A timely investigation into the ethics, history, and potential of human cloning from Professor Ian Wilmut, who shocked scientists, ethicists, and the public in 1997 when his team unveiled Dolly-that very special sheep who was cloned from a mammary cell. With award-winning science journalist Roger Highfield, Wilmut explains how Dolly launched a medical revolution in which cloning is now used to make stem cells that promise effective treatments for many major illnesses. Dolly's birth also unleashed an avalanche of speculation about the eventuality of cloning babies, which Wilmut strongly opposes. However, he does believe that scientists should one day be allowed to combine the cloning of human embryos with genetic modification to free families from serious hereditary disease. In effect, he is proposing the creation of genetically altered humans.