http://precedings.nature.com/tags/cooperation Recently posted documents tagged with 'cooperation' Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://precedings.nature.com/documents/3071/version/1 Explaining the evolution of cooperative behavior has been one of main challenges in evo- lutionary theory1-6. Cooperation may collapse a surge of defectors who enjoy the benefit without cooperation in situation called prisoner’s dilemma. In the concept of evolutionary game theory, there are many proposals to explain the evolution of cooperation by adding further mechanism such as, kin selection1, reciprocity7, punishment8,9 and the finiteness of the population6. In evolutionary game theory, a pair is randomly picked from population, and play a prisoner’s dilemma game. Here we also show the finiteness encourages cooperation but use different approach: in spite of random-pick, individuals join and leave a spot or territory with a limited capacity to form a pair and play prisoner’s dilemma game during their stay in the spot. We use a simple finite-state continuous-time Markov chain to analyze the dynamics in the spot and find that, given large cooperation benefit, just leaving together from the spot is enough for cooperation to be emerged. Further, we show that the coexistence of cooperators and defectors may become stable in highly congested spots. http://precedings.nature.com/documents/3071/version/1 Thu, 16 Apr 2009 09:34:51 UTC Evolution of Cooperation on Playing Prisoner's Dilemma Game in the Finite-Capacity Spot hdl:10101/npre.2009.3071.1 2009-04-16 Hiroshi Toyoizumi Nature Precedings 2009-04-16T09:34:51Z Manuscript Evolutionary Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/3035/version/1 The emergence of cooperation has been widely studied in the context of game theory on structured populations. Usually the individuals adopt one strategy against all their neighbors. The structure can provide reproductive success for the cooperative strategy, at least for low values of defection tendency. Other mechanisms, such punishment, can also be responsible for cooperation emergence. But what happens if the players adopt simultaneously different strategies against each one of their opponents, not just a single one? Here we study this question in the prisoner dilemma scenario structured on a square lattice and on a ring. We show that if an update rule is defined in which the players replace the strategy that furnishes the smallest payoff, a punishment response mechanism against defectors without imputing cost to the punishers appears, cooperation dominates and, even if the tendency of defection is huge, cooperation still remains alive. http://precedings.nature.com/documents/3035/version/1 Wed, 08 Apr 2009 09:16:55 UTC Adoption of simultaneous different strategies against different opponents enhances cooperation hdl:10101/npre.2009.3035.1 2009-04-08 Lucas Wardil Nature Precedings 2009-04-08T09:16:55Z Manuscript Evolutionary Biology http://creativecommons.org/licenses/by/3.0/ http://dx.doi.org/10.1038/npre.2009.3028.1 Natural selection is often regarded as a result of severe competition. Defect seems beneficial for a single individual in many cases.However, cooperation is observed in many levels of biological systems ranging from single cells to animals, including human society. We have yet known that in unstructured populations, evolution favors defectors over cooperators. On the other hand, there have been much interest on evolutionary games1,2 on structured population and on graphs3-16. Structures of biological systems and societies of animals can be taken as networks. They discover that network structures determine results of the games. Together with the recent interest of complex networks17,18, many researchers investigate real network structures. Recently even economists study firms' transactions structure19. Seminal work11 derives the condition of favoring cooperation for evolutionary games on networks, that is, benefit divided by cost, b/c, exceeds average degree, (k). Although this condition has been believed so far20, we find the condition is b/c (knm) instead. knm is the mean nearest neighbor degree. Our condition enables us to compare how network structure enhances cooperation across different kinds of networks. Regular network favors most, scale free network least. On ideal scale free networks, cooperation is unfeasible. We could say that (k) is the degree of itself, while knm is that of others. One of the most interesting points in network theory is that results depend not only on itself but also on others. In evolutionary games on network, we find the same characteristic. http://dx.doi.org/10.1038/npre.2009.3028.1 Mon, 06 Apr 2009 09:36:52 UTC A condition of cooperation. Games on network doi:10.1038/npre.2009.3028.1 2009-04-06 Tomohiko Konno Nature Precedings 2009-04-06T09:36:52Z