40 years ago, James Watson and Francis Crick discovered the code of law that governed inheritance, the base-pairing rules of DNA. Since then, there has been an explosion of research. Scientists can now manipulate DNA to correct a damaged cell, nurture an endangered embryo, arrest degenerative diseases, detect foetal chromosome abnormalities and secure convictions by genetic fingerprinting. The underlying potential of such a powerful knowledge creates grounds for explosive ethical and legal debate. Written by a prize-winning biologist, this accessible text proposes a complete instruction book for all living things. He offers evidence that the responsibilities of changing the human genome are enormous, and that researchers must achieve a greater understanding of the multiple meanings of DNA, or court disaster.