Agriculture is what made Europeans light-skinned; new findings

[Domen]

Loschbour (late Northern European hunter from Luxembourg; 8000 years ago) and Stuttgart (early farmer immigrant from the Middle East; 7000 years ago):

Note that the Northern European hunter was NOT lighter-pigmented (except for eyes) than the Middle Eastern immigrant farmer:

See here:

http://www.ancestraljourneys.org/autosomaladna.shtml#pigmentation

And also:

Loschbour Northern European hunter (8000 years ago) - reconstruction (location "5" on the map posted above):

La Brana man from north-west Iberia (7000 years ago) - reconstruction (location "3" on the map posted above):

http://www.dailymail.co.uk/sciencet...-old-DNA-reveals-European-African-traits.html

Man, dubbed La Brana 1, also shows similarity to Scandinavian DNA

New scientific findings show that prehistoric European hunter-gatherers were rather dark-skinned (and this applies also to prehistoric Scandinavian hunter-gatherers). It seems that they did not need additional vitamin D from sunlight, because they had enough vitamin D from food - being hunters and gatherers, they were eating a lot of vitamin D-rich meat, fish, mushrooms and fruits. Only with the switch to agriculture several thousand years ago, amount of vitamin D-rich food in diet decreased - and as the result evolution of very pale skin tone among Europeans started.

Check also:

Debunking the theory that lighter skin gradually arose in Europeans nearly 40,000 years ago, new research has revealed that it started evolving much recently - only 7,000 years ago. (...) light-skin genes in Europeans evolved much more recently than previously thought. The findings, which were detailed today (Jan. 26, 2014) in the journal Nature, "also hint that light skin evolved not to adjust to the lower-light conditions in Europe compared with Africa, but instead to the new diet that emerged after the agricultural revolution", said study co-author Carles Lalueza-Fox, a paleogenomics researcher at Pompeu Fabra University in Spain.

The finding implies that for most of their evolutionary history, Europeans were not what many people today would call 'Caucasian', said Guido Barbujani, president of the Associazione Genetica Italiana in Ferrara, Italy, who was not involved in the study.

Instead, "what seems likely, then, is that the dietary changes accompanying the so-called Neolithic revolution, or the transition from food collection to food production, might have caused, or contributed to cause, this change," Barbujani said.

In the food-production theory, the cereal-rich diet of Neolithic farmers lacked vitamin D, so Europeans rapidly lost their dark-skin pigmentation only once they switched to agriculture, because it was only at that point that they had to synthesize vitamin D from the sun more readily.

"Most people of the world make most of their vitamin D in their skin as a result UV exposure. But at northern latitudes and with dark skin, this would have been less efficient. If people weren’t getting much vitamin D in their diet, then having lighter skin may have been the best option." - said co-researcher Mark Thomas of University College London.

 

[Berzerker]

so people living in arctic regions will better retain pigment?

 

[James Stuart]

Jesus, it's back. It has not been conclusively shown that skin pigmentation has any effect on Vitamin D production, so this seems to be putting the cafrt before the horse. So far as I am aware, the lowest amounts of Vitamin D in humans is amongst the Chinese and Indian populations, who have widely variated diets and pigmentations. And there's no reason to bring hair colour into the discussion at all.

 

[bhavv]

I disagree with the research because I am 100% sure that the direct cause of this phenomenon is genetics.

 

[gay_Aleks]

Yes, but genetics usually happens to be affected by the environment that said being lives in.

Nobody knows why, really.

 

[Domen]

so people living in arctic regions will better retain pigment?

1) There are no real Arctic regions in Europe. 2) Apparently they will not become pale as long as they are not farmers.

3) Most of modern Europeans are lighter-skinned than natives of Siberia, Alaska, Canada and than Eskimos of Greenland.

Moreover, Japanese and Northern Chinese people also tend to be very pale-skinned, even compared to North-East Asians living in more northern latitudes than them. Which is most likely as well caused by fact that China and Japan switched to agriculture early on, while those peoples north of them didn't.

 

[Borachio]

In any case, this isn't a new idea.

