Light skin allele of SLC24A5 gene was spread by the Indo-Europeans (R1a + R1b)

[Angela]

According to the ALlele FREquency Database, the Hausa have 10.5% of A111T mutations, which is the highest for Central Africa. The Fulani and Kirdi are not tested. The Mandenka of West Africa (around Gambia and Senegal) have 15% and have about 5% of E-M81.

They even have a map too.

This data also shows that the Kuwaiti and Levantine Bedouins possess respectively 96% and 93% of this light skin allele.

I suppose everything is in the eye of the beholder. Looking at this map, the most striking thing to me is that while the epicenter seems to be the Middle East, the spread is to the southeast, down into India, west along the coast of north Africa, and then north and north east

Usually, I think you're supposed to look for the most parsimonious explanation, and that seems to me to be the fact that this is tracking the movement of agriculture, or perhaps specifically animal husbandry? I would think multiple yDNA and mtDNA lineages would have been involved in its spread. I doubt that scientists would be able to track the actual occurrence to one specific group with one specific y lineage, but it's possible I suppose. Subsequent migrations would affect the results as well. For example, it's interesting that Orcadians show a bit of yellow...perhaps that's a Siberian segment from the east? There's one in southern Spain as well...perhaps the Moorish invasions? You would think in that case the Sicilians would show a slice of yellow, but perhaps they weren't tested.

The allele, once present in an expanding population such as one that has adapted agriculture could spread very quickly. We only have to look at G2a Oetzi in 3300 BC who was already homozygous for it, as Nobody 1 mentioned up thread.

One thing that I don't think it means, however, is that even being homozygous for it means that people would have been fair in the way that people in this thread seem to be imagining. I believe that Razib Khan mentioned in one of his posts on this subject that he is homozygous for it as well.

Then, the mere presence of these alleles doesn't mean that they were always expressed in the same way. Gene expression is a very complicated and not very well understood phenomenon. So, just as selection or deselection for the alleles could occur based on a combination of climate and perhaps diet, these things could also affect the expression of the alleles in certain conditions. Someone living in cloudy Britain could express the alleles differently than someone baking by the sea in Crete.

Then, there's the other more European specific allele for skin pigmentation, 374f.

That has also been studied: You can find the list of values for European cities in this Lucotte et al paper. Unlike the prior snp, it has not quite reached fixation in Europe, which to me indicates it may be younger than the prior snp. To me, it looks like a more straight north south cline, with the Scandinavian countries having the highest values, although France presents a more complicated picture.

Does anyone remember if this is the snp for which Oetzi was heterozygous? Anyway, here's the paper:

http://www.academicjournals.org/article/article1379514057_Lucotte and Yuasa pdf.pdf

 

[Nobody1]

Does anyone remember if this is the snp for which Oetzi was heterozygous?

Rememberence according to what study?

 

[epoch]

First this: The fact that Chinese, Koreans and Japanese developed lighter skin with different genes involved than Europeans basically points to evolutionary pressure. So what would that be? Most probably vitamin D. Apart from Rachitis a number of diseases seem to be affected by vitamin D deficiency:

http://anthrogenetics.wordpress.com/2010/10/22/evolution-of-vitamin-d-pathyway-genes/

The list has a number of interesting health issues. Lower fertility, higher mortality, infectious diseases. Now, as far as I understand the part of mankind that departed Africa carried for a large part a number of genes that give lighter skin. This feature is shared with East-asians , Indian and Amerindians. Apparently this is enough "lightening" of the skin for hunter gatherers as American Indians basically carry these. Off course, hunter gatherers eat basically game and fish, which is relatively rich in vitamin D. Especially if you'd eat fish liver. So, we have a number light skinned genes that allow for more sunlight to reach the skin to make vitamin D, but not yet the light skin of European. Remember that the Loschbourg mesolthic hunter-gatherer does not share any of these specifically European light skin genes with us, even if he possibly had blue eyes.

Now the neolithic revolution kicks in. The amount of available food is high but it's mostly cereals. So far less vitamin D enters the body via food. Since farming is considered to be related to the emerging of a number infectious diseases the notion that vitamin D is highly involved in immune system evolutionary pressure for more light skin is quite relevant. It is also noteworthy that in similar environment both Europeans and East-Asians, heavy cereal using agricultural cultural conglomerates, develop genes for lighter skin independently, whereas the mostly hunter-gatherer American Indians do not. That may serve as evidence for neolithic selective pressure.

