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Abstract

The values of some morpho-anatomical features (the size and shape of the epidermic cells of the leaves, as well as the size and features of the stomata) recorded in some fossil vegetal species and their actual correspondent species were analysed. These differences offer information about the evolution process. In the case of the analysed species (Ginkgo sp., Taxus sp., Magnolia sp. and Buxus sempervirens), two hypotheses concerning the genetic mechanisms involved in evolution and in the speciation processes or in the adaptation to the environmental conditions can be considered. These genetic mechanisms are: the multiplication of genomes and the process of gene amplification. They both result in an increase in epidermic cells and stomata size, as well as in the enzymatic activity, which determines a better adaptation to the environmental conditions, as well as to the settlement of the speciation process.

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