In the 1970s, Luca Cavalli-Sforza suggested that the selective sweep that rendered light skin ubiquitous in Europe might be correlated with the advent of farming and thus have taken place only around 6,000 years ago;[36] This scenario found support in a 2014 analysis of mesolithic (7,000 years old) hunter-gatherer DNA from La Braña, Spain, which showed the version of these genes corresponding to dark skin color.

http://en.wikipedia.org/wiki/Human_skin_color

 

[Domen]

This scenario found support in a 2014 analysis of mesolithic (7,000 years old) hunter-gatherer DNA from La Braña, Spain, which showed the version of these genes corresponding to dark skin color.

And a 2013/2014 analysis of hunter from Loschbour also showed that he had dark skin:

http://www.nature.com/nature/journal/v513/n7518/full/nature13673.html

Received 23 December 2013 / Accepted 11 July 2014 / Published online 17 September 2014

 

[H4run]

so lighter skin absorb vitman D much more easier?

 

[Domen]

Yes, there is virtually a scientific consensus about this.

From wiki:

(...) Humans with light skin pigmentation have natural skin with low amounts of eumelanin, and have fewer melanosomes than humans with dark skin pigmentation. Light skin provides better absorption qualities of ultraviolet radiation. This helps the body to synthesize higher amounts of vitamin D for bodily processes such as calcium development.[3][10] (...)

European hunter-gatherers had diets which were rich in vitamin D and calcium. However, after the Neolithic Revolution - when diet switched from that of hunters to that of agriculturalists - farmers with darker skin were at higher risk of rickets and other diseases caused by shortages of vitamin D and of calcium.

As for calcium - it can be found in milk and other dairy products. It was perhaps the driving force behind the evolution of lactase persistence:

https://en.wikipedia.org/wiki/Lactase_persistence

Lactase persistence is the continued production of the enzyme lactase required to digest the beta carbohydrate lactose found in milk. This is normally switched off in humans in the late teens. However, due to a mutation or rather, four distince and geographically separated mutations but which all achieve the same result, some adults continue to produce the lactase enzyme.

New findings show that only 5% of prehistoric Scandinavians had lactase persistence gene, while today vast majority of Scandinavians have it:

"High frequency of lactose intolerance in a prehistoric hunter-gatherer population in northern Europe":

http://www.biomedcentral.com/1471-2148/10/89

http://link.springer.com/article/10.1186/1471-2148-10-89

Here we investigate the frequency of an allele (-13910*T) associated with lactase persistence in a Neolithic Scandinavian population. From the 14 individuals originally examined, 10 yielded reliable results. We find that the T allele frequency was very low (5%) in this Middle Neolithic hunter-gatherer population, and that the frequency is dramatically different from the extant Swedish population (74%).

(...) positive selection could have dramatically increased the frequency of the derived allele (...)

"Absence of the lactase-persistence-associated allele in early Neolithic Europeans":

http://www.pnas.org/content/104/10/3736.abstract

================================

So it seems that when deprived of vitamin D and calcium-rich diet of hunter-gatherers, two adaptive traits helped those early farmers:

1) Evolution of pale skin tone to increase absorption of vitamin D from sunlight,

2) Evolution of lactase persistence to increase absorption of calcium from food.

 

[Domen]

BTW - modern Europeans are to a large extent descendants of Asian (including Near Eastern) immigrants from the last 8000 years:

http://dna-explained.com/2014/10/21/peopling-of-europe-2014-identifying-the-ghost-population/

And also:

http://www.ancestorcentral.com/decennial-conference-on-genetic-genealogy-sunday/

Decennial Conference on Genetic Genealogy
by Jennifer Zinck, 12 October 2014

From a 2014 study - "Ancient human genomes suggest 3 ancestral populations for present-day Europeans":

Link to this study: http://arxiv.org/ftp/arxiv/papers/1312/1312.6639.pdf

Link to appendices: http://biorxiv.org/content/biorxiv/suppl/2014/04/05/001552.DC4/001552-3.pdf

Western Hunter-Gatherers (WHG) - they lived in Europe (but also in Central-Western Asia) prior to 8000 years ago
Early European Farmers (EEF) - they were immigrants from the Middle East, who came during the Neolithic period
Ancient North Eurasians (ANE) - they were also immigrants to Europe, who came even later than those farmers

(PS: don't pay attention to these red frames, these were added by me - I highlighted several populations for comparison):

 

[H4run]

very interesting post Domen, so blue eyes appear just 7000 years ago while lighter skin even more recent than that. It is really interesting discovery thanks for sharing

 

[Domen]

Blue eyes are older. 7000 years ago they were already widespread.

