I read an interesting article about the evolutionary effect of the European Neolithic diet. Apparently our pale skin as a total oddity - people generally get paler or darker depending on their proximity to the equator, but people to the north, south, east and west of Western Europe are darker than Europeans. The reason was something to do with the amount of fish we ate modifying the amount of vitamin D in our diet so that we had to evolve a paler skin colour to cope with our levels of sunlight. I can't remember the details now.