Where do red hair come from?

As a geneticist with a focus on human genetics and evolution, I can explain the origin of red hair. Red hair is the result of a genetic variation that affects the production of melanin, the pigment responsible for the color of our hair, skin, and eyes. The specific gene responsible for red hair is the MC1R gene, which is involved in the production of eumelanin, a dark pigment. When a person inherits a specific variant of the MC1R gene from both parents, it leads to the production of a different type of melanin called pheomelanin, which results in red or orange hair.

Red hair is most commonly found in people of Celtic descent, particularly in regions where Celtic tribes historically lived, such as Scotland, Ireland, and Wales. The genetic trait is relatively rare, occurring in only 1 to 2 percent of the global population. The trait is recessive, which means that both parents must carry the gene for a child to have red hair.

It's important to note that while the genetic basis for red hair is well understood, the exact evolutionary reasons for its persistence are still a subject of scientific debate. Some theories suggest that the trait may have been advantageous in regions with lower sunlight levels, as the red hair and pale skin may allow for more efficient synthesis of vitamin D.

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.