Figure 5.

A set of 80 random genotypes (times) was optimized for higher mutant diversity, conserving their phenotype (open circles). A hill-climbing process was performed with each one so that either the fraction of neutral mutants (μ) decreased, or the diversity of the different mutants (δ) increased. The initial average values of (0.63, 0.12), indicating very robust networks, were changed into (0.17, 0.29), suggesting the big differences in the sensitivity to mutations of genotypes within the same neutral network.