Garland Edward Allen III (February 13, 1936 – February 10, 2023) was an American historian and biographer at Washington University in St. Louis. His research interests lie primarily in the history of genetics, eugenics and evolution.

Garland Edward Allen III was born on February 13, 1936, in Louisville, Kentucky.^[1] He graduated from the University of Louisville in 1957. He completed his PhD in the history of science at Harvard University in 1966 under the direction of Ernst Mayr and Everett Mendelsohn after spending a few years as a high school biology teacher.^[2] He taught at Washington University and held several visiting professorships at Harvard.

Allen died on February 10, 2023, at the age of 86.^[3]

Allen offered the fullest treatment of the life and work of Thomas Hunt Morgan, himself a Kentucky native. Allen's extensive review of Morgan presented the story of an experimentalist who staunchly avoided open political ties to science for fear of biasing the research. His discussion of the fly room, first at Columbia, then at Caltech, suggests that the collaborative environment within which Morgan worked with his students, H.J. Muller, Alfred Sturtevant, Calvin Bridges, and Theodosius Dobzhansky played an important role in establishing Drosophila melanogaster as a model organism for genetics, and launching the careers of these titans of 20th century genetics.^[4] Allen's work contributes to the body of history chronicling the emergence of American science.

Allen was an international leader on the history of eugenics.^[5] His work suggests that eugenics movements were not merely localized to Germany, Britain and America, but rather that eugenics constituted an international ideological shift from social Darwinism, whereby nature would weed out people with poor heredity, to an ideology where humanity must control its own genetic stock.^[6] He suggested that with the unveiling of the human genome, we should be cautious of a new wave of the eugenics movement.^[7]

• Matter, Energy, and Life (4 Editions)
• Life Sciences in the 20th Century (1975)
• Thomas Hunt Morgan: The Man and his Science (1978)
• Biology: Scientific Process and Social Issues (2002)

• 2011: Fellow of American Association for the Advancement of Science^[8]
• Trustee and Chairman of the history committee at the Marine Biological Laboratory
• President of the International Society for the History, Philosophy and Social Studies of Biology
• 2017: George Sarton Medal AAAS