Evolutionary biologist and master skeleton builder Ben Garrod discovers how the skeleton has adapted for vertebrates to move on land in a remarkable number of ways. They can swing through the trees, slide on the forest floor, dig through dark subterranean worlds and run at speed across the savannahs. Ben explores the role of the spine in both cheetahs and snakes, shows how adaptations to the pentadactyl limb have helped gibbons and horses thrive and how one unique bone in the animal kingdom has been puzzling scientists for years.