Evolutionary Game Theory in Growing Populations

Existing theoretical models of evolution focus on the relative
fitness advantages of different mutants in a population while the
dynamic behavior of the population size is mostly left
unconsidered. We present here a generic stochastic model which
combines the growth dynamics of the population and its internal
evolution. Our model thereby accounts for the fact that both
evolutionary and growth dynamics are based on individual
reproduction events and hence are highly coupled and stochastic in
nature. We exemplify our approach by studying the dilemma of
cooperation in growing populations and show that genuinely
stochastic events can ease the dilemma by leading to a transient
but robust increase in cooperation.