What Causes Different Skin Colours?

The colour of a human being's skin depends on three "pigments", or colour materials, found in the body. The first of these is called "melanin", which is a brown substance. The second is called "carotene", which is a yellow substance. And the third is called "haemoglobin", which is the red pigment of blood.

The differences in skin colour found in the races of the world depend almost entirely on the amount of melanin found in the skin. We know that sunlight causes the skin tissues to produce more melanin, so people who live in hot climates have darker skin.If we go back to earliest times, we find that there were three chief groups of people developing at the same time. One was the Mongolian branch, which tended to have yellow to brown colouring. The second was the Negroid branch, which had dark to black colouring. And the third was the Caucasian branch, which had white to dark colouring.

In the course of centuries, these strains often became mixed together. This was less true of the Negroid branch, which was isolated until recently. Despite this mixing up, it used to be believed that there were five clearly separated races of mankind: Caucasian (white), Mongolian (yellow). Malayan (brown), Negro (black) and American (red). Today, scientists do not believe the human race can be divided into five separate colours. There are too many ranges of colour, even in the same stock of people!
The white race, for instance, is a mixture of three principal stocks: Mediterranean, which has a dark complexion, Nordic, which has a blond complexion, and Alpine, which has a medium dark complexion!