PDA

View Full Version : Ancient DNA and the rewriting of human history: be sparing with Occam’s razor



Heber
01-19-2016, 08:52 PM
Ancient DNA and the rewriting of human history: be sparing with Occam’s razor

Marc Haber, Massimo Mezzavilla, Yali Xue and Chris Tyler-SmithEmail author

Genome Biology201617:1
DOI: 10.1186/s13059-015-0866-z© Haber et al. 2016
Published: 11 January 2016

Populating Europe

Europe was first populated by modern humans around 45,000 ya, but (except for some southern areas) was depopulated during the glacial maximum that occurred 25,000 ya and subsequently repopulated as the climate improved, with farming beginning ~8000 ya during the Neolithic transition (Box 3). Decades of debate have been dedicated to understanding the origin of agriculture in Europe, focusing particularly on whether it spread from its place of origin in the Near East by demic diffusion (movement of farmers) or by acculturation of the indigenous hunter-gatherers (movement of ideas). Geneticists first attempted to answer this question by sampling modern populations from Europe and the Near East and then comparing the genetic diversity of classical protein markers (Box 1) between the two regions.

In 1978, the cover of Science magazine featured an image by Cavalli-Sforza and colleagues showing maps of Europe constructed with ten loci using multivariate techniques to reveal clines [23], which they interpreted as agreement with the demic diffusion model. Many genetic studies followed, investigating a variety of loci including mitochondrial DNA and the Y-chromosome. Some of these studies were uninformative, some were interpreted as supporting acculturation [24, 25] and others as favoring demic diffusion [26], with perhaps a balance supporting the latter [27].

Recent aDNA studies reveal, however, that populating Europe has been a much more complex process, and that the Neolithic transition (Box 3) was not even the event that most influenced the present-day genetic landscape.

The first aDNA complete genome sequence from Europe came from the Tyrolean Iceman; a 5300-year-old (Late Neolithic or ‘Copper Age’) natural mummy discovered in 1991 in the Ötztal Alps. Surprisingly, the Iceman had more genetic affinity to present-day Sardinians than to the present-day populations inhabiting the region where he probably lived [28], showing that major demographic changes have occurred in Europe after the Neolithic era. A more substantial revision of the demic diffusion model was introduced when several 7000–8000-year-old individuals from Western Europe [29] and a 24,000-year-old individual from Siberia [30] were sequenced. Analysis showed that at least three different ancient populations contributed to the genetics of present-day Europeans: (1) West European hunter-gatherers, (2) ancient north Eurasians related to Upper Paleolithic Siberians, and (3) early European farmers, who were mainly of Near Eastern origin [29]. The contributions of these three populations to modern European ancestry were not necessarily direct, and the demic diffusion model was further refined by analyzing 69 additional Europeans who lived between 3000 and 8000 ya (Fig. 1). The refined model shows that the arrival of the first farmers during the Early Neolithic from the Near East was followed by a massive migration from the Eurasian Steppe ~4500 ya involving people from the Yamnaya culture [31]. Controversially, these people were suggested to have also brought Indo-European languages into Europe [31]. The Yamnaya population distantly shares ancestry with the ancient Siberians; it is probably one of the sources of the Ancient north Eurasian ancestry previously identified among the three ancient populations that contributed to present-day Europeans [32]. It is worth noting here that the arrival of the Ancient north Eurasian ancestry in Europe through a surrogate population could not have been identified without analyzing the Yamnaya population: a reminder that even the interpretation of partial aDNA findings is vulnerable to the pitfalls of the parsimonious model. The genetic impact of the Yamnaya migration is strikingly illustrated by the transition in European Y-chromosomal haplogroups from a predominance of G2a beforehand to R1a and R1b afterwards [31], an impact that is, retrospectively, detectable in present-day DNA [33, 34].

7373

Fig. 1
Populating Europe. aDNA research shows that present-day Europeans are the result of a mixture of different ancient populations (blue diamonds): (1) West hunter-gatherers who had inhabited Europe since Paleolithic times; (2) Early European farmers, who descended from Near Eastern farmers and entered Europe during the Early Neolithic; and (3) Steppe herders, who arrived in Europe during the Bronze Age. The steppe herders themselves were a mixture of eastern Eurasian hunter-gatherers (Eastern hunter-gatherers) and Near Easterners (orange squares). Additionally, Europeans have ~2 % archaic ancestry from mixture with Neanderthals that arose ~50,000–60,000 ya, probably somewhere in the Near East (purple star). There is also evidence that admixture with Neanderthals occurred again in Europe (purple triangle), as evident from the DNA of a 37,000–42,000-year-old human from Romania. However, this population appears not to have contributed detectably to later humans in Europe. Grey arrows represent the model for populating Europe inferred from modern DNA analysis. aDNA research refined this model by adding several additional layers of information, including multiple migrations and mixtures leading to present-day Europeans (black arrows)
In summary, aDNA findings have provided conclusive evidence for the movement of farmers at the beginning of the Neolithic transition, but also for the incorporation of the hunter-gatherer gene pool, and therefore support what might be called a ‘leaky demic diffusion’ model. In this respect, the new findings merge the previous ideas. But in demonstrating the large genetic contribution of the Yamnaya during the Bronze Age, they again reveal major events that were not anticipated in the earlier genetic debate.

http://genomebiology.biomedcentral.com/articles/10.1186/s13059-015-0866-z?utm_content=bufferee1b3&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer#Sec3

Jean M
01-19-2016, 10:24 PM
An excellent review paper, apart from a rather silly conclusion on skin colour.

jeanL
01-19-2016, 11:54 PM
An excellent review paper, apart from a rather silly conclusion on skin colour.

What's so silly about their conclusion on skin color?

Heber
01-20-2016, 09:30 AM
Box 3 The Neolithic transition

The Neolithic transition or revolution refers to the change in lifestyle of humans from hunting-gathering to agriculture, through domestication of plants and animals, which led to the development of permanent settlements, towns, cities, trade and eventually the rise of civilization. Neolithic transitions occurred independently in several parts of the world; the one that transformed Europe started in the Near East around 10,000 years ago and spread through Europe over the next few millennia. This cultural transition had considerable consequences for human genetic variation by stimulating growth in population size, and triggering multiple expansions and mixtures, as well as adaptation to certain diets and diseases.

Jean M
01-20-2016, 10:15 AM
What's so silly about their conclusion on skin color?

They have gone for sexual selection (groan) because northern hunter-gatherers in Europe did not have the now common European mutations for pale skin. Ye gods! The authors cannot have read much on the topic. It would be amazing if sexual selection for pale skin only worked in the higher latitudes of Europe and Asia, and for some strange reason people did not choose pale partners in the tropics!! Here is what I say online: http://www.ancestraljourneys.org/looks.shtml

Dark skin protects people from ultra-violet light, but may make it more difficult for their skin to synthesise vitamin D, essential for bone growth and activation of the immune system. Pale people in sunny places are at higher risk of skin cancer and folate deficiency, while dark people in cooler climes are prone to problems of low vitamin D. So it has long been supposed that the range of skin colours we see today arose through natural selection.

How does that work? Since our genes code for functions, a mutation generally results in loss of function. The code has become faulty. So it is with the mutations that cause paler colouring. Mutations in specific genes prevent the body from producing melanin - the most important pigment influencing skin and hair colour. In places drenched in ultra-violet light, such mutations would be a disadvantage. People carrying them could die before they had a chance to reproduce at all. Or they could have fewer surviving offspring. But in cloudier climes such mutations give their bearers an advantage, so gradually they would gain ground in a population there.

The rainbow look of Europeans suggests strong selection for a cold climate. It may seem a logical deduction that the process began as man left Africa. Certainly polymorphisms in two genes, ASIP and OCA2 (A355G), seem to play a role in light and dark pigmentation across the globe. They are probably so old that they pre-date the exodus from Africa. Yet scientists calculate that a new allele causing paler skin cropped up on gene SLC24A5 around 10,000 years ago, probably in the Middle East. It is nicknamed the golden gene, as it also causes golden stripes in zebrafish.

Support for this theory comes from two hunter-gatherers, one who lived in Iberia and the other in Central Europe around 6000 BC. Both carried the ancestral form of SLC24A5, rather than the mutation which is almost universal in those of European ancestry today, and which is found in an early farmer in Central Europe who lived around 5000 BC.

While the golden gene and three others (SLC45A2, TYRP1 and KITLG) cause most of the paleness of Europeans and their relatives, East Asians have their own colour-drainer (His615Arg in OCA2), as well as KITLG, showing independent evolution after their ancestors moved deep into Asia. The similar distribution of alleles in the KITLG gene within Western Eurasians and East Asians suggests that the mutation causing paler skin occurred before the ancestors of these populations separated. One estimate puts the KITLG change at 30,000 years ago. The Western Eurasian-type alleles at TYRP1, SLC24A5, and SLC45A2 appear to have arisen much later - all within the last 11,000-19,000 years.

So it seems that the evolution of colour variation took a leap in the era of the earliest farmers, probably because their diet was lower in vitamin D. Early Europeans boosted their vitamin D intake by eating fatty fish. Salmon bones, fish hooks, and paintings of salmon, trout, and pike have been found in caves they occupied. The start of farming in the Near East created a higher reliance on cereals.

