Instead of Mendelism, Lysenko adhered to Lamarck’s —now widely rejected —theory of the ‘inheritance of acquired characteristics’, which suggests that individuals have the ability to modify their features during their lifetime and bestow these features onto their offspring. If giraffes need to feed on tall trees, they would simply grow a longer neck and, rather conveniently, give birth to long-necked youngsters. According to Lamarckism, nurture, rather than nature, was the driving force for evolution.