The assassin's bullet misses, the Archduke's carriage moves forward, and a catastrophic war is avoided. So too with the history of life. Re-run the tape of life, as Stephen J. Gould claimed, and the outcome must be entirely different: an alien world, without humans and maybe not even intelligence. The history of life is littered with accidents: any twist or turn may lead to a completely different world. Now this view is being challenged. Simon Conway Morris explores the evidence demonstrating life's almost eerie ability to navigate to a single solution, repeatedly. Eyes, brains, tools, even culture: all are very much on the cards. So if these are all evolutionary inevitabilities, where are our counterparts across the galaxy? The tape of life can only run on a suitable planet, and it seems that such Earth-like planets may be much rarer than hoped. Inevitable humans, yes, but in a lonely Universe.

The Cambridge Sandwich; 1. Looking for Easter Island; 2. Can we break the great code?; 3. Universal Goo: life as a cosmic principle?; 4. The origin of life: straining the soup or our credulity?; 5. Uniquely lucky? The strangeness of Earth; 6. Converging on the extreme; 7. Seeing convergence; 8. Alien convergences?; 9. The non-prevalence of humanoids?; 10. Evolution bound: the ubiquity of convergence; 11. Towards a theology of evolution; 12. Last word.