Melvyn Bragg and guests discuss the simple animals which informed Charles Darwin's first book, The Structure and Distribution of Coral Reefs, published in 1842. From corals, Darwin concluded that the Earth changed very slowly and was not fashioned by God. Now coral reefs, which some liken to undersea rainforests, are threatened by human activity, including fishing, pollution and climate change.

With

Steve Jones Senior Research Fellow in Genetics at University College London

Nicola Foster Lecturer in Marine Biology at the University of Plymouth

And

Gareth Williams Associate Professor in Marine Biology at Bangor University School of Ocean Sciences

Producer Simon Tilllotson.