Red hair, also known as ginger hair, is a human hair color found in 2–6% of people of Northwestern European ancestry, typically those of Celtic ancestry, and smaller amounts in other populations. It is most common in individuals homozygous for a recessive allele on chromosome 16 that produces an altered version of the MC1R protein.
Red hair varies in hue from a deep burgundy or bright copper, or auburn, to burnt orange or red-orange to strawberry blond. Characterized by high levels of the reddish pigment pheomelanin and relatively low levels of the dark pigment eumelanin, it is typically associated with type I of the Fitzpatrick scale, freckles, and sensitivity to ultraviolet light, although it is also frequent in darker skinned individuals of different races.
Cultural reactions to red hair have been varied. The term "redhead" has been in use since at least 1510, while the term "ginger" is sometimes used, especially in Britain and Ireland, to describe a person with red hair.
Geographic distribution Modern Northwestern Europe
Red hair is most commonly found at the northwestern fringes of Europe; it is centred around populations in the British Isles and is particularly associated with the Celtic nations.
Scotland has the highest number of red-haired people per capita in the world, with the percentage of those with red hair at around 13%, followed by Ireland and Wales. The highest concentration of red head carriers in the world is found in Edinburgh. Red hair gene variants in Scotland are most frequent in the south-east, with 40% of people being carriers of them. The lowest prevalence of red hair gene bearers are found in the Gaelic, North-West and Hebrides, where only 29% of people carry them, which is comparable to Cornwall and Devon in South West England. Another study, the largest ever study of hair colour in Scotland, which analysed over 500,000 people, found the percentage of Scots with red hair to be slightly lower at 5.3%.
Jewish peoples
Red hair is also commonly found amongst Jewish populations. In 1903, 5.6% of Polish Jews had red hair.Elkind. Evrei Trudi Antropologitshes-kavo Amdilla, xxi., Moscow, 1903 Other studies have found that 3.69% of Jewish women overall were found to have red hair, but around 10.9% of all Jewish men have red beards.Maurice Fishberg (1911). Jews, race & environment. 99. Transaction Publishers. In European culture before the 20th century red hair was often seen as a stereotypically Jewish trait. During the Spanish Inquisition, all those with red hair were identified as Jewish. In Italy, red hair was associated with Italian Jews. Additionally, Judas was traditionally depicted as red-haired in European art. The stereotype that red hair is Jewish remains in parts of Eastern Europe and Russia.
Eastern Europe
Byzantine writers Jordanes and Procopius described the early Slavic peoples as having ruddy hair and skin tone.
In the late 18th century, ethnographers considered the Finno-Ugric Udmurt people of the Volga Region in Russia to be "the most red-headed men in the world". The Volga region still has one of the highest percentages of red-headed people.
Southern Europe In Italy, red hair is found at a frequency of 0.57% of the total population, without variation in frequency across the different regions of the country.Consanguinity, Inbreeding, and Genetic Drift in Italy, Princeton University Press, 15 Feb 2013, Luigi Luca Cavalli-Sforza, Antonio Moroni, Gianna Zei, page 270 In Sardinia, red hair is found at a frequency of 0.24% of the population.
North Africa and Mediterranean The Berber populations of Morocco and northern Algeria have occasional redheads. Red hair frequency is especially significant among the Riffians from Morocco and Kabyles from Algeria,"Their pigmentation is characteristically brunet, but definite blonds occur. Black and dark brown hair run to 85 percent (85%) of the whole, while reds number 4 percent (4%)", Carleton S. Coon, The Races of Europe (1939), Greenwood Press, 1972, p. 478"There are, however, a noticeable number of Kabyles with red hair, blue eyes and fair skin", Area Handbook for Algeria, American University, 1965, p. 91 respectively.
Asia (all regions)
In Asia, red hair can be found among some peoples of Afghan, Arab, Iranian, Armenian, East Indians, Mongolian, Turkic, Miao, and Hmong descent.
Several preserved samples of human hair have been obtained from an Iron Age cemetery in Khakassia, South Siberia. Many of the hair samples appear red in color, and one skull from the cemetery had a preserved red moustache.
Genetic evidence of a red hair and blue eye genome was discovered in the ancient human remains of the Areni-1 cave in Armenia, dating back to the Chalcolithic (4300–3500 BCE) period.
Ancient human remains described as having red or auburn hair have been discovered in various parts of Asia, including the Tarim mummies of Xinjiang, China. In Chinese sources, ancient Kyrgyz people were described as fair-skinned, green- or blue-eyed and red-haired people with a mixture of European and East Asian features. In the Book of Wei, Chinese author Wei Shou notes that Liu Yuan was over tall and had red strands of hair in his long beard.Helfen-Maenchen, Otto, The World of the Huns: Studies of Their History and Culture, p.373. University of California Press The ethnic Miao people of China are recorded with red hair. According to F.M Savina of the Paris Foreign Missionary Society, the appearance of the Miao was "pale yellow in complexion, almost white, their hair is often light or dark brown, sometimes even red or corn-silk blond, and a few even have pale blue eyes". In appearance the Miao are pale yellow in complexion, almost white, their hair is often light or dark brown, sometimes even red or corn-silk blond, and a few even have pale blue eyes"- F.M, Savina A phenotype study of Hmong people shows they are sometimes born with red hair.
