‘The important point is that since the origin of life belongs in the category of at-least-once phenomena, time is on its side. However improbable we regard this event, or any of the steps which it involves, given enough time it will almost certainly happen at least once. And for life as we know it, with its capacity for growth and reproduction once may be enough. Time is in fact the hero of the plot. The time with which we have to deal is of the order of two billion years. What we regard as impossible on the basis of human experience is meaningless here. Given so much time, the “impossible” becomes possible, the possible probable, and the probably virtually certain. One has only to wait: time itself performs the miracles.’
George Wald (late Professor of Biology, Harvard University), ‘The origin of life’. Scientific American, vol.191 (2), August 1954, p.49.