On June 26, 2000, scientists completed a draft of the human genome sequence. While the possibilities are exciting, questions inevitably follow: What is the timetable for the annotation of the code? How will this information transform preventive, diagnostic, and therapeutic medicine? Will this discovery reconstruct the major steps in the evolution of life on Earth? What are the technological and medical repercussions that spring from the study of genes? Readers will now be able to expand their understanding of this fascinating scientific subject with essays from the top scientists working in the field.