George Wells Beadle ’31, Genetics (Biology)
Nowadays, even the youngest elementary school students learn about how DNA works to produce changes in an organism – animated videos show brightly colored base pairs, and proteins being churned out of the assembly line. Anyone with $99 to spare can send a cheek swab to a company that can, from the other side of the country, tell them whether they are likely to have blue eyes or freckles or diabetes. Genetics permeates the way we talk about, think about, and understand our families and ourselves.
George Wells Beadle, who held a doctoral degree in biology from Cornell, gave us the tools to think about how we go from genotype (what an organism’s genes “say”) to phenotype (the expression of those genes – your mother’s red hair or your great-grandfather’s height). Beadle and his collaborator, Edward Tatum, won a Nobel Prize in 1958, “for their discovery that genes act by regulating definite chemical events.” Their ideas eventually came to be known as the ‘one gene-one enzyme hypothesis’. The next half-century of genetic research has shown this theory to be something of an oversimplification, but it set the stage for the development of the field of molecular biology.
Beadle was born in Wahoo, Nebraska, a farm town set in the sea of fields west of Omaha. He earned his undergraduate and Masters degrees in biology at the University of Nebraska, where he studied hybrid strains of wheat. One of his professors urged him to head east to Cornell to continue his studies at the doctoral level. He left Nebraska, but continued to work in an agricultural vein, focusing his research at Cornell on corn – specifically “Genetical and Cytological Studies of Mendelian Asynapsis in “Zea mays”.
Having received his Ph.D., he again headed west, to the California Institute of Technology, with a research fellowship in hand. There, for the first time, he began working with Drosophila melanogaster – the common fruit fly. But the work that won him the Nobel Prize, which took place at Stanford in partnership with Edward Lawrie Tatum, was based on research from neither plants nor animals, but Neurospora crassa – a humble strain of red bread mold. When Lawrie and Beadle induced mutations in the mold’s genome after exposure to X-rays, they were able to demonstrate the link between the genetic mutations and altered enzymes in the metabolic pathways of the mold.
Beadle’s later career as an academic took him back to Cal Tech, and then eventually to the University of Chicago, where he became President of the University in 1961. He also received several awards and distinctions, including the presidencies of the Genetics Society of America and the American Association for the Advancement of Science.
After his retirement from his administrative careers, however, Beadle returned to the subject of some of his earliest research. Eschewing the tools of molecular biology, the field that he, in part, created, Beadle showed that contemporary maize derives from a Central American wild grass, teosinte, by cross-breeding plants – just as Gregor Mendel did over a century before.