Pre-history

Interesting show on pre-historic events: Ancient Apocalypse. What seems to be missing is more discussion of how many waves of prehistory to history, to fall of civilizations were there. Did we have several Asimov: Nightfall type situations, where whether due to barbarianism, ecocatastrophes, or climate change, that people moved away from previous, thriving examples of civilization, culure, technology, and engineering? Graham Hancock keeps asking important questions for science. Why are they opposed to new facts, or ideas? Such as having human/neanderthal activity in places?