Autocatalyst selection

The speculations about bifurcation in autocatalytic systems lead us to conclude that the adaptive natural selection of biological systems analogue may have a primitive in analogue, and even in abiogenic autocatalytic, systems where chemical "mutations" of the autocatalyst may occur [2],... 

Let several "populations" of autocatalysts (a = 1, 2,. ..) that are generated by the same "food" R function simultaneously in the system. A decrease in R to the value R results in the complete "extinction" of those autocatalysts for which Rcra = 82a/sia < R. If the amount (concentration) of "food" then increases (i.e., if R rises), the populations of the extinct autocatalysts do not restore because of the disappearance of the respective autocatalyst inoculants. However, if the autocatalysts are capable of mutating toward a decrease in critical parameter Rcra, the inoculants of the autocatalysts with minimal R a can persist even at the reduced concentration of food. For this reason, the population of these selected autocatalysts will start growing with the increase in R, if any. In other words, an analogue of natural selection adapts the autocatalyst system to the conditions of "starvation in "food" R. 

Jarvis K, Parry S, Piper J (2001) Temporal and spatial studies of autocatalyst-derived platinum, rhodium, and palladium and selected vehicle-derived trace elements in the environment. Environ Sci Technol 35 1031-1036... 

The catalytic action of an en2 yme modifies the growth properties of an autocatalyst in the limit of high template concentrations exponential growth changes into linear growth. The competitive behaviour of different autocatalysts, however, was not affected by the enzyme, only the quantity which is selected for may be different under different conditions. 

Selection can be studied appropriately and in great detail under conditions which allow a straightforward mathematical analysis (Eigen and Schuster, 1979 Schuster et al., 1980). A convenient system, more elaborate than serial transfer experiments or stirred flow reactors, consists of an evolution reactor (Fig. 12) which allows to control the concentrations of all important reactants or products. In the simplest case we keep these concentrations constant as well as the sum of all concentrations of polynucleotides. Then, the relative concentrations of autocatalysts are the only remaining variables. 

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