Operational description of microsystems formation in prebiological molecular evolution.

A theoretical analogue of microsystems formation in prebiological molecular evolution, known, for instance, as microspheres of Fox and marigranules of Yanagawa and Egami, is presented for a model solution system of polyamino acids in which the polymerization due to peptide bond synthesis is initially not in a complete balance with the hydrolysis. The homogeneous solution of polyamino acids, which is in a nonequilibrium state in the sense that a complete balance among all the participating reactions has not yet been established, is unstable against forming microscopic compartments of locally condensed peptide bond linkages. It also follows that both the accumulation of polyamino acids and the number of peptide bond linkages inside the localized microsystems increase with time so long as the solution remains in a nonequilibrium state lacking the balance between the polymerization and the hydrolysis. The phase separation of microsystems from the homogeneous solution of polyamino acids is just a representation of the unidirectional dynamic process that any reaction system, which initially lacks a complete balance among all the participating reactions, evolves toward a goal, if any, at which an equilibrium balancing of reactions be finally established.