Heber
01-20-2016, 10:56 AM
Two items of interest in Fig 1:

The steppe herders themselves were a mixture of eastern Eurasian hunter-gatherers (Eastern hunter-gatherers) and Near Easterners (orange squares).

7377

Does the orange square component (5-7 Kya) represent the CHG component as identified by Jones et Al.

http://www.cam.ac.uk/research/news/fourth-strand-of-european-ancestry-originated-with-hunter-gatherers-isolated-by-ice-age

Or could it reflect the expansion of Uruk towards Maikop as described by Cunliffe in Steppes, Desert and Oceans.

7376

https://books.google.ie/books?id=cEpoCgAAQBAJ&pg=PA91&lpg=PA91&dq=cunliffe+uruk+Maikop&source=bl&ots=VWDdceAwid&sig=KrQ1e4amfrf3teAYV45AIaoRq24&hl=en&sa=X&ved=0ahUKEwii8bTfmrjKAhWGRg8KHWBSCBMQ6AEIIjAA#v=on epage&q=cunliffe%20uruk%20Maikop&f=false

Fig 1 shows the expansion out of Iberia 5-6kya. Is this the linked to the expansion of mtDNA H out of Iberia as described by Brandt and could it be linked to the early Bell Beaker expansion.

7378

Tomenable
01-20-2016, 12:00 PM
What the article forgot to mention while discussing skin pigmentation (or where do "white people" originally come from), is, however, that Eastern hunter-gatherers were on average the most white-skinned population out of all those ancient populations shown by their map:

(based on frequencies od deived alleles rs1426654 / rs16891982):

https://docs.google.com/spreadsheets/d/1xe9sgt0PSt6cUQ3cYp14foBoaVGsOKZBmmHJoKz0HB0/edit#gid=1800275085

The article mentions only, that Western hunter-gatherers from the Franco-Cantabrian refuge - who repopulated Western Europe after the Last Glacial Maximum - were dark-skinned, while Scandinavian hunters and Near Eastern farmers were lighter. This is correct. But the article doesn't mention what colour were Eastern hunters. And they were the lightest (based on average frequencies of known skin-lightening alleles):

http://www.snpedia.com/index.php/Appearance#Skin

http://www.snpedia.com/index.php/Skin_pigmentation

Steppe herders (originating largely - in about 60% - from Eastern hunters, and in 40% from hunters of Caucasus region) were also lighter than Scandinavian HG (who were mixed Western HG with some input from Eastern HG) and than Neolithic Farmers from Anatolia.

Modern European skin pigmentation basically came to Europe from Russia.

Near Eastern farmers and Scandinavian hunters were lighter than Western hunters, but still darker than modern Europeans.

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

Frequencies of skin-lightening derived alleles rs1426654 and rs16891982:

Western HG = 12,5% and 0% (combined 13) ---> darkest-skinned of them all
Caucasus HG = 100% and 0% (combined 100)
Sweden HG = 58,3% and 66,7% (combined 125)
Anatolia NF = 100% and 34,8% (combined 135)
Russian HG = 100% and 75% (combined 175)

Showing, that Eastern HG (from Russia) were the lightest-skinned group.

Tomenable
01-20-2016, 12:11 PM
By the way, I have heard that ENF samples from Greece were considerably darker-skinned than those NF from Anatolia.

Is this confirmed?

Tomenable
01-20-2016, 12:15 PM
The steppe herders themselves were a mixture of eastern Eurasian hunter-gatherers (Eastern hunter-gatherers) and Near Easterners (orange squares).

These orange squares are Caucasus HG (even though the map shows them as beginning their northward migration around Armenia):

But these are genomes from Kotias Klde and Satsurblia, in Western Georgia:

http://www.persee.fr/doc/paleo_0153-9345_2007_num_33_2_5220

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4213019/

Those CHG perhaps came - ultimately - from the south or south-east, but they settled in Georgia just after the Last Glacial Maximum.

Tomenable
01-20-2016, 12:28 PM
So it seems that the evolution of colour variation took a leap in the era of the earliest farmers

This theory was valid before the discovery of light pigmentation in samples from SHG hunters and EHG hunters.

The discovery of equally light skin in SHG - and even lighter skin in EHG - seriously undermines the whole idea.

When WHG were found out to be dark-skinned, it was a "sensation" - "all Europeans were dark 8000 years ago!" (headlines told us).

However, now it seems that it was a huge exaggeration. Likely dark-skinned WHG were an exception, not a rule.

Remember, that WHG were descended from a small group which survived LGM in the Franco-Cantabrian Refuge.

Tomenable
01-20-2016, 12:48 PM
An excellent review paper, apart from a rather silly conclusion on skin colour.

Not silly at all, considering that a lot has changed since we had only WHG and Central Euro ENF samples. I agree with them on this. Now we have pigmentation SNPs from many other HG groups (CHG, SHG, EHG) and from other Non-HG groups (Anatolia ENF, Greece ENF, many Steppe groups), etc. There is no clear pattern such as "all HG = dark", "all Farmer = light". Greece ENF were dark, Anatolia and Central Euro ENF were lighter, WHG were dark, CHG lighter, SHG just as light as Anatolia and Central Euro ENF. But it seems that the lightest group of them all were EHG.

Silly was the initial hype after the discovery of WHG skin colour and the spurious conclusion that "ALL Europeans were dark recently".

And the idea that Europeans "rapidly evolved" light skin is just as silly as claiming that Americans "rapidly evolved" blonde hair between 1400 and 1900 AD. Most of those changes in pigmentation were due to migrations and admixtures, selection played only a secondary role.

Change of skin colour is a long process taking thousands of years, and by the end of LGM some groups had to already be light, others dark. Most of changes of pigmentation observed after that point, were largely due to expansion of some of those groups, and extinction of others.

Jean M
01-20-2016, 01:34 PM
.... Silly was the initial hype after the discovery of WHG skin colour.....

The point I am making is that there is a marked correlation between skin colour and latitude all over the world. Forget the details of the picture in Europe for the moment. All over the world, the darkest skin is found closest to the tropics (apart from the descendants of migrants since the Age of Exploration).

7379

This pattern is so obviously connected to levels of sunlight that all experts on the topic are agreed that there is a relationship. This is not simply in Europe. There are paler Chinese in northern China than southern China. There are darker native Americans in areas closest to the equator. Almost native Americans are descended from the same group of people who arrived in America from Asia. So differences in skin colour have evolved since then. This cannot be due to sexual selection. It is due to natural selection.

lgmayka
01-20-2016, 02:58 PM
Forget the details of the picture in Europe for the moment.
We cannot "forget" it because it is precisely the issue under discussion. The question is not whether generally, over tens of thousands of years, natural selection slowly lightens skin color; but rather, How did European skin color change so completely (especially in the north), so rapidly? It is naive to dogmatically assert that natural selection sufficed to accomplish this.

This popular-science article (in Polish) (http://www.kurierlubelski.pl/artykul/3722410,odtworzyli-twarz-wojownika-z-epoki-brazu-jego-grob-byl-pod-hrubieszowem,id,t.html) describes a Bronze Age warrior buried near Hrubieszów who lived 4000 years ago. He had a dark complexion.
---
Nieocenioną pomocą okazały się wyniki badań szkieletu z Rogalina. Także genetyczne. Dzięki nim wiemy, że wojownik miał ciemną karnację, ciemne włosy oraz oczy.
---

Unfortunately, I cannot find the actual research paper.

parasar
01-20-2016, 03:25 PM
We cannot "forget" it because it is precisely the issue under discussion. The question is not whether generally, over tens of thousands of years, natural selection slowly lightens skin color; but rather, How did European skin color change so completely (especially in the north), so rapidly? It is naive to dogmatically assert that natural selection sufficed to accomplish this.

This popular-science article (in Polish) (http://www.kurierlubelski.pl/artykul/3722410,odtworzyli-twarz-wojownika-z-epoki-brazu-jego-grob-byl-pod-hrubieszowem,id,t.html) describes a Bronze Age warrior buried near Hrubieszów who lived 4000 years ago. He had a dark complexion.
---
Nieocenioną pomocą okazały się wyniki badań szkieletu z Rogalina. Także genetyczne. Dzięki nim wiemy, że wojownik miał ciemną karnację, ciemne włosy oraz oczy.
---

Unfortunately, I cannot find the actual research paper.

I believe Atmar had reported that those comments on phenotype - dark hair, eyes, skin - are not to be relied upon.

Nevertheless, to support your point, the Black Sea paper showed a rapid change.
"pigmentation loci range from 2 to 10% and are among the strongest signals of recent selection in humans"
http://www.pnas.org/content/111/13/4832.abstract

Jean M
01-20-2016, 03:52 PM
We cannot "forget" it because it is precisely the issue under discussion.

I merely meant to suggest putting the details on one side for the moment to view the bigger picture.

Genetic genealogy interest in the matter can be overly narrow. It is natural that people think about their own ancestors. Can the face they see in the mirror be traced back to some ancestor many, many thousands of years ago? Sometimes one can see a resemblance continued over several generations, as we see sometimes when people post up family pictures. But we know really that we each have multitudes of ancestors and we cannot be identical to all of them!