So, whatever the scenario that brought in the mentioned mutations, I am beginning to get the idea that evolutionary selective pressure assured the ascendancy to 100% of the current genetic make up.

 

[LeBrok]

First this: The fact that Chinese, Koreans and Japanese developed lighter skin with different genes involved than Europeans basically point to evolutionary pressure. So what would that be? Most probably vitamin D. Apart from Rachitis a number of diseases seem to be affected by vitamin D deficiency:

http://anthrogenetics.wordpress.com/2010/10/22/evolution-of-vitamin-d-pathyway-genes/

The list has a number of interesting health issues. Lower fertility, higher mortality, infectious diseases. Now, as far as I understand the part of mankind that departed Africa carried for a large part a number of genes that give lighter skin. This feature is shared with East-asians , Indian and Amerindians. Apparently this is enough "lightening" of the skin for hunter gatherers as American Indians basically carry these. Off course, hunter gatherers eat basically game and fish, which is relatively rich in vitamin D. Especially if you'd eat fish liver. So, we have a number light skinned genes that allow for more sunlight to reach the skin to make vitamin D, but not yet the light skin of European. Remember that the Loschbourg mesolthic hunter-gatherer does not share any of these specifically European light skin genes with us, even if he possibly had blue eyes.

Now the neolithic revolution kicks in. The amount of available food is high but it's mostly cereals. So far less vitamin D enters the body via food. Since farming is considered to be related to the emerging of a number infectious diseases the notion that vitamin D is highly involved in immune system evolutionary pressure for more light skin is quite relevant. It is also noteworthy that in similar environment both Europeans and East-Asians, heavy cereal using agricultural cultural conglomerates, develop genes for lighter skin independently, whereas the mostly hunter-gatherer American Indians do not. That may serve as evidence for neolithic selective pressure.

So, whatever the scenario that brought in the mentioned mutations, I am beginning to get the idea that evolutionary selective pressure assured the ascendancy to 100% of the current genetic make up.

I think this is a brilliant observation and conclusion.:69:
The farmers needed to be whiter than WHG to live up North, because they were more deficient in D3.

 

[kamani]

If the farmers were whiter than WHG, then Southern-Europeans are darker than North-Europeans because of natural selection and adaptation to sunlight, not because of Near-Eastern admixture. I guess I can buy that.

 

[nordicwarrior]

First this: The fact that Chinese, Koreans and Japanese developed lighter skin with different genes involved than Europeans basically points to evolutionary pressure. So what would that be? Most probably vitamin D. Apart from Rachitis a number of diseases seem to be affected by vitamin D deficiency:

http://anthrogenetics.wordpress.com/2010/10/22/evolution-of-vitamin-d-pathyway-genes/

The list has a number of interesting health issues. Lower fertility, higher mortality, infectious diseases. Now, as far as I understand the part of mankind that departed Africa carried for a large part a number of genes that give lighter skin. This feature is shared with East-asians , Indian and Amerindians. Apparently this is enough "lightening" of the skin for hunter gatherers as American Indians basically carry these. Off course, hunter gatherers eat basically game and fish, which is relatively rich in vitamin D. Especially if you'd eat fish liver. So, we have a number light skinned genes that allow for more sunlight to reach the skin to make vitamin D, but not yet the light skin of European. Remember that the Loschbourg mesolthic hunter-gatherer does not share any of these specifically European light skin genes with us, even if he possibly had blue eyes.

Now the neolithic revolution kicks in. The amount of available food is high but it's mostly cereals. So far less vitamin D enters the body via food. Since farming is considered to be related to the emerging of a number infectious diseases the notion that vitamin D is highly involved in immune system evolutionary pressure for more light skin is quite relevant. It is also noteworthy that in similar environment both Europeans and East-Asians, heavy cereal using agricultural cultural conglomerates, develop genes for lighter skin independently, whereas the mostly hunter-gatherer American Indians do not. That may serve as evidence for neolithic selective pressure.

So, whatever the scenario that brought in the mentioned mutations, I am beginning to get the idea that evolutionary selective pressure assured the ascendancy to 100% of the current genetic make up.

