My precedents have already Explained in detail why this book is breathtaking and incredibly vast at the sametime. I am a big fan of sci-fi and I struggle to put this book into one category, as indeed it is science, even if told in very novelistic & entertaining way. But as it goes backwards (Millions of years indeed) and Explains based on theories on how mostcommon humankined evolved, it goes unusual ways for sci-fi Which normally is Determined by extrapolating a present situation or idea into the future. What I like most about this book is indeed it`s amazingly mind-opening - After Reading it (and you need a long breath for it, there are some slow passages) I see myself and life in a different way. Our behavior, society, religion can all be Explained through evolutionary thinking. It`s worth the patience needed in between. I love this book.