With regards to the skin colour this shouldn't come as a surprise. Everyone knew that Humanity originated from Africa and that people didn't grow from out the ground after the ice retreated 10,000 years ago.
Considering people like Blackleaf are likely to believe Britain was white, always was white and was never any other color are out there, I thought it was an interesting thing to post up as a "told you so".
That being said, the color of skin before and during migrations of humans is fascinating in and of itself.
Recent immigrants to northern climes? The arctic asiatic people probably settle there well after the last ice age. As far as i can figure there are 3 main types of malanin..eumelanin, pheomelanin and neuromelanin.. the first, eumelanin, is present in skin and hair and is especially abundant in dark skinned races and especially low in the blonde pale skin traditionally seen in northern European and Scandinavian populations. Genetic advantage would indicate over generations this would prevail in low UV environments in the north.
I wouldn't call the settlement of the northern climes "recent". As well, you have darker colorings of people in the southern hemisphere as well (look at Aztec/Myans; fairly dark colored and not likely due to 'tanning).
While I agree that the white coloring (of anything, humans and animals) is a northern trait, considering the other colors of both animals and humans and how white, IMO, is more a minority color, it's just made me now wonder why people believe white to be superior?