The original question was:
If all human races originated from the sons of Noah, how come there are such big differences between the different races? I have heard the colour differences can be explained by some theory on pigmentation and references to black people having white kids which are not Albino. Also, why are there skeletal differences that enable some races to be better than others in certain types of sport, as well as tell-tale differences in the skull and the shapes and sizes of noses, cheekbones etc.?
Answer by Diane Eager
The “big differences” between human races are actually not so great when you look at them.
Let us be very clear: there is only one human Kind, and it contains only one recognisable species, Homo sapiens, and that species has sub groups that have been labelled ‘races’ based on what have been regarded as distinctive racial characteristics. It turns out that these ‘racial features’ result from variations of features that all human races have, and no racial group has any structure or function that does not exist in another race.
The most obvious variation across mankind is skin colour, ranging from the black skin of some Africans and Melanesian Islanders to the very pale skin of northern Europeans. In spite of this apparently great difference, all skin colours are variations on the same theme. Every person’s skin colour is a combination of the same pigments: melanin, carotenoids and haemoglobin. Melanin is a dark brown pigment, carotenoids are yellow and orange, and haemoglobin is the red pigment in blood. All racial groups have all of these pigments. The differences in colour come only from variations in how much pigment is in the skin, and in their distribution within the layers of skin.
Carotenoids are found in the outermost layer of skin. Therefore, if this layer is thicker, the skin will appear more yellow. If you are a white skinned Europeans you may have noticed this on the soles of your feet, where the layer is very thick in all people. Some racial groups tend to have a relatively thick outer layer in other parts of their body, and their skin can have yellowish tinge.
Melanin is made by specialist pigment producing cells, named melanocytes. All races have much the same number of melanocytes, but they vary in how much melanin they produce, i.e. how active the cells are. In very dark people the melanocytes are active all the time, producing lots of melanin. In pale people melanocytes are not very active at any time. Most of the human race is a mid-brown colour, with melanocytes being moderately active. Furthermore, in most people the activity of melanocytes can be increased and decreased depending on factors such as exposure to the sun, or changes in hormones. However, not everyone responds equally to the same amount of sunlight – some people tan easily, some hardly at all. This gives another clue as to racial differences – they are mainly variations in the regulation, or control, of a body structure or function, and not the result of one race having a feature while another racial group doesn’t.
In the case of the skeletal variation mentioned in the question, the regulatory variation in occurs during the growing period. Variations of nose size, head shape, limb proportions, etc. result from small differences in the rates of growth of bone or other support tissue during the growth spurt periods in a person’s life. Thanks to recent advances in human genome research we know that body structures and functions are controlled by a large number of genetic switches that turn genes on and off. (See our report on the ENCODE project here.) Therefore, differences between people’s height, limb proportions, head shape, etc., result from the variation in the times when genes for growth of bone, cartilage, muscle, fibrous tissue, etc. are switched on or off.
Can racial differences be explained by all races being descendants of Noah’s family?
To answer this we need to look at the history of the human race after Noah’s flood.
Variations in skin colour were already present in Noah’s family, as indicted in the names of Noah’s sons. The name Ham means dark, and the name Japheth means fair, or light coloured. Shem’s name has nothing to do with colour so we can assume his dad thought he was normal, meaning the same colour as Noah. The ‘colour’ names of Noah’s sons indicate there were differences in skin pigmentation levels already present in Noah’s family, which would have been passed onto their immediate descendents, along with any other variations, e.g. in height, body shape, etc.
One possible outcome would have been for the descendants of the three brothers to have intermarried and over many generations these variations could have been distributed evenly throughout the whole human race. However, that did not happen because only a few centuries after the flood, mankind rebelled against God at the Tower of Babel, and God split Noah’s descendants who spoke only one language, into separate language groups and forced them to separate. ( see Genesis 10-11). God would not have split up Parents and Children in a family group because the family was His creation, so therefore the original new language groups were probably the equivalent of a clan group of related people, who would have lot of features in common, i.e. they had family resemblances. Thus, at the Tower of Babel a large and varied gene pool was split into a number of smaller, less varied gene pools that remained separate for a long time. For many generations the subgroups only bred amongst themselves, and whatever variations in skin, skeletal and other characteristics they already possessed, became the characteristic features of that people group. In other words black Africans were black before they went to Africa, Caucasians were white before they went to Europe etc.
Over succeeding generations there would also have been some natural selection at work, especially as some of the dispersed groups had to survive in tough climates where their original skin colour and body shape would be a disadvantage. For example, very dark people cannot get enough vitamin D if they live in high latitude places with long dark winters, such as northern Europe. Very pale people are prone to get skin cancer if they live in places with strong sunlight. Thin, wiry framed people tend to lose heat easily and find it hard to keep warm in very cold climates, but would have an advantage in a hot climate, especially if they needed to be physically active hunter/gatherers.
In other words if you weren’t black before you went to Africa you didn’t change after you got there – you died out from skin cancer. All the tall thin Eskimos have been eliminated by natural selection because man does not evolve to cope with the climate, the climate eliminates any who can’t cope. This is natural selection, but it is not evolution. In fact it is the reverse of evolution because it decreases the gene pool in extreme environments.
There was also a certain amount of social selection, i.e. what physical characteristics are considered attractive, and therefore desirable in marriage partners. In most cases it is easy to prove that so called racial features have been preserved not by the environment but human choice.
Finally, the fact that distinctive racial features are really only small variations of structures and functions that all human beings have has been confirmed in the last couple of centuries as the previously separated people groups started moving around the world and mixing with each other. So-called “mixed race” people are becoming more common, and they are living proof that there is only one human kind, just as Genesis tells us. That’s why there is really only one Human species, even though there are separate groups with varying ‘racial’ characteristics.
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