English: An experiment demonstrating allopatric speciation in the fruit fly (Drosophila pseudoobscura) conducted by Diane Dodd. A single population of flies was divided into two, with one of the populations fed with starch-based food and the other with maltose-based food. After the populations had diverged over many generations, the groups were again mixed; it was observed that the flies would mate only with others from their adapted population.Dodd, D.M.B. (1989) "Reproductive isolation as a consequence of adaptive divergence in Drosophila pseudoobscura." Evolution 43:1308–1311.