Europeans are the product of thousands of years of adaptation to the environment, which is a matter partly of chance and partly of natural selection. Ancient DNA is telling us that some of the features we have today, like the ability to drink milk, were not present in the hunter-gatherers of Europe or Near Eastern farmers, but began to appear in the Bronze Age, gradually increasing in the population since then.

lgmayka
01-20-2016, 03:58 PM
I believe Atmar had reported that those comments on phenotype - dark hair, eyes, skin - are not to be relied upon.
I found Artmar's comment on this (http://www.anthrogenica.com/showthread.php?3732-Reconstruction-and-possibly-a-genetic-analysis-in-the-future-of-4-000YBP-Pole&p=82547&viewfull=1#post82547):
---
His pigmentation is a fantasy, allele for a pigmentation of hair, eyes and skin are to be tested soon.
---

I can't find any more recent information.

jeanL
01-20-2016, 04:11 PM
They have gone for sexual selection (groan) because northern hunter-gatherers in Europe did not have the now common European mutations for pale skin. Ye gods!

Last I checked the Motala Hunter Gatherers are Northern Hunter Gatherers and they did have the now common European mutations for pale skin. So both SHG and EHG had the now common European mutations for pale skin, it was the WHG that did not carry them. Thus I'm not sure where the issue is? BTW why do you keep quoting your own book when it comes to debunking(Which you didn't by the way!) their statements?

Jean M
01-20-2016, 04:22 PM
BTW why do you keep quoting your own book when it comes to debunking... their statements?

That is not my book. It is an online page which I put together especially so that I had something handy to quote when the topic came up, as it periodically does. The online original has all the citations in place. So I don't have to ferret around looking for the relevant papers every time.

Jean M
01-20-2016, 04:25 PM
Last I checked the Motala Hunter Gatherers are Northern Hunter Gatherers and they did have the now common European mutations for pale skin. So both SHG and EHG had the now common European mutations for pale skin, it was the WHG that did not carry them. Thus I'm not sure where the issue is?

The issue for me is nothing to do with which European individuals had which mutations, but with the conclusion of this paper's authors that paler skin arose in Europe by sexual selection, rather than natural selection. Their argument is that it couldn't have been natural selection because not all of the tested ancient individuals had the now common colour-drainer mutations. Is this logical? In my view - no, no, a thousand times no.

Tomenable
01-20-2016, 04:37 PM
Jean M (Re: post #12), I would like to see a really reliable map for skin pigmentation in native populations.

The one you posted in #12, is not reliable. This one is closer to the truth, but I'm not sure if perfectly accurate:

7382

As can be seen, the correlation with lattitude and climate is far from perfect, especially in certain regions:

http://i.imgur.com/RuejUQT.png?1

Tomenable
01-20-2016, 04:41 PM
I agree, that some correlation with climate and lattitude (and sun exposure) exists, but it is really not perfect.

Especially in the Americas you can see, that Native Americans did not "return back" to African-like pigmentation.

15,000 years since crossing from Siberia until Columbus were still not enough to "evolve back into dark-skinned".

Kale
01-20-2016, 07:22 PM
Well since Americans were bottlenecked out of Siberia, it's no surprise they didn't drift back to tropical pigmentation completely, they probably don't have the genes to.

Krefter
01-20-2016, 09:00 PM
I agree with Jean M. There's distinct traits in humans all over the world and it's hard to know why they became so popular. It's very confusing and IMO saying it's because of sexual-selection is far-fetched. Why are people with slanted eyed or wide faces or pale skin more attractive? It isn't unanimous those traits are more attractive.

I think it's a bit crazy to think they became popular because of sexual selection. If you go by the sexual selection-theory, that'd mean Red hair was sexually selected for in Britain and Ireland 4,000-2,000 years ago. I don't think many academics would go along with that idea. It's probably just local random drift or whatever. That's probably the same reason so many Australians look like they're from the same family. Austrilian-features or whatever weren't selected for it's just randomness.

lgmayka
01-20-2016, 11:15 PM
Why are people with slanted eyed or wide faces or pale skin more attractive? It isn't unanimous those traits are more attractive.
So-called sexual selection for a phenotypic feature is not generally based on superficial attractiveness, but on more important attributes (e.g., money, power, fame) perceived to be correlated with the feature.

Tomenable
01-21-2016, 06:38 AM
It isn't unanimous those traits are more attractive.

Wait - since when is there one universal beauty standard around the whole globe? Certain things are more attractive to some cultures, but less attractive to other cultures. Preferences vary greatly, and people mold themselves (over evolutionary time) according to their preferences. What about differences in hair structure (such as thick straight hair in East Asians, wavy thin hair in Europoids, curly hair, fil-fil hair, etc.):

http://antropologia-fizyczna.pl/antropometria/cefaloskopia/ksztalt-wlosow

Khoisanids have fil-fil hair (unlike Negroids, and unlike people who live in similar climates as Khoisanids but in Northern hemisphere):

https://upload.wikimedia.org/wikipedia/commons/c/c6/San_lady_botswana.jpg

BTW - Khoisan (such as this lady with fil-fil hair) have much lighter skin than Bantu living next to them, but Khoisan live in South Africa for dozens of thousands of years, while Bantu came there from equatorial regions only shortly before Dutch settlers founded Cape Town:

7390

https://upload.wikimedia.org/wikipedia/commons/c/c6/San_lady_botswana.jpg

Climate also plays a role, but other factors too. And I don't think, that climate works rapidly, rather over a few dozen thousand years.


That's probably the same reason so many Australians look like they're from the same family.

Australian phenotypes used to be more diverse before and during colonization. In some sources it was mentioned, that various tribes look differently from each other. There were also Negrito-type people in Australia (probably later immigration from Sundaland), but got extinct.

Here is a good website about Negritos (including those extinct from Northern Australia - there exist photos showing them):

George Weber's "Lonely Islands. The Negrito Peoples & the Out-of-Africa story of the human race":

Current version (restored back to life after some period of inactivity): http://www.andamans.org/

Previous, archival versions (even more complete than current version):

Index: https://web.archive.org/web/20130520190644/http://www.andaman.org/index.htm

Genetics: https://web.archive.org/web/20130402150943/http://www.andaman.org/BOOK/chapter6/text6.htm

About Negrito groups which could exist in the Middle East in the past:

https://web.archive.org/web/20130402190016/http://andaman.org/BOOK/chapter47/text47.htm

More about the diversity of phenotypes in Australia before colonization (it can be noted, that various tribes in Australia had different skin shades - from black as coal to light brown - and some Australian tribes also had high percentages of light-haired / blonde individuals):

http://babel.hathitrust.org/cgi/pt?id=uc1.b4381154;view=1up;seq=15

"(...) The tribes live in complete isolation. Their intercourse is strictly limited and their isolation is so thorough that one might be justified in regarding them as different races and not as various components of the same race. Not only have tribes who live close together entirely different languages* - so different that they have great difficulty in understanding one another and have to employ interpreters - but one also finds surprising differences in build and general appearance among tribes who are geographically not very distant. (...)"

*This is also true among close genetic relatives of Australians - Papuans. In Papua New Guinea there are currently as many as 820 different languages in use (according to Ethnologue and other sources), none of which is spoken by more than 1% of the population:

https://www.ethnologue.com/

7391

http://s17.postimg.org/f7c5bf3yn/Tribes.png

Krefter
01-21-2016, 10:08 AM
So-called sexual selection for a phenotypic feature is not generally based on superficial attractiveness, but on more important attributes (e.g., money, power, fame) perceived to be correlated with the feature.

I think sexual selection based on important attributes (e.g., money, power, fame) is even less valid. "Superficial attractiveness" I don't think it is at all. I know that at least Eurasian Men unanimously prefer straight long hair. Is this because evolution of straight-hair and long hair in females, is hard-wired in their DNA? It's totally possible. I'd bet that most people prefer others from their own genetic-background.


Wait - since when is there one universal beauty standard around the whole globe? Certain things are more attractive to some cultures, but less attractive to other cultures

I'll make the same point I just made to Igmayka. I think "beauty is in the eye of the beholder" is overrated. It's an excuse to say "People are called ugly because society is evil". What culture tells you is cool or powerful or valuable, can't force you to be attracted to it. It has to follow set guidelines which are hardwired in our DNA. Everyone from African to European men/women are attracted to the same traits, this has been proven.

Different cultures have different values of what is attractive in the same way that different cultures have different values on what is macho or dishonest or etc. What is attractive or macho or dishonest in different cultures goes through the same human filter, they express the same values/ideas differently because of different circumstances not because what is attractive/macho/dishonest/etc. is mostly determined by culture.

So back to my original point. It isn't unanimous certain certain regional traits are more attractive Also ancient-cultures can't force people to be attracted to those regional-traits. If a study proves to me some groups of humans unanimously prefer certain traits(like I suggested for long-straight hair) then sexual-selection argument is more valid.

Stellaritic
01-21-2016, 10:32 AM
So-called sexual selection for a phenotypic feature is not generally based on superficial attractiveness, but on more important attributes (e.g., money, power, fame) perceived to be correlated with the feature.

The attributes you mentioned are only desirable in our modern times.
A few points to consider :
Money: I highly doubt prehistorical Europeans had a currency/money .
Power: in Europe mtDNA haplogroup are much more older than the Y-DNA haplogroups which makes me believe that males chose females not the other way around. Generally speaking a male wouldn't choose a female based on how powerful she is but rather on how fertile she looks(young,healthy...)
BTW, how does light skin fit into this ?

