One of the greatest conundrums of life is how we emerge from a single cell into a walking, talking, multi-trillion-celled organism that we call the human body.

In the second of this year's Christmas Lectures, Dr Alison Woollard from the University of Oxford unravels this mystery of life. She reveals that the extraordinary diversity has all come about by genetic mutation. Life revolves around the survival of the fittest mutant.

In this year's final Christmas Lecture, Dr Alison Woollard from the University of Oxford, tackles a question that has intrigued scientists and natural philosophers for centuries. The cycle of life and death affects all cells, but Alison reveals a shocking truth - that 'cell death' plays an important part in life. It enables the development and survival of most multi-celled organisms from hedgehogs to humans.