Theodosius Dobzhansky: Biography of this Ukrainian geneticist

Although the twentieth century began with the widely held modern theory of Darwinian evolution, there was much doubt about how natural selection came about. The inheritance of traits was something very recent study and Mendel’s work was still very unknown to the scientific community.

Genetics was emerging and one of its most famous scholars was Theodosius Dobzhansky, who used it to explain how the evolutionary process unfolded.

This Ukrainian-born geneticist is considered one of the most important figures in the study of evolutionary biology and today we will discover what his life was like through a biography of Theodosius Dobzhansky in summary form.

    Brief biography of Theodosius Dobzhansky

    Theodosius Dobzhansky was a geneticist and evolutionary biologist of Ukrainian descent whose work is considered fundamental in the field of evolutionary biology. With his studies, he managed to shed light on the question of how natural selection came about behind the evolution of species. His 1937 book “Genetics and the Origin of Species” has become one of the most outstanding works of genetic research of all time. He was awarded the United States National Science Medal in 1964 and the Franklin Medal in 1973, among many other accolades.

    The first years

    Theodosius Grygorovych Dobzhansky was born on January 25, 1900 in Nemýriv, a Ukrainian village which was then part of the Russian Empire. He was the only child of Grigory Dobzhansky, professor of mathematics, and his mother was Sophia Voinarsky. His parents gave him this name because they wanted to have a child but they were already a little older and they were afraid that they would not have one, so they begged Saint Theodosius of Chernigov to grant him a son.

    In 1910, the Dobzhansky family moved to Kiev, where Theodosius attended his high school.. There he spent his youth entertaining collecting butterflies, a hobby that made him want to be a biologist when he grew up. In 1915, he met Victor Luchnik, an entomologist who convinced him to specialize in research on beetles.

    Youth and university internship

    Between 1917 and 1921 Theodosius Dobzhansky attended Kyiv University, completing his studies in 1924 majoring in entomology, that is, the study of insects. He then moved to St. Petersburg, Russia, where he studied under the guidance of Yuri Filipchenko in a laboratory specializing in the study of Drosophila melanogaster, known both as the vinegar fly and the common fruit fly. fruits.

    On August 8, 1924, Dobzhansky married geneticist Natalia “Natasha” Sivertzeva, who worked with zoologist Ivan Ivanovich Shmalgauzen in Kiev. The couple had a daughter, Sophie, who would marry American archaeologist and anthropologist Michael D. Coe. Before emigrating to the United States, Theodosius Dobzhansky published 35 scientific papers on entomology and genetics.

      Transfer to the United States

      Theodosius Dobzhansky emigrated to the United States in 1927 on a scholarship from the Board of International Education of the Rockefeller Foundation. He arrived in New York City on December 27 of the same year and almost immediately joined the Drosophila Genus Research Group at Columbia University, working with geneticists Thomas Hunt Morgan and Alfred Sturtevant. This research group has revealed very important information about the cytogenetics of flies, that is, the hereditary material of these insects.

      Add to that, Dobzhansky and his team helped establish Drosophila subobscura as a very suitable animal model for evolutionary biology studies.. Theodosius Dobzhansky’s initial belief, after studying with Yuri Filipchenko, was that there were serious doubts about how to use the data obtained from phenomena occurring in local populations (microevolution) and phenomena occurring on a global scale (macroevolution).

      Filipchenko believed that there were only two types of inheritance: Mendelian inheritance, which would explain variation within species, and non-Mendelian inheritance, which would be designed more for macro-evolutionary significance. Dobzhansky would later consider Philippchenko to have opted for the wrong option.

      Theodosius Dobzhansky followed Morgan to the California Institute of Technology (CALTECH) from 1930 to 1940. In 1937 published one of the most important works for modern evolutionary synthesis, The Synthesis of Evolutionary Biology with Genetics, entitled “Genetics and the Origin of Species” (Genetics and origin of species). In this work, among others, he defined evolution as a change in frequency of an allele within the gene pool.

        Obtaining American citizenship

        In 1937, he became a full citizen of the United States, which allowed him to have even more relevance in the field of American genetic research.

        The work of Theodosius Dobzhansky helped spread the idea that natural selection occurs through mutations in genes.. Perhaps out of envy or competitiveness, it is also this time that he quarrels with Alfred Sturtevant, one of his teammates in the Drosophila group.

        In 1941, Dobzhansky received the Daniel Giraud Elliot Medal from the United States National Academy of Sciences, the same year, he became president of the Genetic Society of America in 1941. In 1943, the University of Sao Paulo awarded him an honorary doctorate. She returned to Columbia University from 1940 to 1962. She is also known to be one of the signatories of the debate raised by UNESCO in 1950 on the racial question.

        In 1950 he received the title of President of the American Society of Naturalists, President of the Society for the Study of Evolution in 1951, President of the American Society of Zoologists in 1963, Member of the Board of Trustees of the American Society of Eugenics in 1964., and president of the Teilhard Association of American Chardin in 1969.

          Last years

          Theodosius Dobzhansky’s wife, Natasha, died of coronary thrombosis on February 22, 1969, a misfortune that joined the one she had suffered the previous year when she was diagnosed with lymphoid leukemia. The prognosis was that he would live a few more months, at most a few years at best.

          In 1971 he retired and moved to the University of California, where his student Francisco J. Ayala became an assistant professor and where Dobzhansky continued to work as a professor emeritus. In 1972, he was elected first president of the BGA (Behavior Genetics Association). and has been socially recognized for his work in behavioral genetics and founder of this association, and the Dobzhansky Prize has also been awarded to those who have dedicated themselves to the study of this discipline.

