The Noahide Flood

[Gawdzilla Sama]

Okay, four females and four males on the Ark. 75% presumptively of breeding age. How many kids would the women have to pop out to reach 7,888,000,000 people today? Pick any likely date for the Flood, it will be as accurate as any other.

If you ignore effects of things like limits of ecological carrying capacity, plagues, hereditary diseases made worse by incest, and other mass culling influences, then the reproductive rate required to start with a tiny founder population and fill the earth with writhing humans within a few thousand years is amazingly low, given any reasonable estimate of reproductive age.    If you assume generation gap is 16 years and average life expectancy is 32 years (true for most of human history), then each woman only need to pop out an average of between 2.1 and 2.2 offsprings who go on to reproduce to get you to population of billions of people within 5000 years.

Even with all the limits of ecological carrying capacity, plagues, hereditary diseases made worse by incest, and human sacrifice and other culling influences competing to kill them off,  the native Americans still went from a founder population of at most a few hundred people about 13000 years ago to over 100 million people just before Europeans showed up and killed 95% of them with mostly plague.

Thing is, there were more than that number of childbearing age a long time before the window for the Noachian nonsense, world wide. China was already headed down the overpop road.