Manuscript Evolutionary Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2610/version/1 The analysis of network topology and dynamics is increasingly used for the description of the structure, function and evolution of complex systems. Here we summarize key aspects of the evolvability and robustness of the hierarchical network-set of macromolecules, cells, organisms, and ecosystems. Listing the costs and benefits of cooperation as a necessary behaviour to build this network hierarchy, we outline the major hypothesis of the paper: the emergence of hierarchical complexity needs cooperation leading to the ageing of the constituent networks. Local cooperation in a stable environment may lead to over-optimization developing an ‘always-old’ network, which ages slowly, and dies in an apoptosis-like process. Global cooperation by exploring a rapidly changing environment may cause an occasional over-perturbation exhausting system-resources, causing rapid degradation, ageing and death of an otherwise ‘forever-young’ network in a necrosis-like process. Giving a number of examples we explain how local and global cooperation can both evoke and help successful ageing. Finally, we show how various forms of cooperation and consequent ageing emerge as key elements in all major steps of evolution from the formation of protocells to the establishment of the globalized, modern human society. Thus, ageing emerges as a price of complexity, which is going hand-in-hand with cooperation enhancing each other in a successful community. http://precedings.nature.com/documents/2610/version/1 Fri, 05 Dec 2008 21:01:30 UTC Ageing as a price of cooperation and complexity: Self-organization of complex systems causes the ageing of constituent networks hdl:10101/npre.2008.2610.1 2008-12-05 Peter Csermely Nature Precedings 2008-12-05T21:01:30Z Manuscript Genetics & Genomics Bioinformatics Evolutionary Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1710/version/1 Altruism (helping others at a cost to oneself) may evolve via group selection if the cost of altruism to the individual is compensated for by growth differences among groups when (1) there is high genetic variation among members of different groups; (2) more altruistic groups grow faster and (3) between-group migration is low. Nevertheless, group selection may not fully explain the actual evolution of helping behaviour if between-group migration was sufficiently common to have reduced between-group genetic variance. Lethal intergroup competition, which amplifies such growth differences between groups, appears to have been frequent in humans’; ancestral environments and could bear importantly on the evolution of altruism. Here we show that between-group migration and resulting genetic similarity can promote the evolution of costly helping behavior in the context of lethal intergroup conflict, albeit by selection at the individual level and not by group selection. The standard group selection models do not capture such basic elements of lethal intergroup competition as the possibility of an individual’s altruism being critical to the group’s success when that possibility is inversely proportional to genetic variation among members of the competing groups. http://precedings.nature.com/documents/1710/version/1 Mon, 24 Mar 2008 15:08:10 UTC Genetic similarity promotes evolution of cooperation under lethal intergroup competition hdl:10101/npre.2008.1710.1 2009-03-04 Oleg Smirnov Nature Precedings 2008-03-24T15:08:10Z Manuscript Evolutionary Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1695/version/1 Ever since Premack & Woodruff’s classic article1, which introduced the term “theory of mind”, researchers have claimed that strategic deception is the most natural behavioural consequence of understanding false belief. Here we challenge that claim, and provide evidence for the first time that the earliest manifestation of false belief understanding in human development is found in young children’s emerging pro-social behaviours. In a modified false belief task, children were asked either to choose one protagonist they should help to find the object (the pro-social context), or to choose one they need to deceive so that none of the protagonists can find the object (the competitive context). The results show that the pro-social motive, but not the competitive motive, boosts early false belief understanding. This is most clearly contrasted with findings that apes, our closest living relatives, are capable of intentionally manipulating others by concealing information only under competitive motives, not under cooperative alternatives. Thus, the current findings are the strongest to date that sophisticated understanding of others’ belief in humans has its unique origin, separate from the primate origin at some point in recent evolution, when cooperative and communicative