Oxygen – we all need it, we can't live without it. It's integral to life on this planet. And it's probable that, as you watch this film, you will be breathing in an oxygen atom that was also breathed by Genghis Khan – or by the first ever apes to stand upright on the plains of Africa. The oxygen that we breathe is made from two oxygen atoms joined together – O2. They were first joined more than 3 billion years ago by the earliest blue-green algae to evolve. The oxygen molecule first came from bacteria and was present in the fires that destroyed the dinosaurs and the chemical reactions in all human cells, and as ozone they protect the earth from radiation. Since then, both together and apart, they've had the most extraordinary adventures. Each of the two atoms in an oxygen molecule is virtually indestructible – so they have been first-hand players in some of the most dramatic events in the whole of Earth's history. It's often said that we are breathing the same oxygen that the cavemen did. The life of a single molecule of oxygen is traced on it's astonishing journey spanning millions of years, from its creation, into photosynthesis, through the age of the dinosaurs, early man, and on into today.
David Harewood narrates a documentary exploring three of the most exotic and remote islands on the planet, beginning with the unique and extraordinary wildlife of Madagascar. As the oldest island on Earth, life has had time to evolve and there are now more unique plants and animals on Madagascar than any other, with footage of ring-tailed lemurs, labord's chameleons and Decken's sifakas.
This episode details the relationship between flowers and insects. There are some one million classified species of insect, and two or three times as many that are yet to be labelled. Around 300 million years ago, plants began to enlist insects to help with their reproduction, and they did so with flowers. Although the magnolia, for instance, contains male and female cells, pollination from another plant is preferable as it ensures greater variation and thus evolution. Flowers advertise themselves by either scent or display. Some evolved to produce sweet-smelling nectar and in turn, several insects developed their mouth parts into feeding tubes in order to reach it.
On a journey across Africa towards the war-torn Congo, the travellers encounter chimpanzees, gorillas and elephants, but are there any northern white rhinos still alive in the wild? The news is not good but there is some hope in the remarkable project under way to save the black rhino in Kenya.