The early twenty-first century is an era of genetics. Genetic science, genetic technologies, genetically based diseases, animal and human cloning, and genetically modified organisms are regular visitors to the news and entertainment culture. Together with the revolution in information technologies, and sometimes going hand in hand, the biotech revolution promises to transform the world. The well-known successes of molecular biology in the 1950s and 1960s have transformed biology and especially genetics. But because from the very beginning genetics has been intimately involved with human values, the revolutionary changes of this science and technology have challenged moral reflection.

A brief historical review of the development of genetics research will help place such challenges in context. For present purposes this history may conveniently be divided into three periods. The first, and longest, period was one of protogenetics, in which human values played a dominant...