Figure portrays the change of network structure en route from a randomly seeded initial assembly (left) to the self-reproducing attractor (right). While the seeded nonreproducing network contains 64 types of molecules, the target reproducing attractor has only 16. Such repertoire diminution happens in all different 10,000 examined β-matrices of catalytic values (Figure ). Further, the efficacy of attractor attainment is rather similar across a range of diminished chemical repertoires (MR < 1000 chemical steps) (Figure ). Thus, it appears that catalytic networks may reach a self-reproducing state by repertoire "distillation" and without a need for repertoire augmentation, a cornerstone of the CAS model . The distillation is shown in Figure ,C, depicting an enrichment of high catalytic values in the attractor as compared to the original distribution. The concept of repertoire diminution en route to more effective catalytic network is also inferred in a different network model , showing that a minimum network with essential components would achieve a higher reproduction rate. The emerging diminution is reminiscent of the transition from prebiotic messy chemistry (1) to life, as exemplified by the fact that living cells utilize a small subset of the possible assortment within compound classes such as amino acids, sugars and lipids . In both simulated prebiotic systems and present day cells this repertoire attenuation is associated with reduced entropy .