In 1993, investigators from George Washington University Medical Center separated the cells of 17 human embryos and produced 48 embryos, an average of three embryos for each original. The method, variously called twinning, cloning, embryo splitting, and blastomere separation, demonstrated that human embryos could be split to create genetically identical entities during conception. When publicized, however, the experiment brought to mind a different view of cloning repeated since the beginning of the new reproductive technologies. In the early 1970s, when research (...) on in vitro fertilization was in its infancy, commentators worried that cloning–defined as the duplication of persons–would be next, leading to a scenario of “boys genetically exactly like the father, girls like the mother, or individuals like some true or false hero of art, science, or sports, or like some demagogue or some saint.”. (shrink)