SHMALHAUZEN, IVAN IVANOVICH

(b. Kiev, Russia, 23 April 1884; d. Moscow, U.S.S.R., 7 October 1963)

biology.

The son of a professor of botany at Kiev University, Shmalhauzen graduated from the natural sciences section of the Physics and Mathematics Faculty of Kiev University in 1909. He remained there as assistant to A. N. Severtsov until 1911, passed his master’s degree examination in 1912, and in 1914 presented his thesis, “Neparnye plavniki ryb; ikh filogeniticheskoe razvitie” (“Unpaired Fins of Fish; Their Phylogenetic Development”), at Moscow University. In 1916 Shmalhauzen defended his doctoral dissertation, “Razvitie konechmostey amfiby i ikh znachenie v voprose proiskhozhdenia nazemnykh pozvonochnykh” (“The Development of Extremities in Amphibians and Their Significance in the Origin of Land Vertebrates”). He was professor at Yuriev (Tartu) University, from 1916 to 1920 and headed the department of embryology and dynamics of development at Kiev from 1920 to 1937. At Kiev he organized the Biological Institute (later the Institute of Zoology) at the Ukrainian Academy of Sciences and was its director from 1941. From 1936 to 1948 Shmalhauzen was director of the A. N. Severtsov Institute of Evolutionary Morphology and of the Academy of Sciences of the U.S.S.R. and was head of the department of Darwinism at Moscow University from 1939 to 1948. During his last years he worked at the Zoological Institute of the Academy of Sciences. He was elected academician of the Ukrainian Academy of Sciences (1922) and of the Academy of Sciences of the U.S.S.R., (1935).

Beginning his scientific career as a comparative anatomist, Shmalhauzen later expanded his research to the study of individual development and directed research in experimental embryology. Studying the growth of animals, he formulated a theory of growth according to which that process has an exponential character exhibiting an inverse relationship between growth and differentiation: attenuation of growth is described by a parabolic curve, since the specific rate of growth decreases in inverse proportion to age. During various distinct periods of individual life the energy of growth can be expressed by the constant of growth C_v, for the computation of which Shmalhauzen proposed the formula constant, where ν₀ and ν₁ are the mass of the body at the moments t₀ and t₁. He later studied the correlations of growth in individual and historic development that are the basis of the integrity of the organism and arise through the effect of natural selection.

In specialized monographs (1938, 1939, 1946) Shmalhauzen examined the course and regularities of the evolutionary process. In particular he provided a basis for classifying the types of natural selection. He established, in addition to an “active” natural selection that stabilizes mutational changes favoring survival under changed conditions, the existence of “stabilizing” natural selection. The latter preserves “normal” characteristics and eliminates deviations as long as the environment remains relatively unchanged. In the process of stabilizing selection “under the cover of the normal phenotype,” recessive or balancing genes accumulate; with environmental changes they can serve as material for “active” natural selection.

In 1938, while studying the relations that exist in ontogeny and in phylogeny, Shmalhauzen suggested the idea, later (1968) substantiated in detail, that methods of cybernetics might be applied to the study of ontogenetic and phylogenetic development. His many years of teaching resulted in tex-tbooks on comparative anatomy and on Darwinism. During the last years of his life Shmalhauzen resumed the study of the origin of land vertebrates and published a monograph on that subject (1964).

BIBLIOGRAPHY

I. Original Works. Shmalhauzen wrote more than 200 works, including the following monographs: Rost organizmov (“The Growth of Organisms”; Kiev, 1932), in Ukrainian: Organizm kak tseloe v individualnom i istoricheskom razvitii (“The Organism as a Whole in Individual and Historical Development”: Moscow–Lenin-grad, 1938; 2nd ed., 1942); Puti i zakonomernosti evolyutsionnogo protsessa (“The Ways and Regularities of the Evolutionary Process”; Moscow-Leningrad, 1939); Faktory evolyutsii. Teoria stabiliziruyushchego atbora (“Factors of Evoluation. Theory of Stabilizing Selection”; Moscow–Leningrad, 1946; 2nd ed., 1968); also in English trans. (Philadelphia, 1949); Proiskhozhdenie nazemnykh pozvonochnykh (“The Origin of Terrestrial Vertebrates”; Moscow, 1964), also in English trans. (New York, 1968); and Kiberneticheskie voprosy biologii (“Cybernetic Questions of Biology”: Novosibirsk, 1968).

II. Secondary Literature. See A. A. Makhotin, “Ivan Ivanovich Shmalhauzen (1884–1963),” in Zoologicheskii zhurnal, 43 , pt. 2 (1964), 297–302; and L. P. Tatarinov and B. A. Trofimov, “Akademik Ivan Ivanovich Shmalhauzen (1884–1963),” in Paleontologicheskii zhurnal (1964), no. 2, 169–173.

L. J. Blacher