A THEORY OF EVOLUTION THAT INCLUDES PREBIOTIC SELF-ORGANIZATION AND EPISODIC SPECIES FORMATION

A theory has been proposed that encompasses pre-replication changes in RNA synthesis and non-gradual variant formation, in addition to compe titive replication. Using a fundamental theorem of natural selection a nd maximum principle scaled to nucleotide condensation, evolution in v itro was demonstrated to maximally damp both kinetic and thermodynamic forces driving this reaction, from its pre-replication stage. This le d to the finding that evolution follows a path of least action. These principles form the framework for a general theory of evolution, whose scope extends beyond evolution modeled by synthesis of noninteracting RNA molecules. It applies, in particular, to standard processes, such as competitive crystallization. In calculations simulating de novo fo rmation of self-replicating RNA molecules in the Q beta replicase syst em, spontaneous changes in strand secondary structure promoted the tra nsition from random copolymerization to template-directed polymerizati on. This finding indicates selection preceded genome self-propagation. Non-gradual species formation was attributed to the presence of heter ogeneous thermodynamic forces. Growth unconstrained by competition fol lows mutation to a variant able to utilize a free energy source alien to its progenitors. Evolution in a heterogeneous system can, therefore , exhibit discontinuous rates of species formation and spawn new speci es populations. Natural selection among competing self-propagators thu s gives way to a principle of wider scope stating that evolution optim ally damps the physicochemical forces causing change within an evolvin g system.