I can live with this too. It explains the "various hues of whiteness" that we see in Northern Europe today. Many Nordics have kept the ability to tan (we see this in Norway, Sweden, parts of Denmark) and then we have the British Islanders (especially Irish and Scottish) who skip the suntan and go right into sunburn. Seperate alleles would account for these differences.

**EDIT** I am speaking in gross generalities here. Certainly not every Swede or Irishman would fit neatly in these boxes, but overall I do see a trend that matches this conclusion.

 

[Alan]

It's a dangerous assumption since the Turks have considerable levels of European admixture (up to 25%) and the Pakistani and Balochi have more European admixture than the Iranians. The Iraqi and Syrians have close to no European admixture. Syrian and Iraqi data on A111T could have helped us determine if that mutation arose among R1 people or among other Middle Eastern people.

The other "European" among Turks is connected to their East Mediterranean admixture but since we know that this allele has no connection with farmer isolate population

With the current reveals in genetics, I find the "European " and "non European" label, used to describe some components, wrong anyway. Considering the current data I doubt that the Eastern Mediterranean component is more or less European than the other.

 

[Maciamo]

With the current reveals in genetics, I find the "European " and "non European" label, used to describe some components, wrong anyway. Considering the current data I doubt that the Eastern Mediterranean component is more or less European than the other.

I agree. In this kind of discussions, when I say European admixture it only means Mesolithic European (before the big migrations of the Neolithic and Bronze Age).

 

[Maciamo]

First this: The fact that Chinese, Koreans and Japanese developed lighter skin with different genes involved than Europeans basically points to evolutionary pressure. So what would that be? Most probably vitamin D. Apart from Rachitis a number of diseases seem to be affected by vitamin D deficiency:

http://anthrogenetics.wordpress.com/2010/10/22/evolution-of-vitamin-d-pathyway-genes/

The list has a number of interesting health issues. Lower fertility, higher mortality, infectious diseases. Now, as far as I understand the part of mankind that departed Africa carried for a large part a number of genes that give lighter skin. This feature is shared with East-asians , Indian and Amerindians. Apparently this is enough "lightening" of the skin for hunter gatherers as American Indians basically carry these. Off course, hunter gatherers eat basically game and fish, which is relatively rich in vitamin D. Especially if you'd eat fish liver. So, we have a number light skinned genes that allow for more sunlight to reach the skin to make vitamin D, but not yet the light skin of European. Remember that the Loschbourg mesolthic hunter-gatherer does not share any of these specifically European light skin genes with us, even if he possibly had blue eyes.

Now the neolithic revolution kicks in. The amount of available food is high but it's mostly cereals. So far less vitamin D enters the body via food. Since farming is considered to be related to the emerging of a number infectious diseases the notion that vitamin D is highly involved in immune system evolutionary pressure for more light skin is quite relevant. It is also noteworthy that in similar environment both Europeans and East-Asians, heavy cereal using agricultural cultural conglomerates, develop genes for lighter skin independently, whereas the mostly hunter-gatherer American Indians do not. That may serve as evidence for neolithic selective pressure.

So, whatever the scenario that brought in the mentioned mutations, I am beginning to get the idea that evolutionary selective pressure assured the ascendancy to 100% of the current genetic make up.

I never thought about this, but that's a great explanation of how and why genes for white skin were selected among early farming populations in Eurasia.

As diet became more complex and varied over time (mix of cereals, vegetables, fruits, meat and dairy products), this original advantage would have lost its significance and skin colour might have reverted to darker tones in particularly hot and sunny regions like North Africa, the Middle East and South Asia, especially among lower class farmers who were often exposed to the sun. That would explain why in East Asia and South Asia people have traditionally regarded lighter skin as more desirable as it slowly turned into a sign of higher social class.

White skin would nevertheless have continued to be positively selected in northern latitudes where sunlight was scarce, especially in very cloudy regions like the British Isles, the Low Countries and Norway, where other mutations for even fairer skin (MC1R gene) could significantly increase UV absorption to create vitamin D. Ironically, fairer skin in northern Europe may have originally increased first among the lower classes who most needed extra vitamin D due to poorer diets (less meat and dairy products) than among the upper classes. However in relatively egalitarian societies like Scandinavia or Ireland that wouldn't have made a lot of difference.

