Theodosius Dobzhansky: biography of this Ukrainian geneticist

Although the 20th century began with the widespread modern theory of Darwinian evolution, there were many doubts about how natural selection occurred. The inheritance of traits was something whose study was very recent and Mendel's works were still very unknown in the scientific community.

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

This geneticist of Ukrainian origin is considered one of the most important figures in the study of evolutionary biology and today we are going to discover what happened to his life through a biography of Theodosius Dobzhansky in summary format.

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Brief biography of Theodosius Dobzhansky

Theodosius Dobzhansky was a Ukrainian-born geneticist and evolutionary biologist whose work is considered fundamental to the field of evolutionary biology. With his studies he managed to shed some light on the question of how natural selection occurred behind the evolution of species. His 1937 work "Genetics and the Origin of Species" became one of the most remarkable genetic research works of all time. He was awarded the United States National Medal of Science in 1964, and the Franklin Medal in 1973, among many other recognitions.

Early years

Theodosius Grygorovych Dobzhansky was born on January 25, 1900 in Nemýriv, a Ukrainian village at that time part of the Russian Empire. He was the only child of Grigory Dobzhansky, a math teacher, 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 feared they couldn't have one, so they prayed to Saint Theodosius of Chernigov for a child.

In 1910 the Dobzhansky family moved to Kiev, where Theodosius attended his institute. There he spent his youth entertaining the butterfly collection, 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 stage

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

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

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Transfer to the United States

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

Added to this, Dobzhansky and his team helped establish the Drosophila subobscura as an animal model well suited for evolutionary biology studies. Theodosius Dobzhansky's original belief, after studying with Yuri Filipchenko, was that there were serious doubts about how to use data obtained from phenomena that occurred in local populations (microevolution) and phenomena that occur on a global scale (macroevolution).

Filipchenko believed that there were only two types of inheritance: Mendelian inheritance, which would explain the variation within species, and non-Mendelian inheritance, which would be conceived more for a sense macroevolutionary. Dobzhansky would later consider that Filipchenko had bet on the wrong option.

Theodosius Dobzhansky followed Morgan to the California Institute of Technology (CALTECH) from 1930 to 1940. In 1937 he 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 the Origin of Species). In this work, among other things, he defined evolution as "a change in the frequency of an allele within the gene pool."

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Obtaining North American Citizenship

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

Theodosius Dobzhansky's work was essential to extend the idea that natural selection occurs through mutations in genes. Maybe out of envy or competitiveness, it was also at this time that he had a fight with Alfred Sturtevant, one of his companions in the Drosophila group.

In 1941 Dobzhansky received the Daniel Giraud Elliot Medal from the United States National Academy of Sciences., the same year that he became president of the Genetic Society of America in 1941. In 1943 the University of Sao Paulo awarded him an honorary doctorate. He returned to Columbia University in 1940-1962. He is also known for being one of the signatories in the 1950 UNESCO debate on The Racial Question.

In 1950 he was granted the title of president of the Society of American Naturalists, president of the Society for the Study of Evolution in 1951, president of the Society of American Zoologists in 1963, a member of the Board of Directors of the American Eugenics Society in 1964, and president of the American Teilhard de Chardin Association in 1969.

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Last years

Theodosius Dobzhansky's wife, Natasha, died of a coronary thrombosis on February 22, 1969, a misfortune that she added to that which she had already suffered since the previous year when he was diagnosed with lymphocytic leukemia. The prognosis was that he was going to live a few more months, at best a few years at best.

In 1971 he retired and transferred 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 chosen as the first president of the BGA (Behavior Genetics Association). and he was socially recognized for his work on behavioral genetics and founder of that association, also creating the Dobzhansky Prize awarded to those who have dedicated themselves to the study of this discipline.

Despite being retired, It was in the last years of his life that he published one of his most famous essays, "Nothing in Biology Makes Sense Except in the Light of Evolution." ("Nothing makes sense in biology except in the light of evolution") and, around that time, he influenced the paleontologist and priest Pierre Teilhard de Chardin.

