BLUE EYES, BLUE SKY

by Abellio

Beijing, 15 November 2012

My wife and I have one fundamental difference: I notice people’s looks and she notices people’s characters. One result of this is that after living in a part of the world where everyone has black hair and dark eyes, I have become intensely aware of differences in hair and eye colouring, whereas my wife is quite indifferent to it. So it was that yesterday, when my wife and I were sitting at our favourite café and we found ourselves sitting across from a European expat, I was transfixed by his blue eyes while she didn’t notice. After spending a suitable moment marvelling at the sight, I began to ask myself some questions. Questions which my wife’s iPad, which I commandeered, and the café’s wifi allowed me to find answers to.

Perhaps the most amazing fact is this. Every person in the world with blue eyes (and the closely linked grey and green eyes) has one single, common ancestor! A mutation occurred in some corner of this person’s DNA and that little mutation has been passed on down the generations ever since. Up to that point, the colour of all humans’ eyes had been dark. And then, some ten thousand years ago somewhere in the north-western part of the Black Sea region (geneticists have managed to pinpoint the source that accurately), someone was born with blue eyes.  Can you imagine what that must have been like? Was the person treated as a wonder or as a dangerous freak, I ask myself? I have to think the former, since this person was able to sire children who passed on the mutation.

I suppose blue eyes are most associated with Europe: blondes or the red-heads with blue eyes.

But actually, according to very recent research, the original Ol’ Blue Eyes was probably dark skinned and dark haired. And in fact blue eyes are found everywhere:

Algeria …

Palestine …

Lebanon …

Syria …

Jordan …

Iran …

Afghanistan …

India …

Central Asia …

Even China! (although more green than blue) …

Even Africa!! …

But most basic of all, why are eyes blue? Because the irises lack melanin. It’s melanin which makes the human eye – and skin, and hair – dark. But why aren’t blue eyes colourless then? Because of the same effect that makes the sky blue: “longer wavelengths of light tend to be absorbed by the dark underlying epithelium, while shorter wavelengths are reflected and undergo Rayleigh scattering in the turbid medium of the stroma. This is the same frequency-dependence of scattering that accounts for the blue appearance of the sky” (1). So eyes are blue because the sky is blue. Now how cool is that …

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1. http://en.wikipedia.org/wiki/Eye_color#Blue

Links for the pix:

Little European blonde girl: http://ts3.mm.bing.net/th?id=I.4963638661679662&pid=1.7&w=237&h=155&c=7&rs=1

Little European red-headed girl: http://ts3.mm.bing.net/th?id=I.4615243792843710&pid=1.7

Algerian old woman: http://pulitzercenter.org/reporting/algeria-aures-mountains-facial-tattoos-culture-portrait-series

Palestinian man: http://i56.tinypic.com/2vao8av.jpg

Syrian man: http://www.hobotraveler.com/123_07baghdadistanbul/0077.JPG

Jordanian man: http://www.lurvely.com/photo/4259694961/A_face_from_Jordan/

Little Iranian girl: http://www.worldisround.com/articles/73022/photo653.html

Afghan woman: http://en.wikipedia.org/wiki/Nuristani_people

Afghan man: http://farm5.static.flickr.com/4041/4696088197_24f3ecf0c4.jpg

Little Indian girl: http://i2.asntown.net/h3/fun/12/beautiful-eyes/asian-people-with-blue-eyes05.jpg

Indian woman in Sari and Indian boy: http://www.asiafinest.com/forum/lofiversion/index.php/t8178-100.html

Indian man with green eyes: http://i.images.cdn.fotopedia.com/flickr-4833454489-hd/Countries_of_the_World/Asia/Portrait-Asia-Demographics_of_Asia-Demographics_of_India-Human-India-Portrait_photography-Rajasthan-Rajasthani_people-hd.jpg

Central Asian man: http://anthrocivitas.net/forum/showthread.php?t=7853

Chinese woman: http://ts1.mm.bing.net/th?id=I.4981686084830908&pid=1.7

African girl: http://korraisnottan.tumblr.com/post/21640006035/anonymous-asked-korra-is-not-tan-korra-is-not

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