 

[Drac II]

Usually, I think you're supposed to look for the most parsimonious explanation, and that seems to me to be the fact that this is tracking the movement of agriculture, or perhaps specifically animal husbandry? I would think multiple yDNA and mtDNA lineages would have been involved in its spread. I doubt that scientists would be able to track the actual occurrence to one specific group with one specific y lineage, but it's possible I suppose. Subsequent migrations would affect the results as well. For example, it's interesting that Orcadians show a bit of yellow...perhaps that's a Siberian segment from the east?

Quite implausible since the same or more "yellow" would also show up among people like Finns.

There's one in southern Spain as well...perhaps the Moorish invasions? You would think in that case the Sicilians would show a slice of yellow, but perhaps they weren't tested.

Again, quite implausible since then Italians would also show it, or perhaps even more from the actually larger and more permanent population of North African and Near Eastern immigrants and slaves that made Rome their home during Roman imperial times. Plus the Moroccans themselves are shown as having as much "yellow" as Italians and non-Andalusian Spaniards.

 

[Maciamo]

I can live with this too. It explains the "various hues of whiteness" that we see in Northern Europe today. Many Nordics have kept the ability to tan (we see this in Norway, Sweden, parts of Denmark) and then we have the British Islanders (especially Irish and Scottish) who skip the suntan and go right into sunburn. Seperate alleles would account for these differences.

That's because people in the British Isles have a higher percentage of mutations for red hair in the MC1R gene. These mutations also prevent skin from tanning.

 

[Maciamo]

I suppose everything is in the eye of the beholder. Looking at this map, the most striking thing to me is that while the epicenter seems to be the Middle East, the spread is to the southeast, down into India, west along the coast of north Africa, and then north and north east

You shouldn't give too much credit to this map from the ALlele FREquency Database as it is based on only 183 samples, while the Mallick study tested 1573 individuals in the Indian subcontinent alone and Canfield has over 3000 samples from various sources. I only posted the link for the extra populations tested, like the Hausa and Kuwaiti.

 

[Nobody1]

Again, quite implausible since then Italians would also show it, or perhaps even more from the actually larger and more permanent population of North African and Near Eastern immigrants and slaves that made Rome their home during Roman imperial times. Plus the Moroccans themselves are shown as having as much "yellow" as Italians and non-Andalusian Spaniards.

Maybe the impact of all the slaves and immigrants from North Africa and Near East (to the city of Rome) were not that great on Italy; The impact of the 800 years Moorish occupation of Spain was obviously greater;

Based on the 374f allele results (Angela post#21)
http://www.academicjournals.org/article/article1379514057_Lucotte and Yuasa pdf.pdf

Italy:
Genoa 0.85
Rome 0.89
Naples 0.85
bergamo 0.96
Tuscany 0.94

Spain:
Barcelona 0.85
Sevilla 0.72

Portugal North 0.72
Portugal South 0.78

Algeria 0.70
Morocco 0.69

The Moors were described as being pretty dark and 800 years in Spain is a long time;

 

[Drac II]

Maybe the impact of all the slaves and immigrants from North Africa and Near East (to the city of Rome) were not that great on Italy; The impact of the 800 years Moorish occupation of Spain was obviously greater;

Based on the 374f allele results (Angela post#21)
http://www.academicjournals.org/article/article1379514057_Lucotte%20and%20Yuasa%20pdf.pdf

Italy:
Genoa 0.85
Rome 0.89
Naples 0.85
bergamo 0.96
Tuscany 0.94

Spain:
Barcelona 0.85
Sevilla 0.72

Portugal North 0.72
Portugal South 0.78

Algeria 0.70
Morocco 0.69

We've been over these kinds of pseudo-arguments before. They did not work then, they won't work now. These alleles prove absolutely nothing regarding actual skin tones. According to such faulty "logic" based on such allele frequencies northern Portuguese should be darker on average than Italians from around Rome, yet when skin tones were actually measured in these populations the opposite was found:

http://dienekes.blogspot.com/2012/11/gwas-study-of-pigmentation-in-four.html

And they prove even less about history. Historians specializing in the history of Spain all point out the "Moors" were only a small elite, a foreign minority, as befits a military intervention, not a mass migration of people. Most historians of Rome, on the other hand, keep pointing out that the foreign population in Roman Italy was quite large, many even became convinced that it actually outnumbered the local Italian populations. And these foreigners were not mostly from Germany or Gaul, as some people would like to argue, but clearly from the Eastern Mediterranean (Greece, Anatolia, Palestine, Syria, Egypt.)

