  We observe the propagation of information in a system of self-replicating
strings of code (``Artificial Life'') as a function of fitness and mutation
rate. Comparison with theoretical predictions based on the reaction-diffusion
equation shows that the response of the artificial system to fluctuations (\eg
velocity of the information wave as a function of relative fitness) closely
follows that of natural systems. We find that the relaxation time of the system
depends on the speed of propagation of information and the size of the system.
This analysis offers the possibility of determining the minimal system size for
observation of non-equilibrium effects at fixed mutation rate.
