On screen and on the street, strawberry blondes and those with red tresses always attract attention. In part, this is because red hair is an odd trait that occurs in only 1 or 2 people out of 100. While the genetic variants that bestow flaming locks are rare, redheads aren’t destined to disappear from the population, despite frequent claims to that effect.
“Redheads are not going to go extinct,” says Katrina Zorina Lichtenwalter, a postdoctoral fellow at the Institute for Behavioral Genetics at the University of Colorado, Boulder.
To understand why this is so, it is necessary to first understand why redheads exist in the first place. As it turns out, it’s not just the tabloids that are interested in people with flaming hair. Scientists too. There’s more research on differences in human hair color than you might expect, and science shows that crimson locks aren’t becoming increasingly rare, and they aren’t going away anytime soon.
It is a feature that dates back to prehistoric times. Analysis of 50,000-year-old DNA revealed that some Neanderthals were pale redheads. A famous 3,800-year-old Bronze Age mummy, known as Beauty Luolan, was discovered from a desert tomb in northwest China with dark brown hair intact. From the fifth century onwards, in what is now southeastern Europe and Turkey, the legendary king Rhesus of the ancient Thracians is depicted on Greek pottery with carrot-colored hair and beard.
The genetic variants in question are recessive, which means that two copies — one from the mother and one from the father — are required to produce a red-haired child. Only if both parents are redheads can they be almost certain that their child will have fiery hair, Zorina-Lichtenwalter says.
in her book Red: the history of the redhead, Author Jackie Collis Harvey describes the odds of having a child with crimson hair this way: “In the great game of genetic cards, red hair is the clubs. It is outshone by every other card in the pack.”
Genetics of the color red
Ginger coloring in humans—as well as horses, dogs, pigs, and other mammals—is conferred by a few genetic mutations that both parents must carry. The red-haired gene was discovered in 1995 by a team including Ian Jackson, now Professor Emeritus at the University of Edinburgh in Scotland.
This gene melanocortin receptor 1, or MC1R, It plays a major role in the production of melanin, the tan pigment that protects the skin from UV rays (sunlight) and also colors the eyes and skin. One type, eumelanin, gives brown or black hair. Pheomelanin creates red or blonde locks and gives them fair skin and freckles.
In people with red hair, the skin cells (melanocytes) that produce pigment have different receptors on the cell surface. When exposed to UV light, this variant fails to turn on the switch that changes the pigment of melanin from yellow/red to protective brown/black. “MC1R It’s one of several genes that work together to produce darker melanin, and without that switch, you’ll have lighter skin,” says Zorina-Lichtenwalter — and burn easily when you’re out in the sun.
In their 1995 research, 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 carry variations in their color MC1R gene. But only 20 percent of brown-haired individuals did.
When they published the study, geneticist Richard Spritz told the media, “This is the first time that a specific gene has been identified for any common visible characteristic.”
Genetic advantage – and risk
The pale coloration gave a major advantage to cultures migrating from sunny regions to northern Europe with their gray skies and short winter days. “There has been an evolutionary pressure to lose skin pigmentation,” explains Zorina-Lichtenwalter, because lighter skin absorbs more UVB radiation, which produces more vitamin D than the limited amount of sunlight in northern regions. Vitamin D helps the body absorb and retain calcium, build stronger bones, and protect against infections.
These health benefits increased a woman’s likelihood of surviving pregnancy and childbirth, as she successfully passed genes for fair skin and red or blond hair to her offspring. This trait has flourished in the United Kingdom and Ireland, where, by far, there are more light-skinned redheads than anywhere else on earth. Some unofficial estimates put the figure closer to 10%.
Much of the research into the genetics of red hair stems from a higher risk of skin cancer. the MC1R Genetic mutations associated with scarlet hair, fair skin, and freckles also allow more UV rays to reach and damage DNA. One study found that people who carry the so-called R variant of MC1R The gene has a 42 percent higher incidence of melanoma, which is one of the most aggressive forms of cancer. Melanoma is 20 times more common in Caucasians than in African Americans.