The Moors were described as being pretty dark and 800 years in Spain is a long time;

Yes, starting with the Romans, who were very well acquainted with them, since they even had Roman rulers who were actually "Moors" (see who Macrinus or Aemilianus were, for example.)

And brush up on some math and geography while you are at it, because the only place in Spain where Islamic (a religion) rule prevailed for 781 years (not 800) was in Granada (not "Spain".) Plus unlike Roman Italy, there was actually an institution called "The Inquisition" throwing people out based on religious beliefs in medieval Spain.

 

[Angela]

Rememberence according to what study?

Sorry, Nobody 1, that it took so long for me to get back to you. I saw from the Kelley paper that you linked that Oetzi was homozygous for the derived state at SLC24A5, but I remember reading somewhere that he was heterozygous for another one of the pigmentation snps. I was wondering if that was correct and if the snp for which he was heterozygous was the SLC45A2 (374f) one and if anyone could point me to a paper where that result could be found.

Thanks for responding.

 

[Nobody1]

We've been over these kinds of pseudo-arguments before. They did not work then, they won't work now. These alleles prove absolutely nothing regarding actual skin tones. According to such faulty "logic" based on such allele frequencies northern Portuguese should be darker on average than Italians from around Rome, yet when skin tones were actually measured in these populations the opposite was found:

http://dienekes.blogspot.com/2012/11/gwas-study-of-pigmentation-in-four.html

And they prove even less about history. Historians specializing in the history of Spain all point out the "Moors" were only a small elite, a foreign minority, as befits a military intervention, not a mass migration of people. Most historians of Rome, on the other hand, keep pointing out that the foreign population in Roman Italy was quite large, many even became convinced that it actually outnumbered the local Italian populations. And these foreigners were not mostly from Germany or Gaul, as some people would like to argue, but clearly from the Eastern Mediterranean (Greece, Anatolia, Palestine, Syria, Egypt.)
The Moors were described as being pretty dark and 800 years in Spain is a long time;
Yes, starting with the Romans, who were very well acquainted with them, since they even had Roman rulers who were actually "Moors" (see who Macrinus or Aemilianus were, for example.)

And brush up on some math and geography while you are at it, because the only place in Spain where Islamic (a religion) rule prevailed for 781 years (not 800) was in Granada (not "Spain".) Plus unlike Roman Italy, there was actually an institution called "The Inquisition" throwing people out based on religious beliefs in medieval Spain.

Ah yes the Candille et al study;
Great study maybe you should read it;
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048294

The figures you are referring to are the Tanning levels (i.e. Skin tone based on UV radiation);

For skin color, global-level variation is likely driven primarily by natural (ecological) selection in response to UV radiation levels.
The inner upper arm was chosen as a site of sampling to avoid as much as possible confounding by variable sun exposure and variability in tanning ability.

And the Polish and Italian students tanned the most; A very valuable information; Makes you wonder why the Portuguese are so afraid of the Sun;

Given that (acc. to Candille et al) the North Portuguese are indeed the darkest (basal-skintone/not tanning)

The frequency of the rs183671 derived allele increases from Southern to Northern Europe: it is 88%, 89%, 98%, and 97% in the Portuguese, Italian, Polish, and Irish cohorts, respectively. We found that this SNP shows some evidence of association with skin pigmentation (p = 6×10⁻⁴, n = 289), and that each copy of the derived allele lightens the skin by 1.2 M index units,

rs183671 allele
88% Portuguese (from the North)
89% Italians (from Rome)
97% Irish
98% Polish

As for the alleles 'not working' and 'prove absolutely nothing' - im not convinced by that;
Given that the alleles truly reflect the Genetic reality and your arguments are just your personal assumptions; Im not sure if you noticed all the studies, maps and links posted on page 1; might want to look at them;

PS: Have you noticed the K=20 admixture analysys in Lazardidis et al 2013 or the IBD sharing results of Botigué et al. 2013???
http://dienekes.blogspot.com.au/2013/06/ibd-sharing-between-iberians-and-north.html
By these scientific data its obvious that the (by your estimates) "small" Moorish elite must have been just as busy as all the Millions of Syrians (Hellenized/Seleucid nonetheless) immigrants in Rome if not even busier;

