Drosophila: Lord of the Fly Room
Thomas Hunt Morgan's discoveries won him the Nobel Prize and forever altered American Laboratories.
Courtesy of the Archives, California Institute of Technology.
By the spring of 1910, the pioneering geneticist Thomas Hunt Morgan was growing frustrated. Years earlier, hoping to study mutations to forge an understanding of how species arise, he had stocked his Columbia University laboratory with one-quart milk bottles filled with millions of fruit flies (collected from ripe bananas on the windowsill), then waited for a mutant to appear. One hundred years ago, after Morgan’s constant search for apparent mutations, a white-eyed fly appeared amid swarms of red-eyed Drosophila melanogaster.
This tiny creature catapulted biology toward the genomics revolution, firmly establishing the chromosomal theory of heredity. And from Morgan’s laboratory—dubbed the Fly Room—came a new model for structuring research laboratories.
Morgan was born in 1866, the year Gregor Mendel published his famous work on the inheritance of certain traits in pea plants. Morgan, who was skeptical of Mendel’s work, thought the theory of factors (now called genes) carried on chromosomes was “an absurdity.” Yet Morgan soon proved that very theory, showing not only the physical mechanism by which genes are inherited but also how they could explain Darwinian evolution. After crossbreeding the white-eyed fly, Morgan determined the mutation was a recessive, sex-linked trait, and that it was positioned near two other mutations that were usually inherited together—on a chromosome. He summarized what appeared to many as “fantastic speculation” and “sensational conclusions” in 1915 in The Mechanism of Mendelian Heredity. For his work, in 1933 Morgan became the first American to receive the Nobel Prize in Physiology or Medicine.
Morgan realized that his investigations left many questions unanswered. How do genes divide into exactly two equal parts during cell division, and how do they remain stable most of the time and only occasionally introduce mutations? And why are they always in the same linear position? The answers to these questions would await the discovery of the structure of DNA in 1953.
Morgan also spearheaded the collaborative nature of American research laboratories. Previously a scientific leader lorded over his students in a strict hierarchy. In Morgan’s “democratic” Fly Room, merit counted more than seniority, and students interacted with lead investigators. “Each carried on his own experiments, but each knew exactly what the others were doing, and each new result was discussed freely,” recalled one of his students. Thus Morgan may take some credit for the fast pace of discovery in American universities.