Daniel Edward Koshland, Jr. was an American biochemist. Daniel E Koshland Jr. was born in New York, New York, on March 30, 1920. He received his BS degree in chemistry from the University of California in 1941 and retained a love of the University for the rest of his life. After a stint working on the Manhattan Project, he completed his Ph.D. at the University of Chicago working with a young Frank Westheimer and, after a short postdoctoral stay at Harvard, began his independent career at the Brookhaven National Laboratory in 1951. Dan Koshland was recognized by a long list of awards. These include the National Medal of Science in 1990, the Albert Lasker Award in 1998, the Welch Award in Chemistry in 2006, and several honorary degrees. He was also a member of the National Academy of Sciences and the American Academy of Arts and Sciences. He died on July 23, 2007 in Walnut Creek, California, United States.