The next programme explores the various sea-living invertebrates. In Morocco, the limestones are 600 million years old, and contain many invertebrate fossils. They fall broadly into three categories: shells, crinoids and segmented shells. The evolution of shelled creatures is demonstrated with the flatworm, which eventually changed its body shape when burrowing became a necessity for either food or safety. It then evolved shielded tentacles and the casings eventually enveloped the entire body: these creatures are the brachiopods. The most successful shelled animals are the molluscs, of which there are some 80,000 different species.
David Attenborough takes a breathtaking journey through the vast and diverse continent of Africa as it has never been seen before. (Part 5: Sahara) Northern Africa is home to the greatest desert on Earth, the Sahara. On the fringes, huge zebras battle over dwindling resources and naked mole rats avoid the heat by living a bizarre underground existence. Within the desert, where the sand dunes 'sing', camels seek out water with the help of their herders and tiny swallows navigate across thousands of square miles to find a solitary oasis. This is a story of an apocalypse and how, when nature is overrun, some are forced to flee, some endure, but a few seize the opportunity to establish a new order.
In the second episode; India is a subcontinent surrounded by mountains. We explore the little-known Western Ghats at the edge India's south. Here are Monsoon hills covered in lush forests and tea gardens which shelter some of the greatest biodiversity in the world. But far to the north lies the mighty Himalayas - so vast they drive the climate by capturing the monsoon winds and protect India from the northern chill. It's a unique world full of life.
Space. It separates you from me, one galaxy from the next, and atoms from one another. It is everywhere in the universe. But to most of us, space is nothing, an empty void. Well, it turns out space is not what it seems. From the passenger seat of a New York cab driving near the speed of light, to a pool hall where billiard tables do fantastical things, Brian Greene reveals space as a dynamic fabric that can stretch, twist, warp, and ripple under the influence of gravity.