HomeScienceGeneticsRedheads will not die out. This is why.

Redheads will not die out. This is why.

On screen and on the street, strawberry blondes and auburn locks attract attention, and they always have. That’s partly because red hair is an exotic trait, found in only one or two in 100 people. While the gene variants that give flaming locks are rare, redheads are not destined to disappear from the population, despite recurring claims to the effect.

“Redheads aren’t going to go extinct,” said Katerina Zorina-Lichtenwalter, a postdoctoral researcher at the Institute for Behavioral Genetics at the University of Colorado, Boulder.

To understand why this is so, it is first necessary to understand why there are redheads in the first place. It turns out that not only tabloids are interested in people with flaming hair. So are scientists. There’s been more research into the variations in human hair color than you’d expect, and the science makes it clear that crimson locks aren’t getting rarer, nor are they going to disappear any time soon.

It is a property that dates back to prehistoric times. This was shown by analysis of 50,000-year-old DNA some Neanderthals were pale redheads. A famous 3800 years old Bronze Age mom, known as the Beauty of Loulan, was unearthed from a desert cemetery in northwestern China with sepia hair intact. From the fifth century in what is now southeastern Europe and Turkey, the mythological King Rhesus of the ancient Thracians was depicted on Greek pottery with root-colored hair and beard.

The gene variants involved are recessive, meaning it takes two copies — one from the mother and one from the father — to produce a red-haired child. Only if both parents are red-haired can they be almost certain that their baby will have fiery hair, says Zorina-Lichtenwalter.

In her book Red: A History of the Redhead, author Jacky Colliss Harvey characterizes the probability of having a baby with crimson hair as follows: “In the great genetic card game, red hair is the two of clubs. It is surpassed by every other map in the pack.”

The genetics of red

Ginger coloring in humans — as well as horses, dogs, pigs and other mammals — is conferred by only a handful of genetic mutations that both parents must carry. The ‘redhead gene’ was discovered in 1995 by a team that included Ian Jackson, now emeritus professor at the Scottish University of Edinburgh.

This melanocortin 1 receptor geneor MC1R, plays a key role in the production of melanin, the brown pigment that protects the skin from ultraviolet rays (sunlight) and also colors the eyes and skin. One type, eumelanin, produces brown or black hair. Pheomelanin creates red or blonde locks and gives fair skin and freckles.

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In people with red hair, the skin cells (melanocytes) that produce pigment have an abnormal receptor on the cell surface. When exposed to UV light, this variant does not activate a switch that changes the melanin pigment from yellow/red to protective brown/black. “MC1R is one of many genes that work together to produce dark melanin, and without that switch, you end up with light skin,” says Zorina-Lichtenwalter — and burn easily when you’re in the sun.

In their 1995 study, Jackson and colleagues compared 30 Irish and British redheads with the same number of brunettes. More than 80 percent of people with pink hair and/or fair skin wore variations in the MC1R gene; but only 20 percent of brown-haired individuals did.

When they published the study, geneticist Richard Spritz told the press “This is the first time in humans that a specific gene for a common visible trait has been identified.”

Genetic advantage – and danger

Pale colors were an important advantage for cultures migrating from sunnier regions to Northern Europe with its gray skies and short winter days. “There was evolutionary pressure to lose skin pigmentation,” explains Zorina-Lichtenwalter, because lighter skin absorbs more UV, which produces more vitamin D from northern regions’ limited amount of sunlight. Vitamin D helps the body absorb and retain calcium, build stronger bones and protect against inflammation.

These health benefits increased the chance that women would survive pregnancy and birth and successfully pass on genes for fair skin and red or blonde hair to their offspring. The trait flourished in the United Kingdom and Ireland, where there are by far more fair-skinned redheads than anywhere else in the world. Some unofficial estimates put the number at about 10 percent.

Much of the research on the genetics of redheads stems from their increased risk of skin cancer. The MC1R gene mutations linked to crimson hair, fair skin and freckles also allow more UV to reach and damage DNA. One study found that people who have a so-called R variant of the MC1R gene had a 42 percent higher incidence of melanoma, one of the most aggressive cancers. Melanoma is 20 times more common in Caucasians than African Americans.

however, the the average age for a diagnosis of melanoma is 65 years. Therefore, says Zorina-Lichtenwalter, “it does not threaten reproductive fitness.” At that age, women have already passed their genes on to the next generation. Therefore, she says, redheads are unlikely to disappear from the gene pool.

