In 1900 three scientists, Carl Correns, Erich von Tschermak and Hugo De Vries, had rediscovered the work of Gregor Mendel, and with it the foundation of genetics. De Vries proposed that new species were created by mutation, bypassing the need for either Lamarckism or Darwinism. As Morgan had dismissed both evolutionary theories, he was seeking to prove De Vries' mutation theory with his experimental heredity work. He was initially skeptical of Mendel's laws of heredity (as well as the related chromosomal theory of sex determination), which were being considered as a possible basis for natural selection.