Some changes in the MC1R gene results in the production of pheomelanin from the pigments. Pheomelanin causes reddish hair as well as freckles. So, if a person carries the pheomelanin version of the MC1R gene, it's likely that she or he will have red hair and develop freckles.
Because most cases of freckles and red hair are caused by the same gene -- MC1R.
Contrary to what many people assume, redheads did not originate in Scandinavia, Scotland or Ireland, but in central Asia. Their coloring is due to a mutation in the MC1R gene that fails to produce sun-protective, skin-darkening eumelanin and instead causes pale skin, freckles and red hair.
The closer together two genes are on a chromosome, the less likely their alleles will be separated by crossing-over. Linkage explains why certain characteristics are frequently inherited together. For example, genes for hair color and eye color are linked.
For example, one gene, MC1R, is tied to both freckles and red hair. If both copies of the gene are changed, you're a redhead. If only one copy is changed, you'll get freckles—but not always. And scientists still don't know why.
It's estimated that somewhere around 80% of redheads have freckles, but did you know we aren't born with them? That's right!
While it's true that such a mutation in people of Celtic heritage causes the stereotypical dot-dot-dots in fair redheads, variations of the MC1R gene lead to freckles in Chinese, Japanese, French, Mediterranean, Israeli, and certain African ethnic groups as well, explains Sharma.
Redheads probably won't go grey. That's because the pigment just fades over time. So they will probably go blonde and even white, but not grey.
Most (natural) redheads will have brown eyes, followed by hazel or green shades.
What is the best hair color for fair skin and freckles? Colorists advise those girls to dye their strands in soft and light shades. They can use chestnut, honey, and similar tones. However, when it comes to the best hair color for too light skin and freckles, cool shades should be considered.
Red Hair And Blue Eyes Is Rare
Red hair occurs naturally in one to two percent of the human population, while just 17 percent of the world's population has blue eyes. The majority of redheads have brown, hazel, or green eyes.
Rarest kind of redhead
Having red hair and blue eyes is the rarest hair/eye color combination possible. The odds of a person having both of those recessive traits is around 0.17%. Instead, most redheads have brown, hazel or green eyes, according to Medical Daily.
Ireland: The Emerald Isle and Home of the Red Heads
With more red-headed residents than anyone else in the world, Ireland is the king of people with red hair. The latest estimates suggest that about 10% of Ireland's population are redheads.
Though there is a myth that redheads don't go grey, Bain says it isn't true. “There is, however, lots of evidence to show that redheads retain their pigment a lot longer than people with other natural colours such as brunettes and blondes,” she explains.
Thanks to higher concentrations of red hair and pale skin in cloudy European environments, redheads gained a greater ability to create their own vitamin D. When they go outside, he or she produces more vitamin D in a shorter amount of time than people with other hair colours.
Redheads Look Older Than They Are
Some evidence suggests redheaded adults often appear older than their actual age. For example, one study published in 2016 in Current Biology found that adults who carry two copies of the MC1R gene variant are more likely to look two years older than other people their age.
The skin of a redhead is thinner compared to others and is derived from the ectoderm. Teeth enamel is also derived from the ectoderm and thus is thinner than usual. Since the enamel coating is thin, the inner layer of tooth-dentin is more visible and offers a yellowish appearance.
Freckles are extremely common and aren't a health threat. They're more often seen in the summer. You're more likely to have freckles if you're lighter-skinned and have blond or red hair. However, freckles can occur in anyone, and appear as darker brown spots if you have darker skin.
Freckles are associated with a variant of a gene called MC1R. MC1R alerts the body when exposed to harmful UV radiation is taking place. This is a dominant gene, meaning anyone with at least one copy of the freckle variant from either parent will have freckles.
Although freckles are hereditary, they are activated by sun exposure. If someone that has the freckle gene (MC1R), they must spend time in the sun in order to produce freckles. A person without the freckles genes will not produce freckles regardless of if they are in the sun or not.
According to Cartman (and thus adopted by society, obviously), a daywalker is a redhead who can handle being in the sun without stressing too much about getting burnt. They may or may not have freckles or pale skin, and generally have brown eyes.
Ireland has the highest per capita percentage of redheads in the world -- anywhere from 10 to 30 percent, according to Eupedia, a website that explores European genetics and ancestry. They are almost equally prevalent in Scotland and other pockets of Celtic pride.
Red hair is caused by a mutation in the MC1R gene. It's also a recessive trait, so it takes both parents passing on a mutated version of the MC1R gene to produce a redheaded child. Because it's a recessive trait, red hair can easily skip a generation.
A redhead is a person with red hair. Although sometimes it looks more like orange, “orangehead” isn't a thing. Only about one percent of the entire population is a real redhead. In England, a redhead is “ginger” haired.
Recessive traits like red hair can skip generations because they can hide out in a carrier behind a dominant trait. The recessive trait needs another carrier and a bit of luck to be seen. This means that it can sometimes take a few generations to finally make its presence known.