Conquest of the Waters
Fish occur in populations of billions and there are over 30,000 species, more than in any other group of backboned animals. The development of the backbone was a crucial advance in evolution -and it probably came from a most unlikely source, a little jelly-like creature called a sea squirt.
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S1 E1
The Infinite Variety
The first ever episode of the landmark natural history series Life on Earth. David Attenborough explores the wildlife and landscape that inspired Charles Darwin's theory of evolution.
S1 E2
Building Bodies
Bright blue starfish, crimson feather stars, shell-less snails in designs as extravagant as any Paris fashion show, shrimps of every colour, others that are transparent - just a sample of the animal wonders to be found in a small area of the Great Barrier Reef.
S1 E3
The First Forests
For most of Earth's history there was no life on land. But over 400 million years ago some tiny plants began an invasion from the water, closely followed by the first animals - the ancestors of millipedes and insects.
S1 E4
The Swarming Hordes
David Attenborough looks at the role of a few of the millions of insect species, some of which have developed extremely close relationships with plants. Insects pollinate flowers and in some cases neither flower nor insect can survive without the other.