  Cooperation is observed widely in nature and is thought an essential
component of many evolutionary processes, yet the mechanisms by which it arises
and persists are still unclear. Among several theories, network reciprocity --
a model of inhomogeneous social interactions -- has been proposed as an
enabling mechanism to explain the emergence of cooperation. Existing
evolutionary models of this mechanism have tended to focus on highly
heterogeneous (scale-free) networks, hence typically assume preferential
attachment mechanisms, and consequently the prerequisite that individuals have
global network knowledge. Within an evolutionary game theoretic context, using
the weak prisoner's dilemma as a metaphor for cooperation, we present a minimal
model which describes network growth by chronological random addition of new
nodes, combined with regular attrition of less fit members of the population.
Specifically our model does not require that agents have access to global
information and does not assume scale-free network structure or a preferential
attachment mechanism. Further our model supports the emergence of cooperation
from initially non-cooperative populations. By reducing dependency on a number
of assumptions, this model offers broad applicability and as such may support
an explanation of the emergence of cooperation in early evolutionary
transitions, where few assumptions can be made.
