"In other words, the fact that it has happened at least once very strongly suggests it has happened more than once." No, it doesn't at all. Maybe just the opp

"In other words, the fact that it has happened at least once very strongly suggests it has happened more than once." No, it doesn't at all. Maybe just the opposite. The universe is mind-bogglingly large, but it's also really, really empty, and really, rally sparse. The numbers games starts to dwindle very quickly in terms of all the ingredients necessary. And the Fermi paradox helps provide crudely indirect evidence. If there was any validity at all to the 'common life theory' - then it would have started long ago and probably spread everywhere to the point wherein there would probably be ample evidence. In the 'common life' scenario, it should be rare/impossible to find life that's disconnected from other life scenarios. There's a decent chance we are alone.