IT is as defining a Scottish characteristic as a love of whisky, an appreciation for golf and an urge to wear a kilt no matter what the formal occasion.

And now scientists say that the secret of the flowing red locks sported by many a son and daughter of Caledonia can be found in their genes.

Researchers at the University of Edinburgh studying how hair gets its distinctive colour say they have solved the mystery of the way redheads inherit their flaming hue - and it is more complicated than first believed. 

For several years it has been thought that red hair is controlled by a single gene, called MC1R, which caused follicles to start sprouting ginger strands when 'switched on.'

But fresh experiments have found that instead of just one gene, eight have to come into play and interact before red hair appears. 

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Famous ginger Ewan McGregor

The study – which also sheds light on blondes and brunettes – is the largest genetic study of hair colour to date.

Previous efforts to solve the secret of red hair had shown that redheads inherit two versions of the MC1R gene that leads to it – one from their mum and one from their dad. 

Although almost everyone with red hair has two copies of the red-haired version of MC1R, not everyone carrying two red-haired versions is a redhead. 
Scientists knew there must be other genes involved but these have mostly remained a mystery until now. 

Scotland is thought to be home to around a fifth of the world's redheads, although it is believed that just 2 per cent of the world’s population have crimson locks. 

Famous Scots to sport ginger locks include the actors Tilda Swinton, Karen Gillan, Ewan McGregor and the singer Lulu, while current manager of the national football team, Alex McLeish, is also a redhead. 

Other famous gingers include Prince Harry, Vincent Van Gogh, Mary Queen of Scots and her nemesis Elizabeth I. 

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Actress Karen Gillan

Karen Gillan has previously said she was bullied over her hair colour as a youngster, although she grew to love her locks in later life. 

In a recent interview the 31-year-old said: “I got teased for being a redhead when I was younger, which is strange because I’m Scottish and there are loads of us – we should unite forces. 

"I love my red hair. I like having hair that looks like a volcano is erupting.”
However, despite its distinctive appeal,  it has been suggested that the pale skin tone which often accompanies red hair may make people more susceptible to certain types of skin cancer.

Redheads may also grow weary of people's expectations that they have a fiery temperament, a myth based on folklore from many countries. 

It is thought that red hair appeared between 20,000 to 100,000 years ago, and that Neanderthals also had the MC1R gene which makes it possible. 

Scientists have also suggested that woolly mammoths, which roamed the earth during the last ice age, were covered in ruddy red fur. based on tufts still found on frozen carcasses from Siberia.

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The Researchers looked at DNA from almost 350,000 people who had taken part in the UK Biobank study. 

The study focused on people of European descent because they have greater variation in hair colour.

Comparing redheads to people with brown or black hair, they identified eight previously unknown genetic differences that are associated with red hair. 

The team also looked at the functions of the genes they identified and found that some of them work by controlling when MC1R is switched on or off. 

In addition to the redhead genes, the researchers uncovered differences in almost 200 genes associated with blondes and brunettes.

Scientists say there is a gradient of colour from black, through dark brown to light brown and blonde, which is caused by increasing number of genetic differences in these 200 genes.

The researchers were surprised to find that many of these 200 genetic differences were associated with hair texture rather than pigmentation.

Others are involved in determining how the hair grows – such as whether curly or straight.

Redhead Emma Kelly, who successfully campaigned to have Apple create a ginger-haired emoji, said the study was a bost to 'ginger pride'.

The businesswoman, who runs the Ginger Parrot lifestyle website for redheads,  said: "It’s absolutely fascinating that more and more information is coming out about how natural red hair occurs - who knew us redheads were so complicated? 

"Red hair is an area of genetics that is still so little known, so it’s great that more research is being dedicated to know how such a rare genetic gift occurs.

"I’m extremely proud of my red hair and learning more about how rare it is genetically just makes me realise how special it is. I hope that this new research will continue to empower all redheads of all ages to feel distinct ginger pride." 

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Redhead Alex McLeish

The study, published in Nature Communications, was funded by the Medical Research Council and the Biotechnology and Biological Sciences Research Council.

Professor Ian Jackson, of the Medical Research Council Human Genetics Unit at the University of Edinburgh, said: “We were able to use the power of UK Biobank, a huge and unique genetic study of half a million people in Britain, which allowed us to find these effects.”

Professor Albert Tenesa, of the University of Edinburgh’s Roslin Institute, added: “We are very pleased that this work has unravelled most of the genetic variation contributing to differences in hair colour among people.”

Melanie Welham, Executive Chair of the Biotechnology and Biological Sciences Research Council, said that the breakthrough the study had been achieved through close collaboration between scientists. 

She said : “Once again collaborative research is helping to provide answers to some of life’s important questions. 

"BBSRC is pleased to have helped support the largest genetic study of human hair colour. It has provided some fascinating insights into what makes us such distinct individuals.”

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