If we have had our current form IE brain size and abilities for over 100,000 years, I have a question? What makes us think that our current development of civilization is the pinnacle? Could we have had other civilizations develop in the preceding 90,000 years. After all we have had a few planet changing events in those years. Higher sea levels, Ice age and meteor strikes etc.
So the question I would like to discuss is were there several great civilizations before our current existence. Please comment.