The fruit flyDrosophilahas played a central role in the development ofbiologyduring the 20th century. First chosen as a convenient organism to test evolutionary theories soon became the central element in an elaborate, fruitful, and insightful research program dealing with the nature and function of the gene. Through the activities of TH Morgan and his students,Drosophiladid more than any other organism to lay down the foundations ofgeneticsas a discipline and a tool forbiology. In the last third of the century, a judicious blend of classical genetics and molecular biology focused on some mutants affecting the pattern of theDrosophilalarva and the adult, and unlocked the molecular mechanisms of development. Surprisingly, many of the genes identified in this exercise turned to be conserved across organisms. This observation provided a vista of universality at a fundamental level of biological activity. At the dawn of the 21st century,Drosophilacontinues to be center stage in the development ofbiologyand to open new ways of seeing cells and to understand the construction and the functioning of organisms.
