The Celts, Germans, and Slavs all had one thing in common and that was their fair skin, in contrast to the relatively darker Mediterraneans, the much darker Indians, and the very dark Ethiopians. This trait is thought to have developed over thousands of years of humans living in northern lands during the ice age. Under such conditions, the diet was probably poor and the pale skin made it easier for the body to synthsize vitamin D from exposure to the sun. Evidence indicates that cannibalism was also common (as is the case in other lands where high-protein foods were not always available, such as the South Seas and West Indies). When these peoples moved south, their diet got better, the sunlight more powerful and cronic sunburn was the result. Folks living further south tended to be increasingly pigmented, in part to protect them from excessive exposure to sunlight. Of course, the present inhabitants of arctic regions, the Eskimos, are dark skinned. But apparently the pale faces lived up north far longer than the Eskimos have. On the other hand, the pale skin might just be another random mutation, with the vitamin D angle being a fortuitous side effect.