Sunday, February 3, 2008

The Eyes Have It

While scientists at Copenhagen University were looking for the gene that caused red hair or 'gingivitis' as it is called in order to shut it off they discovered something else.

Everyone with blue eyes can be traced back 10,000 years to one single individual named Burt from the Black Sea region.

Feared by some and prized by others blue eyes have always been something of a genetic mystery. Until now.

A single mutation which arose as recently as 6-10,000 years ago was responsible for all the blue-eyed people alive on Earth today.

The team, have identified a single mutation in a gene called OCA2, which arose by chance somewhere around the northwest coasts of the Black Sea in one single individual, about 8,000 years ago.

The gene does not "make" blue in the iris; rather, it turns off the mechanism which produces brown melanin pigment. "Originally, we all had brown eyes," says Dr Hans Eiberg, who led the team.

Those from Europe and the Near-East have many characteristics that set them apart from the rest of the human race such as extreme good looks and intelligence.

Not only are Europeans far more likely to have blue eyes (95 per cent in some Scandinavian countries), they also have a far greater range of skin tones and hair colour than any other ethnic grouping.

One theory is that Europe's cold weather and dark skies played a part. Fair skin is better at making Vitamin D and the 8 % of the world's population have blue eyes weak sunlight found in northern latitudes may have been a factor for adapting.

Another suggestion is that the strange skin, eye and hair colours seen in Europe are down to ancient interbreeding with the Neanderthals, who died out about 25,000 years ago.

It has been found that many people in the rural regions of the south of France, Italy, Spain and Greece still have traces of Neanderthal DNA which has been put down to substantial interbreeding between them and Homo sapiens but blue eyes is not a common factor.

The Gallic shrug which is a gesture that has a number of meanings such as, It's not my fault; I don't know; I doubt it can be done and I don't really agree is an indicator of excessive Neanderthal DNA .

Sex selection seems to come into play when there is a lot of competition for mates of one sex or the other. The theory is that in Europe, where men had to spend weeks at a time out on the hunt, males were in very short supply.

In such societies, women who had fair hair stood a better chance of standing out and attracting the attention of the few men that would have been available for mating. Leading to the expression about blondes having more fun.

Blue eyed people have a higher tolerance to pain than brown eyed people but with fair skin and blue eyes being a mutation it is thought that eventually there will be a universal out-breeding with the more common brown skin and brown eyes being dominant so enjoy the difference while you can.

Dr Eiberg has not given up on his goal and has made it his mission in life to rid the world of gingers.


Zoe said...

does that mean they will also do away with red hair dye? please tell me it isn't so!

Gingernuts said...

They can take our hair but they'll never take our FREEDOM!