 

[James Stuart]

Yes, there is virtually a scientific consensus about this.

From wiki:



European hunter-gatherers had diets which were rich in vitamin D and calcium. However, after the Neolithic Revolution - when diet switched from that of hunters to that of agriculturalists - farmers with darker skin were at higher risk of rickets and other diseases caused by shortages of vitamin D and of calcium.

As for calcium - it can be found in milk and other dairy products. It was perhaps the driving force behind the evolution of lactase persistence:

https://en.wikipedia.org/wiki/Lactase_persistence



New findings show that only 5% of prehistoric Scandinavians had lactase persistence gene, while today vast majority of Scandinavians have it:

"High frequency of lactose intolerance in a prehistoric hunter-gatherer population in northern Europe":

http://www.biomedcentral.com/1471-2148/10/89

http://link.springer.com/article/10.1186/1471-2148-10-89



"Absence of the lactase-persistence-associated allele in early Neolithic Europeans":

http://www.pnas.org/content/104/10/3736.abstract

================================

So it seems that when deprived of vitamin D and calcium-rich diet of hunter-gatherers, two adaptive traits helped those early farmers:

1) Evolution of pale skin tone to increase absorption of vitamin D from sunlight,

2) Evolution of lactase persistence to increase absorption of calcium from food.

There most certainly is not a scientific consensus on this. In fact, the most recent research, on West African populations, seems to dispute this claim, as do several parts of your own Wiki link you didn't bother to quote. Don't worry, I'm sure you have an unrelated graph on the topic. As I'm sure you have a reason for bringing lactose tolerance into a discussion about Vitamin D levels and skin pigmentation. As for your claim that Europe has no "real arctic regions," Lappland says hi.

 

[Domen]

James - all the scientific papers that I quoted agree with the vitamin D hypothesis.

Only you disagree, and your non-mainstream sources. Care to provide an alternative explanation?

As I'm sure you have a reason for bringing lactose tolerance

You see, you confuse terms again. Lactase persistence =/= lactose tolerance. These are two different things. For example Bersaglieri's 2004 data show 92.9% of Sardinians are lactase non persistent, lactose intolerance tests show 86% of Sardinians to be lactose intolerant:

"Genetic signatures of strong recent positive selection at the lactase gene" (Bersaglieri et al., 2004):

http://www.ncbi.nlm.nih.gov/pubmed/15114531

93% non persistent, 86% intolerant. Two things, with lactose tolerance being more common than lactase persistence.

I was talking about lactase persistence, not about lactose tolerance.

=============================================

Lactase persistence is about producing the enzyme, while lactose tolerance is about not getting sick from drinking a glass or so of milk:

Lactose intolerance is a little different. Before the genetics of lactose digestion were understood, the test for lactose tolerance/intolerance was rather artifical and involved drinking a measured amount of milk of a certain quality and seeing the effects. It had been noted that individuals varied considerably. Some could drink half a glass of milk happily whlist others got sick from the smallest amount. Others could of course consume large quantities of the stuff with no ill effects whatsoever. Whatever the merits of the tolerance/intolerance tests, it was a line, however artificial. So, whilst Bersaglieri's data show 92.9% of Sardinians are Lactase non persistent, Lactose intolerance tests show 86% of Sardinians to be Lactose intolerant. Consquently a map of Lactose intolerance looks a bit different for a lactase persistence map

Concerning lactase persistence:

http://www.ncbi.nlm.nih.gov/pubmed/15114531

We estimate that strong selection occurred within the past 5,000-10,000 years, consistent with an advantage to lactase persistence in the setting of dairy farming; the signals of selection we observe are among the strongest yet seen for any gene in the genome.

And why did I bring it into a discussion about vitamin D levels ???

