Fig. 5.

Example of how rare chemical reactions, such as the localized production of C₄ or C₅ by a rare reaction between waste products from the original catalytic set and low-abundance food species, could expand the self-propagating system, resulting in movement of a pixel to a new metastable state (with high concentrations of C₄ and C₅). It is supposed that the newly formed non-food species C₄ and C₅ cross-catalyze one another formation and tend to attach to the same mineral surface as C₁, C₂ and C₃. The chemical conversion of food to catalyst plus waste is represented with solid arrows, while dotted lines indicated catalysis.