From the moment it first began to contemplate the world, three questions have occupied the human mind: Where do we come from? What are we? Where are we going? Artists (notably Paul Gauguin), religious thinkers, philosophers, and most recently scientists have all searched for answers. Here, the authors describe how scientists decipher human origin from the record encrypted in the DNA and protein molecules. After explaining the nature of descent and the methods available for studying genealogical relationships, they summarize the information revealed by the molecular archives about the Tree of Life and our location on one of its branches. The knowledge thus gleaned allows them to draw conclusions about our identity, our place in the living world, our future, and the ethical implications of the changed perspective.