Draw a circle on the wall, list all probable causes and maybe’s, throw one dart! You probably came as close as anyone else.
Occam's Razor is useful here for discounting the moon bat theories such as this one. All animals have variations on a theme alive today except for one: humans. There were many humanoids in the past but despite their high intelligence they all died off. The simplest explanation is that they were killed off in war, by us. Modern humans are remarkably all the same and that's because war trims the competing tribes down to best of breed, culture, and technology. Narcissistic leftists refuse to accept that man is a war maker by nature so they grasp at every moon bat theory they can.