While Bryson wrote this book to explain the history of everything on Earth, he constantly comes back to the idea of origins: how did the Earth begin, and how did our life on this planet start? Although each section explores the different components of life on Earth, Bryson continually ties these elements back to our origins as a species and as a planet. Bryson opens the book with the lens drawn back, lookingat things such as the universe and our solar system at large. He then focuses in, tying everything together by illustrating how the very things that comprise these vast structures are also the fundamental building blocks of the human body.

Bryson also provides continual information revealing the origins of each scientist he introduces. For example, rather than just stating the scientist and explaining his or her contribution to the field, Bryson gives an often-thorough background history of each scientist. By doing so, he reveals that each scientist is human, and simultaneously flawed and genius. 

Throughout the text, Bryson demonstrates the painstaking lengths scientists have gone to in order to understand the origins of life on Earth. He lists the wide array of scientists, theories, and technologies that have made our current knowledge possible.