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Monday, October 17, 2011

Pigmentation genetics of Europeans


The maps below are based on three genome-wide SNP markers showing high association with blue and green eyes and/or fair hair in Europeans. The results obviously suggest there's an increase in hair and eye blondism from south to north in Europe, with clear peaks east of the Baltic Sea. The three SNPs include rs1667394 (HERC2 gene), rs12913832 (OCA2 gene), and rs12896399 (SLC24A4 gene).







Indeed, I'm a bit taken aback by the very high rate of suggested blondism in the Belorussians and Mordvinians (second highest dot in Russia). This might have something to do with sampling bias. Perhaps most of the 12 Belorussians and 16 Mordvinians used here came from fairer than average communities within their respective nations? I have no idea. In any case, I don't think the picture is too far from reality, because multiple sampling sites from the same general biogeographic zones, but several hundred kilometers apart, are showing very similar results. This can't be a coincidence.

It's also interesting to note that the East Baltic peak in blondism genotypes correlates closely with the North + East European genome-wide ancestral component in my latest ADMIXTURE experiment (see here). Perhaps this is where natural selection for these traits was most extreme due to very specific environmental pressures, like lack of sunlight? Maybe this is also where these traits spread from, either gradually or during one or several major migrations? Someone should look into that. Meantime, I'll try and update this post with new maps as more samples come in.

Please be aware that I didn't produce the maps. It was actually one of my project members (thanks FR7!). However, I didn't reveal the raw data of project members to him during the process. That wasn't necessary, because the stats I sent through were group averages of the relevant allele frequencies.

13 comments:

Gui S said...

I was looking at the Sardinian averages you sent. And their amount of G allele at rs12913832 is extremely low compared to all other populations (0.1964, compare to next lowest in Turkey at 0.28!!).
Either the allele's been bred significantly out the island, either it spread out mostly after the island's population got isolated.

Fanty said...

I find something like this very interesting.
Hope to see something like this more often.

On different alleles that are known to be connected to traits/physical features etc.

truth said...

Why are not included Basques ?

Italian Stallion said...

Italians are lighter than Spain

Fanty said...

Sardinia is in fact the darkest region of Italy.

This map shows, that Southern Italy is darker than Northern, but Sardinia is the darkest.
Wich is in line with the frequency of alleles that cause this.

http://modabest.com/wp-content/uploads/wpid-Novyie-obrazyi-ot-italyanki-Grace-italiyagrace-0.gif

This map here (European blondness map), sees at least a different center of the actual effect (but who knows how accurate this map is)
The general tendency agrees however.
http://strangemaps.files.wordpress.com/2007/12/blond_hair_map1.jpg

And these are 2 different blue eye maps of Europe:
http://www.summagallicana.it/lessico/c/Coon%20Light_Eyes_Map.JPG

and

http://westernparadigm.files.wordpress.com/2008/02/blue_eyes_map2.jpg?w=500

Italian Stallion said...

Fanty your posting outdated maps with no data. Sardinia doesn’t have a dot and didn’t experience the Moors and Africans like Spain did. I know who truth is he is a delusional Spaniard that thinks Basques were Cro-Magnons and that Spain is Paleolithic.

Fanty said...

What do you eman by "Sardinia doesnt have a dot"?
Look up in the comments section.

In Sardinia, one of those alleles is more rare than in Turkey. ;-)

So, ok, post some actual maps then. If you have better blond hair maps.

Fanty said...

And "Outdated maps" means, back then when the map was done, it was correct, but meanwhile a lot of retired Germans came to Italy and improved the blondhair frequency? ;)

Gui S said...

Hey Fanty and Italian Stallion,I am FR7, I will soon make a new version of the maps with data points for Sardinia and the Basque Country.

Simon Ritz said...

Pigmentation is discoloring of the skin that usually occurs, when the skin has been exposed to the sun and has been damaged. Freckles, age spots and other discoloration are the most common forms of skin pigmentation. Some people are born with, the freckles, while others develop them, as they age and have been exposed to the sun.
pigmentation

Nameless said...

This should NOT be taken as any kind of pigmentation map. The data comes ONLY from ares with dots the rest is just assumed based on distance, and is clearly incorrect according to all other pigmentation maps which were taken based on actually hair and eye colors rather than just associated genes.

Davidski said...

There aren't any accurate hair and eye pigmentation maps online.

Either they're hopelessly outdated or they're based on dodgy statistics from someone looking at pictures of soccer players online.

So these inferred genetic pigmentation maps are more accurate than anything else available online currently.

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