The ribotype theory on the origin of life

The ribotype is defined as the ribonucleoprotein system of any cell. The theory substitutes the genotype-phenotype duality with the trinity genotype-ribotype-phenotype, and proposes that life on earth originated with the ancestors of today's ribotypes.The first three chapters describe separate models on precellular evolution, the evolution of protocells and the nature of the cell respectively, and the unity of the theory comes from the fact that they form a consistent and interdependent whole.The core of the theory is the ribotype hypothesis, of which two formulations are given. The restricted version is based on a link between ribotypes and ribosome biogenesis, and provides an explanation for the difference between 70S and 80S ribosomes. The general version describes a link between ribotypes and cell-types and explains why prokaryotes have 70S ribosomes, eukaryotes 80S ribosomes and endosymbionts a type of ribosomes similar to the bacterial ones.If the creation hypothesis, panspermia and spontaneous generation are set aside, all alternative models of the origin of life belong to two schemes which are referred to as the genotype and the phenotype theories. It is shown that these theories rely on some discontinuity between past and present biological principles because of the need to break their inherent chicken-and-egg paradoxes, while the ribotype theory does not. Its hypotheses, free and arbitrary as they are or appear to be, have been built exclusively on properties and processes for which solid evidence exists, and the continuity between past and present biological laws is assumed as a corollary. Finally, it is shown that falsification tests are possible, and some of them are expected in the relatively near future.