Transhumanists advocate for the development and distribution of technologies that will enhance human intellectual, physical, and psychological capacities, even eliminate aging. What if the dystopian futures and transhumanist utopias found in the pages of science journals, Margaret Atwood novels, films like "Gattaca", and television shows like "Dark Angel" are realized? What kind of world would humans have created? Maxwell J. Mehlman considers the promises and perils of using genetic engineering in an effort to direct the future course of human evolution. He addresses scientific and ethical issues without choosing sides in the dispute between transhumanists and their challengers. However, "Transhumanist Dreams and Dystopian Nightmares" reveals that radical forms of genetic engineering could become a reality much sooner than many people think, and that we need to encourage risk management efforts. Whether scientists are dubious or optimistic about the prospects for directed evolution, they tend to agree on two things. First, however long it takes to perfect the necessary technology, it is inevitable that humans will attempt to control their evolutionary future, and second, in the process of learning how to direct evolution, we are bound to make mistakes. Our responsibility is to learn how to balance innovation with caution.