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More ginger genes

While working on that 1995 genetic analysis, Jackson knew there was more to understand about the factors that cause red hair. “It seemed logical that other genes were involved,” he says, but deeper research was not yet possible: genetic research was extremely slow and expensive. While rapid advances in genetic technologies and computers had launched the Human Genome Project, the initial draft of the genetic map would not be completed until 2001.

Now, a quarter of a century later, fast and cheap genetic research is the norm. Jackson and his colleagues recently revisited their research with resources unthinkable in 1995. They analyzed DNA from the British biobank, which contains genetic and health information about half a million people in the United Kingdom. They discovered eight previously unknown genetic variants affecting red hair and skin pigmentation. “It was very, very satisfying to find those genes using the Biobank,” says Jackson. This research, published in 2022, identified most of the genetic variations that contribute to hair color differences.

Most redheads have two MC1R variants, according to Jackson, one from each parent. But several other genes also influence whether your hair turns red. “It’s a certain combination that gives rise to red hair,” he says. Researchers have assigned each of the genes involved a “genetic risk score”: some variants are more likely to have red locks. Others had much less influence but were still associated. You don’t need them all to have red hair, says Jackson.

MC1R is king when it comes to redness,” says Zorina-Lichtenwalter. “It has a huge amount to say whether we’re going to have dark pigmentation or light pigmentation.” More than four-fifths of redheads wear it MC1R; while the remaining red colors are caused by other genes.

Geography and origin

A recent British genetic study correlated the incidence of polished locks with place of birth, with more redheads in the north and west of the country. “In the Biobank you have the latitude and longitude of each individual’s place of birth.” says Jackson. “The further north you were born, the more likely you are to have red hair.”

Light-skinned redhead genetics thrived in remote areas, closed communities, and islands, such as Scotland (estimates of redheads there range from Jackson’s 6 percent to 12 or 14 percent); Ireland (10 percent); and Great Britain (6 percent). While the populations of these countries are no longer cut off from the rest of the world, “if you have an insular population, isolated from others reproductively, then all the alleles will increase in frequency from generation to generation,” says Zorina-Lichtenwalter.

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However, redheads are not just Celts or whites. Their distribution is a testament to the global movement of DNA through societies and landscapes. although most common in Northern Europe, parts of Russia, and among European descendants in Australia, there are redheads of all ethnicities and races. For example, both Morocco and Jamaica have above-average numbers.

The reason, says Zorina-Lichtenwalter, is that several genes are responsible for activating dark eumelanin production to protect the skin. But for hair color she says “MC1R seems to dominate, hence variants in MC1R can still produce red hair in Jamaicans and other dark-skinned people.

We are not in the midst of a redhead extinction event

Claims that redheads are a dying breed aren’t new, and some were clearly linked to financial gain, Jackson says.

A headline that caused a stir read: “Redheads may soon join polar bears as victims of climate change‘, which is a serious piece. Climate change is causing more extreme temperatures, droughts and floods; but the possibility that it will affect UV radiation enough to alter the genetics of the northern hemisphere — within the predicted few hundred years — is slim, says Zorina-Lichtenwalter. The source of this claim was Alistair Moffat, CEO of the now-defunct genetic testing company Scotland’s DNA.

Prior to that, the Oxford hair foundation (also solved) predicted that redheads would be extinct by 2100, with the gene variant that causes flaming hair fading away. “[The institute] was a cover funded by a hair dye and cosmetics company to spark interest in hair color,” says Jackson.

While recessive genes can become rare, they won’t disappear completely unless everyone carrying that gene dies or doesn’t have children. And that is clearly not going to happen.

Wherever they live, redheads get a lot of attention, sometimes stigmatized, sometimes admired. As proof of their continued presence in the world, they celebrate themselves in annual “red pride” events in the UK, France and Italy, as well as the US. The biggest event may be in August, when thousands of gingers from all over the world gather in the Netherlands for “Redhead days.”

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