A big clue was the fact that people with red hair tend to also have freckles. And that freckled people often have red haired children. Why is this? Because most cases of freckles and red hair are caused by the same gene -- MC1R.
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.
The test will scan each parent's DNA for signs of the so-called MC1R gene that causes redheadedness. "Through a simple saliva test to determine deep ancestry, we can … identify whether an individual is a carrier of any of the three common redhead variants in the gene MC1R," said Dr.
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.
Red hair is a recessive trait, which means that only those who get two “redhead” versions of the gene, one from the mother and one from the father, will have red hair.
Previous studies had shown that redheads inherit two versions of the MC1R gene that leads to red hair – 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.
The variants of the MC1R gene that are linked with freckles started to emerge in the human genotype when humans started to leave Africa. The variant Val92Met arose somewhere between 250,000 and 100,000 years ago, long enough for this gene to be carried by humans into central Asia.
Most (natural) redheads will have brown eyes, followed by hazel or green shades.
Whether or not you have freckles depends on the combination of the freckle (F) and non-freckle (f) versions of MC1R you have. Both FF and Ff people have freckles. What this means is that anyone with at least one copy of the freckle version (F) will have freckles. This is why having freckles is a dominant trait.
So what does that all mean for your chances of having a red-headed child? Since you need two pieces of “red hair” DNA to have red hair, your child will only have red hair if they receive “red hair” DNA from both parents. Even if you don't have red hair, you can still pass on a red hair allele to your child!
In order to be a redhead, a baby needs two copies of the red hair gene (a mutation of the MC1R gene) because it is recessive. This means if neither parent is ginger, they both need to carry the gene and pass it on — and even then they will have just a 25% chance of the child turning out to be a redhead.
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.
While redheads are born all throughout the world, they're more likely to crop up in the Northern hemisphere. Though about 1-2% of the general world population has the red hair gene, that percentage rises to 2 to 6 percent north of the equator.
It's estimated that somewhere around 80% of redheads have freckles, but did you know we aren't born with them? That's right!
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.
'It's extremely rare for people to have hair that is naturally a strawberry blonde color. Basically, strawberry blonde is mostly based on red tones, with blonde highlights dotted here and there. It takes its name from the Italian renaissance.
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.
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.
Freckles tend to run in families. People (especially kids) who have fair complexions are most likely to freckle.
How many redheads are there? Less than 2% of the world's population has red hair. The highest concentration of redheads is in Scotland (13%), followed by Ireland (10%).
This hormone also stimulates a brain receptor that increases pain sensitivity. "In a nutshell, redheads are likely to experience more pain from a given stimulus and therefore require more anesthesia to alleviate that pain," he says. "The art and science of anesthesiology is choosing the right dose," says Liem.
If both parents are auburn-haired, strawberry blonde, or any other blend of red and brown/blonde, there is a 25% chance that their child will be born classic, carrot-top red. That's because both parents carry the gene for pure red hair.
When someone has both of their MC1R genes mutated, this conversion doesn't happen anymore and you get a buildup of pheomelanin, which results in red hair (as well as fair skin and freckles). So, your son may have two mutant MC1R genes, one from you and one from your husband.