How did we get here? Following a trail of clues from the latest scientific research, Dr Alice Roberts re-traces the greatest ever journey taken by our ancestors. Thousands of years ago one small group of our species, Homo sapiens, crossed out of Africa and into the unknown. Their descendants faced baking deserts, sweat-soaked jungles and frozen wildernesses and risked everything on the vast empty ocean.

Professor Brian Cox visits Geneva to take a look around Cern’s Large Hadron Collider before this vast, 27km long machine is sealed-off and the experiment to create the simulation of a black hole begins. When it’s up and running, it will be capable of creating the conditions that existed just a billionth of a second after the Big Bang. Brian joins the scientists who hope that the LHC will change our understanding of the early universe and solve some of its mysteries. The Large Hadron Collider is not just an extraordinary science experiment, it is also a remarkable engineering undertaking. As BBC science reporter James Morgan relates, just getting it built is an astonishing story in itself.

Tiger experts in Bangladesh have a problem: how can they encourage local people to protect the beautiful and endangered Bengal tiger when these animals have developed a taste for human flesh?

The Sundarbans forest is one of the biggest tracts of mangrove forest left in the world. It is rich in wildlife and provides important forest resources for communities living around its edge. But up to 50 forest workers are killed by tigers each year and now the boldest animals are sneaking into villages at night.

This gripping film reveals the tension and heartache of living so close to a killer cat and follows the bold attempt by one village to teach street dogs to scare away the rogue tiger on their doorstep.

Wildlife documentary. Environmentalist and photographer, Sandesh Kadur, has traded a comfortable career in the family business to explore the natural wonders of the Western Ghats mountains. Just a few hours drive from the commercial bustle of his native Bangalore, Sandesh could be a world away. The monsoon pours six metres of rainfall each year on the remote peaks and isolated valleys of the Ghats. Alongside familiar Indian species like elephants, tigers and peacocks are more mysterious creatures that are found nowhere else: a purple frog with a face like a shrew and a monkey with a lion-like mane and tail.

Most intriguing of all, a chance sighting of a grey big cat, unlike anything scientists have seen before. To find out whether this enigmatic cat-in-the-ghat really is a new species, Sandesh must climb to the summit of these mountains. His journey is a reminder that in fast-track, modern India, this cloud-wrapped wilderness is more precious than ever.

State of the Planet is a three-part environmental documentary series, made by the BBC Natural History Unit, transmitted in November 2000. It is written and presented by David Attenborough, and produced by Rupert Barrington. It includes interviews with many leading scientists, such as Edward O. Wilson and Jared Diamond. Each of the programmes attempts to find answers to the potential ecological crisis that threatens the Earth. Attenborough fronted this series in between presenting his 1998 ornithological study, The Life of Birds, and providing narration to the award-winning 2001 series The Blue Planet.
Part 1: Is There a Crisis?
Part 2: Why is There a Crisis?
Part 3: The Future of Life