A human race is defined as a group of people with certain common inherited features that distinguish them from other groups of people. All men of whatever race are currently classified by the anthropologist or biologist as belonging to the one species, Homo sapiens. This is another way of saying that the differences between human races are not great, even though they may appear so, i.e. black vs white skin. All races of mankind in the world can interbreed because they have so much in common.
Most anthropologists recognize 3 or 4 basic races of man in existence today. These races can be further subdivided into as many as 30 sub groups.
(The Australoid or Australian Aborigine, is sometimes regarded as a sub group of the Caucasoid as they have many features in common with this group despite their dark skin. The American Indian is usually classed with the Mongoloid division).
The most significant difference between these races is: -
(a)
language
(b) hair and facial features
(c) skin colour. This distinguishing feature is primarily due to
difference in amount of the pigment, melanin, in the skin. This melanin
protects the body by absorbing ultraviolet (UV) radiation from the
sunlight which falls on the skin. UV radiation can damage the skin and
produce skin cancer if it is not filtered out in this way. The shades of
colour in human skin can be represented by the Von Luschan Scale and
ranges from almost pure white to pure black.
Differences such as hair, skin and facial features are almost certainly inherited, but the way in which their inheritance is controlled is little understood, and definitely not simple. In skin colour, for instance, 2 to 4 pairs of genes are involved. (Genes are the units in each cell of the body that carry inherited information) It is known that some of these genes produce lightness and some darkness. The brown skinned person has genes for both dark and light. The darker person has more genes for darkness and the lighter person has more genes for lightness.