Population biology of the first replicators: on the origin of the genotype, phenotype and organism.

Prebiotic synthesis of short length macromolecules from precursor molecules results in a dynamic of spontaneous creation, which allows for growth from zero density. At this prereplicator stage in the evolution of life there is no life history, since the birth and death processes are intimately coupled through the physical chemistry of a single reaction. With the emergence of nonenzymatic, template-directed replication, the birth and death processes could diverge for the first time, since selection could act differently on the birth and death rates of the replicating molecule. Thus, with replication, natural selection and life-history evolution began. The genotype, or nucleoitide sequence, of the replicating molecule gave rise to several phenotypic properties, the most important of which was its 3-dimensional structure which in turn affected the birth and death processes. For divergence of the phenotype from the genotype it was necessary for the replicator to produce a protein. The evolution of enzyme production is facilitated by the existence of population structure in the distribution of the macromolecules associated with replication. The organism was one extreme of the population structure of the macromolecules associated with life. The organism was the culmination of the encapsulation phase of evolution which proceeded through initial phases of passive localization. -from Author