Trofim Lysenko was a Soviet biologist known for his controversial agricultural theories in the mid-20th century. He rejected Mendelian genetics and promoted the idea that environmental factors could directly alter an organism's traits, a concept known as Lysenkoism. His views gained favor under Joseph Stalin, leading to the suppression of genetic research in the Soviet Union. Lysenko's methods aimed to improve crop yields but often resulted in poor agricultural outcomes. His influence led to the persecution of scientists who supported traditional genetics, causing significant setbacks in biological research. Lysenkoism eventually fell out of favor after Stalin's death, as the scientific community moved back to established genetic principles.