Portions of this entry contributed by Michel Barran

American chemist and biologist who was born in Oakland, California. He was educated at University of California (obtaining his B.S. in 1951), where he was a student of Urey, and then at University of Chicago (where he received his Ph.D. in chemistry in 1954). He was an assistant professor (1958-1960), associate professor (1960-1968), then full professor of chemistry at University of California, San Diego (from 1968).

His research deals with the origin of life (and he is considered a pioneer in the field of exobiology), the natural occurrence of clathrate hydrates, and general mechanisms of anesthesia. He is a member of the National Academy of Science, and received the Oparin Medal. In the 1950s, Urey theorized that the early atmosphere of the Earth was probably like the atmosphere now present on Jupiter --i.e., rich in ammonia, methane, and hydrogen. Miller, working in his laboratory at the University of Chicago, demonstrated that when exposed to an energy source such as ultraviolet radiation, these compounds and water can react to produce amino acids essential for the formation of living matter. However, the early atmosphere of the Earth is no longer believed to have had this composition.

Urey