Figure 7.

RNA abstract phenotype robustness plots for various levels of coarse-graining for (a) RNA12 and (b) RNA15 models. ‘Dot-bracket’ structures are the standard folded RNA obtained from the ViennaRNA program [58] folding results. The subsequent levels of coarse-grained structures are then obtained from the RNAshapes program [57]. Level 1 is the first abstracted (coarse-grained) phenotype, including one or more dot-bracket structures based on coarse-grained topology. Level 2 includes phenotypes that are further coarse-grained from Level 1; Level 3 includes phenotypes that are even further coarse-grained, etc. In the case of RNA12, Levels 4 and 5 are identical because the Level 4 phenotypes are already coarse-grained as much as possible. Also plotted are the bricklayer’s bound indicating the maximum possible robustness, the null model robustness (equation (1.2)), and the minimum robustness for a phenotype that contains only one component (equation (4.1)); this would be the robustness of a star graph [25].