Smaldino Paul E, Schank Jeffrey C
Center for Advanced Modeling in the Social, Behavioral, and Health Sciences, Johns Hopkins University, 5801 Smith Ave, Davis Building, Baltimore, MD 21209, USA.
Theor Popul Biol. 2012 Aug;82(1):48-58. doi: 10.1016/j.tpb.2012.03.004.
The structure of social interactions influences many aspects of social life, including the spread of information and behavior, and the evolution of social phenotypes. After dispersal, organisms move around throughout their lives, and the patterns of their movement influence their social encounters over the course of their lifespan. Though both space and mobility are known to influence social evolution, there is little analysis of the influence of specific movement patterns on evolutionary dynamics. We explored the effects of random movement strategies on the evolution of cooperation using an agent-based prisoner's dilemma model with mobile agents. This is the first systematic analysis of a model in which cooperators and defectors can use different random movement strategies, which we chose to fall on a spectrum between highly exploratory and highly restricted in their search tendencies. Because limited dispersal and restrictions to local neighborhood size are known to influence the ability of cooperators to effectively assort, we also assessed the robustness of our findings with respect to dispersal and local capacity constraints. We show that differences in patterns of movement can dramatically influence the likelihood of cooperator success, and that the effects of different movement patterns are sensitive to environmental assumptions about offspring dispersal and local space constraints. Since local interactions implicitly generate dynamic social interaction networks, we also measured the average number of unique and total interactions over a lifetime and considered how these emergent network dynamics helped explain the results. This work extends what is known about mobility and the evolution of cooperation, and also has general implications for social models with randomly moving agents.
社会互动的结构影响着社会生活的许多方面，包括信息和行为的传播以及社会表型的演变。在扩散之后，生物体在其一生中四处移动，其移动模式会影响它们在整个生命周期中的社会交往。尽管空间和流动性都已知会影响社会进化，但对于特定移动模式对进化动态的影响却鲜有分析。我们使用一个基于主体的囚徒困境模型，其中主体具有移动性，来探索随机移动策略对合作进化的影响。这是对一个模型的首次系统分析，在该模型中，合作者和背叛者可以使用不同的随机移动策略，我们选择这些策略在探索性和搜索倾向的受限程度上形成一个范围。由于已知有限的扩散和对局部邻域大小的限制会影响合作者有效分类的能力，我们还评估了我们的研究结果在扩散和局部容量限制方面的稳健性。我们表明，移动模式的差异会极大地影响合作者成功的可能性，并且不同移动模式的影响对关于后代扩散和局部空间限制的环境假设很敏感。由于局部互动会隐含地生成动态社会互动网络，我们还测量了一生中独特互动和总互动的平均数量，并考虑这些涌现的网络动态如何有助于解释结果。这项工作扩展了我们对流动性和合作进化的认识，并且对具有随机移动主体的社会模型也具有普遍意义。
