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 competitive replication. Using a fundamental theorem of natural selection and maximum principle scaled to nucleotide condensation, evolution in vitro was demonstrated to maximally damp both kinetic and thermodynamic forces driving this reaction, from its pre-replication stage. This led 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 non-interacting RNA molecules. It applies, in particular, to standard processes, such as competitive crystallization. In calculations simulating de novo formation of self-replicating RNA molecules in the Qbeta replicase system, spontaneous changes in strand secondary structure promoted the transition from random copolymerization to template-directed polymerization. This finding indicates selection preceded genome self-propagation. Non-gradual species formation was attributed to the presence of heterogeneous thermodynamic forces. Growth unconstrained by competition follows 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 species populations. Natural selection among competing self-propagators thus gives way to a principle of wider scope stating that evolution optimally damps the physicochemical forces causing change within an evolving system.
Davis
B K
BK
Research Foundation of Southern California, La Jolla 92037, USA.
D005075:Biological Evolution; D008433:Mathematics; D008962:Models, Theoretical; D011777:Q beta Replicase / Q000378:metabolism; D012313:RNA / Q000096:biosynthesis; D013698:Templates, Genetic; D013816:Thermodynamics
D012313:RNA; D011777:Q beta Replicase