Without George Shull's concept of hybrid vigor, the development of high-yield hybrid corn would not have been possible. Shull used maize to demonstrate that repeated self-fertilization of pure lines resulted in inferior ears of corn, but hybrid crosses between different lines produced vigorous plants. Shull originally introduced the concept as "heterosis" at a lecture in Göttingen in 1914. Although both Shull and American geneticist Edward Murray East (1879-1938) realized the potential agricultural uses of hybrid corn, Shull was responsible for urging American seed companies to develop commercial hybrid lines. The use of hybrid agricultural plant lines has dramatically increased agricultural yields, first in the United States and later around the world.

Born on a farm near North Hampton, Ohio, Shull received a largely informal and unorthodox education. In spite of this, Shull published his first article, in American Garden, at the age of 17. After teaching school in...