The Flood Story in the bible may have been inspired from a comet that passed close to earth causing the Ice Age that froze the earth in a icey grip and killed off the dinosaurs while most of the other animals and the cave people (if there were any humans at the time) to go deep under ground in caves not big enough for the woolly mamouths and dinosaurs, and therefore the "Ark" was actually the earth its self and the flood was the Ice-Age, but to the ancient story tellers not being of scientific minded as in later times turned the Ice-Age and the passing of the comet in to a story that would be more acceptable to the people of that time (when the bible was first written) and because of the fundamental belief system of the bible believers they accepted the flood story given by the story tellers as an actual event of it raining forty days and forty nights which may have been the time the comet passed over the earth plunging the earth in to the Ice Age while blocking out the sun. And it might not have happened through out the earth, but nearer its poles at the time is why scientists have discovered plant life in core samples beneath Antarctica, while Australia may have once been the South Pole.