The genetic causes, ethnic origins and history of red hair

Red hair occurs naturally in 1–2% of the human population. It occurs more frequently (2–6%) in people of northern or western European ancestry, and less frequently in other populations. Red-haired variants of the MC1R gene probably arose about 20-40 000 years ago.

Red hair is very rare in Scandinavia and Germany today. It is an Iranictrait. Red hair came to Europe from the Iranic-speaking steppe tribes whoinhabited the areas north of and around the Black Sea from 4,000 years agoto the 6th century, when they were replaced by the Slavs whose predominanthair color is shades of brown and dark blonde.

The answer is the ginger gene shows up in people of many ethnicities. It’s agene. Neanderthals had it, early Homo Sapiens, and it’s found all over theworld, but mostly in the depigmented zone that had the severest Ice Age.

Red hair is a recessive genetic trait caused by a series of mutations in the melanocortin 1 receptor (MC1R), a gene located on chromosome 16. It appears in people with two copies of a recessive gene on chromosome 16 which causes a mutation in the MC1R protein.

As a recessive trait it must be inherited from both parents to cause the hair to become red. Consequently there are far more people carrying the mutation for red hair than people actually having red hair. In Scotland, approximately 13% of the population are redheads, although 40% carry at least one mutation.

There are many kinds of red hair, some fairer, or mixed with blond (‘strawberry blond’), some darker, like auburn hair, which is brown hair with a reddish tint. This is because some people only carry one or a few of the several possible MC1R mutations. The lightness of the hair ultimately depends on other mutations regulating the general pigmentation of both the skin and hair.

Red hair varies from a deep burgundy through burnt orange to bright copper. It is characterized by high levels of the reddish pigment pheomelanin and relatively low levels of the dark pigment eumelanin.

The term redhead has been in use since at least 1510. It is associated with fair skin color, lighter eye colors (gray, blue, green, and hazel), freckles, and sensitivity to ultraviolet light. Cultural reactions have varied from ridicule to admiration; many common stereotypes exist regarding redheads and they are often portrayed as fiery-tempered.

A study on unrelated British and Irish individuals demonstrated that over 80% of people with red hair and/or fair skin that tan poorly have a dysfunctional variant of the MC1R gene. This is compared to less than 20% in people with brown or black hair, and less than 4% in people showing a good tanning response.

The Out-of-Africa model proposes that modern humans originated in Africa and migrated north to populate Europe and Asia. It is most likely that these migrants had a functional MC1R variant and, accordingly, dark hair and skin as displayed by indigenous Africans today.

As humans migrated north, the absence of high levels of solar radiation in northern Europe and Asia relaxed the selective pressure on active MC1R, allowing the gene to mutate into dysfunctional variants without reproductive penalty, then propagate by genetic drift.

Studies show the MC1R Arg163Gln allele has a high frequency in East Asia and may be part of the evolution of light skin in East Asian populations. There is no evidence for positive selection of MC1R alleles in Europe and no evidence of an association between MC1R and the evolution of light skin in European populations.

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, discovered in 1997, appear to be associated with the melanocortin-1 receptor (MC1R), which is found on chromosome 16.

Red hair is associated with fair skin color because low concentrations of eumelanin throughout the body of those with red hair caused by a MC1R mutation can cause both.

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 recessive variant gene that gives people red hair and non-tanning skin is also associated with freckles, though it is not uncommon to see a redhead without freckles. Eighty percent of redheads have an MC1R gene variant, and the prevalence of these alleles is highest in Scotland and Ireland.

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 mode of inheritance. 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 always sufficient, for red hair production.

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 was not the result of positive selection and instead proposed that it occurs because of a lack of negative selection. In Africa, for example, red hair is selected against because high levels of sun would be harmful to untanned skin.

However, in Northern Europe this does not happen, so redheads come about 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 has concluded that some Neanderthals also had red hair, although the mutation responsible for this differs from that which causes red hair in modern humans.

Red hair has long been associated with Celtic people. Both the ancient Greeks and Romans described the Celts as redheads. The Romans extended the description to Germanic people, at least those they most frequently encountered in southern and western Germany. It still holds true today.

Several accounts by Greek writers mention redheaded people. A fragment by the poet Xenophanes describes the Thracians as blue-eyed and red-haired.

Although red hair is an almost exclusively northern and central European phenomenon, isolated cases have also been found in the Middle East, Central Asia (notably among the Tajiks), as well as in some of the Tarim mummies from Xinjiang, in north-western China.

In Asia, red hair has been found among the ancient Tocharians, who occupied the Tarim Basin in what is now the northwesternmost province of China. Caucasian Tarim mummies have been found with red hair dating to the 2nd millennium BC.

