Plant Life Evolution: Opinios and Suppositions
M.V. Lomonosov Moscow State University, Biology Faculty, Department of Geobotany 119899 Moscow
e-mail: shmylev@herba.msu.ru
Evolution of plant life has been considered in the context of phylembryogenesis or heterochronia. However, suggested opinions and suppositions regarding the mechanisms, direction and rate of evolutionary changes are opposite. Concepts of phylembryogenesis and heterochronia originally were developed for the different levels of organization and could be distinguished by different modes of morphological evolution. In this connection, interpretations of evolutional changes of shoots morphogenesis, ontogenesis and plant habitus by different types of heterochronia and modes of phylembryogenesis were delineated. It was proposed that evolution of plants life forms could be considered regarding functional specialization of root-shoot (the basic element of life form structure) that appears as metamorphoses of bud, root and shoot. Evolutional changes of root-shoot could take places at the different stages of development due to anabolies (modifications). At the same time epigenetic and episelectional (organic selection) mechanisms of evolution play an important role in the evolution of plant life forms. Moreover, results of modern genetic and molecular phylogenetic investigations produce evidences for the saltations and reversions in the plant life forms evolution.
