How scientist James Lovelock came to see the Earth as a holistic, self-regulating system.

In the first of a three-part series, Professor Dame Jocelyn Bell Burnell describes how she discovered pulsars, the by-products of supernova explosions which make all life in the universe possible. She describes the moments of despair and jubilation as the discovery unfolded and her excitement as pulsars took the scientific world by storm.

The final part of this series looking at three brilliant contemporary scientists features Sir Tim Hunt, awarded the Nobel Prize for his discovery of the mechanism of how cells divide - a discovery fundamental to the life and growth of every single creature on the planet, as well as a vital clue into the mystery of cancer.

Physicist Professor Andre Geim\'s constant search for new ideas has led to some extraordinary discoveries, from levitating frogs to a tape that sticks to surfaces like a gecko\'s foot. He reveals how his playful approach to his research helped him uncover the properties of graphene, the world\'s thinnest material, and won him a Nobel Prize.

For paleontologist Professor Jenny Clack, who solved one of the greatest mysteries in the history of life on Earth, success was far from inevitable. She recounts how she had to overcome a series of setbacks before she found and described the fossil Acanthostega, a 365 million-year-old creature that offered dramatic new evidence of how fish made the transition onto land.

Professor Richard Dawkins reveals how he came to write his explosive first book The Selfish Gene, a work that was to divide the scientific community and make him the most influential evolutionary biologist of his generation. He also explores how this set him on the path to becoming an outspoken spokesman for atheism.