  Evolutionary mechanism in a self-organized system cause some functional
changes that force to adapt new conformation of the interaction pattern between
the components of that system. Measuring the structural differences one can
retrace the evolutionary relation between two systems. We present a method to
quantify the topological distance between two networks of different sizes,
finding that the architectures of the networks are more similar within the same
class than the outside of their class. With 43 cellular networks of different
species, we show that the evolutionary relationship can be elucidated from the
structural distances.
