Cytogenetics and Evolutionary Synthesis: A Tribute on an Anniversary of Academician I.I. Schmalhausen (1884–1963)

The name of Academician Ivan Ivanovich Schmalhausen (1884–1963), an outstanding evolutionist, Director of the A.N. Severtsov Institute of Evolutionary Morphology (IEM, 1936–1948)—now the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE)—is strongly associated not only with evolutionary morphology, the classical section of evolutionary teaching, in which he proved himself a brilliant experimenter and a major theorist. Schmalhausen is also recognized as one of the creators of evolutionary synthesis, although without personal participation in genetic work. He was interested in everything new that would accelerate the development of science, and, in particular, noted the “dizzying success” (his assessment) of cytogenetics, a new trend that arose in the synthesis of cytology with genetics and flourished literally before his eyes at a nearby institute headed by Academician N.I. Vavilov. The cytogenetic method is included in the modern practice of evolutionary and ecological work at IEE, and in this one can see the legacy of Academician I.I. Schmalhausen. The possibilities of comparative cytogenetics in relation to evolutionary issues are in the focus of this compilation using the example of a well-cytogenetically studied zoological object, a species of Palearctic mammal, the common shrew Sorex araneus L. and a group of related species. The participation of one of the categories of chromosomal rearrangements—whole arm fusions and fissions—is discussed as an inexhaustible source of evolutionary diversity of karyotypes of this supraspecific group. This allows us to correct the traditional point of view of early cytogeneticists and their contemporary evolutionists, who expressed doubt about the evolutionary novelty of interchromosomal rearrangements, which, as summarizes this paper, combined variability in fused chromosome arm combinations with genetic conservatism of the initial evolutionary elements.