Because calcium (which is present in great amount in milk and dairy products) is of similar importance for health as vitamin D:

http://nof.org/articles/10

Calcium-Rich Food Sources

Food is the best source of calcium. Dairy products, such as low-fat and non-fat milk, yogurt and cheese are high in calcium. Certain green vegetables and other foods contain calcium in smaller amounts.

And as you know if you don't get enough of vitamin D then your organism will also not be able to absorb and digest calcium.

So Vitamin D is needed to absorb calcium by your body. And if people have shortage of vitamin D, they also have shortage of calcium:

http://www.emedicinehealth.com/osteoporosis_and_calcium/page7_em.htm

What Assists Absorption of Calcium

Vitamin D is the most significant nutrient for the proper absorption of calcium. Vitamin D and calcium work together to slow down or even reverse osteoporosis. Vitamin D is essential in helping the body absorb and use calcium; in fact, the body cannot absorb calcium at all without some vitamin D.

It appears likely that mutations which facilitate absorption of vitamin D (genes responsible for light pigmentation) developed together with mutations which facilitate absorption of calcium (lactase persistence) - both of which were responses to new diet (deprived of vitamin D) and not enough sunlight.

On the other hand, with the transition from hunting-gathering to animal-breeding and farming, milk and dairy products became available.

 

[H4run]

I have something in my mind, if this hypothesis is true than it mean the skin tone of Ainu and Siberian people are much darker than the skin tone of northern Chinese people? because both Ainu and Siberian were hunter gatherers, while North Chinese people already shift to agrarian earlier. However just comparing by their appear photograph it seems to me that Ainu and Siberian people have lighter skin tone than northern Chinese.

I'm really open to anything, and I'm really curious about this, I just want to know the matter much better.

 

[Borachio]

Let's face it: people's face tone varies with how much they go outside and the time of year. You're not going to get much good information from photographs, imo.

I'm really not sure that skin tone, in itself, is an issue at all.

 

[H4run]

Let's face it: people's face tone varies with how much they go outside and the time of year. You're not going to get much good information from photographs, imo.

I'm really not sure that skin tone, in itself, is an issue at all.

I say that because Domen stated:

Moreover, Japanese and Northern Chinese people also tend to be very pale-skinned, even compared to North-East Asians living in more northern latitudes than them. Which is most likely as well caused by fact that China and Japan switched to agriculture early on, while those peoples north of them didn't.

White European that live in Bali and sun bathing all the time and becoming tanned, doesn't changes their descendant into having more lighter skin right? It is required a very long process of adaptation.

 

[Domen]

Haroon:

North-East Asians (such as Japanese, Chinese, Ainu, Siberians, etc.) often also have light skin, but their light skin evolved from a different mutation. Just like there are 4 mutations for lactase persistence (of which only 1 emerged in Europe - while 3 other emerged in other parts of the world), there is also more than 1 mutation for light skin. East Asians have light skin but their light skin is from other genes. Which is why they do not tan red (while we, Europeans, do).

East Asians - thanks to their different mutation for light skin - do not have the skin cancer problem:

http://theconversation.com/east-asian-genes-may-solve-the-skin-cancer-puzzle-21762

Europeans fall prey to skin cancer because of their lighter skin, while Africans' dark skin protects them. But East Asians, whose skin colour resembles that of Europeans, are similar to Africans in their low susceptibility to melanoma – the deadliest skin cancer.

(...)

In 2005, Keith Cheng at Pennsylvania State University stumbled upon the genetic mutation responsible for light skin colour in Europeans. This was an accidental discovery made using a zebrafish mutant known as “golden”. Zebrafish is an ideal model organism because it has considerable genetic similarities to humans, enabling testing that would otherwise be impossible.

Cheng was initially looking for a gene that was causing a peculiar instability in the fish. The process of finding genes that have a particular function is called genome editing. It involves selectively knocking out genes from a species (which is done while it is still at the egg-stage) and then observing what difference it makes as the species is born and grows up. Repeating the process enough times narrows down the genes acting in the function of interest.

Their last knock out test was on the gene SLC24A5, which led to change in zebrafish’s skin colour. This gene is found in humans, too, and it must have the same role. When Cheng compared the international human genome databases, such as HapMap and 1,000 Genomes, he spotted that SLC24A5 was found in all those with European ancestry.

