Age range 9 to 12

Why do humans walk on two legs? Why do fish have gills? Life on Earth is incredibly diverse and part of the reason for this is evolution, or the theory that living things change with time. Evolution: How Life Adapts to a Changing Environment explores the theory of evolution, its history, how we think it works, examples of creatures who have evolved in response to specific circumstances, and what this might mean for the future of our planet. 

For billions of years, the amazing story of life on Earth has been unfolding. Millions of years ago, life on earth was nothing like it is today. Dinosaurs roamed the earth and pterosaurs flew through the skies. Millions of years before the dinosaurs, it was even more different. Strange ocean creatures lived in the seas, while the land was barren. Throughout its history, Earth has been home to an incredible diversity of living things that have changed dramatically over the many millennia. How have these living creatures changed so much? And how did that change happen? The answer: evolution!