St.-Petersburg Department, Institute of the History of Science and Technics, Russian Academy of Science, Universitetskaya naberezhnaya 5/2, St.-Petersburg 199164, Russia

Abstract

Before the theory of "Evolutionary Synthesis" the investigation of geographic variability were related to the development of different evolutionary conceptions - Lamarkism, Darwinism, mutationism and, rarely, orthogenesis. The geographic differences were explained by the environmental influence (direct or mediated by selection), isolation or changes in intragroup variability, while this group is spreading from the centre of its origin. Some new principles of systematics and theories of evolution (heterogenesis theory, Formenkreislehre, "age and area" hypothesis, theory of isolation) were resulted from study of geographic variability. Among the 'architects" of the "Evolutionary Synthesis" theory there was no agreement on the meaning of geographical variability and the related phenomena. Various ideas concerning species concept, geographic isolation and the meaning of the geographic speciation were developed in terms of the "Evolutionary Synthesis". The advocates of this theory did not considered the problem of geographic speciation as resolved despite the large body of data on geographic variability.