For modelling natural phenomena by a cellular automaton (CA), it is necessary to introduce "imperfections". This simple Demonstration subjects elementary cellular automata to a stochastic perturbation.
Set the rule number of the elementary CA with the top slider. In the case of an elementary CA, there are eight bits in the rule icon; the row of buttons sets how many of them can mutate, that is, to flip one bit. At each step in the evolution of the perturbed CA, the original rule and the current row of cells are perturbed according to the given probabilities.