Drosophila melanogaster's history as a human commensal

When W.E. Castle at Harvard and T.H. Morgan at the Columbia University started using a tiny fly for laboratory experiments in genetics they were probably unaware that the species had only been introduced to the United States a few years earlier. Drosophila melanogaster, now a widely popular organism in biological research, is a human commensal that owes its current cosmopolitan distribution largely to human activity. Since this became clear considerable progress has been made in understanding the historical biogeography of Drosophila melanogaster and its association with human activities. There are even first attempts to describe the ecology of populations not associated with human activities, which might shed light on the evolutionary history of the species.