BBC Nature is changing?

Walk with the dinosaurs and beasts recreated in some of the BBC's best-loved series, unearth the world's ancient secrets in some long-unseen gems from the archive and uncover the dramatic story of life on Earth.

BBC Nature opens up the prehistoric realms, following evolutionary paths from long-extinct ancestors to today's living species, for example elephants and humans.

Explore the extraordinary history of planet Earth: how it would have looked and what life was like. Discover how mass extinctions wiped out vast swathes of living things, find out what caused them and wonder at how life on our planet has managed to cling on through the devastation.

The Earth is a little over 4.5 billion years old, its oldest materials being 4.3 billion-year-old zircon crystals. Its earliest times were geologically violent, and it suffered constant bombardment from meteorites. When this ended, the Earth cooled and its surface solidified to a crust - the first solid rocks. There were no continents as yet, just a global ocean peppered with small islands. Erosion, sedimentation and volcanic ACTIVITY - possibly assisted by more meteor impacts - eventually created small proto-continents which grew until they reached roughly their current size 2.5 billion years ago. The continents have since repeatedly collided and been torn apart, so maps of Earth in the distant past are quite different to today's.

The history of life on Earth began about 3.8 billion years ago, initially with single-celled prokaryotic cells, such as bacteria. Multicellular life evolved over a billion years later and it's only in the last 570 million years that the kind of life forms we are familiar with began to evolve, starting with arthropods, followed by fish 530 million years ago (Ma), land plants 475Ma and forests 385Ma. Mammals didn't evolve until 200Ma and our own species, Homo sapiens, only 200,000 years ago. So humans have been around for a mere 0.004% of the Earth's history.