We evolve network topology of an asymmetrically connected threshold network
by a simple local rewiring rule: quiet nodes grow links, active nodes lose
links. This lends to convergence of the average connectivity of the networ
k towards the critical value K-c = 2 in the limit of large system size N. H
ow this principle could generate self-organization in natural complex syste
ms is discussed for two examples: neural networks and regulatory networks i
n the genome.