seems odd

 Noah and his sons and their four wives come off of the Ark and start multiplying upon the face of the Earth. The Bible plainly states that the entire Earth was repopulated by these eight people. So at first they seem sort of like one big happy family at the Tower of Babel. Then God changes their language into many languages and suddenly they almost don't seem like they have the same DNA anymore. They spread out all over the Earth and they appear to form very unfriendly alliances and relationships. Apparently it becomes common for them to kill each other. About the time we get to Abraham the people living on the earth don't seem like relatives at all. Abraham views the Egyptians as extremely dangerous. He asks Sarah to lie or tell a half truth to keep him alive.

I haven't looked into this carefully but it seems like the first time we see anybody going back and talking about us all coming from Noah is in the New Testament. I think there are a couple of lists of descendants in the Old Testament that may go back to Noah or even Adam. The point is people do not seem to consider themselves as coming from a single source of family members. It's kind of strange they suddenly just seem like they're all from different planets or something. They're all basically competing for resources and they're perfectly willing to slaughter each other in large numbers. It's kind of a strange transition.

I believe that the biblical account of Noah and the repopulation of the planet is accurate and that all people living on the planet at this time came from Noah and his descendants. It just seems strange how shallow and evil we are. When people started killing each other the first time after Adam and Eve God slaughtered everybody and started over with the ark, but after Noah God just presses on. All kinds of super evil stuff is taking place, but God just keeps pressing on with what He's got, slaughtering people as He goes.