title: Selection and evolution in macromolecular systems.
abstract: The notion of a quasi-species represents the ensemble of macromolecular sequences derived by the mechanism of mutation and replication from a single wild type. In Eigen (1971) and Eigen & Schuster (1979), the deterministic evolution of this ensemble under constant environmental conditions is given in terms of continuous models which describe the dynamics of the distribution of polynucleotides. This paper starts from a discrete model of macromolecular evolution and introduces the notion of a genealogy in order to study the dynamics of the quasi-species in constant and variable environments. We introduce, in terms of these genealogies, the notions of entropy and adaptive value of a quasi-species and the notion of capacity of the environment. We discuss the significance of these indices as measures of selective value and we analyse the conditions under which these measures coincide with the growth rate of the quasi-species.
mesh_terms: D001483:Base Sequence; D005075:Biological Evolution; D005789:Genealogy and Heraldry; D046911:Macromolecular Substances; D008954:Models, Biological; D009154:Mutation; D012313:RNA / Q000096:biosynthesis; D012641:Selection, Genetic
chemical_list: D046911:Macromolecular Substances; D012313:RNA