scholarly journals A novel route to cyclic dominance in voluntary social dilemmas

2020 ◽  
Vol 17 (164) ◽  
pp. 20190789 ◽  
Author(s):  
Hao Guo ◽  
Zhao Song ◽  
Sunčana Geček ◽  
Xuelong Li ◽  
Marko Jusup ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Social Dilemmas ◽  
Modern Human ◽  
Voluntary Participation ◽  
Risk Averse ◽  
Bacterial Strains ◽  
Adverse Conditions ◽  
Tit For Tat ◽  
Transitive Set ◽  
Set Up

Cooperation is the backbone of modern human societies, making it a priority to understand how successful cooperation-sustaining mechanisms operate. Cyclic dominance, a non-transitive set-up comprising at least three strategies wherein the first strategy overrules the second, which overrules the third, which, in turn, overrules the first strategy, is known to maintain biodiversity, drive competition between bacterial strains, and preserve cooperation in social dilemmas. Here, we present a novel route to cyclic dominance in voluntary social dilemmas by adding to the traditional mix of cooperators, defectors and loners, a fourth player type, risk-averse hedgers, who enact tit-for-tat upon paying a hedging cost to avoid being exploited. When this cost is sufficiently small, cooperators, defectors and hedgers enter a loop of cyclic dominance that preserves cooperation even under the most adverse conditions. By contrast, when the hedging cost is large, hedgers disappear, consequently reverting to the traditional interplay of cooperators, defectors, and loners. In the interim region of hedging costs, complex evolutionary dynamics ensues, prompting transitions between states with two, three or four competing strategies. Our results thus reveal that voluntary participation is but one pathway to sustained cooperation via cyclic dominance.

scholarly journals Pairwise Interact-and-Imitate Dynamics

2021 ◽  
Author(s):  
Ennio Bilancini ◽  
Leonardo Boncinelli ◽  
Nicola Campigotto
Keyword(s):  
Evolutionary Dynamics ◽  
Social Dilemmas ◽  
Asymptotically Stable ◽  
Globally Asymptotically Stable ◽  
Symmetric Game ◽  
Dominated Strategies ◽  
The Difference ◽  
Payoff Uncertainty

Abstract This paper introduces and studies a class of evolutionary dynamics --- Pairwise Interact-and-Imitate Dynamics (PIID) --- in which agents are matched in pairs, engage in a symmetric game, and imitate the opponent with a probability that depends on the difference in their payoffs. We provide a condition on the underlying game, named supremacy, and show that the population state in which all agents play the supreme strategy is globally asymptotically stable. We extend the framework to allow for payoff uncertainty, and check the robustness of our results to the introduction of some heterogeneity in the revision protocol followed by agents. Finally, we show that PIID can allow the survival of strictly dominated strategies, leads to the emergence of inefficient conventions in social dilemmas, and makes assortment ineffective in promoting cooperation.

Quarantine

2021 ◽  
Author(s):  
◽  
Thomas Murray
Keyword(s):  
Science Fiction ◽  
Modern Human ◽  
The World ◽  
Specific Pathogen ◽  
Infectious Pathogen ◽  
Ease Of Access ◽  
Set Up ◽  
Further Development ◽  
Literature And Film ◽  
Global Population

<p>This thesis is set in a world similar to many pieces of science fiction literature and film. The world is fighting against the outbreak of a lethal and highly infectious pathogen that threatens to decimate the global population. The virus spreads quickly and has no current known cures or vaccines. Whilst the backdrop for this thesis is fictional, it addresses a very real concern that could face society. The research and outcomes of this thesis were based on a detailed study of quarantine solutions with the intention to quickly control and treat a virus pandemic. The focus was given to the architecture of emergency quarantine hospitals but also to a specific pathogen that this proposal is based upon, the H5N1 virus, more commonly known as Bird Flu. This thesis proposes to investigate a movable architecture dedicated to quarantine which can transport itself between cities and set up where it is most needed, be that in a busy city or a cluster of small villages. This allows for ease of access for those infected as well as quick integration back into society should those who are isolated respond well to treatment. The thesis will propose a potential direction for the further development of modern human quarantine, a system that will be ready and waiting for the day that it is desperately required.</p>

scholarly journals M1CR0B1AL1Z3R—a user-friendly web server for the analysis of large-scale microbial genomics data

