In 1974, the Nauka Publishing House in Moscow, under the stamp of the USSR Academy of Sciences and the A. N. Severtsov Institute of Evolutionary Morphology and Ecology of Animals, published a book by V. N. Orlov entitled "Karyosystematics of Mammals". The subtitle of the book read: "Cytogenetic Methods in the Taxonomy of Mammals". The fairly quick release of the monograph, 6-7 years after the first journal publications by domestic authors and 5 years after the organized presentation of the country's karyologists at the II All-Union Conference on Mammals in Moscow (December 1969), confidently marked the emergence of a new direction in the genetic profile in zoology in general and at the Institute in particular. The author of the book, zoologist of the Moscow State University School Viktor Nikolaevich Orlov, his students and employees, over half a century of tireless work with cytogenetic, and then genetic methods, made a significant contribution to the modernization of the species system of modern mammals. Specific changes in the systematic composition of 19 Palearctic genera were recently restructured in a large review by Orlov et al. (2023). The work was published in a special issue of the Zoological Journal dedicated to a triad of anniversaries - the 50th anniversary of the Theriological Society of the Russian Academy of Sciences, the 90th anniversary of its founder Academician V.E. Sokolov, and the 300th anniversary of the Russian Academy of Sciences.
The half-century anniversary of the book is an integral part of the great scientific history of the A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences (IEE RAS), which recently celebrated its 90th anniversary.