A humpback whale mother and calf embark on an epic journey from tropical coral paradises to storm ravaged polar seas. Newly discovered coral reefs in Indonesia reveal head-butting pygmy seahorses, flashing 'electric' clams and bands of sea kraits, 30-strong, which hunt in packs. Elsewhere plagues of sea urchins fell forests of giant kelp. Huge bull fur seals attack king penguins, who despite their weight disadvantage, put up a spirited defence.

The Taiga forest, on the edge of the Arctic, is a silent world of stunted conifers. The trees may be small but filming from the air reveals its true scale. A third of all trees on Earth grow here and during the short summer they produce enough oxygen to change the atmosphere. In California General Sherman, a giant sequoia, is the largest living thing on the planet, ten times the size of a blue whale. The oldest organisms alive are bristlecone pines. At more than 4,000 years old they pre-date the pyramids. But the baobab forests of Madagascar are perhaps the strangest of all.

SETTING: 72 million years ago, near present-day Montana. As a young male daspletosaurus, it's Das' job to herd unsuspecting prey towards the rest of the pack. But he's easily distracted and ruins several hunts getting him in deep trouble with his mother, the pack leader. When a volcano threatens, the dinosaurs are unprepared.

SETTING: 80 million years ago in the South American forests of Patagonia. The world is a very dangerous place for tiny hatchlings like Alpha, a female saltasaur. Follow Alpha along the road of her growth years, from before her birth through asolescence and on to adulthood, as she learns how to survive and beat the odds.

They are the most powerful objects in the universe. Nothing, not even light, can escape the gravitational pull of a black hole. Astronomers now think there are billions of them out in the cosmos, swallowing up planets, even entire stars in violent feeding frenzies. New theoretical research into the twisted reality of black holes suggests that three-dimensional space could be an illusion. That reality actually takes place on a two-dimensional hologram at the edge of the universe.

Everywhere we look in the most hospitable of environments and in the most extreme we find life. On Earth, life exists everywhere we look. Yet we have only ever found life on our planet. How did the stuff of stars come together to create life as we know it? What do we really mean by 'life'? And will unlocking this mystery help us find life elsewhere?