If you have blue eyes, be wary of falling in love with another blue-eyed beauty. According to a study from USA Today, there’s a possibility everyone with blue eyes may be related. Researchers in Denmark say every person with blue eyes descends from one ancestor whose genes mutated 6 to 10,000 years ago. They claim before that one blue-eyed person came about, everyone had brown eyes.
Says Professor Hans Eiberg of the University of Copenhagen in a press release: “Originally, we all had brown eyes. But a genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a ‘switch,’ which literally ‘turned off’ the ability to produce brown eyes.”
Blue eyes are a recessive trait, and the gene must be inherited from both parents. Green eyes involve a related but different gene, one that is recessive to brown but dominant to blue. It wasn’t until the original mutant’s grandchildren or great-grandchildren hooked up-cousin marriage is the norm through most of human history-that the first blue-eyed person came to be.