  Traditionally, resource limitation in evolutionary game theory is assumed
just to impose a constant population size. Here we show that resource
limitations may generate dynamical payoffs able to alter an original prisoner's
dilemma, and to allow for the stable coexistence between unconditional
cooperators and defectors in well-mixed populations. This is a consequence of a
self-organizing process that turns the interaction payoff matrix into
evolutionary neutral, and represents a resource-based control mechanism
preventing the spread of defectors. To our knowledge, this is the first example
of coexistence in well-mixed populations with a game structure different from a
snowdrift game.
