I’ve just found a fantastic article which I really like for its many interesting maps. It tells the story of how surprisingly pale-skinned Europeans are (given that other peoples from similar latitudes are still fairly brown).
Apparently, the explanation is that the Gulf Stream (which keeps Europe much warmer than other places that far north) allowed for the growth of cereals (wheat, etc.) starting about 5,000-13,000 years ago, and the widespread adoption of cereals in Europeans’ diets caused a significant shift in our skin colour – it’s all to do with vitamin D and folates. And the shift in skin colour in turn caused the incidence of blond hair and blue eyes which is so unique to northern Europeans.
Read the article to find out more.