'Blood Brothers' follows the lives of two species, Paranthropus boisei and Homo habilis who embody two alternative ways of ape-man life. Although heavyset, with distinctive gorilla-like faces, the boisei are gentle characters. They live within a strict social structure and are led by a dominant male whose strength and power holds the group together. The habilis have taken a different approach to survival. They don't have the specialisms of the boisei but instead have developed into the archetypal jack-of-all-trades, inquisitive scavengers prepared to try almost anything to survive. Tough, active, gregarious and noisy, they are always on the move and always alert to the possibility of a meal. But in the near drought of the dry season the habilis are struggling. It seems as if their way of life cannot help them when conditions are tough.

A visit to the Amazon jungle - the world's largest rainforest and home to the widest variety of plants and animals on Earth. he diversity of life in the jungle is so great that in just two square miles scientists have counted 3,000 varieties of ants, 530 types of birds and 11 species of monkey. But despite the huge range of life that flourishes here, survival is never easy.

Could we be unique in the universe or is there another planet similar to earth somewhere in the cosmos? Is it possible that Alpha Centauri, our nearest star, is home to another earth-like planet? Earth sized planets have been hard to find, but indirect methods are coming on line to give scientists a good survey of how many such bodies may be in the universe. How rare would it be to find life on another earth-like planet?

A variety of cosmic events have both helpful and harmful effects on life on Earth. From the beauty of the Aurora Borealis and rainbows to the dangers of UV radiation and cosmic rays, from the miracle of photosynthesis to the thrill of a meteor shower, this episode explores how the effects generated by the sun and other extra-solar sources can literally get under our skin, scramble our technology, make life possible and threaten our existence all at the same time

This episode focuses on the Jurassic period, a time when the first giant killers stalked the Earth and lurked in the seas; a time when the slightest advantage meant the difference between life and death. In North America the iconic allosaurus, an ambush hunter with a lethal bite, dominated. Not even the heavily-armoured stegosaurus was safe from this killer, and incredible evidence reveals a glimpse of a vicious battle between these two giants. Life in Jurassic oceans was no easier; in 2008, a fossil was dug out of a frozen island high in the Arctic. It was a colossal marine reptile, twice as big as most ocean predators, at 15 metres long and weighing about 45 tonnes. This was Predator X. Its skull alone was nearly twice the size of a tyrannosaurus rex's, and its bite force unmatched by anything in the Jurassic seas. The balance of power between predator and prey is a fine one, as prey continually evolves different ways to avoid predators. But for the most successful and enduring predators, the battle to survive has always been tipped in their favour

David Attenborough comes face-to-face with a baby rhino and asks what the future holds for this little one. He meets the local people who are standing side-by-side with the wildlife at this pivotal moment in their history. We discover what it takes to save a species, hold back a desert and even resurrect an entire wilderness - revealing what the world was like before modern man.