There is something I want to share with “fellow Europeans”, and it is something hard to describe. It is to, in a moment, “feel” the past. How can I convey this? How can I show this?
Around 7700 BC, white skin had “reached fixation”, or the highest prevalence in the genome until today or some later decline, in modern-day Sweden. Some time around 3500 BC, white skin reached fixation in the rest of Europe.
I don’t say this because white skin is super-important (though melanin is a hormone and it’s absence will have causal effects on behavior), but just to give an idea of how quickly a genetically-based trait can spread. The late Henry Harpending in his book “The 10,000 Year Explosion” explains introgression, whereby the genes of a different population can enter another population, and then those genes get selected upon, the result being that a trait could spread through the population faster than you would expect from traditional natural selection.