1900-1975
Theodosius Dobzhansky, born in the town of Nemirov in the Ukraine on January 25, 1900, was one of the most influential biologists of the twentieth century. He is generally regarded as the pioneer of evolutionary genetics, a field established in the 1930s that sought to integrate Darwinian selection theory with Mendelian genetics. Much of this work was summarized in Dobzhansky’s magnum opus, Genetics and the Origin of Species, published in 1937. It was so influential and widely read that it is regarded as the first "textbook" of evolutionary biology in the twentieth century.
The only child of Sophia Voinarsky and Grigory Dobrzhansky, a high-school mathematics teacher, Dobzhansky early on manifested an interest in natural history and collected insects and especially butterflies in the area of Kiev. He attended the University of Kiev and graduated in 1921 with a major in biology. He subsequently accepted a position on the faculty of agriculture at the Polytechnic Institute of Kiev, where, through the influence of plant geneticist Gregory Levitsky, Dobzhansky’s interests shifted from the systematics of insects like the ladybird beetle (the Coccinelidae) to the newer areas of genetics. Levitsky was part of a wider scientific movement in the Soviet Union that included such individuals as Nikolai Ivanovich Vavilov (1887-1943) and Sergei Chetverikov (1880-1959). These scientists were following efforts in American genetics to understand the mechanism of Mendelian heredity through model organisms, such as the fruit fly (Drosophila sp.). In 1924 Dobzhansky moved to Leningrad (Saint Petersburg), where he became a lecturer in genetics under the wing of Yuri Filipchenko and where he continued to study genetics by turning to basic laboratory studies of Drosophila melanogaster. At this time, he married a coworker in genetics, Natalie (or "Natasha") Sivertsev, who was to be his lifelong companion and coworker; they had one daughter, Sophie.
In 1927 Dobzhansky accepted a fellowship from the Rockefeller Foundation to study genetics with the American leader in the area, Thomas Hunt Morgan (1866-1945), and his group of fly geneticists at Columbia University, a group that included A. H. Sturtevant (1891-1970), Calvin Bridges (1889-1938), and H. J. Muller (1890-1967). While working as an assistant to Morgan, Dobzhansky learned of the latest techniques and insights into understanding the cytogenetics of the fruit fly. In 1928 Dobzhansky moved to the California Institute of Technology with Morgan and subsequently became assistant professor of genetics in 1929.
Dobzhansky’s most notable breakthrough was made in 1933 when he started working with the geographically diverse Drosophila pseudoobscura. He also began to combine the laboratory methods common to the Morgan group with his interests in systematics and biogeography, which reflected his earlier Russian training. His research into the evolutionary history of this complex group of flies was aided by his novel use of the giant salivary or polytene chromosome, which permitted the reconstruction of the phylogenetic history of the model organism. This research formed the backbone of what became known as the genetics of natural populations (GNP) series, a set of studies published as papers and monographs that explored the range of species, races, and varieties of this group of flies and that sought to understand the process of speciation in genetic terms. It also informed Dobzhansky’s 1937 book, his increasing independence from Morgan’s fly group, and his interaction with American mathematical theorist Sewall Wright (1889-1988).
By the late 1930s Dobzhansky was recognized as one of the central figures in the "new" or "modern" synthesis of evolution that integrated Darwinian selection theory and natural history with laboratory methods and insights gleaned from Mendelian genetics. Dobzhansky increasingly drew younger workers to him, and developed an international reputation for being a "charismatic" mentor.
In 1940 he accepted a position at Columbia University, where he continued his research on Drosophila. In the 1950s his interests took a more global direction when he traveled to South America to study the speciation patterns in tropical Drosophila. In 1962 he moved yet again to Rockefeller University, where he remained until his retirement in 1970.
Dobzhansky’s interests were broad and included the application of genetics to evolution and to the understanding of human beings. He wrote extensively, especially in his later years, on subjects with anthropological and philosophical themes. His synthesis of evolution and cultural anthropology appeared in 1962 under the title Mankind Evolving. In 1967 he revealed his lifelong interest in the existential aspects of evolution and in traditional religious concerns in The Biology of Ultimate Concern.
Becoming one of the most famous Soviet emigres in the United States, Dobzhansky closely monitored the progress of science in the Soviet Union and was especially active in campaigning against biologist Trofim Lysenko (1898-1976) and his destructive policies against Soviet genetics. Despite his feeling a strong connection to his first home, Dobzhansky was never allowed to return there.
Following his retirement, Dobzhansky moved to the University of California in Davis, where he continued to supervise an active group of geneticists. He died there on December 18, 1975, after a long battle with leukemia. Although he was closely associated with the newer evolutionary biology of the twentieth century, he remained fundamentally religious and was an active member of the Russian Orthodox Church.
