 Thomas Hunt Morgan began his career in genetics as a saltationist, and started out trying to demonstrate that mutations could produce new species in fruit flies.However, the experimental work at his lab with the fruit fly, "Drosophila melanogaster" demonstrated that rather than creating new species in a single step, mutations increased the supply of genetic variation in the population.By 1912, after years of work on the genetics of fruit flies, Morgan showed that these insects had many small Mendelian factors (discovered as mutant flies) on which Darwinian evolution could work as if variation was fully continuous.