Heber
01-21-2016, 11:44 AM
Copy number variation in the human Y chromosome in the UK population

Wei Wei, Tomas Fitzgerald, [...], and Yali Xue

Conclusions
We have analysed the distribution of Y-chromosomal CNVs in apparently healthy UK males. Although there are limitations to our dataset, including low sensitivity to small events and a resulting bias towards detecting large CNVs, we show that Y-CNVs can readily be detected. We confirm the abundance of this form of variation on the Y chromosome, where over 6 Mb of sequence is copy number variable and affects over one-third of the male-specific Y proteins. Novel CNVs, both common and rare, continue to be discovered and some of these may have implications for phenotypes, especially spermatogenesis.

7392

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4460274/

I don't have enough expertise to determine if this is relevant to sexual selection.
Perhaps some of the expert members could comment.

Tomenable
01-21-2016, 12:02 PM
I think "beauty is in the eye of the beholder" is overrated.

There are certain universal beauty factors (generally they can be collectively described as "healthy look" - including healthy complexion / healthy skin - as well as "symetrical look"). However, apart from this there are very many differences between beauty standards around the world (or used to be in the past). Read about body parts deformations among some peoples (such as skull deformations in Pre-Columbian Americas). They were not done to make people look ugly or scary, especially when those were women (and not warriors) who were subjected to them. That Bushman woman photo of whom I posted above is definitely attractive, but you can see that she does not conform to e.g. East Asian beauty standards.

One of reasons why light skin could be favoured over dark skin, is that any imperfections are more visible when you have light skin.

So light-skinned people can be easier categorized into ones with healthy/beautiful skin and ones with skin diseases.

Tomenable
01-21-2016, 12:07 PM
If a study proves to me some groups of humans unanimously prefer certain traits

Humans differ in possible ways, also their minds are different, why should they unanimously prefer certain traits?

Certain traits could be unanimously preferred by certain populations, but not by humanity as a whole of course.

Tomenable
01-21-2016, 12:12 PM
If you go by the sexual selection-theory, that'd mean Red hair was sexually selected for in Britain and Ireland 4,000-2,000 years ago.

Well, in Norse society red hair was certainly perceived as more prestigous than black hair (as is evidenced for example by poem "Rígsþula", which says that black hair is a trait typical of peasants, red hair is a trait typical of middle class, and blonde hair is a trait of nobility - this tells us something about their beauty standards). In Ireland red hair could be seen as more prestigous than blonde hair, for example.

The poem "Rígsþula" basically says that the various classes of Norse / Scandinavian society were born after god Ríg impregnated three different women - and one of those women born him swarthy/black-haired (svartan, cognate with English word swarthy) children, another one born him ruddy/red-haired children, and the last one born him light-skinned/light-haired (bleikr, cognate with English bleached) children.

Then the poem claims that god Rig liked his light-pigmented children the most, favouring them over his "svartan" children.

Then it says that "svartan" children became peasants, ruddy ones became craftsmen and "bleikr" ones became nobles.

Do you think that it doesn't say anything about standards of beauty in Old Norse society ???

We should underline, that all of those children in that story were ethnically Norse - and they even shared a common father.

MitchellSince1893
01-21-2016, 12:28 PM
Wait - since when is there one universal beauty standard around the whole globe? Certain things are more attractive to some cultures, but less attractive to other cultures.

Apparently there are some characteristics that are universal.


Human infants prefer to look at physically attractive human faces when they are paired with physically less attractive human faces (Langlois, Roggman, Casey, Ritter, Rieser-Danner & Jenkins, 1987). Infant preference for attractive faces has been observed for a range of human faces, including Caucasian and African American adult female faces, adult male faces, and infant faces (Langlois, Ritter, Roggman & Vaughn, 1991; Samuels & Ewy, 1985; Van Duuren, Kendell-Scott & Stark, 2003). The attractiveness effect can be demonstrated even in newborn infants, is orientation dependent, occurring for upright but not inverted faces (Slater, Quinn, Hayes & Brown, 2000), and is driven by the internal features of faces (Slater, Bremner, Johnson, Sherwood, Hayes & Brown, 2000).

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2566458/

Tomenable
01-21-2016, 12:31 PM
Yes, indeed, that's what I wrote in post #29:

http://www.anthrogenica.com/showthread.php?6265-Ancient-DNA-and-the-rewriting-of-human-history-be-sparing-with-Occam%92s-razor&p=134998&viewfull=1#post134998

But universal things aren't related to colour.

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


Human infants prefer to look at physically attractive human faces (...)

By the way, a really objective study should include infants of all races and all ethnic groups.

For example, do Bushmen infants prefer to look at Bushmen faces, or at Japanese faces, etc.

It is possible that innate preferences of infants belonging to distinct ethnic groups are different.

MitchellSince1893
01-21-2016, 12:37 PM
Yes, indeed, that's what I wrote in post #29:

http://www.anthrogenica.com/showthread.php?6265-Ancient-DNA-and-the-rewriting-of-human-history-be-sparing-with-Occam%92s-razor&p=134998&viewfull=1#post134998

But universal things aren't related to colour.

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



By the way, a really objective study should include infants of all races and all ethnic groups.

For example, do Bushmen infants prefer to look at Bushmen faces, or at Japanese faces, etc.

It is possible that innate preferences of infants belonging to distinct ethnic groups are different.

Sorry, I didn't read through the whole thread before posting

Jean M
01-21-2016, 03:21 PM
Well since Americans were bottlenecked out of Siberia, it's no surprise they didn't drift back to tropical pigmentation completely, they probably don't have the genes to.

Exactly. A mutation will often act as an "error" that stops the production of something. This is the case for the mutations that stop production of melanin. Once a population has lost the function, it cannot be selected for, unless another mutation occurs that restores function. However there is a skin colour cline among Native Americans.

Ebizur
01-22-2016, 08:16 AM
There are certain universal beauty factors (generally they can be collectively described as "healthy look" - including healthy complexion / healthy skin - as well as "symetrical look"). However, apart from this there are very many differences between beauty standards around the world (or used to be in the past). Read about body parts deformations among some peoples (such as skull deformations in Pre-Columbian Americas). They were not done to make people look ugly or scary, especially when those were women (and not warriors) who were subjected to them.I would not proclaim so with such certainty. I have enjoyed interacting with people from many different cultures in their homelands, and I have found that their native words that are often translated to English as "beauty" or "beautiful" do not really mean the same thing as English "beauty" or "beautiful," particularly in the sense that "beauty" and "beautiful" are used in this sort of scientific context (strictly referring to physical attractiveness). Many people seem to have difficulty distinguishing "beauty" as a sort of physical assessment or evaluation from the categories provided by their own particular linguistic frameworks, in which the nearest equivalent (or presumed equivalent) to English "beauty" actually conveys more of an emphasis on presumptive moral or psychological attributes. Actually, I have noticed a difficulty in discussing this topic even with other individuals who originate from an Anglophone culture; so many people are prone to conflating (or at least appearing to conflate, intentionally or not) beauty with non-physical qualities.

In other words, people in some cultures may intentionally perform body modifications that are invariably understood to make an individual (even particularly a female) look what would be called "scary" or "ugly" in English and yet use a word in their language that is often translated to English as "beautiful" (perhaps in some other contexts also "good," etc.) to describe a person whose appearance has been modified in such a manner because their culture has taught them to associate "looking ugly" or "looking scary" (i.e. somewhere in the range from physically unattractive to repellent) with "being beautiful (or good or whatever the essential meaning of the particular word is)."


That Bushman woman photo of whom I posted above is definitely attractive, but you can see that she does not conform to e.g. East Asian beauty standards.Odd choice of words.


One of reasons why light skin could be favoured over dark skin, is that any imperfections are more visible when you have light skin.

So light-skinned people can be easier categorized into ones with healthy/beautiful skin and ones with skin diseases.Males may tend to favor light skin in females because it is more translucent, and therefore reveals more about the emotions of the light-skinned person (e.g. through blushing). Normal males should have an innate distaste for deceptiveness (and ability to deceive) in females. In contrast, for a male (at least in the context of traditional Western gender roles), having light skin can be nothing but a handicap. I will refrain from going into detail about what this and other features suggest about the primary agents of sexual selection in the recent evolutionary history of various populations.

Tomenable
01-22-2016, 10:29 AM
Males may tend to favor light skin in females because it is more translucent, and therefore reveals more about the emotions of the light-skinned person (e.g. through blushing). Normal males should have an innate distaste for deceptiveness (and ability to deceive) in females. In contrast, for a male (at least in the context of traditional Western gender roles), having light skin can be nothing but a handicap. I will refrain from going into detail about what this and other features suggest about the primary agents of sexual selection in the recent evolutionary history of various populations.

I agree with you!

But - surprisingly - statistics seem to contradict our point of view.

