Fig. 6.

Phase space for signaling networks with mixing of two Boolean rules. We systematically calculate the exponent α, characterizing the correlations in the dynamics, for systems composed of units operating according to either rule 232 or 50. Each value is an average over five independent runs. (a) One-sixteenth of the units operating according to rule 50 and 15/16ths of the units operating according to rule 232. (b) One-eighth of the units operating according to rule 50 and seven-eighths of the units operating according to rule 232. (c) One-fourth of the units operating according to rule 50 and three-fourths of the units operating according to rule 232. (d) One-half of the units operating according to rule 50 and one-half of the units operating according to rule 232. When both rules are present in the system, and at least 50% of the units operate according to rule 232, we still find several distinct classes of dynamical behaviors, including a wide range of parameter values that generate 1/f noise.