However, the average age for a melanoma diagnosis is 65. Therefore, says Zorina-Lichtenwalter, “it does not threaten reproductive fitness.” At that age, women have already passed their genes on to the next generation. This is why, she says, redheads are not likely to disappear from genes.
More ginger genes
When he was working on the 1995 genetic analysis, Jackson knew there was more to understand about the factors that confer red hair. “It seemed logical that there were other genes involved,” he says, but a deeper exploration was not yet possible: genetic research was too slow and expensive. While rapid advances in genomic and computing technologies have launched the Human Genome Project, the first draft of the genetic map will not be completed until 2001.
Now, a quarter of a century later, fast and inexpensive genetic research has become the norm. Jackson and his colleagues recently revisited their inquiry with Unimaginable Resources in 1995. They analyzed DNA from the UK Biobank, which contains genetic and health information for half a million UK residents. They discovered eight previously unknown genetic variants that affect red hair and skin pigmentation. “Going and finding those genes using the Biobank was very satisfying,” says Jackson. This research, published in 2022, identified most of the genetic variation that contributes to differences in hair color.
Most redheads are two MC1R The variants, according to Jackson, are one from each parent. But many other genes also influence whether your hair will turn red. “It’s a special mixture that causes red hair to appear,” he says. The researchers assigned a ‘genetic risk score’ to each of the genes involved: with certain variants exerting a higher probability of red locks. The others had much less clout but were still related. You don’t need all of them to be red hair, says Jackson.
“MC1R “King when it comes to redheads,” says Zorina-Lichtenwalter. “It has a huge amount of influence on whether we have dark pigmentation or light pigmentation.” It holds more than four-fifths of redheads MC1R; While the remaining red color is caused by other genes.
Geography and lineage
A recent genetic study in the UK linked the occurrence of feathered locks with place of birth, with more redheads in the north and west of the country. “In a Biobank, you have the latitude and longitude of each individual’s place of birth.” Jackson says. “The further north you are born, the more likely you are to have red hair.”
The red-haired and fair-skinned genes thrived in remote regions, closed societies and islands—such as Scotland (estimates for redheads there range from 6 percent to 12 or 14 percent in Jackson); Ireland (10 percent); and Britain (6%). While the populations of these countries are no longer isolated from the rest of the world, “when you have a population that is reproductively isolated from others, then whatever the alleles are, they go up in frequency from generation to generation,” says Zorina Lichtenwalter.
However, redheads are not only Celts or Caucasians. Their distribution is a testament to the global movement of DNA across communities and landscapes. Although it is common in northern Europe, parts of Russia and among European descendants in Australia, there are redheads of all races and genders. For example, Morocco and Jamaica both have above-average numbers.
Zorina-Lichtenwalter says it’s because several genes are responsible for stimulating production of the darkening skin-protecting substance eumelanin. But as for hair color, she says,MC1R They appear to be dominant, which is why variants appear in MC1R It 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 are not new, Jackson says, and some of them are clearly linked to financial gain.
One of the headlines that started the buzz was, “Reds May Soon Join Polar Bears as Victims of Climate Change,” which is a dangerous stretch. Climate change is bringing more extreme temperatures, droughts, and floods; But the likelihood of it affecting UV enough to change genetics in the northern hemisphere — within the expected few hundred years — is slim, says Zorina Lichtenwalter. The source of the claim was Alistair Moffat, CEO of the now-defunct genetic testing company ScotlandsDNA.
Prior to this, the Oxford Hair Foundation (also disbanded) predicted that redheads would become extinct by the year 2100, with the gene variant that gives flaming hair slowly disappearing. “[The institute] It was a front, funded by a hair-dye and cosmetics company to generate interest in hair color,” says Jackson.
While recessive genes can become rare, they don’t disappear completely unless everyone who carries the gene dies — or doesn’t have children. Obviously, this will not happen.
Wherever they are, redheads are highly regarded, sometimes stigmatized, and sometimes admired. As a sign of their continued presence in the world, they celebrate themselves at annual “pride of red” events in the United Kingdom, France and Italy, as well as the United States. The biggest event may be in August, when thousands of gingers from all over the world gather in the Netherlands for Red Hair Days.