2019 ◽  
Vol 47 (W1) ◽  
pp. W88-W92 ◽  
Author(s):  
Oren Avram ◽  
Dana Rapoport ◽  
Shir Portugez ◽  
Tal Pupko
Keyword(s):  
Large Scale ◽  
Ad Hoc ◽  
Evolutionary Dynamics ◽  
Gene Annotation ◽  
Gc Content ◽  
Web Server ◽  
Disease Outbreaks ◽  
Open Reading Frames ◽  
Microbial Genomics ◽  
Bacterial Strains

Abstract Large-scale mining and analysis of bacterial datasets contribute to the comprehensive characterization of complex microbial dynamics within a microbiome and among different bacterial strains, e.g., during disease outbreaks. The study of large-scale bacterial evolutionary dynamics poses many challenges. These include data-mining steps, such as gene annotation, ortholog detection, sequence alignment and phylogeny reconstruction. These steps require the use of multiple bioinformatics tools and ad-hoc programming scripts, making the entire process cumbersome, tedious and error-prone due to manual handling. This motivated us to develop the M1CR0B1AL1Z3R web server, a ‘one-stop shop’ for conducting microbial genomics data analyses via a simple graphical user interface. Some of the features implemented in M1CR0B1AL1Z3R are: (i) extracting putative open reading frames and comparative genomics analysis of gene content; (ii) extracting orthologous sets and analyzing their size distribution; (iii) analyzing gene presence–absence patterns; (iv) reconstructing a phylogenetic tree based on the extracted orthologous set; (v) inferring GC-content variation among lineages. M1CR0B1AL1Z3R facilitates the mining and analysis of dozens of bacterial genomes using advanced techniques, with the click of a button. M1CR0B1AL1Z3R is freely available at https://microbializer.tau.ac.il/.

scholarly journals Interactions among bacterial strains and fluke genotypes shape virulence of co-infection

2015 ◽  
Vol 282 (1821) ◽  
pp. 20152097 ◽  
Author(s):  
Katja-Riikka Louhi ◽  
Lotta-Riina Sundberg ◽  
Jukka Jokela ◽  
Anssi Karvonen
Keyword(s):  
Evolutionary Dynamics ◽  
Parasite Species ◽  
Bacterial Strains ◽  
Parasite Fitness ◽  
Host Parasite Interactions ◽  
Host Health ◽  
Infection Focus ◽  
Host Mortality ◽  
Host Parasite ◽  
Virulent Parasite

Most studies of virulence of infection focus on pairwise host–parasite interactions. However, hosts are almost universally co-infected by several parasite strains and/or genotypes of the same or different species. While theory predicts that co-infection favours more virulent parasite genotypes through intensified competition for host resources, knowledge of the effects of genotype by genotype (G × G) interactions between unrelated parasite species on virulence of co-infection is limited. Here, we tested such a relationship by challenging rainbow trout with replicated bacterial strains and fluke genotypes both singly and in all possible pairwise combinations. We found that virulence (host mortality) was higher in co-infections compared with single infections. Importantly, we also found that the overall virulence was dependent on the genetic identity of the co-infecting partners so that the outcome of co-infection could not be predicted from the respective virulence of single infections. Our results imply that G × G interactions among co-infecting parasites may significantly affect host health, add to variance in parasite fitness and thus influence evolutionary dynamics and ecology of disease in unexpected ways.

scholarly journals Cytonuclear interactions affect adaptive traits of the annual plant Arabidopsis thaliana in the field

2016 ◽  
Vol 113 (13) ◽  
pp. 3687-3692 ◽  
Author(s):  
Fabrice Roux ◽  
Tristan Mary-Huard ◽  
Elise Barillot ◽  
Estelle Wenes ◽  
Lucy Botran ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Evolutionary Dynamics ◽  
Phenotypic Traits ◽  
Pairwise Interactions ◽  
Parental Pair ◽  
Nuclear Differentiation ◽  
Set Up ◽  
Total Seed ◽  
Phenotypic Responses ◽  
Do So

Although the contribution of cytonuclear interactions to plant fitness variation is relatively well documented at the interspecific level, the prevalence of cytonuclear interactions at the intraspecific level remains poorly investigated. In this study, we set up a field experiment to explore the range of effects that cytonuclear interactions have on fitness-related traits in Arabidopsis thaliana. To do so, we created a unique series of 56 cytolines resulting from cytoplasmic substitutions among eight natural accessions reflecting within-species genetic diversity. An assessment of these cytolines and their parental lines scored for 28 adaptive whole-organism phenotypes showed that a large proportion of phenotypic traits (23 of 28) were affected by cytonuclear interactions. The effects of these interactions varied from slight but frequent across cytolines to strong in some specific parental pairs. Two parental pairs accounted for half of the significant pairwise interactions. In one parental pair, Ct-1/Sha, we observed symmetrical phenotypic responses between the two nuclear backgrounds when combined with specific cytoplasms, suggesting nuclear differentiation at loci involved in cytonuclear epistasis. In contrast, asymmetrical phenotypic responses were observed in another parental pair, Cvi-0/Sha. In the Cvi-0 nuclear background, fecundity and phenology-related traits were strongly affected by the Sha cytoplasm, leading to a modified reproductive strategy without penalizing total seed production. These results indicate that natural variation in cytoplasmic and nuclear genomes interact to shape integrative traits that contribute to adaptation, thereby suggesting that cytonuclear interactions can play a major role in the evolutionary dynamics of A. thaliana.

