When the Whales Walked tackles a big, complex subject – the evolution of life on Earth – and succeeds in explaining it clearly, vividly and in way that will catch the imagination of young readers. It examines thirteen case studies, each describing the evolution of a different group of animals, from the earliest fish right up to modern Homo Sapiens. It explains the history of each group with the help of illustrations and diagrams, challenging children to spot the patterns in the ways that different animals have evolved. There’s a timeline of life on Earth, diagrams to explain the evolutionary tree and a cladogram, all there to help make the subject crystal clear. A book that thoroughly respects the intelligence and inquisitiveness of its readers and rewards their attention.