25. Development of Blue Eyes
It’s quite likely that you or someone you know has blue eyes. In fact, it’s relatively common to see eyes of all colors including some that have a mix of two colors. This is actually an evolutionary change that began around 6,000 to 10,000 years ago from one ancient ancestor. This gene mutation and abnormality originated in our ancestors and managed to pass on years later.
This means anyone with blue eyes is likely related to this one person, in some way. The way it works is through a mutation affecting the OCA2 gene. This gene somehow codes the protein needed for producing melanin. For those unaware, melanin gives our skin, hair, and eyes their color. The mutation limited the melanin within the iris, effectively diluting the eye color from normal brown to blue.