scholarly journals Eco-evolutionary dynamics of social dilemmas

2016 ◽  
Author(s):  
Chaitanya S. Gokhale ◽  
Christoph Hauert
Keyword(s):  
Social Interactions ◽  
Evolutionary Dynamics ◽  
Complex Dynamics ◽  
Social Dilemmas ◽  
Microbial Populations ◽  
Evolutionary Processes ◽  
Ecological Processes ◽  
Evolutionary Trajectory ◽  
Changes Over Time ◽  
Better Than

AbstractSocial dilemmas are an integral part of social interactions. Cooperative actions, ranging from secreting extra-cellular products in microbial populations to donating blood in humans, are costly to the actor and hence create an incentive to shirk and avoid the costs. Nevertheless, cooperation is ubiquitous in nature. Both costs and benefits often depend non-linearly on the number and types of individuals involved–as captured by idioms such as ‘too many cooks spoil the broth’ where additional contributions are discounted, or ‘two heads are better than one’ where cooperators synergistically enhance the group benefit. Interaction group sizes may depend on the size of the population and hence on ecological processes. This results in feedback mechanisms between ecological and evolutionary processes, which jointly affect and determine the evolutionary trajectory. Only recently combined eco-evolutionary processes became experimentally tractable in microbial social dilemmas. Here we analyse the evolutionary dynamics of non-linear social dilemmas in settings where the population fluctuates in size and the environment changes over time. In particular, cooperation is often supported and maintained at high densities through ecological fluctuations. Moreover, we find that the combination of the two processes routinely reveals highly complex dynamics, which suggests common occurrence in nature.

scholarly journals M1CR0B1AL1Z3R—a user-friendly web server for the analysis of large-scale microbial genomics data

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Oren Avram ◽  
Dana Rapoport ◽  
Shir Portugez ◽  
Tal Pupko
Keyword(s):  
Large Scale ◽  
Ad Hoc ◽  
Evolutionary Dynamics ◽  
Gene Annotation ◽  
Gc Content ◽  
Web Server ◽  
Disease Outbreaks ◽  
Open Reading Frames ◽  
Microbial Genomics ◽  
Bacterial Strains

Large-scale mining and analysis of bacterial datasets contribute to the comprehensive characterization of complex microbial dynamics within a microbiome and among different bacterial strains, e.g., during disease outbreaks. The study of large-scale bacterial evolutionary dynamics poses many challenges. These include data-mining steps, such as gene annotation, ortholog detection, sequence alignment, and phylogeny reconstruction. These steps require the use of multiple bioinformatics tools and ad-hoc programming scripts, making the entire process cumbersome, tedious and error-prone due to manual handling. This motivated us to develop the M1CR0B1AL1Z3R web server, a ‘one-stop shop’ for conducting microbial genomics data analyses via a simple graphical user interface (Avram, et al., Nucleic Acids Res., 2019). Some of the features implemented in M1CR0B1AL1Z3R are: (i) extracting putative open reading frames and comparative genomics analysis of gene content; (ii) extracting orthologous sets and analyzing their size distribution; (iii) analyzing gene presence-absence patterns; (iv) reconstructing a phylogenetic tree based on the extracted orthologous set; (v) inferring GC-content variation among lineages. M1CR0B1AL1Z3R facilitates the mining and analysis of dozens of bacterial genomes using advanced techniques, with the click of a button. M1CR0B1AL1Z3R is freely available at https://microbializer.tau.ac.il/ [https://microbializer.tau.ac.il/].

scholarly journals Eco-evolutionary dynamics of social dilemmas

2016 ◽  
Vol 111 ◽  
pp. 28-42 ◽  
Author(s):  
Chaitanya S. Gokhale ◽  
Christoph Hauert
Keyword(s):  
Evolutionary Dynamics ◽  
Social Dilemmas
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