๐ How Rare Is Red Hair? 1-2% of the World
๐งฌ The MC1R Gene
Red hair is caused by variants of the MC1R gene on chromosome 16. It's recessive โ both parents must carry it. About 40% of Northern Europeans carry one copy without having red hair themselves. Two carriers have a 25% chance of a red-haired child.
๐ฆ Red Hair Combos
Red hair + blue eyes: ~0.17% (~13M people). Red hair + green eyes: ~0.04% (~3M people). Red hair + heterochromia: ~0.0002% (~16K people). These are some of the rarest natural appearance combinations on Earth.
๐ก Did You Know?
Redheads require 20% more anesthesia than others (MC1R affects pain receptors). Red hair doesn't go gray โ it fades through rose gold to white. Redheads produce their own vitamin D more efficiently, an evolutionary advantage in low-sunlight regions like Scotland and Ireland.