In the 1950s, when D. Elmo Hardy began describing the fantastic diversity of native Drosophila, he realized that a marvelous natural evolutionary experiment was occurring in the island forests. It was as if an earlier geneticist had locked specimens of a close relative of Drosophila melanogaster in a number of extremely large test tubes and allowed them to evolve for thousands or even millions of years ... In 1963, the Hawaiian Drosophila Project began diciphering the genetics and evolution of this amazing group of flies. Over 800 species of Drosophilidae in five genera have been recorded in the islands. This is nearly one-third of the total number of known drosophilid species in the world. Their diversity of form, ecology, and behavior far exceeds the range of known variations in the group outside of Hawai'i.
From Hawaiian Insects and Their Kin (1992) by F.G. Howarth & W. P. Mull. University of Hawaii Press (Honolulu, HI). pg.22.