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warbefore Over then years ago The Genetic Legacy of the Mongols was published. This paper illustrated the surprising genetic effects that historical demographic events might have; the authors found that one particular Y chromosomal lineage was extremely common in Central Eurasia, and, that lineage exhibited an explosive growth over the past 1,000 years. Combined with the high frequency in the Khalkha Mongols in particular the natural inference made was that this lineage was reflective of the reproductive success of the group of warrior elites descended from Genghis Khan.

Some have been skeptical of this relationship. Part of this is due to ignorance or skepticism of what one can learn from genetics broadly among some scholars. In a discussion with John Horgan the cultural anthroplogist R. Brian Ferguson dismissed the possibility of something like the Genghis Khan modal haplotype. This makes sense. Here is a quote from George Orwell’s 1984:

Anything could be true. The so-called laws of Nature were nonsense. The law of gravity was nonsense. ‘If I wished,’ O’Brien had said, ‘I could float off this floor like a soap bubble.’ Winston worked it out. ‘If he thinks he floats off the floor, and if I simultaneously think I see him do it, then the thing happens.’ Suddenly, like a lump of submerged wreckage breaking the surface of water, the thought burst into his mind: ‘It doesn’t really happen. We imagine it. It is hallucination.’ He pushed the thought under instantly. The fallacy was obvious. It presupposed that somewhere or other, outside oneself, there was a ‘real’ world where ‘real’ things happened. But how could there be such a world? What knowledge have we of anything, save through our own minds? All happenings are in the mind. Whatever happens in all minds, truly happens.

Even cultural anthropologists who reject the “Post-Modern” tendencies common in the United states in this field often live at some remove from an enterprise where data dictates the set of plausible models about the world. If science fiction is a vision of the future conditioned on the priorities of the present, cultural anthropology is an ethnography of the present and history of the past conditioned on the ideological values of the present.

In 1984 the dictates of the present determine the past. One of the reasons it is useful to read Lawrence Keeley’s War Before Civilization: The Myth of the Peaceful Savage is that it serves as a record of the stated positions of many cultural anthropologists, and how they have evolved over the years in light of new evidence, without any acknowledgement that their past positions were obviously false. In a progressive conception of science error is essential for the field to slowly converge upon reality as it is over time. But one must admit that one has made errors, and is changing one’s views to match the facts. Often cultural anthropologists strike a pose that “we always knew/believed that.” Many cultural anthropologists have given upon on any pretense that learning about the world out there is possible, and at the extreme even meritorious.

The conclusions of The Genetic Legacy of the Mongols are more plausible in light of a paper which was published last year, A recent bottleneck of Y chromosome diversity coincides with a global change in culture. In the paper the authors show that a massive bottleneck and subsequent explosion of very common Y chromosomal lineages such as R1b and R1a seems to have occurred on the order of 5,000 years ago. The star-shaped phylogeny is not just the legacy of Genghis Khan.

How did this situation come to be? Read Andrew Currey’s Slaughter at the Bridge in Science. It’s riveting. Here are some interesting passages:

Before the 1990s, “for a long time we didn’t really believe in war in prehistory,” DAI’s Hansen says. The grave goods were explained as prestige objects or symbols of power rather than actual weapons. “Most people thought ancient society was peaceful, and that Bronze Age males were concerned with trading and so on,” says Helle Vandkilde, an archaeologist at Aarhus University in Denmark. “Very few talked about warfare.”

DNA from teeth suggests some warriors are related to modern southern Europeans and others to people living in modern-day Poland and Scandinavia

The precis: 3,200 years ago thousands of men clashed around a bridge in a narrow valley in northeast Germany near the Baltic sea. Hundreds of these men died. Their skeletons yield the facts that they were in their 20s, were often killed in the brutal manner that occurs in pitched battle, and isotope analysis suggests that most of them came from hundreds of kilometers away. Both DNA and analysis of their bones to infer their diet suggest that some were similar to modern Southern Europeans, and may have been Southern Europeans in terms of their provenance, though I do not discount that there were pockets of people who were similar to the descendants of the European European Farmers (EEF) who persisted down to that period.

