, which has been previously used to analyze large data sets from DNA arrays. We exemplify the technique in three data sets: US interest rates (USIR), monthly inflation rates and gross domestic product (GDP) growth rates.
Abstract: Reputation systems seek to infer which members of a community can be trusted based on r... more Abstract: Reputation systems seek to infer which members of a community can be trusted based on ratings they issue about each other. We construct a Bayesian inference model and simulate approximate estimates using belief propagation (BP). The model is then mapped onto a problem of equilibrium statistical mechanics that is analyzed theoretically by employing the replica symmetric cavity approach.
▪ RESUMO: Mesmo se, recentemente, parte da crítica literária tem demonstrado interesse na aproxim... more ▪ RESUMO: Mesmo se, recentemente, parte da crítica literária tem demonstrado interesse na aproximação com as ciências “duras”, a resistência a essa aproximação, dentro do âmbito da própria crítica, é ainda bastante presente. Neste artigo, através da revisitação da história da ciência no século vinte, tentamos mostrar como parece ser possível criar algumas transversais entre esses dois caminhos.
Na Antiguidade, os manuscritos, feitos à base de papiros ou pergaminhos, eram produzidos volume p... more Na Antiguidade, os manuscritos, feitos à base de papiros ou pergaminhos, eram produzidos volume por volume em um trabalho artesanal acessível somente às bibliotecas e coleções particulares de reis e outras autoridades. A popularização de manuscritos aconteceria somente a partir da difusão do papel no século XIV e do surgimento de tipografias no século XV. Livros populares já circulavam pela Europa em pleno século XVI. Nessa época, a literatura de cordel ganhava espaço na Espanha e em Portugal.
We employ the methods presented in the previous chapter for decoding corrupted codewords, encoded... more We employ the methods presented in the previous chapter for decoding corrupted codewords, encoded using sparse parity check error correcting codes. We show the similarity between the equations derived from the TAP approach and those obtained from belief propagation, and examine their performance as practical decoding methods.
We discuss the connection between information and copula theories by showing that a copula can be... more We discuss the connection between information and copula theories by showing that a copula can be employed to decompose the information content of a multivariate distribution into marginal and dependence components, with the latter quantified by the mutual information. We define the information excess as a measure of deviation from a maximum entropy distribution. The idea of marginal invariant dependence measures is also discussed and used to show that empirical linear correlation underestimates the amplitude of the actual correlation in the case of non-Gaussian marginals. The mutual information is shown to provide an upper bound for the asymptotic empirical log-likelihood of a copula. An analytical expression for the information excess of T-copulas is provided, allowing for simple model identification within this family. We illustrate the framework in a financial data set.
Como a maior parte das pessoas, aliás, não representaria ela, na vida, o mesmo que, nas florestas... more Como a maior parte das pessoas, aliás, não representaria ela, na vida, o mesmo que, nas florestas, as clareiras em forma de estrela para onde convergem, de pontos diversos, tantas veredas? Eram numerosas, em meu caso, as que se dirigiam para a Srta. de Saint-Loup, ou de seu derredor irradiavam. E, antes de tudo, a ela conduziam os dois grandes "caminhos" de meus passeios e dos sonhos -por seu pai Robert, o de Guermantes, por Gilberte, sua mãe, o de Méséglise, que era o de Swann. M. Proust (1995, p.276-277). ▪ RESUMO: Mesmo se, recentemente, parte da crítica literária tem demonstrado interesse na aproximação com as ciências "duras", a resistência a essa aproximação, dentro do âmbito da própria crítica, é ainda bastante presente. Neste artigo, através da revisitação da história da ciência no século vinte, tentamos mostrar como parece ser possível criar algumas transversais entre esses dois caminhos. ▪ PALAVRAS-CHAVE: Crítica literária. Ciência. Duas culturas. Complexidade. Emergentismo.
Abstract: The ways in which natural selection can allow the proliferation of cooperative behavior... more Abstract: The ways in which natural selection can allow the proliferation of cooperative behavior have long been seen as a central problem in evolutionary biology. Most of the literature has focused on interactions between pairs of individuals and on linear public goods games. This emphasis led to the conclusion that even modest levels of migration would pose a serious problem to the spread of altruism in group structured populations.
Abstract: Stable mixtures of cooperators and defectors are often seen in nature. This fact is at ... more Abstract: Stable mixtures of cooperators and defectors are often seen in nature. This fact is at odds with predictions based on linear public goods games under weak selection. That model implies fixation either of cooperators or of defectors, and the former scenario requires a level of group relatedness larger than the cost/benefit ratio, being therefore expected only if there is either kin recognition or a very low cost/benefit ratio, or else under stringent conditions with low gene flow.
Abstract: The Taylor-Frank method for making kin selection models when fitness is a nonlinear fun... more Abstract: The Taylor-Frank method for making kin selection models when fitness is a nonlinear function of a continuous phenotype requires this function to be differentiable. This assumption sometimes fails for biologically important fitness functions, for instance in microbial data and the theory of repeated n-person games, even when fitness functions are smooth and continuous.
