Walter Sutton

Walter Sutton was an American geneticist and physician who, working independently around 1902 and 1903, was among the first to propose that chromosomes are the physical carriers of Mendelian hereditary factors. Studying the grasshopper Brachystola magna, whose large chromosomes were easy to observe under the microscope of the time, Sutton noted that chromosomes occur in matched pairs, that one member of each pair is inherited from each parent, and that they separate independently of one another during the formation of reproductive cells, a pattern that closely matched the abstract rules of inheritance Gregor Mendel had described decades earlier from his pea plant experiments. The German biologist Theodor Boveri reached closely related conclusions around the same time through separate research, and the resulting synthesis is now generally known as the Sutton-Boveri chromosome theory of inheritance. Sutton's proposal supplied the missing physical, cellular basis for Mendel's previously abstract statistical laws of inheritance, directly setting the stage for Thomas Hunt Morgan's later experimental confirmation of the theory using Drosophila.