Metabolisms viable on multiple carbon sources and genotypic differences among them.

<p><b>a)</b> Average number of metabolisms per genotype network that are viable on <i>k</i> carbon sources for 1 ≤ <i>k</i> ≤ 10. Each curve corresponds to one value of <i>k</i> and is colored as indicated in the legend. <b>b)</b> Fraction of metabolisms viable on <i>k</i> carbon sources. Note the logarithmic scale. Data on ten carbon sources in a) and b) has been previously published [<a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1004329#pcbi.1004329.ref019" target="_blank">19</a>]. <b>c)</b> Genotype network diameter. Black circles indicate the diameter of genotype space for metabolisms of a given size, which is an upper bound to the diameter of any one genotype network. Colored data points indicate the median of the diameter of the genotype networks of metabolisms viable on <i>k</i> carbon sources. At <i>n</i> ≥ 40, almost all genotype networks have the maximally possible diameter. <b>d)</b> Fraction of metabolisms that are viable on <i>k</i> carbon sources and contain no disconnected reactions.