The American biologist James Dewey Watson (born 1928) was a discoverer of the double-helical structure of the deoxyribonucleic acid molecule.

James D. Watson was born April 6, 1928, in Chicago, Illinois. At age 15 he entered the University of Chicago. He graduated in 1947 and went on to pursue graduate study in the biological sciences at Indiana University. There he came under the influence of some distinguished scientists, including Nobel laureate Hermann J. Muller, who were instrumental in shifting his interests from natural history toward genetics and biochemistry. In 1950 Watson successfully completed his doctoral research project on the effect of x-rays upon the multiplication of bacteriophages (viruses that attack bacterial cells).

Watson spent 1950-1951 as a National Research Council fellow in Copenhagen doing postdoctoral work with biochemist Herman Kalckar. He had hoped to learn more about the biochemistry of the genetic material deoxyribonucleic acid (DNA). These studies proved unproductive. It was not until...