The Udmurts, an Uralic tribe living in the northern Volga basin of Russia, between Kazan and Perm, are the only non-Western Europeans to have a high incidence of red hair (over 10%).

So what do all these people have in common? Surely the Udmurts and Tajiks aren’t Celts, nor Germans. Yet, as we will see, all these people share a common ancestry that can be traced back to a single Y-chromosomal haplogroup: R1b.

It has been suggested that red hair could have originated in Paleolithic Europe, especially since Neanderthal also had red hair. The only Neanderthal specimen tested so far (from Croatia) did not carry the same MC1R mutation responsible for red hair in modern humans (the mutation in question in known as Arg307Gly).

But since Neanderthals evolved alongside Homo Sapiens for 600,000 years, and had numerous subspecies across all Europe, the Middle East and Central Asia, it cannot be ruled out that one particular subspecies of Neanderthal passed on the MC1R mutation to Homo Sapiens.

It is however unlikely that this happened in Europe, because red hair is conspicuously absent from, or very low in parts of Europe with the highest percentages of haplogroup I (e.g. Finland, Bosnia, Sardinia) and R1a (Eastern Europe), the only two lineage associated with Mesolithic and Paleolithic Europeans.

We must therefore look for the source of red hair, elsewhere. unsurpisingly, the answer lies with the R1b people – thought to have recolonised Central and Western Europe during the Bronze Age.

The origins of haplogroup R1b are complex, and shrouded in controversy to this day. The present author favours the theory of a Middle Eastern origin (a point upon which very few population geneticists disagree) followed by a migration to the North Caucasus and Pontic Steppe, serving as a starting point for a Bronze-age invasion of the Balkans, then Central and Western Europe. This theory also happens to be the only one that explains the presence of red hair among the Udmurts, Central Asians and Tarim mummies.

Haplogroup R1b probably split from R1a during the Upper Paleolithic, roughly 25,000 years ago. The most likely location was Central Asia, around what is now the Caspian Sea, which only became a sea after the last Ice Age ended and the ice caps over western Russia melted. After the formation of the Caspian Sea, these nomadic hunter-gatherers, ended up on the greener and richer Caucaso-Anatolian side of the Caspian, where they may have domesticated local animals, such as cows, pigs, goats and sheep.

If the mutation for red hair was inherited from Neanderthal, it would have been from a Central Asian Neanderthal, perhaps from modern Uzbekistan, or an East Anatolian/Mesopotamian one. The mutation probably passed on to some other (extinct?) lineages for a few millennia, before being inherited by the R1b tribe. Otherwise, it could also have arisen independently among R1b people as late as the Neolithic period (but no later).

Today, red hair is most commonly found at the northern and western fringes of Europe; it is associated particularly with the people located in the British Isles (although Victorian era. Ethnographers consider the Udmurt people of the Volga to be “the most red-headed men in the world”). Redheads are common among Celtic and Germanic peoples.

Scotland has the highest proportion of redheads; 13% of the population has red hair and approximately 40% carries the recessive redhead gene. Ireland has the second highest percentage; as many as 10% of the Irish population has red, auburn, or strawberry blond hair.

It is thought that up to 46% of the Irish population carries the recessive redhead gene. A 1956 study of hair color amongst British army recruits also found high levels of red hair in Wales and the English Border counties.

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, whose frequence reaches 10% and 4%, respectively. The Queen of Morocco, Lalla Salma wife of king Mohammed VI, has red hair. Abd ar-Rahman I also had red hair, his mother being a Christian Berber slave.

Red hair is also found amongst the Ashkenazi Jewish populations. In European culture, prior to 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, and Judas was traditionally depicted as red-haired in Italian and Spanish art. Writers from Shakespeare to Dickens would identify Jewish characters by giving them red hair. The stereotype that red hair is Jewish remains in parts of Eastern Europe and Russia.

In Asia, genetic red hair is rare, but can be found in the Levant (Cyprus, Syria, Lebanon, Jordan, Israel and Palestine), in Turkey, in Caucasia, in Northern Kazakhstan, and among Indo-Iranians. The use of henna on hair and skin for various reasons is common in Asia. When henna is used on hair it dyes the hair to different shades of red.

Emigration from Eurasia and North Africa added to the population of red haired humans in the Americas, Australia, New Zealand and Southern Africa. In the United States, it is estimated that 2–6% of the population has red hair. This would give the U.S. the largest population of redheads in the world, at 6 to 18 million, compared to approximately 650,000 in Scotland and 420,000 in Ireland.

Red hair is also found amongst Polynesians, and is especially common in some tribes and family groups. In Polynesian culture red hair has traditionally been seen as a sign of descent from high-ranking ancestors and a mark of rulership.

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