Thompson Eli, Everett Jasmine, Rowell Jonathan T, Rychtář Jan, Rueppell Olav
Department of Mathematics, Miami University, Oxford, OH 45056, USA.
Department of Mathematics, Bennett College, Greensboro, NC 27401, USA.
Lett Biomath. 2015;2(1):67-78. doi: 10.1080/23737867.2015.1090890. Epub 2015 Oct 22.
Evolutionary Game Theory and the Prisoner's Dilemma (PD) Game in particular have been used to study the evolution of cooperation. We consider a population of asexually reproducing, age-structured individuals in a two-dimensional square lattice structure. The individuals employ fixed cooperative or defecting strategies towards their neighbors in repeating interactions to accumulate reproductive fitness. We focus on the effects of the persistence of past interactions and interactive neighborhood size on the evolution of cooperation. We show that larger neighborhood sizes are generally detrimental to cooperation and that the persistence of fitness effects decreases the likelihood of the evolution of cooperation in small neighborhoods. However, for larger neighborhood sizes the persistence effect is reversed. Thus, our study corroborates earlier studies that population structure increases the evolutionary potential for cooperative behavior in a PD paradigm. This finding may explain the heterogeneity of previous results on the effect of neighborhood size and cautions that the persistence of fitness outcomes needs to be considered in analyses of the evolution of cooperative behavior. The persistence of fitness outcomes of pairwise interactions may vary dramatically in biological and social systems and could have profound effects on the evolution of cooperation in various contexts.
进化博弈论，尤其是囚徒困境博弈，已被用于研究合作的进化。我们考虑一个处于二维方格结构中的无性繁殖、具有年龄结构的个体群体。个体在重复互动中对其邻居采用固定的合作或背叛策略，以积累繁殖适应性。我们关注过去互动的持续性和互动邻域大小对合作进化的影响。我们表明，较大的邻域大小通常对合作不利，并且适应性效应的持续性会降低小邻域中合作进化的可能性。然而，对于较大的邻域大小，持续性效应则相反。因此，我们的研究证实了早期的研究结果，即种群结构增加了囚徒困境范式中合作行为的进化潜力。这一发现可能解释了先前关于邻域大小影响的结果的异质性，并提醒在分析合作行为的进化时需要考虑适应性结果的持续性。两两互动的适应性结果的持续性在生物和社会系统中可能会有很大差异，并且可能对各种背景下的合作进化产生深远影响。
