"None of us privileged few who first saw the double helix in the spring of 1953 ever contemplated that we might in our lifetime see it completely decoded"

James Watson, 2000

The uncovering of the structure of DNA triggered a revolution so profound that, 50 years on, humanity has still to come to terms with it. When Francis Crick and James Watson, working together in Cambridge, announced on 25 April 1953 that DNA was a double helix linked over and over again by the same four bits of chemistry, they had identified both the code of all life and how it copies itself. The sequence A, T, G and C spells out the genes that turn a single cell into a baby, and then make each baby different from every other. Crick and Watson had identified the machinery of evolution and laid the foundations for the Human Genome Project, which is due to complete the decoding of the human genome in 2003. Society's challenge for the future will be to keep pace with scientific advance and the astonishing possibilities it continues to present.