The whole world in our hands: “the origin of life is a puzzle. Think of it as a kind of reverse murder mystery. The bringing-to-life happened in a locked room in a strange world 3.4 bn years ago. There is no surviving scene of the not-crime. There are no footprints, no strewn clues. The evidence was destroyed by the very creatures that rose from original experiments in fashioning the living chemistry from non-living chemicals. Whatever conditions made life possible were promptly erased by the action of life itself. The last surviving universal common ancestor went round eliminating all chances of new rivals emerging.”