FROM THE MUTATION THEORY TO THE THEORY OF THE MUTATION PROCESS

The main contributions to the biology made by N.V. Timofeev-Ressovsky and his co-authors (in “three gentlemen paper”, 1935) were: radiobiological approach to the mutation process, materialization of the gene as a macromolecule and foundation of molecular biology. These directions appeared as development of the template principle, offered previously by N.K. Koltzov, the teacher of Timofeev. Finally Timofeev formulated his principle of con-variant reduplication, which united two main biological features - inheritance and variations as a single one. Study of primary lesions and repair was added to the theory of mutations from this point of view. Nevertheless, we have no satisfactory definition of mutation so far and even contemporary classification of types of variations is contradictory now. The situation is explainable by the fact that the classification was introduced rather from the phenomenological approach than from the mechanisms underlying the variation phenomena. It is proposed to divide variations for two groups: those connected with replication of genetic material and those connected with expression of genetic information. This classification should be introduced without apriory division of variations on inherent and non-inherent because the same mechanisms may be involved both in inherent and non-inherent variations, depending upon taxonomic position and stage of ontogenetic development of the organism.