Britain's foremost astrobiologist offers an accessible and game-changing account of why life is like it is. The puzzles of life astound and confuse us like no other mystery. But in this revolutionary new book, Charles Cockell reveals how nature is far more understandable and predictable than we think. Refining Darwin's theory of natural selection, Cockell puts forward a remarkable and elegant account of why evolution has taken the paths it has. From animals to atoms, he shows that is it not biology, but physics, which is the true touchstone for understanding life in all its extraordinary forms.