Komarov Botanical Institute, Russian Academy of Sciences
197376 St.-Petersburg, Prof. Popov, 2
e-mail: ygamalei@mail.ru
Evolutionary prerequisites of dicots current ecological diversity are studied. Structural and functional differences of the taxa generations replacing one another under the influence of the planet climate changes are described. The results of comparison of plant groups belonging to different subclasses confirm the adaptive parallelism in the structural and functional evolution, as well as the relationship between adaptogenesis and climate changes in the Cenozoic. The supposition is made that the system of structural and functional traits of a taxon forms in compliance with climate specificity at the time and place of its establishment. Stability of plant species characters and their environmental requirements is corroborated by shift of species ranges in full accordance with habitat drift under climate changes influence. The similarity of evolutional and zonal series of dicots is shown. The present structural and functional diversity of taxa and ecosystems is considered to be a consequence of dissimilarity in their phylogenetic age. The conclusion is made that the current biological diversity is founded on historical diversity of habitats and plant species being phylogenetically adapted to them.
