"The Genetic Ancestry of Every Blue-Eyed Person Traces Back to a Single Human Ancestor"

Every person with blue eyes on Earth is a descendant of one single human who lived between 6,000 and 10,000 years ago, as a genetic mutation from the HERC2 gene completely turns off the OCA2 gene, diluting brown pigment into blue. This discovery, made in 2008, suggests that all blue-eyed individuals share a common ancestor and that the mutation likely spread when humans migrated from Africa to Europe. The study also explains the rarity of blue eyes, estimating that 8 to 10 percent of the world's population have them, mainly among people of European descent.