Hmm. The more you know.

Should I take this to imply that what I learned in high school and wikipedia is wrong, or very poorly understood? From what I know, throughout the paleolithic populations started developing the knowledge and techniques for sedentary lifestyles, food preservation, and growing plants, while at the same time spreading out across the globe. Then came the end of the ice age, and these populations started slowly applying this knowledge at various points in time, with a difference in the 10^4 order of magnitude between the earliest and slowest populations.

That looks very much like the human species had "already been selected" before it was completely split into separate populations, though admittedly that alone as described in my previous comment isn't enough to explain how close they came to one another on the timeline (I would have expected a variance of ~50-80k years or so, if that were the only factor, rather than 10-11k).

Edit: I only realized after posting both comments that I have a very derogatory / adversarial / accusational tone. This is not (consciously) intentional, and I'm really grateful you brought up this point. I'm learning a lot from these comments.