James Watson

James Dewey Watson (born 1928) is an American molecular biologist who, with Francis Crick, proposed the double-helix structure of DNA in 1953. He shared the 1962 Nobel Prize in Physiology or Medicine with Crick and Maurice Wilkins.

Working at the Cavendish Laboratory in Cambridge, Watson and Crick built a model of DNA in which two strands of nucleotides wind around each other, with the bases paired inside by hydrogen bonds: adenine with thymine, and guanine with cytosine. The pairing explained how genetic information could be copied, as each strand can serve as a template for a new partner. Their paper in Nature in April 1953 noted that the structure "immediately suggests a possible copying mechanism for the genetic material."

The model depended on X-ray diffraction images of DNA made at King's College London, including the famous Photo 51 by Rosalind Franklin and Raymond Gosling. Watson and Crick saw this data without Franklin's knowledge, and her contribution was long underrecognized. Franklin died in 1958, and Nobel Prizes are not awarded posthumously.

Watson led Cold Spring Harbor Laboratory for decades, wrote the best-selling memoir The Double Helix (1968) and headed the early Human Genome Project in 1990 to 1992. His later public statements about race and genetics were widely condemned as unscientific, and the laboratory ended his remaining honorary titles in 2019. See the double helix and genome for the science.