 

[Angela]

Maybe the impact of all the slaves and immigrants from North Africa and Near East (to the city of Rome) were not that great on Italy; The impact of the 800 years Moorish occupation of Spain was obviously greater;

Based on the 374f allele results (Angela post#21)
http://www.academicjournals.org/article/article1379514057_Lucotte and Yuasa pdf.pdf

Italy:
Genoa 0.85
Rome 0.89
Naples 0.85
bergamo 0.96
Tuscany 0.94

Spain:
Barcelona 0.85
Sevilla 0.72

Portugal North 0.72
Portugal South 0.78

Algeria 0.70
Morocco 0.69

The Moors were described as being pretty dark and 800 years in Spain is a long time;

I wouldn't bet money on the numbers being totally precise; for example, it's a little counter-intuitive in terms of the numbers for Genova vs. Rome. Rome being the large university city that it is, you might have students from the north as well as the south.

However, the big picture seems correct. I think the numbers correlate very well to some maps for solar radiation in Europe.

Look, for instance, at this map:
http://www.greenrhinoenergy.com/solar/radiation/images/SolarGIS-Solar-map-Europe-en.jpg

Then look at this map for the incidence of 374f in Europe from the Lucotte et al paper. I think there's a remarkable correspondence.
http://blogs.discovermagazine.com/gnxp/files/2013/03/slc45a21.png

After the initial spread, it looks like selection has taken place based on environmental factors, and perhaps later more minor population flows from people further south.

 

[Drac II]

Ah yes the Candille et al study;
Great study maybe you should read it;
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048294

The figures you are referring to are the Tanning levels (i.e. Skin tone based on UV radiation);

For skin color, global-level variation is likely driven primarily by natural (ecological) selection in response to UV radiation levels.
The inner upper arm was chosen as a site of sampling to avoid as much as possible confounding by variable sun exposure and variability in tanning ability.

And the Polish and Italian students tanned the most; A very valuable information; Makes you wonder why the Portuguese are so afraid of the Sun;

Given that (acc. to Candille et al) the North Portuguese are indeed the darkest (basal-skintone/not tanning)

The frequency of the rs183671 derived allele increases from Southern to Northern Europe: it is 88%, 89%, 98%, and 97% in the Portuguese, Italian, Polish, and Irish cohorts, respectively. We found that this SNP shows some evidence of association with skin pigmentation (p = 6×10⁻⁴, n = 289), and that each copy of the derived allele lightens the skin by 1.2 M index units,

rs183671 allele
88% Portuguese (from the North)
89% Italians (from Rome)
97% Irish
98% Polish

As for the alleles 'not working' and 'prove absolutely nothing' - im not convinced by that;
Given that the alleles truly reflect the Genetic reality and your arguments are just your personal assumptions; Im not sure if you noticed all the studies, maps and links posted on page 1; might want to look at them;

PS: Have you noticed the K=20 admixture analysys in Lazardidis et al 2013 or the IBD sharing results of Botigué et al. 2013???
http://dienekes.blogspot.com.au/2013/06/ibd-sharing-between-iberians-and-north.html
By these scientific data its obvious that the (by your estimates) "small" Moorish elite must have been just as busy as all the Millions of Syrians (Hellenized/Seleucid nonetheless) immigrants in Rome if not even busier;

You should follow your own "advice" and read it yourself, as they are not any "tanning levels". I already informed you before in another thread that such measurements are taken from areas of the body not exposed to the sun precisely to avoid tanning from possibly interfering with the values. Even your very own quotation says so:

For skin color, global-level variation is likely driven primarily by natural (ecological) selection in response to UV radiation levels.
The inner upper arm was chosen as a site of sampling to avoid as much as possible confounding by variable sun exposure and variability in tanning ability.

Thanks for disarming your own "argument". So, no, Italians were indeed found darkest skinned in that study, not based on conjectures about any allele frequencies but on actual measurements of non-exposed skin tones.

