[Old problems of new bacterial systematics].
This review analyzes the situation that arose after the existence of adaptive mutations had been proven. Manifold acceleration of the mutation process and intragenome rearrangements in nondividing cells demonstrates the inapplicability of the theory of neutral evolution to bacteria, the lack of isochronism between the evolution of individual macromolecules and the organism as a whole, and thus, the invalidity of using rRNA homologies as markers of the position of the organism in the phylogenetic tree and in the taxonomic system.