> The fact of the matter is that for a long time we simply did not have the population density to scale up to modern civilization standards That's true and I a

> The fact of the matter is that for a long time we simply did not have the population density to scale up to modern civilization standards That's true and I agree. But how would we know what the population density was of a conjectured civilization that would have been virtually totally destroyed over a hundred thousand years ago by catastrophic climate change?[1] I'm not positing some super society with flying cars and crystal skyscrapers or anything, but something more like the ancient Egyptian or Mesopotamian kingdoms that we do know about. There is a difference in kind and not degree between stating that it's absolutely impossible for any complex human civilization to have existed before 12,000 years ago and it's possible but we have little to no evidence for it. In the former world view any evidence to the contrary is immediately ignored as being impossible, whereas in the latter lines of inquiry remain open, despite being admittedly rather barren. [1] https://en.wikipedia.org/wiki/Last_Glacial_Period https://en.wikipedia.org/wiki/Last_Glacial_Period