The first major challenge to conventional eugenics based on genetic inheritance was made in 1915 by Thomas Hunt Morgan. He demonstrated the event of genetic mutation occurring outside of inheritance involving the discovery of the hatching of a fruit fly ("Drosophila melanogaster") with white eyes from a family with red eyes, demonstrating that major genetic changes occurred outside of inheritance. Additionally, Morgan criticized the view that certain traits, such as intelligence and criminality, were hereditary because these traits were subjective. Despite Morgan's public rejection of eugenics, much of his genetic research was adopted by proponents of eugenics.