Theodosius Dobzhansky, Ukrainian-American geneticist and biologist (d. 1975)
Theodosius Grygorovych Dobzhansky (Ukrainian: Теодо́сій Григо́рович Добжа́нський; Russian: Феодо́сий Григо́рьевич Добржа́нский; January 25, 1900 – December 18, 1975) was a prominent Ukrainian-American geneticist and evolutionary biologist, and a central figure in the field of evolutionary biology for his work in shaping the modern synthesis. Dobzhansky was born in Ukraine, then part of the Russian Empire, and became an immigrant to the United States in 1927, aged 27.His 1937 work Genetics and the Origin of Species became a major influence on the modern synthesis. He was awarded the US National Medal of Science in 1964, and the Franklin Medal in 1973.