An important gap in the relation between artificial evolutionary
systems and their biological counterpart is the inability of
artificial models to construct functional
hierarchical
structures in an
emergent
way. For composite structures to emerge
and prosper in a biological hierarchical system, some form of
selection is required at each level . In this paper we examine an
abstract model of immune networks in terms of the selection dynamics
present at the individual level and at the network level. In this
context, a property of the individuals is examined in relation to
its impact on the reproductive succes on the individual and network
level.