This episode is devoted to the evolution of reptiles. They are not as restricted as their amphibian ancestors, since they can survive in the hottest climates. The reason is their scaly, practically watertight skin. The scales protect the body from wear and tear and in the case of some species of lizard, such as the Australian thorny devil, serve to protect from attack. The horned iguana from the West Indies is also one of the most heavily armoured. The skin is rich in pigment cells, which provide effective means of camouflage, and the chameleon is a well-known example. Temperature control is important to reptiles: they cant generate body heat internally or sweat to keep cool.
In the final film, he reflects on the dramatic impact that humankind has had on the natural world within his own lifetime. He tells the surprising and deeply personal story of the changes he has seen, of the pioneering conservationists with who he has worked - and of the global revolution in attitudes towards nature that has taken place within the last six decades. In a journey that takes him from the London Zoo to the jungles of Borneo, Attenborough reveals what inspired him to become a conservationist. He remembers classic encounters with mountain gorillas, blue whales and the giant tortoise, Lonesome George. These are all characters that have helped to change public attitudes to the natural world.
A look at one of the most famous habitats on the planet, the Serengeti in East Africa, a vast grassland that is home to some of the greatest concentrations of herbivores on the continent. But what is the key to this exceptional grassland that allows such density and diversity?
Using a specially designed hive, with a formidable arsenal of cutting-edge technology to monitor the bees, we enter the bees' miniature world. Chris and Martha also put to the test the very latest scientific findings about bees, to discover why they are one of the most incredible creatures on our planet.
Helen reveals the latest scientific insights into icebergs. From side-scanning sonar that scrutinises the edge of glaciers where icebergs are born, to satellite images that show how icebergs create hotspots for life and eyewitness pictures that give us a unique glimpse of how they transform over time, we can now capture on camera the mysteries of icebergs - and how their lifecycle is intricately linked to our changing planet.