The Miller-Urey experiment was the first attempt to scientifically explore ideas about the origin of life. Stanley Miller simulated conditions thought be common on the ancient Earth. The purpose was to test the idea that the complex molecules of life (in this case, amino acids) could have arisen on our young planet through simple, natural chemical reactions.
In southern Africa, a pride of lions has rewritten the rules - by learning to take down elephants. In this follow up to Africa's Giant Killers, we join the pride at the start of the rainy season. As the elephants depart, a catalogue of dramatic events unfolds. The pride males turn against each other, an inexperienced mum puts her new born cubs in mortal danger, a rival group of lions challenge the pride for its territory and, when lightning strikes, fires burn day and night. When the dust eventually settles, the pride is left with only one choice - to face their old foe the elephants or risk starvation. The final showdown awaits.
A behind-the-scenes special offering an insider's look at Sir David Attenborough's innovative series exploring the macroscopic world of bugs. David reveals how the film-makers got up close with the insect and arachnid world for the innovative documentary series
The documentary series reveals the extraordinary riches and wonders of the Polar Regions that have kept people visiting them for thousands of years. Today, their survival relies on a combination of ancient wisdom and cutting-edge science. Most Arctic people live in Siberia, either in cities like Norilsk - the coldest city on earth - or out on the tundra, where tribes like the Dogan survive by herding reindeer, using them to drag their homes behind them. On the coast, traditional people still hunt walrus from open boats - it is dangerous work, but one big walrus will feed a family for weeks. Settlers are drawn to the Arctic by its abundant minerals; the Danish Armed Forces maintain their claim to Greenland's mineral wealth with an epic dog sled patrol, covering 2,000 miles through the winter. Above, the spectacular northern lights can disrupt power supplies so scientists monitor it constantly, firing rockets into it to release a cloud of glowing smoke 100 kilometres high. In contrast, Antarctica is so remote and cold that it was only a century ago that the first people explored the continent. Captain Scott's hut still stands as a memorial to these men. Science is now the only significant human activity allowed; robot submarines are sent deep beneath the ice in search of new life-forms, which may also be found in a labyrinth of ice caves high up on an active volcano. Above, colossal balloons are launched into the purest air on earth to detect cosmic rays. At the South Pole there is a research base designed to withstand the world's most extreme winters. Cut off from the outside world for six months, the base is totally self-sufficient, even boasting a greenhouse.
The Rockies are the spine of North America, a beautiful wilderness of snow-capped peaks and hidden valleys. Cougars hunt in abandoned ranches, wolverines search the deep snow for food and grizzly bears hunt in the high mountain meadows. Daredevil wingsuit flier’s leap from mile-high cliffs and Native American tribes compete in breakneck horse races. It is also the range of surprises, with tiny cannibal salamanders hunting in mountain ponds and hummingbirds making enormous migrations