The author of the best-selling Your Inner Fish gives us a lively and accessible account of the great transformations in the history of life on Earth—a new view of the evolution of human and animal life that can help to determine whether our presence here is accidental or inevitable. Over billions of years, ancient fish evolved to walk on land, reptiles transformed into birds that fly, and ape-like primates evolved into humans that walk on two legs, talk, and write. For more than a century, paleontologists have traveled the globe to find fossils that show how changes such as these have happened. We have now arrived at a remarkable moment—archaic fossils coupled with new DNA technology have given us the tools to answer some of the basic questions of our existence: How do big changes in evolution happen? Is our presence on Earth the product of mere chance? This new science reveals a multibillion-year evolutionary history filled with twists and turns, trial and error, accident and invention. In Some Assembly Required, Neil Shubin takes readers on a journey of discovery spanning centuries, as explorers and scientists seek to understand the origins of life's immense diversity.