PS: we also already went through the tactic of trying to use IBDs, which are not admixture results, do not indicate gene flow (even the blogger whom you posted a link for clearly notes so), plus even the authors themselves acknowledged that the IBDs they made the subject of their study can be as recent as only a hundred to a couple hundred years old (long after the much ballyhooed "Moors" from the 8th century AD.) The Lazaridis et al. 2013 study used larger Spanish samples (they even used samples from the Canary Islands) than other Europeans, the authors make a note of that and considered it as a possible explanation as to why it seems to be larger. Plus they dated the DNA that you have in mind in Spain to 2000+ years (approx. 65 to 73 generations), long before even Islam itself existed.

 

[Wilhelm]

The impact of the 800 years Moorish occupation of Spain was obviously greater;
The Moors were described as being pretty dark and 800 years in Spain is a long time;

Why are you so ignorant, the "moors" never stayed 800 years in "Spain". First of all, it was only Granada that lasted the full 780 under muslim rule, most of Spain lasted from a few years to about 300-400 years, the process of reconquista was gradual. Second, it was not a "moorish occupation" but a religious rule (Islamic rule), the population was natives that converted to Islam, so the population remained the same. There was not genetic impact nor admixture. Any north-african input in Iberia (which is low ) is pre-historic (it has already been discussed many times).

 

[Nobody1]

You should follow your own "advice" and read it yourself, as they are not any "tanning levels". I already informed you before in another thread that such measurements are taken from areas of the body not exposed to the sun precisely to avoid tanning from possibly interfering with the values. Even your very own quotation says so:

For skin color, global-level variation is likely driven primarily by natural (ecological) selection in response to UV radiation levels.
The inner upper arm was chosen as a site of sampling to avoid as much as possible confounding by variable sun exposure and variability in tanning ability.

Thanks for disarming your own "argument". So, no, Italians were indeed found darkest skinned in that study, not based on conjectures about any allele frequencies but on actual measurements of non-exposed skin tones.

Exactly;
Those figures are UV radiation exposure (i.e. tanning levels) and they tested it (to avoid it as much) on the inner-upper arm - that says it all;
PS: do you really think alleles are sun exposed as opposed to the upper arm?
Since you are such a fan of UV radiation here are a few other studies based on the same method;

Jablonski - 2000 study - skin tone map on p.76
http://www2.bgsu.edu/departments/ch...em447/PDF_files/Jablonski_skin_color_2000.pdf

Rindermann et al 2012 - Chemnitz Uni. p.11
https://lesacreduprintemps19.files.wordpress.com/2012/05/haprinderm.pdf

p.11 - Skin bright:
Norway - 1.57
Sweden - 1.57
Iceland - 1.57
Slovenia - 1.57
Netherlands - 1.49
Germany - 1.48
Czech Rep. - 1.42
---
Albania - 1.27
Italy - 1.27
Bulgaria - 1.27
Ukraine - 1.27
---
Cyprus - 1.12
Spain - 1.19
Greece - 1.12
Portugal 1.12


As for the Genetic reality (alleles) of skin-pigmentation you will surely find a host of infomation of page 1; So knock yourself out;

PS: we also already went through the tactic of trying to use IBDs, which are not admixture results, do not indicate gene flow (even the blogger whom you posted a link for clearly notes so), plus even the authors themselves acknowledged that the IBDs they made the subject of their study can be as recent as only a hundred to a couple hundred years old (long after the much ballyhooed "Moors" from the 8th century AD.) The Lazaridis et al. 2013 study used larger Spanish samples (they even used samples from the Canary Islands) than other Europeans, the authors make a note of that and considered it as a possible explanation as to why it seems to be larger. Plus they dated the DNA that you have in mind in Spain to 2000+ years (approx. 65 to 73 generations), long before even Islam itself existed.

Ah the excuses and relativations again i.e. complete fiction;
This is what Botigue et al had to say herself:

North African samples that have highest IBD sharing with Iberian populations also tend to have the lowest proportion of the European cluster in ADMIXTURE(Fig.1), e.g. Saharawi, Tunisian, Berbers and South Moroccans. This suggests that gene flow occurred from Africa to Europe rather than the other way around.

And the most massive gene flow from Africa to Iberia (Spain) was the Moorish invasion and occupation for hundreds of years; As for Lazaridis et al - the chart says it all; Certain elements are virtually absent in the rest of South Europe but an integral (every single sample tested positive for it) in Spain; Obviously the Moorish legacy; You might want to look at K=20 again Canary islands are separate - and you do know that each stripe indicates a sample and its individual admixture?;