James Dewey Watson with his original DNA model, 9 June 1994.
© Science Museum / Science & Society Picture Library
James Dewey Watson (b 1928) discovered the structure of DNA with Francis Crick (b 1916) at the Cavendish Laboratory, Cambridge in 1953. The model showed that the DNA molecule (deoxyribonucleic acid) has the form of a double helix, consisting of two parallel chains of alternate sugar and phosphate groups linked by pairs of organic bases. The discovery later led to far-reaching discoveries concerning the genetic code.