What does this tell us? In The Shape of Ancient Thought, most of which was written decades ago, there are presumptions about the nature of transmission of ideas from civilized (e.g., Mesopotamian) to non-civilized (e.g., archaic Greeks and Vedic Aryans) peoples. But what these results, and books such as War Before Civilization, remind us that writing and literacy is only one of the aspects of complex human organization. Complex societies seem necessary for literacy, but literacy is not necessary for social complexity (E.g., the Inca domains). Keeley documents suggestive evidence of large-scale conflict between the first farmers to arrive in Central Europe and marine foragers along the coastal littoral thousands of years before the slaughter at the bridge. Rather than being the start of something new, I suspect what occurred at Tollense was the later stages of a tradition of preliterate conflict and competition which persisted down the period of Christianity.

 
• Category: History, Science • Tags: Europe, Genetics 
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200px-Lascaux2A new article in Horizon, Ice-age Europeans roamed in small bands of fewer than 30, on brink of extinction (via Eurogenes), basically gives away the game in the headline. But please keep in mind my earlier post, as low effective population numbers may not accurately convey the actual census size over long periods of time. These results are not particularly surprising, as the ancient genomes we have from hunter-gatherers tend to indicate a very high level of inbreeding in comparison to modern populations. The main difference here is that it seems that they have more and more ancient genomes sampled from diverse locations to add confidence to the original conjecture:

Prof. Pinhasi’s team has found that the genomes sequenced from hunter-gatherers from Hungary and Switzerland between 14 000 to 7 500 years ago are very close to specimens from Denmark or Sweden from the same period.

These findings suggest that genetic diversity between inhabitants of most of western and central Europe after the ice age was very limited, indicating a major demographic bottleneck triggered by human isolation and extinction during the ice age.

The term “very close” is vague. I’m sure he has some quantitative measure in mind (e.g., identity by descent blocks). It is probably not coincidence that you see the same dynamic among Neandertals. Those from Europe are surprisingly similar to those from the Altai. Why the homogeneity? Probably on the huge broad northern expanse of hominin habitation metapopulation dynamics characterized by extinction and resettlement from survivor lineages was very common. There is circumstantial evidence from wolves that the same happened to them. Why? This might simply be a biogeographic tendency among Palearctic species during the Pleistocene. The Ice Age was tough, and the glaciers were capricious, and the warming could be ephemeral (see the Younger Dryas).

Of course I’m going to put European in quotes in the title. Europeans, like modern day Puerto Ricans, are trihybrid. They only emerged in their current form in the past ~5,000 years or so. The north-south gradient of increased heterozygosity in Southern Europe may then be a function not of serial founder effects from the expansion of the Pleistocene refugia, but the higher fraction of hunter-gatherer ancestry in Northern Europeans, who exhibited decrease genetic diversity due to the bottlenecks.

 
• Category: Science • Tags: Europe, Genetics 
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Planet Money recently did a report on the difficulty of maintaining high economic productivity in southern Italy. I won’t rehash the specifics of the story, but, I think it is important to get a visual sense of just how large the contrast between the south and north of Italy is. Too often we speak of nation-states. Nation-states are real, and they are important, but they are often not comparable. Just like comparing the USA to Sweden is only marginally informative, so comparing a small nation like Ireland to a more substantial one like Italy is deceptive. Here is a 2008 regional GDP map with sub-national breakdowns. Though some of the values are certainly lower now (basically, everything outside of Germany and Sweden), the relationships still hold.

There has been a gap between the north and south of Spain and England, as well as the west and east of Germany, but none of these are of the same magnitude of what you see in Italy (for one, southern Italy is much more populous than eastern Germany). Sicily and the southern provinces are the poorest regions of western Europe. In contrast, the area between Milan and Bologna in the north is among the wealthiest.

Here is a map of unemployment rates:

 

 

(Republished from Discover/GNXP by permission of author or representative)
 
• Category: Economics, Science • Tags: Culture, Europe, Geography 
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Early this year I received an email from Dr. Peter Ralph, inquiring if I might discuss some interesting statistical genetic results from analyses of the POPRES data set which might have historical relevance. I’ve been excitingly waiting for the preprint to be made public so it could trigger some wider discussion. I believe that the methods outlined in the paper perhaps show us a path into the near future, where we might gain a much sharper perspective upon the recent past. So it’s finally out, and you can read it in full. Ralph and Dr. Graham Coop have posted put it up at arXiv, The geography of recent genetic ancestry across Europe. The paper uses ~500,000 SNPs from the POPRES data set individuals, and looks at patterns of identity by descent as a function of geography. By identity by descent, we’re talking about segments of the genome which are derived from a common ancestor. Because of recombination the length of the segments can give us a sense of the date of the last common ancestor; long segments indicate more recent ancestry because fewer recombination events have chopped up sequence.

