  We propose the characterization of binary cellular automata using a set of
behavioral metrics that are applied to the minimal Boolean form of a cellular
automaton's transition function. These behavioral metrics are formulated to
satisfy heuristic criteria derived from elementary cellular automata. Behaviors
characterized through these metrics are growth, decrease, chaoticity, and
stability. From these metrics, two measures of global behavior are calculated:
1) a static measure that considers all possible input patterns and counts the
occurrence of the proposed metrics in the truth table of the minimal Boolean
form of the automaton; 2) a dynamic measure, corresponding to the mean of the
behavioral metrics in $n$ executions of the automaton, starting from $n$ random
initial states. We use these measures to characterize a cellular automaton and
guide a genetic search algorithm, which selects cellular automata similar to
the Game of Life. Using this method, we found an extensive set of complex
binary cellular automata with interesting properties, including
self-replication.
