Evolution of metabolic fluxes and measures of optimality and predictability.

<p>We consider three ways to analyze changes in metabolism that relate an ancestor (Anc, blue) to an evolved isolate (E_i, green) in regard to an FBA-predicted optimum (Opt, red). A) Evolution of metabolic fluxes can be evaluated from the perspective of changes in proximity to the theoretical maximum for a given optimality criterion (Δ% Optimality). B) A vector of flux ratios defines a position in multi-dimensional flux space. One can then consider the relative Euclidian distance of a given evolved population in this space from its optimum (D_EO) compared to that of an ancestor from its optimum (D_AO; plotted as log(D_EO/D_AO)). C) At the most detailed level, one can compare the FBA-predicted value for a given flux ratio versus that observed via ¹³C labeling.