There is no shortage of myths when it comes to those with red hair. From feisty temperament, to connections to vampires (because the burn so quickly in the sun). They can have differences in pain tolerance, temperature change sensitivity, and bruising. Because of the rarity of red-heads, it has been believed they are headed for extinction. I am here to say that they are here to stay and they continue to maintain their coveted status.
Hair Genetics
Chromosome 16 is a gene that influences your hair, skin, and eye color. The Melanocortin 1 receptor gene (MC1R) controls cells called melanocytes which makes the pigment called melanin. There are two specific types of melanin. The first, and of interest to us is eumelanin, which is a dark shade of brown and pheomelanin, which is more red. The MC1R gene determines how much of each pigment is produced, and in turn determines your hair color.
You get two copies of your genes, one from each of your parents. They can contain conflicting instructions. European Monk Gregor Mendel (1822 – 1884) conducted research using pea plants and was able to determine that some genes are dominant and overpower other genes when they are paired with them. Some genes can be recessive and they can be hidden. Dark hair is a dominant gene, and red hair is recessive. Blue eyes are also recessive. As a result, blue eyed redheads are the most rare combination in the world. Only about 1 percent of the world’s population are that combination.
Skin Type and Eye Color
Those with red hair usually have brown or hazel eyes. Redheads also have fewer hairs on the head, which range about 90,000 strands, compared to 110,000 for blonds, and 140,000 for darker shades of hair color. The paler, freckled skin and less protective hair make those with red hair more susceptible to sunburn and skin cancer. Redheads do have an upside. Their fair skin has an easier time manufacturing vitamin D with less sun exposure. Maybe that is why Europe boasts the highest concentration of redheads in the world, which is estimated at 13 percent in Scotland alone, much higher than the 2 percent in the United States.
Skipping Generations
If two parents have dark hair, how could their child still have red hair? Grandparents can pass down the recessive MC1R gene. A brown hair gene is more dominant, so each dark-haired parent could have one dominant brown and one recessive red gene. It only takes the two recessive reds to match up in the offspring and you have a child with red hair.