According to stats from some dating websites, among men of all races, Asian and Latino (so brown-skinned, because Asian includes also Indian, Philipino, etc.) women are more popular than White women, while among women of most races, White men are most popular:

http://img.qz.com/2013/11/ethnic-preferences2.png?w=640

http://img.qz.com/2013/11/ethnic-preferences2.png?w=640

And more stats from another study:

Much more White women want to date ONLY White men, while a much smaller percent of White men have such strict preferences (so White men are much more eager to date Latino, Asian, Indian, Black, etc. women, than are White women to date Non-White men):

http://blogs.discovermagazine.com/gnxp/files/racedating1.png

http://blogs.discovermagazine.com/gnxp/files/racedating1.png

Also this data shows, that White females (not White males) are the group which is least likely to date outside of their race:

http://wtfwhiteprivilege.tumblr.com/post/25653732956/some-data-okcupid-has-collected-about-race-and

http://blog.okcupid.com/index.php/your-race-affects-whether-people-write-you-back/comment-page-11/

White women most strongly prefer to date someone of their own skin colour:

http://cdn.okcimg.com/blog/race_affects/Match-Question-2.png

That 54/46 vs. 40/60 difference might explain why males in Europe have a bit lighter skin than females (see below).

Data suggesting that women prefer whiter men seems also supported by fact that men have consistently lighter skin than women:

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0048294


Figure 1. Distribution of skin, hair, and eye pigmentation.

Skin pigmentation histogram (A) and boxplot by country of sampling and sex ( B ) in 469 individuals showing the normality of the phenotype distribution and the differences between sexes and among countries. Males (M) have consistently lighter pigmentation (lower scored) than females (F) in all four countries. Among countries, the largest pigmentation difference is with Ireland, where, in our sample, individuals have lighter pigmentation or lower M index on average than in Poland, Italy, or Portugal. Hair pigmentation histogram (C) and boxplot by country (D) in 341 individuals showing the distribution of hair pigmentation and the differences among countries. In our sample, individuals from Northern European countries (Ireland, Poland) have on average lighter hair pigmentation than individuals from Southern European countries (Italy, Portugal). The distributions in males are similar to those in females in all countries except Ireland, where, in our sample, males have darker hair color than females (not shown). Eye pigmentation histogram (E) and boxplot by country (F) in 468 individuals showing the bimodal distribution of eye pigmentation and the differences among countries. Comparison with self-reported phenotypes shows that the two modes of the distribution correspond to blue and brown eye color, while individuals reporting green and hazel eye color have intermediate C’ values. As with hair pigmentation, in our sample, individuals from Northern European countries have on average lighter eye pigmentation than individuals from Southern European countries.

So, when it comes to this:


I will refrain from going into detail about what this and other features suggest about the primary agents of sexual selection in the recent evolutionary history of various populations.

You wanted to say, that males played the most important role in sexual selection when it comes to skin, etc.

I was also thinking so. In the past, males had power and could choose women for themselves.

So logical conclusion would be that they were the primary agents. But, it is not certain given the data above.

lgmayka
01-22-2016, 03:50 PM
I know that at least Eurasian Men unanimously prefer straight long hair.
Uh, where in the world did you get this idea? Women "cursed" with straight hair have been deliberately curling their hair for thousands of years (http://nymag.com/thecut/2014/03/brief-time-line-of-odd-hair-treatments.html#):
---
Researchers have also found curling tongs buried with [ancient Egyptian] mummies.
...
[In the Victorian era] Hair-curling tongs that looked like blunt, rounded scissors were also popular. (Curling technology apparently hasn’t changed much since Egyptian times.) Women heated the ends of the tongs in the fire, then wrapped their hair in special curling papers so their hair wouldn’t scorch.
...
Pre-World War II: The Icall permanent-wave machine, a horrifying-looking device, was actually quite technically advanced for its time. The curlers were suspended from a frame via electrical wires so that no electricity or heat directly touched women’s heads. The curlers were heated up, then unplugged before being applied, assuring that no one was accidentally electrocuted. These fell out of favor when the chemical perm was invented in the late 1930s.
---

Here is a 100-year pictorial history of America's fondness for curls (http://www.today.com/style/curly-hair-cuts-styles-throughout-history-2D80438443).

Jessie
01-22-2016, 04:38 PM
Well, in Norse society red hair was certainly perceived as more prestigous than black hair (as is evidenced for example by poem "Rígsþula", which says that black hair is a trait typical of peasants, red hair is a trait typical of middle class, and blonde hair is a trait of nobility - this tells us something about their beauty standards). In Ireland red hair could be seen as more prestigous than blonde hair, for example.

The poem "Rígsþula" basically says that the various classes of Norse / Scandinavian society were born after god Ríg impregnated three different women - and one of those women born him swarthy/black-haired (svartan, cognate with English word swarthy) children, another one born him ruddy/red-haired children, and the last one born him light-skinned/light-haired (bleikr, cognate with English bleached) children.

Then the poem claims that god Rig liked his light-pigmented children the most, favouring them over his "svartan" children.

Then it says that "svartan" children became peasants, ruddy ones became craftsmen and "bleikr" ones became nobles.

Do you think that it doesn't say anything about standards of beauty in Old Norse society ???

We should underline, that all of those children in that story were ethnically Norse - and they even shared a common father.

I don't think it has anything to do with being seen as more prestigious. I think red hair would be a disadvantage in a lot of places. I think red hair is one of the side affects of very fair skin. In places like Ireland and Britain it is very cloudy and most people have fair and freckled skin. Where fair and freckled skin is most common there will be a higher percentage of redheads.

https://upload.wikimedia.org/wikipedia/commons/f/f8/Europe_sunshine_hours_map.png

I have 3 family members and myself tested and we all carry the a red hair variant. I also have a high number of relatives that are redheads. Interestingly enough most of the redheads in my family trace their ancestry to the area on the map in Ireland with the least amount of sunlight.

Megalophias
01-22-2016, 04:41 PM
Uh, where in the world did you get this idea? Women "cursed" with straight hair have been deliberately curling their hair for thousands of years (http://nymag.com/thecut/2014/03/brief-time-line-of-odd-hair-treatments.html#)

Yep. Women with dark hair dye it blond, women with blond hair dye it dark; women with light skin tan, women with dark skin use lightening cream; curvy women want to be thin, thin women want to be curvy; short women want to be tall, tall women complain about how the short women poach the tall men. :D

Krefter
01-22-2016, 05:50 PM
Uh, where in the world did you get this idea? Women "cursed" with straight hair have been deliberately curling their hair for thousands of years (http://nymag.com/thecut/2014/03/brief-time-line-of-odd-hair-treatments.html#):
---
Researchers have also found curling tongs buried with [ancient Egyptian] mummies.
...
[In the Victorian era] Hair-curling tongs that looked like blunt, rounded scissors were also popular. (Curling technology apparently hasn’t changed much since Egyptian times.) Women heated the ends of the tongs in the fire, then wrapped their hair in special curling papers so their hair wouldn’t scorch.
...
Pre-World War II: The Icall permanent-wave machine, a horrifying-looking device, was actually quite technically advanced for its time. The curlers were suspended from a frame via electrical wires so that no electricity or heat directly touched women’s heads. The curlers were heated up, then unplugged before being applied, assuring that no one was accidentally electrocuted. These fell out of favor when the chemical perm was invented in the late 1930s.
---

Here is a 100-year pictorial history of America's fondness for curls (http://www.today.com/style/curly-hair-cuts-styles-throughout-history-2D80438443).

Most naturally straight-haired women don't curl their hair.

This is the type of curly hair the first humans probably had. It's much more curly than the curls that naturally straight haired people get artificially and from curly haired people in West Eurasian populations.
http://i50.tinypic.com/20h0iur.png

kingjohn
01-23-2016, 02:38 AM
and in the photo andamanese
who poses haplogroup D brother of E
which among africans curly is high.
the curly hair could be trait in the yap+ common ancestor.
regards
adam

Tomenable
01-23-2016, 08:24 PM
In places like Ireland and Britain it is very cloudy and most people have fair and freckled skin. Where fair and freckled skin is most common there will be a higher percentage of redheads.

Ireland was entirely repopulated just few thousand years ago, in the Bronze Age (as new studies show) - do you think that few thousand years is enough for people to become fair-skinned and freckled due to local climate? Do you think that current wave of Sub-Saharan immigrants to Britan will all become pale-skinned and freckled and red-haired or blonde by year 6500 AD ??? I don't think so. By the way - the most red-haired ethnic group in Europe are Udmurts, who live in areas with sunshine duration 1600-1800 hours per year (green colour in the map).

Tomenable
01-27-2016, 12:36 AM
A comment regarding skin pigmentation by Peter Frost (link):

http://www.biorxiv.org/content/early/2015/10/10/016477.figures-only


I agree that Europeans became light-skinned relatively late in time. Beleza et al. (2013) estimate that the derived alleles at SLC45A2 and SLC24A5 originated between 19,000 and 11,000 years ago. Canfield et al. (2014) suggest a time range of 19,200 to 7,600 years ago for the derived allele at SLC24A5. These are estimates, and the exact dates will remain unknown until we can retrieve ancient DNA from the late Upper Paleolithic / early Holocene. Most likely this change took place during the second half of the last ice age.

I disagree with the conclusion that these derived alleles originated among early European farmers. Yes, these alleles are absent from late hunter-gatherers in Spain, Luxembourg, and Hungary, but they are present in late hunter-gatherers from Sweden (Motala), Karelia, and Russia (Samara) (see discussion at: http://www.eupedia.com/forum/archive/index.php/t-30957.html)

The authors acknowledge this point towards the end of their text:

"We find a surprise in six Scandinavian hunter-gatherers (SHG) from the Motala site in southern Sweden. […] A second surprise is that, unlike closely related western hunter-gatherers, the Motala samples have predominantly derived pigmentation alleles at SLC45A2 and SLC24A5."