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

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Genetics and the Origin of Species

Theodosius Dobzhansky made three editions of his most famous book "Genetics and the Origin of Species". Although this book was written for an audience specializing in biology, its wording was careful to make it as understandable as possible. It is considered one of the most important books written throughout the 20th century on evolutionary biology. In each revision that was made of “Genetics and the Origin of Species”, Dobzhansky added new content to update it..

The first edition of the book, published in 1937, tried to highlight the most recent findings about genetics and how they could be applied to the concept of evolution. The book begins by referring to the problem of evolution and how the most modern discoveries in genetics could help to find a solution. The main topics discussed are: the chromosomal basis of Mendelian inheritance, how changes affect chromosomes larger than gene mutations and how mutations form specific and racial differences.

The second edition of "Genetics and the Origin of Species" came in 1941, and in it he added even more information explaining, in addition, what scientific findings in the field of genetics he made in the four years between the first and the second. About half of the new research he conducted in that period was added to the last two chapters of the book: Patterns of Evolution, and Species as Natural Units Natural).

The third revision of the book was published in 1951 and in it Dobzhansky he reviewed all ten chapters of the work due to the many discoveries he had made throughout the 1940s.. In it he added a new chapter entitled "Adaptive Polymorphism" (Adaptive Polymorphism), and in the work to generate includes precise and quantitative evidence about natural selection replicated in the laboratory and seen in the nature.

The Racial Question

In evolutionary biology, the debate on race starring Theodosius Dobzhansky and Ashley Montagu is well known.. The use and validity of the term "race" was debated for a long time, without reaching an agreement on whether it was pertinent to use it in science or not. Montagu was of the opinion that this word was associated with highly toxic facts, which is why it was best to eliminate it entirely from science, while Dobzhansky disagreed.

Dobzhansky, on the other hand, believed that science should not give in to the abuses that could have been done socially in a word, considering that the term "race" could continue to be used if it was adequately defined and not misinterpreted in a political key or Social. Montagu and Dobzhansky never reached an agreement and, in fact, Dobzhansky put up a sour comment in 1961 commenting on Montagu's autobiography, which translates as follows:

"The chapter on" Ethnicity and Race "is, of course, deplorable, but we are going to say that it is good that in a democratic country any opinion, no matter how deplorable, can be published ”(Farber 2015 p. 3).

The concept of "race" has been important in many life sciences. The modern synthesis revolutionized the concept of race, going from being used as a biological and social label to classify human beings in different groups, attributing physical traits and intellectual capacities, to be used today as a mere description of populations that differ in their frequencies genetic The main reason why science today is reluctant to use the term "race" is because of the great abuses that have been committed throughout its history.

That Dobzhansky was in favor of the term "race" not disappearing from the biological sciences did not mean that he was an advocate of racism. In fact, his investigation led him to conclude that racial miscegenation did not imply any medical problems, something observed with his multiple experiments with vinegar flies, crossing several races of them. He did observe that if the flies belonged to very different races there were chances that their offspring were not fertile, but he did not extrapolate it to the human species.

Many anthropologists, before the UNESCO debate on The Racial Question began, were trying to find the traits of each "race" to clearly establish what defined each a. Dobzhansky considered that this had no scientific value since he had observed that the variation between individuals of the same population was greater than that between groups. In other words: it would be easier to find a generic human prototype than one from each race, since it was not so clear that it made a person belong to one race or another.

His views on genetics, evolution, and racial miscegenation generated controversy. He claimed that race was not about groups but rather about individuals and that therefore it is not the races that mix but the individuals. Second, that if the races do not mix then they will eventually become different species, and therefore it is necessary for them to mix to avoid this. In fact, the current races would be the product of past racial crossbreeds, and in Dobzhansky's view there would be no race that was pure.

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