Great point, DB! So now we're talking of a considerably smaller geographical area! Because there was an obvious population explosion AFTER the flood, even given the fact that longevity plummeted. As those living after the flood still lived remarkably long lives (even though
Noah himself had lived 950 years). Add in the still, far-larger number of fertile years of fathering children, this would have naturally put extensive pressures for people to seek out more and more territory for expanding their herds and any farming. But something about that post-flood world had really changed, as Noah's son,
Shem, lived 350 less years than his father, Noah. And this longevity spiral continued.
Fathered two years after the flood by Noah's son Shem,
Noah's grandson, Armpachshad, lived 435 years. And Armpachsad's son, Shela, lived
433 years. And Shelah's son, Eber, lived to be
464 years old. But beginning with Eber's son, Peleg, something shifted in the genetics that greatly diminished the longevity seen even post-flood, as Peleg, Noahs GGG grandson, "only" lived to
239 years old. And by Peleg's G grandson, Nahor, the longevity plunged again - as Nahor "only" lived to
148 years (Nahor was Noah's GGGGGG grandson. So, between Noah's grandson, Armpachshad (the first-born / post-flood child, who died at 435), and Nahor (dying at 148),
longevity had dropped 287 more years.
I don't know how long people were fertile, post-flood, but as men are known to be fertile well into their elderly years, and as plural marriages with far younger wives came into play, we can imagine the population explosion and expansion that continued after the flood. It would be interesting to have some idea of world population in that pre-flood world.
Here's an interesting conversation we had on this topic over two years ago:
viewtopic.php?t=41832