The assassin's bullet misses the Archduke's carriage moves forward & a catastrophic war is avoided. So too with the history of life. Re-run the tape of life as Stephen J. Gould claimed & the outcome must be entirely different: an alien world without humans & 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 & it seems that such Earth-like planets may be much rarer than hoped. Inevitable humans yes but in a lonely Universe.