Here’s the big takeaway of the paper: …There is substantial regional variation in the number of shared genetic ancestors: especially high numbers of common ancestors between many eastern populations likely date to the Slavic and/or Hunnic expansions, while much lower levels of common ancestry in the Italian and Iberian peninsulas may indicate weaker demographic effects of Germanic expansions into these areas and/or more stably structured populations. Recent shared ancestry in modern Europeans is ubiquitous, and clearly shows the impact of both small-scale migration and large historical events….


When I first saw the panels above, which illustrate the proportion of IBD sharing between populations, with the starred population being the focal one, I immediately thought of the early medieval Slavic expansion. There is already evidence of this in the genetic data. Dienekes noted that modern Greeks seem to have a significant component of “northern” ancestry, which is attenuated in Turks, and nearly absent in Greek Cypriots. These results suggest that the peoples of eastern Europe share a very large number of common ancestors within the past 1,500 years, irrespective of geographic distance (note that it is difficult to observe a decay in the size of the circles, which is more evident in other panels).

The other surprising pattern, at last to me, is the deep structure of the Italian population. These results imply that Italian relatedness has a notably deeper time depth than that of other European nation-states. I’ll quote the authors here: This suggests signi cant substructure and large population sizes within Italy, strong enough that di erent groups within Italy, share as little recent common ancestry as other distinct, modern-day countries, substructure that was not homogenized during the migration period. These patterns could also reflect in part a history of settlement of Italy from various sources, including: settlement of Greeks in southern Italy, settlement of Illyrians in eastern Italy, and an influx of people from across the Roman empire, including gene flow from Africa…but is unlikely to be entirely due to these eff ect. Spain seems to exhibit the same distinctness from the rest of Europe as Italy, but has a much more normal pattern of IBD, with shallower time depth to common ancestry.

There are plenty of other possible inferences one could make. For example, is the negative correlation between IBD tracts in individuals of UK origin affiliated with Germany and Ireland a function of a difference in Celtic and Germanic ancestry dating to the Dark Ages, or is it simply due to the fact that the United Kingdom has had a recent wave of Irish ancestry in the 19th century, or perhaps just a natural result of a geographic continuum and isolation by distance? The last is an issue which will need addressing in the future. The authors make the case that because of the power of the IBD method one can make inferences without a finer geographic granularity, but what is sufficient for statistical genetics is not sufficient for historical-demographic inference. The POPRES data set was collected in London and Lausanne, and there are limits to how much geographic information you can squeeze out of this. I assume in the near future these sorts of methods which infer IBD tracts will be applied extensively, so this is just here to whet out appetites.

This paper has a wealth of results. You can create many stories. But to create credible stories you need “thick” and “deep” knowledge. So I invite readers to dig through the results and see what jumps out at them. It’s no cost to you, and I don’t think the time spent pursuing this material is going to be time wasted.

(Republished from Discover/GNXP by permission of author or representative)
 
• Category: History, Science • Tags: Demographics, Europe 
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A new paper in Science has just been published which in its broad outlines has been described in conference presentations. When examining the autosomal genetic variation of three individuals of the hunter-gatherer Pitted Ware Culture (PWC), and one of the agriculturalist Funnel Beaker Culture (TRB), the authors found that the two groups were sharply differentiated. The number of SNPs was on the order of 10,000 or so if I read the methods correctly. This is rather thin for studying contemporary within European population differences (~100,000 or more seems to be safe), in particular using hypothesis based clustering algorithms (it seems more manageable for PCA). But the findings are strong enough that I think we shouldn’t discount them. The most fascinating aspect of the results is that while the PWC seem to exhibit affinities with Northern and Northeastern Europeans, the TRB individual seems more similar to extant Southern Europeans!

Others have already commented extensively on the results. Keeping in mind the small sample sizes, limitation of comparisons, and the relatively thin marker set, I think the primary result we can take away from these findings is that old models of pure cultural and demographic diffusion are false. By this, I mean that prior debates which culminated in the early aughts on the “Paleolithic vs. Neolithic” contribution to the ancestry of modern Europeans were fundamentally premised on a demographic diffusion dynamic, whereby genes and ideas exhibited a continuous flow across a flat and featureless landscape. On the contrary, the basic outlines we are seeing here is that the human past exhibited spatial and temporal discontinuity. And why should this surprise us? There is no dialect continuum between Spanish and Chinese across Eurasia. Rather, broad language families are sharply differentiated from each other at zones of contact. Though there are theoretical reasons why the variation in genes should be more clinal, the reality remains that cultural parameters are going to shape the outlines of genetic variation, and those parameters are discontinuous.