A framework for the mathematical modeling of evolution in group structured populations is introdu... more A framework for the mathematical modeling of evolution in group structured populations is introduced. The population is divided into a fixed large number of groups of fixed size. From generation to generation, new groups are formed that descend from previous groups, through a two-level Fisher-Wright process, with selection between groups and within groups and with migration between groups at rate $m$. When $m=1$, the framework reduces to the often used trait-group framework, so that our setting can be seen as an extension of that approach. Our framework allows the analysis of previously introduced models in which altruists and non-altruists compete, and provides new insights into these models. We focus on the situation in which initially there is a single altruistic allele in the population, and no further mutations occur. The main questions are conditions for the viability of that altruistic allele to spread, and the fashion in which it spreads when it does. Because our results and methods are rigorous, we see them as shedding light on various controversial issues in this field, including the role of Hamilton's rule, and of the Price equation, the relevance of linearity in fitness functions and the need to only consider pairwise interactions, or weak selection. In this paper we analyze the early stages of the evolution, during which the number of altruists is small compared to the size of the population. We show that during this stage the evolution is well described by a multitype branching process. The driving matrix for this process can be obtained, reducing the problem of determining when the altruistic gene is viable to a comparison between the leading eigenvalue of that matrix, and the fitness of the non-altruists before the altruistic gene appeared. This leads to a generalization of Hamilton's condition for the viability of a mutant gene.
Moral Foundation Theory states that groups of different observers may rely on partially dissimila... more Moral Foundation Theory states that groups of different observers may rely on partially dissimilar sets of moral foundations, thereby reaching different moral valuations. The use of functional imaging techniques has revealed a spectrum of cognitive styles with respect to the differential handling of novel or corroborating information that is correlated to political affiliation. Here we characterize the collective behavior of an agent-based model whose inter individual interactions due to information exchange in the form of opinions are in qualitative agreement with data. The main conclusion derived connects the existence of diversity in the cognitive strategies and statistics of the sets of moral foundations and suggests that this connection arises from interactions between agents. Thus a simple interacting agent model, whose interactions are in accord with empirical data on conformity and learning processes, presents statistical signatures consistent with those that characterize moral judgment patterns of conservatives and liberals.
We employ the Bayesian framework to define a cointegration measure aimed to represent long term r... more We employ the Bayesian framework to define a cointegration measure aimed to represent long term relationships between time series. For visualization of these relationships we introduce a dissimilarity matrix and a map based on the sorting points into neighborhoods (SPIN) technique, which has been previously used to analyze large data sets from DNA arrays. We exemplify the technique in three data sets: US interest rates (USIR), monthly inflation rates and gross domestic product (GDP) growth rates.
Abstract: Reputation systems seek to infer which members of a community can be trusted based on r... more Abstract: Reputation systems seek to infer which members of a community can be trusted based on ratings they issue about each other. We construct a Bayesian inference model and simulate approximate estimates using belief propagation (BP). The model is then mapped onto a problem of equilibrium statistical mechanics that is analyzed theoretically by employing the replica symmetric cavity approach.
▪ RESUMO: Mesmo se, recentemente, parte da crítica literária tem demonstrado interesse na aproxim... more ▪ RESUMO: Mesmo se, recentemente, parte da crítica literária tem demonstrado interesse na aproximação com as ciências “duras”, a resistência a essa aproximação, dentro do âmbito da própria crítica, é ainda bastante presente. Neste artigo, através da revisitação da história da ciência no século vinte, tentamos mostrar como parece ser possível criar algumas transversais entre esses dois caminhos.
Na Antiguidade, os manuscritos, feitos à base de papiros ou pergaminhos, eram produzidos volume p... more Na Antiguidade, os manuscritos, feitos à base de papiros ou pergaminhos, eram produzidos volume por volume em um trabalho artesanal acessível somente às bibliotecas e coleções particulares de reis e outras autoridades. A popularização de manuscritos aconteceria somente a partir da difusão do papel no século XIV e do surgimento de tipografias no século XV. Livros populares já circulavam pela Europa em pleno século XVI. Nessa época, a literatura de cordel ganhava espaço na Espanha e em Portugal.
We employ the methods presented in the previous chapter for decoding corrupted codewords, encoded... more We employ the methods presented in the previous chapter for decoding corrupted codewords, encoded using sparse parity check error correcting codes. We show the similarity between the equations derived from the TAP approach and those obtained from belief propagation, and examine their performance as practical decoding methods.
We discuss the connection between information and copula theories by showing that a copula can be... more We discuss the connection between information and copula theories by showing that a copula can be employed to decompose the information content of a multivariate distribution into marginal and dependence components, with the latter quantified by the mutual information. We define the information excess as a measure of deviation from a maximum entropy distribution. The idea of marginal invariant dependence measures is also discussed and used to show that empirical linear correlation underestimates the amplitude of the actual correlation in the case of non-Gaussian marginals. The mutual information is shown to provide an upper bound for the asymptotic empirical log-likelihood of a copula. An analytical expression for the information excess of T-copulas is provided, allowing for simple model identification within this family. We illustrate the framework in a financial data set.
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