This seems to undermine the argument that light European skin originated in Neolithic farmers from Anatolia, and then spread into Europe through migration. Such an argument fails to account for the presence of the same alleles in northern and eastern Europeans at the same time, if not earlier. Again, we won’t be able to resolve this problem until we can retrieve earlier ancient DNA, particularly from the hunter-gatherers of northern and eastern Europe.

References

Beleza, S., Murias dos Santos, A., McEvoy, B., Alves, I., Martinho, C., Cameron, E., Shriver, M.D., Parra E.J., & Rocha, J. (2013). The timing of pigmentation lightening in Europeans. Molecular Biology and Evolution, 30, 24-35.

Canfield, V.A., Berg, A., Peckins, S., Wentzel, S.M., Ang, K.C., Oppenheimer, S., & Cheng, K.C. (2014). Molecular phylogeography of a human autosomal skin color locus under natural selection, G3, 3, 2059-2067.

So it seems that both mutations for light skin had originated already in the Upper Paleolithic period.

By the Mesolithic, there could be many populations with relatively light(er) skin. And some of them later invented agriculture.

Tomenable
01-27-2016, 02:51 PM
Something about the LGM and how distinct "races" (so to speak) could emerge due to isolation and endogamy in various LGM refugia:

http://www.anthrogenica.com/showthread.php?5142-Where-would-the-main-ancestor(s)-of-I2a-Din-have-been-located-in-the-BA&p=136635&viewfull=1#post136635

By the way:

Assuming that derived alleles for light skin emerged originally in a male (or in two males), those could be carriers of J haplogroup.

Here is my reasoning behind it:

- WHG hunters with I and C were dark-skinned (with the exception of SHG, who were most likely EHG-admixed, see the link above),

- this suggests that mutations for light skin emerged after the split of IJ into I and J (because I males originally did not have them),

- EHG hunters in Russia (Karelia and Samara) were lighter-skinned and so were ENF farmers in West Anatolia (see Peter Frost),

- which is the only Y-DNA haplogroup connecting Mesolithic Karelia with Early Neolithic Western Anatolia? The answer is: J.

In Karelia 1 out of 2 male hunters had J, and in Western Anatolia 1 out of 16 male farmers had J2a.

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

But perhaps a better link with spreading derived alleles for light skin can be established for carriers of some mtDNA haplogroup(s).

Tomenable
01-27-2016, 03:40 PM
Frequencies of skin-lightening derived alleles rs1426654 and rs16891982:

Western Hunters (4 genomes) = 12,5% and 0% (combined 13)
Caucasus Hunters (2 genomes) = 100% and 0% (combined 100)
Sweden Hunters (6 genomes) = 58,3% and 66,7% (combined 125)
Anatolian Farmers (17 genomes) = 100% and 34,8% (combined 135)
Russian Hunters (2 genomes) = 100% and 75% (combined 175)
================================
Britain Iron Age (6 genomes) = 100% and 85,7% (combined 186)
================================
Britain Modern (91 genomes) = 100% and 97,3% (combined 197)
Iberia Modern (107 genomes) = 100% and 81,8% (combined 182)

Sources:

(see data from "A%" column, as I used % of derived alleles among all alleles, not % of people with 2 copies of derived allele):

Prehistoric: https://docs.google.com/spreadsheets/d/1xe9sgt0PSt6cUQ3cYp14foBoaVGsOKZBmmHJoKz0HB0/edit#gid=1800275085

91 modern Brits with 182 alleles (91x2) of rs16891982, of which just 5 "ancestral" alleles C and 177 (97,3%) derived alleles G:

Modern Europe: https://docs.google.com/spreadsheets/d/1JxxjOa-KOd2b5hhQ9DQ9L5z7rxf8WW2MRN6owtf22ag/edit#gid=0

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

Out of Mesolithic and Early Neolithic populations, the lightest-skinned group were EHG hunters in Russia (including Karelia).

But some people complain about a small sample size (only 2 genomes, though I think that at this point we already have 3).

Tomenable
01-27-2016, 03:48 PM
However, it seems, that not all of modern populations have such high frequencies of derived allele rs16891982:

Here is data for modern Middle East, but only for rs16891982 (no data for rs1426654 - unlike in spreadsheets linked above):

https://docs.google.com/spreadsheets/d/1tsv3eJkbes6pNbq3ACSYPUuXgTXe2IfhBasUiTSVNWI/edit#gid=0

But look at figures for Europe - it suggests that Austrians should be darker than Iberians (which I don't think is the case ???).

It is Krefter's data, maybe he can explain these strange fluctuations?

Tomenable
02-01-2016, 01:27 AM
Wait - since when is there one universal beauty standard around the whole globe?

Not only that, but even in the same part of the globe, beauty standards can evolve rapidly (in a matter of decades).

Proof (one is composite image of women considered attractive in the 2000s; the other one - the same thing but in the 1940s):

http://dienekes.blogspot.com/2008/03/which-of-these-two-women-is-more.html

http://s28.postimg.org/g8colhkql/70_years.png

^^^ One of comments from the comment section guessed it right:




The woman on the right looks like she might have been a movie star during the "Golden Age of Hollywood" from about 1920-1950. The face on the left represents a more modern ideal.

Jessie
02-01-2016, 04:25 AM
Ireland was entirely repopulated just few thousand years ago, in the Bronze Age (as new studies show) - do you think that few thousand years is enough for people to become fair-skinned and freckled due to local climate? Do you think that current wave of Sub-Saharan immigrants to Britan will all become pale-skinned and freckled and red-haired or blonde by year 6500 AD ??? I don't think so. By the way - the most red-haired ethnic group in Europe are Udmurts, who live in areas with sunshine duration 1600-1800 hours per year (green colour in the map).

As far as I'm aware Udmurts haven't had a great deal of study unless you know of any? I've not seen any myself. Nearly half the population of Britain and Ireland carry one of the genes for red hair and most Irish are either skin type I or II so what explanation would you give?

Tomenable
11-02-2016, 09:22 AM
An excellent review paper, apart from a rather silly conclusion on skin colour.

Their conclusion on skin colour is this:


Adaptation to non-African environments was also believed to be the cause of human variation in skin color. It was thought that the light skin of Europeans was a Paleolithic adaptation to facilitate vitamin D production in reduced sunlight regions [43]. Consistent with this hypothesis, aDNA analyses show that Scandinavian hunter-gatherers and Early European farmers indeed carried derived alleles contributing to light skin [44]. However, western hunter-gatherers of central and southern European populations survived in Palaeolithic Europe with dark skin pigmentation [44, 45]; thus, light skin has not been an essential adaptation for survival in this environment, and perhaps has resulted instead from sexual selection.

I think this conclusion is in agreement with what various algorithms have shown before. Check this article:

"Is AI RACIST? Robot-judged beauty contest picks mostly white winners out of 6,000 contestants":

http://www.dailymail.co.uk/sciencetech/article-3781295/Is-AI-RACIST-Robot-judged-beauty-contest-picks-white-winners-6-000-submissions.html

This reader's comment below the article is interesting:


Also it can be hypothesized that as it is easier to see when contrast is higher, that would mean that a very dark object that doesn't have much contrast will be less attractive, and there is an optimal level of whiteness for human skin where features would be most distinguishable, and hence most attractive. What draws infants to faces is the detail and features in the faces, the greater the contrast, greater the perception of detail in the face.

AI also has problems with properly classifying faces when they are dark-skinned; it caused few scandals:

https://www.cnet.com/news/google-apologizes-for-algorithm-mistakenly-calling-black-people-gorillas/

Huitzilopochtli
11-02-2016, 12:28 PM
Not only that, but even in the same part of the globe, beauty standards can evolve rapidly (in a matter of decades).

Proof (one is composite image of women considered attractive in the 2000s; the other one - the same thing but in the 1940s):

http://dienekes.blogspot.com/2008/03/which-of-these-two-women-is-more.html

http://s28.postimg.org/g8colhkql/70_years.png

^^^ One of comments from the comment section guessed it right:

The right composite is from Oscar winners and the left composite is from AskMen. Chances are they were picked more for their ability to act rather than their looks. A composite of women from a Men's magazine of the time or of pin-up models would look different and probably significantly hotter.

jdean
11-02-2016, 01:05 PM
The right composite is from Oscar winners and the left composite is from AskMen. Chances are they were picked more for their ability to act rather than their looks. A composite of women from a Men's magazine of the time or of pin-up models would look different and probably significantly hotter.

Perhaps I don't pick up the subtle nuances that appear soooo obvious to others here, but take a wet wipe to these two and put hats on them and they look the same don't they ?????

Jean M
11-02-2016, 02:57 PM
So it seems that both mutations for light skin had originated already in the Upper Paleolithic period. By the Mesolithic, there could be many populations with relatively light(er) skin. And some of them later invented agriculture.

The time and location of these mutations do not really matter from my point of view. Mutations crop up all the time. A mutation will often act as a "mistake" in the DNA code which stops a particular function.


