Palla Ákos szerk.: Az Országos Orvostörténeti Könyvtár közleményei 37. (Budapest, 1965)

Tóth Tibor: The Variability of the Brain-Weight by Homo

THE VARIABILITY OF THE BRAINWEIGHT BY HOMO By TIBOR TÓTH (Budapest) T

he evolution of the brain, as we know, is a manifestation of one of the most important morphophysiological laws, aromorphosis (Severtzov, 1949) which, by steady interaction with increasingly intensive activity, raised man to an outstanding positionin the order of Primates. Undoubtedly, the brain — in addition to hands and soles — is one of the primary phylogenetic features of man. It is also recognized that Homo sapiens (which includes present man) evolving in the final period of anthropogenesis, forms a single species. It must be simultaneously noted that additional anthropological areals were formed in connection with the ecumenical increase of Homo sapiens, and by man developed secondary morphotaxonomical features. At the same time the evolution of the brain, together with the specific biological development of the hand, sole and the entire organism (in close relation to the increasingly complicated human activity), was complete at the time of the Upper Paleolithic. This implies that in the postglacial period (Holocene) no phylogenetic (macroevolutionary) transformations which could be considered essential in the mass and sructure of the brain. In the last decade extensive research—resulting in considerable individual variability of the mass of the brain (Kotshetkova, 1964) — has been done to illuminate the relation between the evolution of the brain and human activity. Naturally this variability continued during the last few milleniums along with the increase of humanity.