Exact analytical results in a simple model of self-organized biological evolution

Author(s):  
Yu. M. Pis’mak

1994 ◽  
Vol 73 (6) ◽  
pp. 906-909 ◽  
Author(s):  
Jan de Boer ◽  
Bernard Derrida ◽  
Henrik Flyvbjerg ◽  
Andrew D. Jackson ◽  
Tilo Wettig


1997 ◽  
Vol 11 (12) ◽  
pp. 1411-1444 ◽  
Author(s):  
Ning-Ning Pang

Recently, Bak and Sneppen proposed a simple model, the Bak–Sneppen (BS) model, as a coarse-grained description of biological evolution. It has attracted a lot of attention from interdisciplinary statistical physics community, for its simple model definition but extremely rich properties to be explored. The aim of this paper is to give a pedagogical and update review of this fast-developing topic. The emphasis is on the mechanism by which the BS model approaches the self-organized critical state, the universal properties of the system at criticality, and the relation with other topics, such as directed percolation, random walk, and a few self-organized critical models.



2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Pedro E. S. Silva ◽  
Ricardo Chagas ◽  
Susete N. Fernandes ◽  
Pawel Pieranski ◽  
Robin L. B. Selinger ◽  
...  

AbstractCellulose-based systems are useful for many applications. However, the issue of self-organization under non-equilibrium conditions, which is ubiquitous in living matter, has scarcely been addressed in cellulose-based materials. Here, we show that quasi-2D preparations of a lyotropic cellulose-based cholesteric mesophase display travelling colourful patterns, which are generated by a chemical reaction-diffusion mechanism being simultaneous with the evaporation of solvents at the boundaries. These patterns involve spatial and temporal variation in the amplitude and sign of the helix´s pitch. We propose a simple model, based on a reaction-diffusion mechanism, which simulates the observed spatiotemporal colour behaviour.





2000 ◽  
Vol 11 (06) ◽  
pp. 1263-1272 ◽  
Author(s):  
GÉRARD WEISBUCH ◽  
SORIN SOLOMON

There is a discrepancy between the standard view of equilibrium through price adjustment in economics and the observation of large fluctuations in stock markets. We study here a simple model where agents decisions not only depend upon their individual preferences but also upon information obtained from their neighbors in a social network. The model shows that information diffusion coupled to the adjustment process drives the system to criticality with large fluctuations rather than converging smoothly to equilibrium.





2020 ◽  
Author(s):  
Luís F Seoane ◽  
Ricard Solé

Brain reorganization after hemispherectomy (i.e. the removal of a whole hemisphere) is perhaps the most remarkable example of large-scale brain plasticity. Most often patients survive and recover their skills. Functional traits located in the lost side (e.g. language areas) can sometimes be completely reassembled in the remaining hemisphere, which seamlessly take on the additional processing burden. This demands drastic rearrangements, perhaps involving the readaptation of functionally and structurally diverse neural structures. We lack mathematical models of how this happens. We introduce a very simple model, based on self-organized maps, that provides a rationale to the clinical aftermath of the intervention, putative windows for recovery, and the origins and nature of observed thresholds for irreversible function loss. The implications for brain symmetry and potential scenarios in simulated pathologies, including efficient suggested treatments, are outlined.



2004 ◽  
Vol 15 (09) ◽  
pp. 1189-1195 ◽  
Author(s):  
E. AHMED ◽  
M. F. ELETTREBY

Self-Organized Criticality (SOC) phenomena could have a significant effect on the dynamics of ecosystems. The Bak–Sneppen (BS) model is a simple and robust model of biological evolution that exhibits punctuated equilibrium behavior. Here, we will introduce random version of BS model. We also generalize the single objective BS model to a multiobjective one.



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