Flood accounts do not equate to a worldwide deluge where even the mountains are submerged and an ark is needed to save a selection of people and animals in order to repopulate the earth......It did not happen, the story is impossible.
The story was probably embellished from a localized flood event/hero legend what a family saved their themselves and their livestock under difficult conditions, to the amazement of the surrounding tribes.
But DNA studies are showing a lot of evidence for the human race coming from a single couple and then a wipeout and then re-population. Maybe you don't believe the evidence gathered from DNA.
The DNA evidence suggests that a bottleneck in the human population occurred about 70,000 years ago wherein we may have been reduced to as few as 10,000 individuals on the planet.
