SCIENTISTS DISCOVER THAT ALL PEOPLE WITH BLUE EYES SHARE A COMMON ANCESTOR

According to research from the University of Copenhagen, everyone with blue eyes descended from a single ancestor some 6,000–10,000 years ago. Professor Hans Eiberg of the Department of Cellular and Molecular Medicine says, "Originally, we all had brown eyes." However, a genetic mutation that affected our chromosomes' OCA2 gene led to the development of a "switch," which effectively "turned off" the capacity to produce brown eyes. Although this switch' does not shut down the gene in blue-eyed people (as it does in those who have albinism), it does restrict the amount of melanin that is produced in the iris until brown eyes turn blue.

Professor Eiberg and his colleagues came to this conclusion by contrasting the melanin content of blue and green eyes with that of brown and green eyes. They discovered that the latter has very little variation in melanin. Eiberg goes on, "We can infer that all blue-eyed people are related to the same ancestor from this." "The identical switch was inherited by them all at precisely the same location in their DNA." This study, which started in 1996, involved a sizable sample of blue-eyed people from Europe and the Middle East, which included Jordan and Turkey.

All in all, this mutation seems to have no effect on anything save eye colour. On Science Daily, you can read more about this research.