motives played an essential role for their survival. http://precedings.nature.com/documents/1695/version/1 Sat, 22 Mar 2008 04:48:44 UTC Pro-social motive promotes early understanding of false belief hdl:10101/npre.2008.1695.1 2008-03-22 Tomoko Matsui Nature Precedings 2008-03-22T04:48:44Z Manuscript Developmental Biology http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1392/version/1 Cooperation among competitors-whether sharing the burden of wind resistance in the Tour de France, forming price-fixing cartels in economic markets, or adhering to arms-control agreements in international treaties-seldom spreads in proportion to the potential benefits. To gain insight into the minds of uncooperative agents, economists and social psychologists have used the prisoner’s dilemma task to examine factors leading to cooperation among competitors. Two types of factors have emerged in these studies: the relative rewards of defecting versus cooperating and breakdowns in trust, forgiveness and communication. The generalizability of economic and social psychological factors, however, relies on the assumption that agents’ comparisons of gains and losses (whether for themselves, others, or both) preserves ratio information over arbitrary units, such as dollars and cents, and real rewards, such as food. This assumption is inconsistent with psychophysical studies on how the brain represents quantitative information, which suggests that mental magnitudes increase logarithmically with actual value. Thus, discrimination of two numerical magnitudes improves as the numerical distance between them increases and decreases as the magnitudes increase. Here we show an important consequence of this representational system for economic decision making: in the prisoner’s dilemma game, purely nominal increases in the numerical magnitude of payoffs (such as, converting dollar values to cents or whole grapes into grape-parts) has a large effect on cooperative behaviour. Moreover, a logarithmic scaling of the ratio of rewards for cooperation versus defection predicted 97% of variability in observed cooperation, whereas the objective ratio predicted 0% of variability. By linking the brain’s system of representing the magnitude of rewards to motivations for cooperative behaviour, these findings suggest that the nature of numerical representations may also account for the subjective value function described by Bernoulli, in which the apparent value of monetary incentives increases logarithmically with actual value. http://precedings.nature.com/documents/1392/version/1 Wed, 05 Dec 2007 22:11:35 UTC Numbers, not value, motivate cooperation in humans and orangutans hdl:10101/npre.2007.1392.1 2007-12-05 Ellen E. Furlong Nature Precedings 2007-12-05T22:11:35Z Manuscript Developmental Biology Ecology http://creativecommons.org/licenses/by/3.0/ http://dx.doi.org/10.1038/npre.2007.740.1 Defection is frequently seen in co-operative systems [1-3]. Game theoretical solutions to stabilize cooperation rely on reciprocity and reputation in iterated games[4-5]. One of the basic requirements for reciprocity or reputation building is that the strategies of players and the resulting payoffs should be open at the end of every interaction. For games in which the strategies and payoffs remain hidden, these stabilizing factors are unlikely to work. We examine the evolution of cooperation for hidden-strategy games using human mating game as an example. Here faithful parenting can be considered as cooperation and extra-pair mating (EPM) or cuckoldry as defection. Cuckoldry may get exposed only occasionally and the genetic benefits of cuckoldry also remain hidden from the players. Along with mate guarding, social policing is enabled in humans by language and gossiping. However, social policing can be invaded by second order free riders. We suggest that opportunistic blackmailing, which is unique to hidden strategy games can act as a keystone strategy in stabilizing co-operation. This can counteract free riding and stabilize policing. A game theoretical model results into a rock – paper – scissor (R-P-S) like situation with no evolutionary stable strategy (ESS). Simulations result into a stable or stably oscillating polymorphism. Obligate monogamy is an essential trait in the co-existence. In a gender difference model too, polymorphism is seen in both genders but with different traits predominating in the two genders. The model explains intra-gender, inter-gender as well as cross cultural variability in mating strategies in humans. http://dx.doi.org/10.1038/npre.2007.740.1 Tue, 21 Aug 2007 05:37:18 UTC Evolution of Co-operation When the Strategies are Hidden: The Human Mating Game doi:10.1038/npre.2007.740.1 2009-03-04 Milind Watve Nature Precedings 2007-08-21T05:37:18Z Manuscript Evolutionary Biology http://creativecommons.org/licenses/by/2.5/