Feeds

All blue-eyed people share one common ancestor

Genetic mutation responsible for Sinatra

The Power of One Infographic

A University of Copenhagen team has identified the gene which around 6-10,000 years ago underwent a genetic mutation in one individual who eventually gave rise to all blue-eyed people.

Professor Eiberg from the Department of Cellular and Molecular Medicine began his research in 1996, when he "first implicated the OCA2 gene as being responsible for eye colour", as ScienceDaily puts it.

Over the next decade, he and his colleagues "examined mitochondrial DNA and compared the eye colour of blue-eyed individuals" in countries including Denmark, Jordan and Turkey.

Eiberg explained: “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."

Specifically, ScienceDaily explains, the OCA2 gene "codes for the so-called P protein, which is involved in the production of melanin". The “switch”, located in the gene adjacent to OCA2, doesn't turn off the gene entirely, but "limits its action to reducing the production of melanin in the iris", thus “diluting” brown eyes to blue.

That the switch doesn't entirely disable the OCA2 gene is significant, because a complete shut-down of melanin production would result in albinism.

The proof that all blue-eyed people have a common ancestor comes from the fact that whereas eye colours ranging from brown to green are caused by relatively large differences in the amount of melanin in the iris, controlled by "considerable individual variation" in the area of the DNA responsible for melanin production, the variation in iris melanin levels across all blue-eyed individuals is very small.

Eiberg elaborated: “From this we can conclude that all blue-eyed individuals are linked to the same ancestor. They have all inherited the same switch at exactly the same spot in their DNA.”

Eiberg noted that the blue eyes mutation is neither "positive nor negative", since it doesn't affect chances of survival. He concluded: "It simply shows that nature is constantly shuffling the human genome, creating a genetic cocktail of human chromosomes and trying out different changes as it does so.” ®

Eight steps to building an HP BladeSystem

More from The Register

next story
Malaysian Airlines flight MH17 claimed lives of HIV/AIDS cure scientists
Researchers, advocates, health workers among those on shot-down plane
Forty-five years ago: FOOTPRINTS FOUND ON MOON
NASA won't be back any time soon, sadly
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Mwa-ha-ha-ha! Eccentric billionaire Musk gets his PRIVATE SPACEPORT
In the Lone Star State, perhaps appropriately enough
MARS NEEDS OCEANS to support life - and so do exoplanets
Just being in the Goldilocks zone doesn't mean there'll be anyone to eat the porridge
Diary note: Pluto's close-up is a year from … now!
New Horizons is less than a year from the dwarf planet
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
prev story

Whitepapers

Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.