If that function is essential for the life of the organism then the mutated organism will die before or shortly after birth.
If that function is not essential, but helpful, then the organism will be handicapped and may not survive/reproduce as well as normal.
If that function is not beneficial in a particular environment, and in fact the lack of it is beneficial, then the organism that carries the mutation survives/reproduces better in that environment than those without it. Over time the advantage to such a mutated organism (in this case a human being with paler skin in climates with less sunshine) will be such that more survive with the mutation than without it.
This is what we mean by natural selection. For this to work, a mutation has to crop up first. Over thousands of years, several mutations having the same effect could crop up multiple times in different places, just by chance. Only if one such mutation happens to occur in a place where it is beneficial, rather than catastrophic, will natural selection favour its propagation.

ren
11-02-2016, 06:50 PM
Actually there is no difference between northern and southern Chinese in skin color, or even eye-shape all that much. There is a difference in skin color between Koreans and Chinese. There should be some historical selections that happened after ethnic groups formed. Southern Chinese face-shape-wise are closer to SE Asian, while pigmentation and eye shape are very much the same as northern Chinese.

ren
11-02-2016, 07:05 PM
Jean M (Re: post #12), I would like to see a really reliable map for skin pigmentation in native populations.

The one you posted in #12, is not reliable. This one is closer to the truth, but I'm not sure if perfectly accurate:

7382

As can be seen, the correlation with lattitude and climate is far from perfect, especially in certain regions:

http://i.imgur.com/RuejUQT.png?1

But SE Asians and Native Americans are both originally from northern a
lattitudes.

Jessie
11-03-2016, 03:42 AM
Ireland was entirely repopulated just few thousand years ago, in the Bronze Age (as new studies show) - do you think that few thousand years is enough for people to become fair-skinned and freckled due to local climate? Do you think that current wave of Sub-Saharan immigrants to Britan will all become pale-skinned and freckled and red-haired or blonde by year 6500 AD ??? I don't think so. By the way - the most red-haired ethnic group in Europe are Udmurts, who live in areas with sunshine duration 1600-1800 hours per year (green colour in the map).

I'm not sure about the Udmurts as I don't think any scientific studies have been done on them. People often say the Udmurts have the highest percentage of red hair but I'd like to see a linked scientific study to back this up. It could be true about the Udmurts but places like the UK and Ireland have had studies done showing that a significant amount of the population carry a non-functioning MC1-R gene; this combined with the fact that Britain and Ireland are one of the most overcast and cloudy areas in Europe it makes sense. Red hair and fair skin is a definite disadvantage in places with a lot of sunshine as is evidenced by studies in places like Australia where skin cancer is unfortunately very high and a lot of the population are of British and Irish extraction. People with darker skin would be at a disadvantage in places like Britain and Ireland as they would need to take Vitamin D supplements as they need more sun exposure to produce Vitamin D.

http://www.care2.com/greenliving/vitamin-d-melanin.html

Observer
11-03-2016, 08:24 AM
Jean M (Re: post #12), I would like to see a really reliable map for skin pigmentation in native populations.

The one you posted in #12, is not reliable. This one is closer to the truth, but I'm not sure if perfectly accurate:

7382

As can be seen, the correlation with lattitude and climate is far from perfect, especially in certain regions:

http://i.imgur.com/RuejUQT.png?1

Jean M's map is reliable, it's from Chaplin G 2004 & updated in 2007, while the other map is based on data from R. Biasutti prior to 1940. There are many things wrong with 1940s data map.

https://c2.staticflickr.com/6/5329/30660666781_686695e5fb_b.jpg

Encyclopedia britannica map (https://media1.britannica.com/eb-media/59/61759-004-9A507F1C.jpg) (2012) also seems reliable.


I don't think it has anything to do with being seen as more prestigious. I think red hair would be a disadvantage in a lot of places. I think red hair is one of the side affects of very fair skin. In places like Ireland and Britain it is very cloudy and most people have fair and freckled skin. Where fair and freckled skin is most common there will be a higher percentage of redheads.

https://upload.wikimedia.org/wikipedia/commons/f/f8/Europe_sunshine_hours_map.png

I have 3 family members and myself tested and we all carry the a red hair variant. I also have a high number of relatives that are redheads. Interestingly enough most of the redheads in my family trace their ancestry to the area on the map in Ireland with the least amount of sunlight.

That's interesting, Ireland carries all three red hair variants.

https://blog.23andme.com/wp-content/uploads/2015/01/Red_hair_map.jpg

I think Motala_HG (SHG) is earliest known carrier of red hair gene so far, correct me if i'm wrong (?)

Tomenable
11-03-2016, 08:42 AM
https://c2.staticflickr.com/6/5329/30660666781_686695e5fb_b.jpg

Nope. There is simply no way that this map is even close to being correct. Many things are wrong.

Just one example - indigenous South Amerindians do not have nearly as dark skin as Sub-Saharans.

According to this map, Native Peruvians are as dark-skinned as Nilotic peoples. Good for laughs! :lol:

Tomenable
11-03-2016, 08:46 AM
But SE Asians and Native Americans are both originally from northern a
lattitudes.

How do you define "originally" though ??? Oiginally, we are all - ultimately - from Africa.

But indeed, ancestors of Native Americans lived in Siberia for several thousand years.

However, we don't really know when exactly did they become relatively lighter.

Do we know at least what was pigmentation of Clovis Anzick or Kennewick Man?

Tomenable
11-03-2016, 09:00 AM
Jean M's map is reliable, it's from Chaplin G 2004 & updated in 2007, while the other map is based on data from R. Biasutti prior to 1940.

Chaplin's map shows only environmental factors supposedly influencing skin coloration. It just does not show actual skin coloration.

The Biasutti map is much more reliable when it comes to actual skin coloration. Which doesn't correlate perfectly with those factors.

And we know that in the past actual coloration also did not correlate with those factors in Europe.

Mesolithic WHG were still dark-skinned after a few dozens of thousands of years of living in Europe.

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

In the animal world you have dark-skinned Bonobos and light-skinned Chimpanzees living in the same environment.

You often have variation in skin colour within the same animal species as well, and it doesn't correlate much with climate.

Bonobos & Chimpanzees used to be considered the same species in the past, not sure how are they classified now.

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

Edit:

This paper suggests energy-saving instead of sexual selection, but also claims that it has nothing to do with sunshine:

http://phys.org/news/2016-06-paper-current-gain-loss-heavy.html


Popular theories of why our human ancestors gained and then lost dark skin over the course of evolution may be incorrect, according to a new paper by UC San Francisco authors, who suggest that heavily pigmented skin evolved because it forms a stronger barrier against a host of environmental challenges. Because deeply pigmented skin requires more energy to produce, they propose, our ancestors shed some of these pigments through natural selection as they moved north and needed less protection against these threats.

"Work in our lab has shown that darkly pigmented skin has far better function, including a better barrier to water loss, stronger cohesion, and better antimicrobial defense, and we began to ponder the possible evolutionary significance of that," said Peter Elias, MD, professor of dermatology. (...)

On the other hand, as our human ancestors migrated north from Africa, many theories propose, their skin became lighter to allow more UV light to be absorbed by the skin, because a portion of the UV spectrum of light is necessary for the production of vitamin D in the skin.

In the new paper, Elias and Williams point out the potential flaws in these popular hypotheses.

For example, the peak incidence of the most common form of fatal skin cancer occurs above the age of 70. Because ancestral humans did not live nearly that long, and because this age is well after peak reproductive years in any case, the authors argue that natural selection is unlikely to have favored the stronger cancer protection afforded by dark skin. Although folic acid is critical for normal development, Elias said, the type of UV rays that destroy this nutrient rarely penetrate the skin down to the blood vessels where it resides. Moreover, the incidence of significant congenital malformations from folic acid deficiency is low, and unlikely to have influenced natural selection for additional pigmentation.

As for vitamin D production, while reduced exposure to UV rays may have played a role in the evolution of the extremely light skin found in residents of the northernmost areas of Europe and Asia, Elias and Williams propose that the moderate pigment reduction seen in Central European and Asian populations did not evolve to support additional vitamin D production. In support of this proposition, they cite studies by other researchers showing that even darkly pigmented individuals, though better protected from UV light, are still quite efficient at producing vitamin D.

As an alternative hypothesis to the evolution of dark pigmentation on the African savannah, Elias and Williams lay out largely overlooked benefits of dark skin: a more efficient permeability barrier, more cohesive and mechanical strength, and superior antimicrobial defense, a key basis for which is lower pH at the surface of darkly pigmented skin.

Previous research by Elias and colleagues found that the pH of skin in darkly pigmented individuals is substantially lower than that of their fair-skinned counterparts—the surface of dark skin is more acidic. This higher acidity increases protection against pathogenic microbes while also promoting increased production of molecules critical for moisture retention, for physical strength and cohesion, and for warding off inflammation, he said.

The new paper also proposes that pigmentation was lost in central European and Asian populations because a pigmented skin barrier, which is metabolically expensive to produce, became less important. "It's all about diverting precious resources towards the most urgent requirements," Elias said, a concept known in medicine as metabolic conservation.

As ancestral humans moved northwards from Africa into Europe and Asia to cooler and more moist environments, they began donning clothing, which provides a partial barrier. Elias and Williams theorize that the enhanced barrier function provided by dark skin became less critical. At the same time, as they entered cooler climates, modern humans' need to stay warm became more critical. Evolution would have driven a reduction in the production of intense pigmentation under such conditions, Elias said, offering intriguing examples of pigment reduction in modern humans under metabolic stress: lactating women and growing children display paler skin than that seen in individuals who have fewer metabolic demands.