Light skin in Europeans comes from mutation A111T in gene SLC24A5, which is 10,000 years old (according to this article):

http://www.hinduhumanrights.info/li...tween-india-and-the-middle-east-claims-study/

Light skin in Europeans stems from ONE 10,000-year-old ancestor

But this article says that there are two genes responsible for light skin among Europeans (not only SLC24A5, but also A2):

http://news.psu.edu/story/147191/2012/08/30/study-tribe-could-help-find-east-asian-skin-color-genes

While the genetics of skin color is largely unknown, past research using zebrafish by Penn State College of Medicine's Keith Cheng, M.D., Ph.D., identified the gene in Europeans that differs from West Africans and contributes to a lighter skin color. Mutations in the genes SLC24A5 and SLC45A2 are largely responsible for European pigmentation, showing only single amino acid differences between Europeans and West Africans. Each version of a gene is called an allele.

While East Asians -- Chinese, Japanese and Korean -- also are light skinned, these European alleles are not present, suggesting that while both groups' lighter skin color evolved to allow for better creation of vitamin D in northern climates, they did so in a different way. This difference also affects skin cancer rates. Europeans have 10 to 20 times higher rates of melanoma than Africans. However, despite also having lighter skin, East Asians have the same melanoma rates as Africans. The reason for this difference can only be explained when the gene mutations for both groups are found.

"By finding the differences, we have the potential to find ways to make people with the European ancestry genes less susceptible to skin cancer," said Cheng, professor of pathology.

This is a challenge, because to find the unidentified mutations, researchers must study a population that includes a blend of original African ancestry and East Asian ancestry, with little European contribution.

The Senoi, one of three indigenous tribes from Peninsular Malaysia, meet this condition. The Senoi are believed to include ancestry of a dark-skinned tribe called the Negrito, and a regional Mongoloid population of Indo-China, such as the Proto-Malay. Since the skin color of the Senoi is darker than that of Northeast Asians, researchers will be able to focus on finding the primary genetic mutation of light skin color in Asians without seeing further skin lightening mutations.

Khai C. Ang, Ph.D., postdoctoral fellow in the Cheng lab, visited the Senoi, developed a positive relationship with them, and was able to collect 371 blood samples. Characterization of the Senoi's skin color was recently reported in PLoS ONE.

"As the world is becoming globalized, populations are becoming increasingly mixed," Ang said. "Time is running out and it will become increasingly difficult to establish how East Asian skin colors evolved."

The researchers will now map genes in the DNA using the collected samples to identify which might be responsible for the skin color of East Asians. In the Cheng lab, the candidate genes and mutations can then be tested in zebrafish for verification.

"Skin color has been tied to human welfare in modern history," Cheng said. "It is important for us as a species to realize that our skin color is determined by only a small number of minute changes in our DNA -- changes that have nothing to do with the value of human beings."

====================================

Borachio:

Let's face it: people's face tone varies with how much they go outside and the time of year.

This is simply not true. If you have Skin Type 1 or 2 on Fitzpatrick's Skin Scale, then you can go outside as much as you want but you can only get red - certainly you will not get very dark (it is easier for you in such case to get skin cancer than to turn into some chocolate-coloured guy).

For example 70% of Polish people have Skin Types 2 and 1 on Fitzpatrick's Scale - as defined here:

http://img.docstoccdn.com/thumb/orig/171411961.png

 

[H4run]

@Domen

I don't know if I don't get your answer or you don't understand my question.

My comparison is between asian, not Asian and European. A hypothesis that diet affected skin tone is a very interesting hypothesis. If this hypothesis is true than the Siberian and Ainu who were hunter gatherers should have more darker skin than Northern Chinese and Northern Japanese who shift to Agrarian much earlier. However the fact seems to be quite different.

I need to see the report or photograph of pre-modern Ainu (19c) to verified this but so far it seems Ainu skintone lighter than Northern Chinese, which falsified the hypothesis if it correct. This question is just for my curiosity, I don't have any standing regarding this. I'm just testing/verifying.