The evolution of mutualism from reciprocal parasitism: more ecological clothes for the Prisoner’s Dilemma

摘要: Many mutualisms involve reciprocal exploitation, such that each species in a mutualism is consumer of resource provided by the other. Frequently, are reformed generation, and where they close physiological contact, as between mycorrhizal fungi plants, can be considered examples parasitism. Here we place interactions framework Prisoner’s Dilemma, examine conditions for spread using population genetics model analogous to used understanding genetic numerical dynamics host-parasite interactions. Genetic variants within two determine whether interaction mutualistic or selfish, latter being represented resistance exploited parasitized. We assume there fitness costs which present even absence interaction. Just interactions, effect assuming encounter rates potential mutualists (and therefore entry into Dilemma ‘game’) depend on density frequency different types interacting individuals. These elements ecological realism greatly facilitate evolution spatial structure iterative encounters. Moreover, stable polymorphisms resistant (selfish) susceptible (mutualistic) alleles maintained, something not possible with classical formulation. The sensitivity outcomes levels density-dependence mortality rate suggests environmental well processes likely important determining directions this pathway mutualism.