The Caucasian Race and Albinos

The question

Is the Caucasian race descended from emigrated albinos?

M. van der Eems, Hoogezand

The answer

This question is based on a misunderstanding: Caucasians are not albinos. Albinism is a hereditary disease that can afflict humans and animals, but also plants. Human and animal albinos do not have a gene that regulates the production of melanin, which leads to white skin, white hair and red eyes. There are different types (depending on where the genetic material has been modified), with some where there is still some pigment in the skin or hair. This is not, however, the same as being ‘Caucasian’; Caucasians do not have any anomalies in the genes coding for melanin. Exposure to the ultraviolet (UV) light in sunlight causes Caucasian skin to produce melanin and the skin tans (although this varies from person to person). Albinism also can afflict Caucasians, although to a lesser degree than it will the populations of Sub-Saharan Africa and in some populations where mixing of genetic material has remained at a minimum for lengthy periods of time.

Albinism often also involves various skin and eye diseases and disorders, an increased chance of types of skin cancer and disorders in the blood and/or nervous tracts and/or the immune system. Albinos often die early. The disorder is rare. Albinos are fertile. The hereditary disorder is recessive, which means that both genes (from the father and the mother) must be present for albinism to manifest itself. Children with an albino and a ‘coloured’, i.e. normally pigmented, parent thus will also be normally pigmented, unless the normally pigmented parent is a carrier of albinism due to genes inherited from his or her parents (this means that the chance is 50%).

Another reason to disbelieve that albinos migrated is the gradual change in skin colour related to the distance from the equator (this is true in a general sense and if mass migration is taken into consideration).

So what is the explanation for the differences in skin colour? Evolution can explain it. A dark skin provides the best protection against UV damage due to (tropical) sunlight. In temperate climate zones, however, a dark skin limits the amount of sunlight responsible for vitamin D production. Vitamin D is required for calcium absorption and bone growth. The skin colour best adapted to a particular latitude (i.e. distance from the equator) is the one that provides protection from UV damage on the one hand, and vitamin D production on the other. There are a few exceptions, but these can be explained: Inuit (Arctic populations) have a relatively dark skin but do not lack vitamin D, which is found in large quantities in their diet (in fish fat and marine mammals).

Kind regards,

C.M. Ree Science Shop University of Groningen

Translated by Anniversary Project Group