The Cell - The Spark of Life (Part 3/6)

Dr Adam Rutherford concludes his compelling journey through 350 years of science to discover the secrets of the cell and of life itself. The Spark Of Life begins with some of the earliest evidence of life on Earth: fossilised cells that are a staggering one billion years old. It is now believed that all life on Earth began with one primordial cell from which every living thing evolved. Today, however, knowledge of the cell has brought humankind to the brink of something truly profound. Scientists may be about to create living cells from scratch and, if they succeed, it will be the first life form on Earth that has not evolved from that original cell. It would be the Second Genesis.

To show how this has become possible, Adam traces the scientific quest to understand how the first cells came into existence in Earth's distant past. From bizarre experiments that recreated the toxic chemical soup of the early Earth, to startling new revelations from inside meteorites, he tracks down evidence of the very first living cells on the planet.

At Harvard University, Adam meets the scientists at the Origin Of Life initiative who are coming close to creating living cells in the laboratory. Filmed for the first time are Professor Jack Szostak's "proto-cells", which can feed, grow and divide in primitive ways fulfilling some of the key requirements of life. Even more astonishing are Professor George Church's synthetic cell parts, which can perform the single most important process at the heart of all life: reading DNA code and carrying out its instructions.

Scientists using Church's techniques have already manipulated naturally occurring cells to do extraordinary things. Adam meets a team in San Francisco, led by Dr Steve del Caldayre, that has radically re-engineered bacteria cells so that, when fed sugar, they produce clean diesel oil. This new science of synthetic biology is already coming up with life-changing solutions to some of the most pressing challenges facing humankind. But Adam asks how much further scientists will go when they cross the threshold and create new cells from scratch