1,721,017 research outputs found
The dynamics of innovation through the expansion in the adjacent possible
Full text linkThe experience of something new is part of our daily life. At different scales, innovation is also a crucial feature of many biological, technological and social systems. Recently, large databases witnessing human activities allowed the observation that novelties —such as the individual process of listening a song for the first time— and innovation processes —such as the fixation of new genes in a population of bacteria— share striking statistical regularities. We here indicate the expansion into the adjacent possible as a very general and powerful mechanism
able to explain such regularities. Further, we will identify statistical signatures of the presence of the expansion into the adjacent possible in the analyzed datasets, and we will show that our modeling scheme is able to predict remarkably well these observations
A complex system approach to language evolution. The case of regular versus irregular verbs in English
No full textRegularities in natural language systems, despite their cognitive advantages in terms of storage and learnability, often coexist with exceptions, raising the question of whether and why irregularities survive. We offer a complex system perspective on this issue, focusing on the irregular past tense forms in English. Two separate processes affect the overall regularity: new verbs constantly entering the vocabulary in the regular form at low frequency, and transitions in both directions (from irregular to regular and vice-versa) occurring in a narrow frequency range. The introduction of new verbs leads to an increase in regular types, that, entering at low frequencies, have a small impact on the perceived irregularity in terms of tokens. The frequency of usage acts as a control parameter, the majority of verbs types being fully-regular(irregular) at low(high) frequencies, with no evidence of irregularity facing extinction. Very few verbs types in an intermediate frequency region exhibit both regular and irregular forms at the same time, suggesting that the coexistence is unstable. The observed pattern of usage showing an abrupt change in response to small variations of the control parameter only appears in agent-based models provided that the word state is non-binary. By introducing this key ingredient, high-frequency irregular past-tense can survive the tendency to regularize over time, as observed in natural languages
Language Games. Comment on "Modeling language evolution: examples and predictions" by Tao Gon, Lan Shuai, Menghan Zhang
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Language dynamics
No full textThirty authors of different disciplines, ranging from cognitive science and linguistics to mathematics and physics, address the topic of language origin and evolution. Language dynamics is investigated through an interdisciplinary effort, involving field and synthetic experiments, modelling and comparison of the theoretical predictions with empirical data. The result consists in new insights that significantly contribute to the ongoing debate on the origin and the evolution of language. In this Topical Issue the state of the art of this novel and fertile approach is reported by major experts of the field. © 2012 World Scientific Publishing Company
Why are basic color names "basic"?
No full textIt is widely known that color names across the world's languages tend to be organized into a neat hierarchy with a small set of "basic names" featuring in a comparatively fixed order across linguistic societies. However, to date, the basic names have only been defined through a set of linguistic principles. There is no statistical definition that quantitatively separates the basic names from the rest of the color words across languages. Here we present a rigorous statistical analysis of the World Color Survey database hosting color word information from 110 non-industrialized languages. The central result is that those names for which a population of individuals show a larger overall agreement across languages turn out to be the basic ones exactly reproducing the color name hierarchy and, thereby, providing, for the first time, an empirical definition of the basic color names
Dynamically correlated mutations drive human Influenza A evolution
No full textHuman Influenza A virus undergoes recurrent changes in the hemagglutinin (HA) surface protein, primarily involved in the human antibody recognition. Relevant antigenic changes, enabling the virus to evade host immune response, have been recognized to occur in parallel to multiple mutations at antigenic sites in HA. Yet, the role of correlated mutations (epistasis) in driving the molecular evolution of the virus still represents a challenging puzzle. Further, though circulation at a global geographic level is key for the survival of Influenza A, its role in shaping the viral phylodynamics remains largely unexplored. Here we show, through a sequence based epidemiological model, that epistatic effects between amino acids substitutions, coupled with a reservoir that mimics worldwide circulating viruses, are key determinants that drive human Influenza A evolution. Our approach explains all the up-to-date observations characterizing the evolution of H3N2 subtype, including phylogenetic properties, nucleotide fixation patterns, and composition of antigenic clusters
Spin glasses on Bethe lattices for large coordination number
No full textWe study spin glasses on random lattices with finite connectivity. In the infinite connectivity limit they reduce to the Sherrington Kirkpatrick model. In this paper we investigate the expansion
around the high connectivity limit. Within the replica symmetry breaking scheme at two steps, we
compute the free energy at the first order in the expansion in inverse powers of the average
connectivity (z), both for the fixed connectivity and for the fluctuating connectivity random
lattices. It is well known that the coefficient of the 1/z correction for the free energy is
divergent at low temperatures if computed in the one step approximation. We find that this annoying
divergence becomes much smaller if computed in the framework of the more accurate two steps
breaking. Comparing the temperature dependance of the coefficients of this divergence in the replica
symmetric, one step and two steps replica symmetry breaking, we conclude that this divergence is an
artefact due to the use of a finite number of steps of replica symmetry breaking. The 1/z
expansion is well defined also in the zero temperature limit
In Silico Linguistics Comment on "Modeling the cultural evolution of language" by Luc Steels
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