The Kipchak people were a Turkic ethnic group from Central Asia who served in the Golden Horde military forces after being conquered by the Mongols. In the Chinese historical document Kang mu, the Kipchak people are described as red haired and blue-eyed.
Americas, Oceania and Sub-Saharan Africa
Reddish-brown (auburn) hair is also found among some Polynesians, and is especially common in some tribes and family groups. In Polynesian culture, reddish hair has traditionally been seen as a sign of descent from high-ranking ancestors and a mark of rulership. Emigration from Europe has increased the population of red haired humans in the Americas, Australia, New Zealand and South Africa.
Historical Several accounts by Greek writers mention redheaded people. A fragment by the poet Xenophanes describes the Thracians as blue-eyed and red-haired. The ancient Budini and Sarmatians are also reported by some classical Greek authors to be blue-eyed and red-haired. It was once believed that Sarmatians owed their name to their red hair, but this claim was later debunked.
In Asia, red or auburn hair has been found among the ancient Tocharians, who occupied the Tarim Basin in what is now the northwesternmost province of China. Tarim mummies have been found with red hair dating to the 2nd millennium BC.
In certain Biblical accounts, Hebrew and Israelite individuals were described as having ruddy hair. For example, Esau and David (Gen. 25:25; 1 Sam. 16:12, 17:42.), are described in the Masoretic text as "admoni", meaning red or ruddy, although Josephus described David as golden haired and Esau as red haired.
Biochemistry and genetics The pigment pheomelanin gives red hair its distinctive color. Red hair has far more of the pigment pheomelanin than it has of the dark pigment eumelanin.
The genetics of red hair appear to be associated with the melanocortin-1 receptor (MC1R), which is found on chromosome 16. In 1995, Valverde, et al. identified alleles on MC1R associated with red hair. The number of alleles linked to red hair has since been expanded by other authors, and these variants are now identified as the RHC (red hair colour) alleles. Eighty percent of redheads have an MC1R gene variant within the RHC. "Valverde et al was the first to identify MC1R associations pheomelanogenic red hair color (RHC), and subsequently, several other authors have extended these results to identify what are today called the RHC phenotype alleles (all SNPs, Box, et al. [28, 32]; Duffy et al. ; Smith et al. : Parmer et al. ; Bastiaens et al. [33, 34]; Kennedy et al. ; Flannagan et al , and reviewed by Sturm, )." Red hair is also associated with fair skin color because the MC1R mutation also results in low concentrations of eumelanin throughout the body. The lower melanin concentration in skin confers the advantage that a sufficient concentration of important vitamin D can be produced under low light conditions. However, when UV-radiation is strong (as in regions close to the equator) the lower concentration of melanin leads to several medical disadvantages, such as a higher risk of skin cancer. The MC1R variant gene that gives people red hair generally results in skin that is difficult or impossible to tan. Because of the natural tanning reaction to the sun's ultraviolet light and high amounts of pheomelanin in the skin, freckles are a common, but not universal, feature of red-haired people.
Red hair can originate from several changes on the MC1R-gene. If one of these changes is present on both chromosomes, then the respective individual is likely to have red hair. This type of inheritance is described as an autosomal recessive. Even if both parents do not have red hair themselves, both can be carriers for the gene and have a redheaded child.
Genetic studies of dizygotic (fraternal) twins indicate that the MC1R gene is not solely responsible for the red hair phenotype; unidentified modifier genes exist, making variance in the MC1R gene necessary, but not sufficient, for red hair production.
Genetics The alleles Arg151Cys, Arg160Trp, Asp294His, and Arg142His on MC1R are shown to be recessives for the red hair phenotype. The gene HCL2 on chromosome 4 may also be related to red hair. There are at least 8 genetic differences associated with red hair color.
In species other than primates, red hair has different genetic origins and mechanisms.
Beards The genes responsible for red hair can express themselves to different extents in different people. One consequence of this is that a number of people have both dark hair and red beards. This may reflect the presence of a single copy of the MC1R gene, leading to differential expression in the beard versus the scalp hair. However, some red-bearded people lack MC1R genes.
Evolution Origins Red hair is the rarest natural hair color in humans. The non-tanning skin associated with red hair may have been advantageous in far-northern climates where sunlight is scarce. Studies by Bodmer and Cavalli-Sforza (1976) hypothesized that lighter skin pigmentation prevents rickets in colder climates by encouraging higher levels of vitamin D production and also allows the individual to retain heat better than someone with darker skin. In 2000, Harding et al. concluded that red hair is not the result of positive selection but of a lack of negative selection. In Africa, for example, red hair is selected against because high levels of sun harm pale skin. However, in Northern Europe this does not happen, so redheads can become more common through genetic drift.
Estimates on the original occurrence of the currently active gene for red hair vary from 20,000 to 100,000 years ago.
A DNA study of Neanderthal genomes determined that the MC1R gene resulting in red hair in modern humans was not present in Neanderthal, and "if variants contributing to red hair were present in Neanderthals, they were probably not at high frequency."
Extinction hoax