The cloning of Dolly in 1996 from the cell of an adult sheep was a pivotal moment in history. For the first time, a team of scientists, led by Ian Wilmut and Keith Campbell, was able to clone a whole mammal using a single cultured adult body cell, a breakthrough that revolutionized three technologies--genetic engineering, genomics, and cloning by nuclear transfer from adult cells—and brought science ever closer to the possibility of human cloning. In this definitive account, the scientists who accomplished this stunning feat explain their hypotheses and experiments, their conclusions, and the ethical and scientific ramifications of their work. Written with award-winning science writer Colin Tudge, The Second Creation is a landmark work that details the most exciting and challenging scientific discovery of the twentieth century.