Phenotypical Behavior and Evolutionary Slavery
  A new evolutionary solution to Prisoner Dilemma situations is proposed in this paper. A specific genetic code may have different phenotypes, meaning different strategies for different individuals carrying that gene. This means that, under the right parameters, it is a good evolutionary solution to create two types of phenotypes with different strategies, here called as leaders and servants. In this solution, servants always cooperate with the leaders and leaders never do with the servants. Inside the same class, the usual strategies apply. Possible applications of this solution are discussed. 
Andre C. R. Martins