There "were" 8 people on the ark, so the entire world population would have been reduced to 8, with only three reproducing couples. The Bible doesn't record Noah and his wife as having any children after the flood. Instead we get: "These three were the sons of Noah, and from these the whole earth was populatesd." Gen 9:19Mr_E wrote:We should actually start 4000 years ago with 9 people after the flood. What i am trying to figure out, is whether or not it is possible for 9 to turn into 7 billion in 4000 years.
So it's probably best to stick with 6 for the starting population.
It's definitely possible for the human population to grow this fast if they are able to create enough agricultural surplus.