Elias said that his evolutionary ideas are deeply informed by his many years of practicing dermatology as a physician at the San Francisco VA Medical Center, a UCSF partner hospital. "It helps to have knowledge of the skin when you're exploring these hypotheses," he said. "Through publications like this, addressed to non-dermatologists, we're trying to get people in other sciences to take the skin seriously—it's been trivialized since the time of Aristotle."

But they did not mention that the WHG were dark-skinned, despite living in northern latitudes for thousands of years.

R.Rocca
11-03-2016, 12:37 PM
Nope. There is simply no way that this map is even close to being correct. Many things are wrong.

Just one example - indigenous South Amerindians do not have nearly as dark skin as Sub-Saharans.

According to this map, Native Peruvians are as dark-skinned as Nilotic peoples. Good for laughs! :lol:

As with Brazil, the areas showing darker-skin in Peru likely reflects strong African influx due to slavery.

Tomenable
11-03-2016, 07:05 PM
It is about skin coloration of indigenous populations.

And there is no any strong African influence in Peru:

http://www.anthrogenica.com/showthread.php?6799-Ancestry-of-Peruvians


"Tracing the genomic ancestry of Peruvians reveals a major legacy of pre-Columbian ancestors":

https://www.researchgate.net/publication/249997244_Tracing_the_genomic_ancestry_of_Peruvian s_reveals_a_major_legacy_of_pre-Columbian_ancestors

Average K5 ancestry proportions for 551 Peruvians (data from Table 1. on page 5):

Native American - 83%
Oceanian - 4,4%
East Asian - 3,5%
West Eurasian - 7,4%
African - 1,7%

Something like this is a typical / average Peruvian:

http://oi61.tinypic.com/169jfkh.jpg

http://oi61.tinypic.com/169jfkh.jpg

palamede
11-03-2016, 07:24 PM
As with Brazil, the areas showing darker-skin in Peru likely reflects strong African influx due to slavery.

Peru have some black men on the coast, but it is wrong to speak of strong African influx. The majority of Peruvians are etther pure blood or weakly mixed : The skin is very coloured, but not really black.
Other problems : Ethiopian plateau population have clearer skin than the remaining sub-saharan pops, Yemen has an important mixing, but not enough to compare to the sub-saharian people.

In fact , the map based on data from R. Biasutti prior to 1940 is the most correct in the reality, the map is wanted to be the reality before 1500AD and the modern migrations.
The map from Chaplin G 2004 & updated in 2007 shows what the skin colour should be according to the environmental conditions, but it is different from the reality due to human migrations.

R.Rocca
11-03-2016, 07:51 PM
Peru have some black men on the coast, but it is wrong to speak of strong African influx. The majority of Peruvians are etther pure blood or weakly mixed : The skin is very coloured, but not really black.

Of course there is variation. Do a lookup of the Peruvian football team and you'll see the very strong African influx in some. I'm not saying all, but definitely enough to be much darker than the typical American-Indian. Northern Brazil of course is much greater African input. Either way, my point is that without this African input, American-Indian Peruvians are nowhere near as dark skinned as Africans nor Australian Aborigines.

palamede
11-04-2016, 11:29 AM
Of course there is variation. Do a lookup of the Peruvian football team and you'll see the very strong African influx in some. I'm not saying all, but definitely enough to be much darker than the typical American-Indian. Northern Brazil of course is much greater African input. Either way, my point is that without this African input, American-Indian Peruvians are nowhere near as dark skinned as Africans nor Australian Aborigines.

According to K5 of Tomenable 1.7%

in Wikipedia https://en.wikipedia.org/wiki/Peru
Population
• 2015 estimate 31,151,643
According to a 2015 genealogical DNA testing, the average Peruvian is estimated to be 79.1% Native American, 19.8% European, and 1.1% Sub-Saharan African overall.


In https://en.wikipedia.org/wiki/Afro-Peruvian
Total population
616,283 (aprox) Therefore 2.1%

In https://en.wikipedia.org/wiki/Peruvians
The remaining is constituted by Afro-Peruvians, which are around 1.2%[15] a legacy of Peru's history as an importer of slaves during the colonial period. Today also mulattos (mixed African and European) and zambos (mixed African and Amerindian) constitute an important part of the population as well, especially in Piura, Tumbes, Lambayeque, Lima and Ica regions. The Afro-Peruvian population is concentrated mostly in coastal cities south of Lima, such as that of those found in the Ica Region, in cities like Cañete, Chincha, Ica, Nazca and Acarí in the border with the Arequipa Region.
Racial and Ethnic Composition in Peru (2006 self-identification survey)[15]
Instituto Nacional de Estadística e Informática (INEI)
Race/Ethnicity
Mestizo 59.5%
Quechua 22.7%
Aymara 2.7%
Amazonian 1.8%
White 4.9%
Black/Mulatto 1.6%
Others 6.7%

A french paper speaks about 10% of Peruvian pop are descendants of black slaves , but considered the data are not really fiable.
http://geopolis.francetvinfo.fr/perou-les-noirs-population-discriminee-76473
Pendant la colonisation espagnole en Amérique du Sud, des esclaves africains sont venus compléter la main d’oeuvre indienne dans les mines ou les plantations du continent. Au Pérou, l’esclavage a été aboli en 1854. Mais de nos jours, les Noirs, qui constituent environ 10% des 30 millions d’habitants, restent mal intégrés. Même si le pouvoir politique fait des efforts pour améliorer leur sort.
...
Selon des données (peu fiables), les descendants d’esclaves noirs, historiquement concentrés sur la côte Pacifique, notamment à El Carmen (à 180 km au sud de Lima, la capitale), constitueraient quelque 10 % de la population.


You have never seen the French footbal team .

Tomenable
11-04-2016, 05:27 PM
Do a lookup of the Peruvian football team and you'll see the very strong African influx in some.

You have never seen the French footbal team.

Heh: :biggrin1:

http://pbs.twimg.com/media/CmdW28CWAAAVC0L.jpg:large

R.Rocca
11-04-2016, 05:52 PM
You have never seen the French footbal team .

I have, but there is a big difference... Peruvian African ancestry seems to have been mixing with American Indian for hundreds of years, French African ancestry is relatively recent. That's why all Peruvians on the football team have Spanish last names and a big percentage of the players on the French squad do not have French last names.

lgmayka
11-11-2016, 10:21 AM
Encyclopedia britannica map (https://media1.britannica.com/eb-media/59/61759-004-9A507F1C.jpg) (2012) also seems reliable.
Here's a larger version of Britannica's map (https://www.britannica.com/media/full/648562/52059), with sourcing and explanation.

Gravetto-Danubian
11-11-2016, 10:53 AM
Here's a larger version of Britannica's map (https://www.britannica.com/media/full/648562/52059), with sourcing and explanation.


This map doesn't quite seem correct
It has messed up the Fitzpatrick scheme, and seems to imply that one would see the same skin tone walking in Zagreb as in Cairo ?

Ebizur
11-11-2016, 11:40 AM
This map doesn't quite seem correct
It has messed up the Fitzpatrick scheme, and seems to imply that one would see the same skin tone walking in Zagreb as in Cairo ?
You are too forgiving. Japanese people having lighter skin color than Europeans? That is incredibly ridiculous even if one considers the skin only in its untanned state.

R.Rocca
11-11-2016, 12:30 PM
This map doesn't quite seem correct
It has messed up the Fitzpatrick scheme, and seems to imply that one would see the same skin tone walking in Zagreb as in Cairo ?

Yes, this one is a real laugher.... so according to this map Northern Europeans colonists found Native American people that were lighter skinned then they were when they set up the colonies of New Sweden, New Amsterdam and eastern Canada.

Observer
11-11-2016, 01:55 PM
You are too forgiving. Japanese people having lighter skin color than Europeans? That is incredibly ridiculous even if one considers the skin only in its untanned state.

I agree, in context of Asia and Europe, 1940s map looks unreliable. It also undermines variations that exists in Asia and Europe, as there is no such uniformity shown in 1940s map. While Chaplin 2004-2007 map seems reliable for Eurasia at least.

Tomenable
08-28-2018, 03:14 PM
https://www.biorxiv.org/content/biorxiv/suppl/2017/09/19/135616.DC4/135616-1.pdf

"Western hunter-gatherers (WHG) had a distinctive blue-eyed, dark skin pigmentation
phenotype1,2 that emerged in the Mesolithic.6 In contrast, we show that Mesolithic and
Neolithic individuals from Ukraine, Latvia and the Iron Gates had, like Scandinavian and
Eastern hunter-gatherers, intermediate to high frequencies of the derived skin pigmentation
allele at SLC24A5. Unlike Scandinavian and Eastern hunter-gatherers, however, they have
low frequency of the derived SLC45A2 allele. The derived OCA2/HERC2 allele associated
with light (particularly blue) eye color is common in WHG, SHG, and hunter-gatherers from
Latvia, but at low frequency in hunter-gatherers from Ukraine and the Iron Gates. This allele
appears to be differentiated in a North-South gradient, as it is today – suggesting the
possibility of long-term balancing selection due to geographic variation in selective pressure.
The WHG phenotype of light eye and dark skin pigmentation1 thus appears to be restricted to
western Europe and is far from universal in European hunter-gatherers, with light skin
pigmentation common in Northern and Eastern Europe before the appearance of agriculture."