INVASION DYNAMICS OF THE FINITELY REPEATED PRISONERS-DILEMMA

Computer simulations have shown that mutation-selection processes freq uently lead to the establishment of cooperation in the repeated prison er's dilemma. To simplify the mathematical analysis, it has usually be en assumed that the interaction is repeated infinitely often. Here, we consider the finitely repeated case. Using renewal equations, we deri ve analytic results on the adaptive dynamics of monomorphic population s evolving in trait-space, describe the cooperation-rewarding zone and specify when unconditional defectors can invade. Tit for tat plays an essential, but transient, role in the evolution of cooperation. A lar ge part of the paper considers the case when players make their moves not simultaneously, but alternatingly. (C) 1995 Academic Press, Inc.