Did you know…
This isn’t news- the research was done in 2008, but still interesting.
All people with blue eyes are descendants of a common ancestor, who lived between 6000 and 10 thousand years ago, probably in the area of the black sea. Before this time it is thought that there were only brown eyed people. Scientists know this by looking at the mitochondrial DNA of blue eyed individuals- they found that blue eyed people all have such similar DNA that they had to have a common lineage, and by looking at the differences between their DNA were able to calculate how recently this gene mutation occurred.
It was found that a gene (OCA2) affects the amount of melanin that blue eyed people can produce, which accounts for their eye colour, and also their generally fairer hair and skin. It is thought that this is why there is a significant preponderance of Scandinavians with blue eyes- their fairer skin allows them to absorb more sunlight, which allows them to produce more Vitamin D than darker skinned folks. This gives blue eyed, fair skinned people an advantage in areas where there is less sunlight.