Table 1. Network properties and robustness compiled from all networks resulting from 100 simulations for each of the evolutionary scenarios.

	M1	M2	R	V	M1fromV	M2fromV	RfromV
N Independent Fluxes	1.3	1.4	1.2	4.1	1.4	1.5	1.6
N Enzymes	545	542	509	724	596	600	587
N Multifunctional Enzymes	48	49	35	177	21	32	31
Avg. Robustness per Multifunctional Enzyme	0.890	0.874	0.935	0.677	0.886	0.929	0.893
Avg. Robustness per Monofunctional Enzyme	0.078	0.104	0.127	0.416	0.210	0.111	0.134
Avg. Robustness For Networks With Multifunctional Enzyme	0.281	0.297	0.338	0.614	0.263	0.313	0.427
Avg. Robustness For Networks Without Multifunctional Enzyme	0.046	0.070	0.096	0.382	0.082	0.102	0.242

The columns labeled M1, M2, R, and V display results from networks evolved under the two minimal media, the rich media and the fluctuating media respectively. The last three columns show results of continued evolution of those networks, which were obtained under fluctuating evolution, in stable media M1, M2 and R. Multifunctional enzymes are defined as those, which can catalyze more than one group transfer reaction (see Methods ). Shown robustness values for networks evolved under fluctuation environment are those measured under rich media.