Four years in the making, Life will set a new benchmark in family entertainment and natural history epics. Many animals and plants go to extremes to give themselves a chance. Aerial photography reveals how bottle-nosed dolphins trap fish in a ring of mud, and time-lapse cameras show how the Venus flytrap ensnares insect victims. The strawberry frog carries a tadpole high into a tree and drops it in a water-filled bromeliad. Fledgling chinstrap penguins undertake a heroic and tragic journey through the broken ice to get out to sea. Many can barely swim and the formidable leopard seal lies in wait

Reptiles and amphibians look like hang-overs from the past. But they overcome their shortcomings through amazing innovation. The pebble toad turns into a rubber ball to roll and bounce from its enemies. Extreme slow-motion shows how a Jesus Christ lizard runs on water, and how a chameleon fires an extendible tongue at its prey with unfailing accuracy. The camera dives with a Niuean sea snake, which must breed on land but avoids predators by swimming to an air bubble at the end of an underwater tunnel. In a TV first, Komodo dragons hunt a huge water-buffalo, biting it to inject venom, then waiting for weeks until it dies. Ten dragons strip the carcass to the bone in four hours.

The documentary deals with the future of conservation. It begins by looking at previous efforts. The 'Save The Whales' campaign, which started in the 1960s, is seen to have had a limited effect, as whaling continues and fish stocks also decline. In the 1990s, as head of the Kenya Wildlife Service, Richard Leakey took on the poachers by employing armed units. Although it was successful in saving elephants, the policy was detrimental to the Maasai people, who were forced from their land. The need for "fortress" areas is questioned, and the recently highlighted Raja Ampat coral reef in Indonesia is an example. The more tourism it generates, the greater the potential for damage — and inevitable coastal construction. Sustainable development is viewed as controversial, and one contributor perceives it to currently be a "contradiction in terms". Trophy hunting is also contentious. Those that support it argue that it generates wealth for local economies, while its opponents point to the reducing numbers of species such as the markhor. Ecotourism is shown to be beneficial, as it is in the interests of its providers to protect their environments. However, in some areas, such as the Borneo rainforests, the great diversity of species is being replaced by monocultures. The role of both religion and the media in conservation is argued to be extremely important. Contributors to the programme admit a degree of worry about the future, but also optimism.

In this final episode we complete our journey, travelling back from the March equinox to the end of June. Kate Humble is in the Arctic at a place where spring arrives with a bang, whilst Helen Czerski chases a tornado to show how the earth's angle of tilt creates the most extreme weather on earth.

The tropical island of Mauritius is home to Melrose maximum security prison, where 800 of the country's worst drug smugglers, sex offenders and murderers are locked up. Every convict is watched day and night and even the smallest infraction is met with extreme punishment.

Welcome to an extreme landscape of rock, ice and snow. We tour the mightiest mountain ranges, starting with the birth of a mountain at one of the lowest places on Earth and ending at the summit of Everest. Find out how some of the most secretive animals rise to the challenge of mountain life. Share one of Earth's rarest phenomena, a lava lake that has been erupting for over 100 years. The same forces built the Simian Mountains where we find troops of gelada baboons nearly a thousand strong. In the Rockies, grizzlies build winter dens inside avalanche-prone slopes and climb the peaks to devour abundant summer moths. In another world first, the programme brings us astounding images of a snow leopard hunting on the Pakistan peaks.