Ivan lvanovich Schmalhausen (1884-1963) was a Soviet evolutionary biologist who openly embraced the neo-Darwinian theory of evolution through natural selection, which holds that those organisms with genetic traits that confer advantages in the environment achieve the greatest reproductive success. His views thus conflicted with those of Trofim Denisovich Lysenko (1898-1976), whose neo-Lamarckian theory of evolution was in the ascendant in 1940s Soviet science. In contrast to proponents of natural selection, Lysenko believed that environment could directly alter the heritable qualities of an organism—that the nongenetic traits an individual organism acquires during its lifetime could be passed down to its offspring.

Schmalhausen's career in Soviet science was ruined by his opposition to Lysenko's idea of heritable acquired characteristics. But Schmalhausen's theory about the relationship between heredity and environment, one of the most prescient of his generation, was directly indebted to the challenges posed by the neo-Lamarckian orthodoxy. That is because, unlike evolutionary biologists outside the Soviet Union, who simply dismissed Lysenko's views in favor of neo-Darwinian natural selection, Schmalhausen was forced to take into account the Lysenko agenda. This led him to develop a more nuanced theory of the interpenetration of heredity and environment than was found in either neo-Lamarckian or neo-Darwinian theory at the time.