Watson’s boyhood enthusiasm for bird-watching led him to entry, aged 15, to Chicago University where he graduated in zoology when only 19. He worked for his PhD at Indiana University at Bloomington, studying phages (bacterial viruses), learning much about bacterial viruses and biochemistry and becoming convinced that the chemistry of genes, then little understood, was of fundamental importance for biology. A fellowship took him to Copenhagen in 1950 to study bacterial metabolism, but soon his enthusiasm for DNA led him to Cambridge and to collaboration with Crick in the Cavendish Laboratory. Their talents and personalities were highly complementary; their joint ideas, assisted by X-ray diffraction studies by Rosalind Franklin and by M H F Wilkins (1916 - ), achieved a revolution in biology with publication in 1953 of the proposed double helix structure for DNA, together with a suggestion of a path for the replication of genes (the basis of heredity) and the effective beginning of the whole new science of ‘molecular biology’ (see Crick’s entry for a brief account). Watson’s book The Double Helix (1968) gave a striking and uninhibited non-technical account of its discovery; and his The Molecular Biology of the Gene proved an influential textbook.
Watson, Crick and Wilkins shared the Nobel Prize for physiology or medicine in 1962. From 1955 Watson was at Harvard, from 1976 he directed the Cold Spring Harbor Laboratory of Quantitative Biology and from 1988 directed the Human Genome Research project of the National Institutes of Health, which aims to elucidate the chemistry of the 100 000 genes making up the human genome: he resigned in 1993 in opposition to the principle of patenting genetic information from the project. (See Human Inherited Disease and the Human Genome Project.)