The idea of human-nonhuman combinations has been a recurrent theme throughout different periods and cultures, from the myths of ancient Greece and the Middle Ages through to modern science fiction. In recent years, scientific advances have demonstrated the potential to make these visions a reality through the creation of genetic inter-species combinations, leading to pressing and perplexing ethical questions. This book is the first accessible survey of the different ethical aspects of potential human-nonhuman combinations and offers clarification, analysis and a thorough overview which will act as a springboard for future debate. Introducing the reader to the historical context of human-nonhuman experimentation, current legislation surrounding scientific advances and an outline of potential future developments, it identifies and examines key ethical and theological issues from a variety of contemporary perspectives. Including discussion from within world religions such as Christianity, Islam and Buddhism, it is the first work to draw together interreligious and other cultural and worldview perspectives on these neglected issues.