  We study the cooperation problem in the framework of evolutionary game theory
using the prisoner's dilemma as metaphor of the problem. Considering the
growing process of the system and individuals with imitation capacity, we show
conditions that allow to form highly cooperative networks of any size and
topology. Introducing general considerations of real systems, we reduce the
required conditions for cooperation to evolve approaching the benefit-cost
ratio r to the theoretical minimum r=1, when the mean connectivity of the
individuals is increased. Through the paper, we distinguish different
mechanisms that allow the system to maintain high levels of cooperation when
the system grows by incorporation of defectors. These mechanisms require
heterogeneity among individuals for cooperation to evolve. However, the
required conditions and heterogeneities are drastically reduced as compared to
those required for static networks.
