Red Head Facts
In France, to be red-headed is thought to be a very bad fate.
Red hair is a genetic mutation.
Percentages of redheads in different countries range from single digits to a fraction of 1 per cent — a recent estimate for France is 0.03 per cent of people.
Redheads generally are more numerous in northern latitudes, but also turn up among Hungarians, Egyptians, Israelis and certain Nigerian tribes.
In Denmark, it is an honour to have a red-headed child.
In Corsica, if you pass one in the street, you spit and turn around.
Short temper and sexual fieriness are attributed to them. It is "common knowledge" that redheads have hot tempers, but no one has ever seen a controlled study that tested the correlation. So while some like to use that excuse, it probably isn't a valid one. As for the sexual fieriness – trial and error I say
In Poland, if you pass three red-heads you'll win the state lottery,
Harvard dermatologist Madhu Pathak calls redheads "three-time losers" because their red pigment is an inadequate filter of sunlight and their skin is more susceptible to sunburn, skin cancer and wrinkling with age.
"There are two kinds of redhead," says Mary Spillane, managing director of British image consultants Colour Me Beautiful. There's "the autumn type with hazel eyes", and the "Celtic type with translucent skin, light eyes and carrot top — leprechaun redness" that people have trouble with.
Redheads have always been thought untrustworthy. As some claim – Judas was red-haired.
Superstitions: red hair is unlucky; it's lucky to rub your hand on a redhead's head; bees sting redheads more readily. The Egyptians regarded the colour as so unlucky that they had a ceremony in which they burned red-headed maidens alive to wipe out the tint.
Red hair is commonly associated with people of British or Irish descent, although red hair is found in many other parts of the world.
Scotland is the country with the highest content of red haired people, which includes approximately 13% of their population.
Skin and hair pigment is made up of different types of melanin. There are two broad groups of melanin, eumelanin, which is brown, and phaeomelanin, which is red. Somebody with dark hair will have predominantly eumelanin. Somebody with very bright red hair will have little eumelanin but lots of phaeomelanin.
People with auburn hair will have some of both. Skin and hair colour often go together, but not always. For instance, people with red hair are usually fairly pale skinned, they don't tend to tan, they burn in the sun and are more likely to have freckles. There are exceptions however to this rule.
Several years ago it was discovered that the melanocortin 1 receptor, a protein encoded by a gene previously discovered in mice, was responsible for the production of red hair in humans. Everybody has two copies of this gene but there are slight changes in the gene that are very common in European populations.
If you have one of about four or five common changes in this gene and, one of these changes are found on both of your chromosomes, then you are likely to have red hair. A little bit of basic genetics; you have two copies of every gene, you inherit one from your mother and one from your father. If both of these genes are different, with respect to the changes that might lead to red hair, then you will have red hair. If however you only have one change, you have an increased chance of having red hair, but it is not certain that you will have red hair.
Such a type of inheritance is described to by geneticists as an autosomal mode of inheritance. This means, in practice, that both your parents may not have red hair, but both could be carriers for the gene for red hair. If this was the case, perhaps one in four of children might have red hair. If one of the parents has bright red hair, and therefore carries two of the changes (one on each of their chromosomes), and the other parent is a carrier, then perhaps 50% of the children might have red hair.
It is this aspect of genetics, and the mode of inheritance, that explains why hair colour might skip generations. There are different sorts of red hair. Some people seem to have what we call “strawberry blonde”, some bright red and some auburn. As far as we know, the genetics underlying these differences are fairly similar, in that changes in the gene referred to above, seem to be important for all sorts of red hair. However, if you have bright red hair it seems you are much more likely to carry two different copies of the gene than if you are a strawberry blonde.
There are some other puzzles about red hair. Some men might have red beards but dark-coloured hair. This is not entirely surprising, as in many mammals the front of the body is a slightly different colour to the back. In some animals, the molecular basis of this is clearly understood, as in these animals, they produce a different protein that seems to have the opposite effects to the red hair gene mentioned above. In man, we don't think this is the case, but we also observed that people who do have red beards are more likely to carry at least one different copy of the red hair gene.
Another puzzle is why hair colour changes so much during life. Most people are aware that hair colour tends to be lighter at birth and gets darker, particularly during adolescence and puberty. Apart from saying that the cells that produce melanin become more active at this period, we don't understand why this is. Similarly, of course, we don't really understand greying and lightening of the hair in old age. People with red hair often have different coloured hair at different times of their life. It seems that it is more likely to be red in childhood or in early adult life, than in later life.
One medical importance of red hair is that individuals with red hair are, on average, more likely to burn in the sun, and they are at an increased risk of skin cancer. The sensible advice seems to remain that since it is painful and uncomfortable to burn repeatedly in the sun, it is sensible to alter your behaviour such that you don't suffer the discomfort! On the other hand, the risks of skin cancer should also be put in context.
Online medical info useful for science essays:
Source: http://www.ginga.co.nz/?sid=14