I have yet another dumb question.
How could the “great leap” have occured in all those divergent groups, considering that they had already diverged?
We inherited our humanity from peoples in southern Africa 300,000 years ago. The alternative—that everyone, everywhere coincidentally became fully human in the same way at the same time, starting 65,000 years ago—isn’t impossible, but a single origin is more likely. The Great Leap occurred 65,000 years ago, but not all groups participated equally. According to the author, the "humanity" was there in all of them, and they were all capable of making the leap (this I doubt), even if their group didn't do much with that inherent ability. They all may have begun using spears, etc., around the same time, but it's fairly evident some merely copied their neighbors, not invented new tools.
