Molecular phylogenetic studies were initiated in Moscow University by A.N.Belozersky and his collaborators in the end of 50-ies. Nowadays the efforts of the staff of Department of evolutionary biochemistry are concentrated on the study of phylogenetic links of the main taxa of land plants and invertebrate animals and of molecular studies of microevolution. For this purpose various fragments of nuclear and chloroplast DNAs are sequenced and the results obtained employed for the construction of phylogenetic trees. The results are also used for further development of a new branch of systematics which is suggested to call genosystematics (Prof. A. Antonov, 1974). It follows from the results obtained that the adopted systems of these major groups of eukaryotes sometimes differ substantially from the results obtained by genosystematicists. When a phylogenetic tree of land plants was constructed basing on the results of sequencing of a fragment of chloroplast DNA it appeared that even the system of angiosperms needs to be revised. Dicots seem to be paraphyletic to monocots, and the earliest angiosperms were closer to paleoherbs than to woody Magnoliaceae. Bryophyta are to be subdivided into two monophyletic taxa, one of them including vascular plants.

Sequencing of 18S rRNA gene allows suggesting some principal changes in the adopted systems of invertebrate animals. For example, a group of Aschelminthes appeared to be a conglomerate of unrelated taxa. Contrary to a common knowledge, nematodes are a group close to higher invertebrates, etc. Genome variability study of different populations and species of some fish and mammal taxa lead to some hypothesis of a role of repeated DNA sequences in microevolution (Prof. B. Mednikov, 1995)

Summing up, in the recent years the efficacy of genosystematic approach was convincingly demonstrated in the studies of some hot problems of modern biology.

1. Samigullin T.H., Valiejo-Roman K.M., Troitsky A.V., Bobrova V.K., Filin V.R., Martin W., Antonov A.S. Sequences of rDNA internal transcribed spacers from the chloroplast DNA of 26 bryophytes: Properties and phylogenetic utility. FEBS Lett. (1998) 422, 47-51.

2. Goremykin V., Bobrova V., Pahnke J., Troitsky A., Antonov A., Martin W. Noncoding sequences from the slowly evolving chloroplast inverted repeat in addition to rbcL data do not support gnetalean affinities of angiosperms. Mol. Biol. Evol., (1996) 13, 383-396.

3. Antonov A. (1996) "Genosystematics." Chapter 11 In: Ratner V.et al. "Molecular Evolution", Springer, Wien.

4. Mednikov B.M., Bannikova A.A., Lomov A.A., Melnikova M.N., Shubina E.A., Restriction analysis of the repeated DNA sequenves: species criteria and species origin. Molec. Biol. (Moscow) (1995) 29, 1308-1319.

5. Aleshin V.V., Vladychenskaya N.S., Kedrova O.S., Milyutina I.A., Petrov N.B. Phylogeny of invertebrates: comparison of 18S rRNA gene sequences. Molec. Biol. (Moscow) (1995) 29, 1408-1426. 6. Troitsky A.V., Melekhovets Yu.F., Rakhimova G.M., Bobrova V.K., Valiejo-Roman K.M., Antonov A.S. Angiosperms origin and early stages of seed plant evolution. J. Mol. Evol., (1991) 32, 253-261.