Explaining the "Tragedy of the Commons" of the evolution of cooperation remains one of the greatest problems for both biology and social science.Asymmetrical interaction,which is one of the most important ch...Explaining the "Tragedy of the Commons" of the evolution of cooperation remains one of the greatest problems for both biology and social science.Asymmetrical interaction,which is one of the most important characteristics of cooperative systems,has not been sufficiently considered in the existing models of the evolution of cooperation.Considering the inequality in the number and payoff between the cooperative actors and recipients in cooperation systems,discriminative density-dependent interference competition will occur in limited dispersal systems.Our model and simulation show that the local but not the global stability of a cooperative interaction can be maintained if the utilization of common resource remains unsaturated,which can be achieved by density-dependent restraint or competition among the cooperative actors.More intense density dependent interference competition among the cooperative actors and the ready availability of the common resource,with a higher intrinsic contribution ratio of a cooperative actor to the recipient,will increase the probability of cooperation.The cooperation between the recipient and the cooperative actors can be transformed into conflict and,it oscillates chaotically with variations of the affecting factors under different environmental or ecological conditions.The higher initial relatedness(i.e.similar to kin or reciprocity relatedness),which is equivalent to intrinsic contribution ratio of a cooperative actor to the recipient,can be selected for by penalizing less cooperative or cheating actors but rewarding cooperative individuals in asymmetric systems.The initial relatedness is a pivot but not the aim of evolution of cooperation.This explains well the direct conflict observed in almost all cooperative systems.展开更多
基金supported by the National Basic Research Program of China (Grant No 2007CB411600)the National Natural Science Foundation of China (Grant Nos 30670272, 30770500 and 10761010)+1 种基金the Yunnan Natural Science Foundation (Grant No 2009CD104)the West Light Foundation of the Chinese Academy of Sciences and the National Social Science Foundation of China (Grant No 08XTJ001)
文摘Explaining the "Tragedy of the Commons" of the evolution of cooperation remains one of the greatest problems for both biology and social science.Asymmetrical interaction,which is one of the most important characteristics of cooperative systems,has not been sufficiently considered in the existing models of the evolution of cooperation.Considering the inequality in the number and payoff between the cooperative actors and recipients in cooperation systems,discriminative density-dependent interference competition will occur in limited dispersal systems.Our model and simulation show that the local but not the global stability of a cooperative interaction can be maintained if the utilization of common resource remains unsaturated,which can be achieved by density-dependent restraint or competition among the cooperative actors.More intense density dependent interference competition among the cooperative actors and the ready availability of the common resource,with a higher intrinsic contribution ratio of a cooperative actor to the recipient,will increase the probability of cooperation.The cooperation between the recipient and the cooperative actors can be transformed into conflict and,it oscillates chaotically with variations of the affecting factors under different environmental or ecological conditions.The higher initial relatedness(i.e.similar to kin or reciprocity relatedness),which is equivalent to intrinsic contribution ratio of a cooperative actor to the recipient,can be selected for by penalizing less cooperative or cheating actors but rewarding cooperative individuals in asymmetric systems.The initial relatedness is a pivot but not the aim of evolution of cooperation.This explains well the direct conflict observed in almost all cooperative systems.