From 1934 to 1940, under Lysenko's admonitions and with Stalin's approval, many geneticists were executed (including Isaak Agol, Solomon Levit, Grigorii Levitskii, Georgii Karpechenko and Georgii Nadson) or sent to labor camps. The famous Soviet geneticist Nikolai Vavilov was arrested in 1940 and died in prison in 1943.[9] Hermann Joseph Muller (and his teachings about genetics) was criticized as a bourgeois, capitalist, imperialist, and promoting fascism so he left the USSR, to return to the USA via Republican Spain.
In 1948, genetics was officially declared "a bourgeois pseudoscience";[10] all geneticists were fired from their jobs (some were also arrested), and all genetic research was discontinued. Nikita Khrushchev, who claimed to be an expert in agricultural science, also valued Lysenko as a great scientist, and the taboo on genetics continued (but all geneticists were released or rehabilitated posthumously). The ban was only waived in the mid-1960s.
Thus, Lysenkoism caused serious, long-term harm to Soviet knowledge of biology. It represented a serious failure of the early Soviet leadership to find real solutions to agricultural problems, throwing their support behind a charlatan at the expense of many human lives.