This in-depth yet highly readable volume examines all aspects of animal cloning, including its controversial nature, from a neutral standpoint. Well-written entries discuss natural cloning and early cloning experiments beginning in the 1950s; the research that led to the creation of Dolly, the first animal cloned from an adult cell; as well as the recent sheep-human, goat-human, and pig-human hybrids scientists have experimented with using cloning technology. Substantial coverage deals with the driving forces behind cloning research, including the production of large quantities of medically important proteins such as blood clotting factor IX, used to treat hemophilia B; human serum albumin, used to treat burn victims; and anti-thrombin III, an anti-clotting protein used to treat heart attack and stroke victims. While the focus is on animal cloning, specific coverage of human cloning is also presented.