For thousands of years, such questions have been explored through philosophy and religion, but the answers now seem to lie firmly within the grasp of an empirical approach to the world and our place within it. By peering deep into the past and dragging clues out into the light, science can now provide some of the answers to the questions that people have always asked. From the first spark of life on earth 3.8 billion years ago, the evolution and connectivity of all living things can be tracked. The footsteps of ancestors took them from Africa into Asia and around the Indian coastline, to Australia, north into Europe and Siberia, and, eventually, to the last continents to be peopled: the Americas. Along the way, some other human species were encountered. The sophistication of some of the earliest civilizations will be examined, and the science behind what we know and why we think what we think will be discussed. This is the story of life, from single cell to civilization.