Efeitos locais na evolução da cooperação

• Ano de defesa: 2019
• Autor(a) principal: Elton José da Silva Júnior
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: heterogeneidade; dilema do prisioneiro; teoria de jogos evolutivos; Cooperação; Teoria dos jogos
• Link de acesso: http://hdl.handle.net/1843/SMRA-BDVMZG

Cooperative phenomena has been mainly studied under the light of evolutionary game theory. Such behavior is puzzling because cooperating implies in paying a cost to generate benefits to another one, among other reasons. So cooperators might be the focus of exploiters¿ actions, which indicates that altruism could not thrive. However we observe cooperation in several instances and contexts in nature, from cooperative organellas working together constituting a cell to lots of individuals living as huge societies. Prisoner¿s dilemma game is often used to illustrate the cooperation issue. Individuals interact with each other adopting strategies like cooperation (C) and defection (D). In evolutionary game theory strategies are associated with species and payoffs coming from each interaction between players are associated with fitness (interpreted as reproductive success). In this way we can study the evolution of fractions of individuals that adopt a specific strategy in a population depending on parameters of our model. This work is composed by two studies approaching the role played by local features in the evolution of cooperation. In the first study we analyze a type of spacial heterogeneity in which individuals might be located in spots that do not offer enough resources in other to a player cooperates. These spots are called inactive sites. We found that cooperation level in a population is directly related to both fraction of active sites and temptation to defect. Inactivity can promote or not promote cooperation depending on that parameters. In the second study we analyze the effects of population density on the evolution of cooperation by modeling a intrinsic death rate over individuals. Our results reveal the dependency of level of cooperation on both death rate and tendency to defect; cooperative behavior is enhanced by moderate death rates. We intend adding to this model the migratory process and investigate how it can impact on cooperation.