For even if the life of my own Earth and this other Earth on which I stood had started out identically (and they might well have started out identically) there still would be, along the way, millions of little deviations, no one of which, perhaps, by itself, would be significant, but the cumulative effects of all these deviations eventually would result in a life and culture that would bear no resemblance to any other Earth.
Clifford D. Simak