          Despite his retirement, It was in his later years that he published one of his most famous essays, “Nothing in Biology Makes No Exception in the Light of Evolution”. (“Nothing makes sense in biology except in the light of evolution”) and, at this time, influenced the paleontologist and priest Pierre Teilhard de Chardin.

          In 1975 his leukemia worsened and on November 11 he traveled to San Jacinto, California for treatment and care. Working until the last moment as a professor of genetics, Theodosius Grygorovych Dobzhansky died of heart failure on December 18, 1975 in Davis, California, at the age of 75. He was cremated and his ashes were scattered by the Californian nature.

            Genetics and origin of species

            Theodosius Dobzhansky has made three editions of his most famous book Genetics and the Origin of Species. Although this book was written for an audience specialized in biology, its writing has been meticulous to make it as understandable as possible. It is considered to be one of the most important books written throughout the twentieth century on evolutionary biology. At each revision of “La genetics and the origin of species, “Dobzhansky added new content to update it..

            The first edition of the book, published in 1937, sought to highlight the most recent findings in genetics and how they might be applied to the concept of evolution. The book begins by discussing the problem of evolution and how the most modern discoveries in genetics could help Find a solution. The main topics covered are: the chromosomal basis of Mendelian inheritance, how changes in chromosomes affect them more than genetic mutations, and how mutations form specific and racial differences.

            The second edition of “Genetics and the Origin of Species” appeared in 1941, and added still more information explaining, in addition, what scientific discoveries in the field of genetics he made during the four years between the first and the second. About half of the new research he did during this time was added to the last two chapters of the book: Patterns of Evolution and Species as Natural Units.

            The third revision of the book was published in 1951 and in it Dobzhansky reviewed the ten chapters of the play due to the many discoveries he made throughout the 1940s. He added a new chapter titled “Adaptive Polymorphism” and, in the work to be generated, it includes precise and quantitative evidence on natural selection replicated in the laboratory and on nature.

            The racial question

            In evolutionary biology, the race debate with Theodosius Dobzhansky and Ashley Montagu is well known.. The use and validity of the term race has been debated at length, with no agreement on whether or not to use it in science. Montagu believed that this word was associated with very toxic facts, which is why it was better to remove it completely from science, while Dobzhansky disagreed.

            Dobzhansky, on the other hand, was of the view that science should not give in to the socially abusive abuse of a word, considering that the term race could continue to be used if it was properly defined and not misinterpreted politically. or socially. Montagu and Dobzhansky never came to an agreement, and in fact Dobzhansky made an acidic comment in 1961 when commenting on Montagu’s autobiography, which translates as follows:

            “The chapter on ‘Ethnic group and race’ is, of course, deplorable, but we will say that it is good that in a democratic country any opinion, however deplorable, can be published” (Farber 2015 p. 3) .

            The concept of “race” has been important in many life sciences. Modern synthesis has revolutionized the concept of race, from being used as a biological and social label to classify human beings into different groups, ascribing to them physical traits and intellectual abilities, to being used today as a mere description. populations that differ in their genetics. frequencies. The main reason why science today is reluctant to use the term race is due to the great abuses that have been committed throughout its history.

            That Dobzhansky was in favor of the term non-disappearing race from the biological sciences did not mean that he was an advocate of racism. In reality, his research led him to conclude that racial interbreeding did not involve any medical problem, somewhat observed with his multiple experiences with vinegar flies, crossing several races. He observed that while the flies were of very different races, there was a chance that their offspring was not fertile, but he did not extrapolate it to the human species.

            Many anthropologists, before the start of the UNESCO debate on the racial question, tried to find the characteristics of each “race” to establish clearly what each defined. Dobzhansky considered that this had no scientific value because he had observed that the variation between individuals in the same population was greater than that between groups. In other words: it would be easier to find a prototype of a generic human than one of each race, not being so clear that this makes a person belong to one or the other race.

            His views on genetics, evolution, and racial crossbreeding have sparked controversy. He asserted that race had nothing to do with groups but rather with individuals and that it is therefore not races that are mixed but individuals. Second, that if the races are not mixed, they will in the long run become different species, and therefore must be mixed to avoid this. In fact, the current races are said to be the product of past racial crossbreeding, and according to Dobzhansky, there would be no purebred.

            Dobzhansky tried to put an end to the alleged science which claimed that physical traits determined race and, on this basis, position in society. He considered that it was not possible to identify a true lineage for human beings, that the genetic background did not determine the size of a person.

            Bibliographical references

            • Pelayo, Francisco. From creation to evolution. Darwin. Tres Cants, Madrid: Nivola, Books and editions, December 2001, p. 160 161.
            • Mark B. Adams, ed. (2014). The Evolution of Theodosius Dobzhansky: Essays on His Life and Thought in Russia and America. Princeton University Press. ISBN 9781400863808.
            • Dobzhansky, Theodosius (1978). Genetic diversity and human equality. Editorial work. ISBN 978-84-335-2416-4.
            • Dobjansky, Theodosius; Ayala, FJ; Stebbins, GL and Valentine, JW (1979). Evolution. Omega editions. ISBN 978-84-282-0568-9.
            • Ayala, Francisco J .; Dobzhansky, Theodosius (1983). Studies on the philosophy of biology. Editorial Ariel. ISBN 978-84-344-8008-7.
            • Dobzhansky, Theodosius (1997). Genetics and origin of species. Circle of readers. ISBN 978-84-226-5641-8.
            • Farber, Paul Lawrence (2015). “Dobzhansky and Montagu’s Race Debate: The Consequences. Journal of the History of Biology. 49 (4): 1-15. doi: 10.1007 / s10739-015-9428-1. PMID 26463495. S2CID 27698937

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