George Shull and "Hybrid Vigor"

George Shull was a Carnegie Institution scientist appointed by Charles Davenport in 1904. As a result of his work at the Station for Experimental Evolution and by following Mendel's example, Shull obtained pure-bred lines of corn through self-pollination. The pure-bred lines were less vigorous and productive, but when he crossed the pure-bred lines, the hybrid yields were better than any of the parents' or those pollinated in the open fields. In 1908, he published the paper, "The Composition of a Field of Maize," on the phenomenon of "Hybrid Vigor", which showed that crossbreeding corn resulted in 20% higher yields than natural pollination.

Shull's maize fields behind (northeast) the Main Building where he conducted his research.