There are two framing issues which make this paper’s results intelligible. The first is general. Agriculture likely did not spread in Europe simply through the random-walk “bottom up” expansion of small groups of farmers into an empty frontier. Rather, these populations were almost certainly organized on some supra-clan political level, and used their organizational resources to map out appropriate zones of settlement prior to expansion. The result in the early periods was a “leapfrog” point to point migration pattern, focusing on inland river valleys and coastal zones of rich land factor inputs and clement habitation. This sort of interleaving settlement pattern could easily explain sharp genetic distinctions between co-located populations, which only admixed over time as the last hunter-gatherers did acculturate. The second issue is specific to Scandinavia: it seems that because of its ecological conditions agriculture came late to this zone of Europe, and hunter-gatherer populations reliant on marine organisms were demographically particularly robust. The discontinuous expansion and stasis of farming on the ecological frontier was certainly the case in Scandinavia for nearly 1,000 years, as hunter-gatherers persisted as the spread of farming was halted.

Most of the information in the paper is well summarized by figure 1, which I’ve reedited considerably to illustrate the primary finding. Please note the relative affinities of the LBK and PWC individuals. The LBK individual in the PCA is placed near the Basque and Sardinian populations of Southwest Europe, while the PWC individuals are outside of the distribution of the HGDP Northern Europeans. In another PCA they seem to cluster with East Baltic populations, such as the Latvians. This is in line with earlier mtDNA work.

Also observe the pattern in ADMIXTURE: again, a close correspondence with the Sardinian and Basque samples for the LBK. Of particular interest is the relative lack of component yellow (K = 4) in all of the ~5,000 year old samples. The difference in proportion of this is what also distinguishes the French from the French Basque, and the Tuscans from the Sardinians (along with K = 2, the blue component in the case of the latter). I have truncated the Finnish samples, but unfortunately I suspect what we’re seeing here is something similar to the Kalash, a very homogeneous and relatively inbred population throwing up its own component. So I do not believe K = 1, the purple, is particular informative. The most likely model for the ethnogenesis of the Finnic peoples in Northeastern Europe seems to involve an exogenous Siberian element. From reading the supplements I do not see this affinity in the PWC. That may then date the expansion of the Finns as a circum-polar group of ethnicities in Western Eurasia.

In any case, as Dienekes has noted, I suspect that what is missing from the model outlined in the paper are subsequent population movements in Europe after the initial contact between the indigenes of the north and the LBK from the south. This may be why the PWC individuals in some PCA analyses seem to be placed outside of contemporary distributions, just like Otzi the Iceman.

Using a two-way admixture model the authors construct a framework whereby Northwest Europeans are about 50 percent farmer and 50 percent hunter-gatherer; that is, 50 percent LBK and 50 percent PWC. But as Maju cautions we need to be careful about substituting these ancient populations for all ancient populations. Additionally, the two-way admixture model estimates that Sardinians are 95 percent farmer, while Swedes are 40 percent farmer, farmer as understood as the descendants of LBK. I think the problem here, as I have argued before, and Dienekes has also suggested, is that there were almost certainly multiple waves of agriculturalists within Europe. The Sardinians seem to be relatively unadulterated descendants of an early farmer demographic expansion, which has been supplemented across much of Europe. I’ve you with their estimates of Neolithic farmer ancestry:

Image credit: Oskar Karlin

(Republished from Discover/GNXP by permission of author or representative)
 
• Category: Science • Tags: Agriculture, Anthropology, Europe 
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The image above come from John Hawks’ weblog. I was thinking today about the resettlement of Europe since the Last Glacial Maximum. It is clear that much of northern Europe was not habitable until the Holocene, after the Ice Age. And those regions which were habitable were often marginal. But, there were zones of southern Europe which remained relatively clement. One model of how Europe was settled after the warming is that hunter-gatherers expanded north out of these southern refuges. This can explain the lower heterozygosity of northern populations (see map to left). They may have lost their genetic diversity to some extent through population bottlenecks or simply drift on the wave of demographic advance. And yet something jumped out at me on this map: the southwest portion of Portugal is reputedly the zone with the highest African admixture in continental Europe (for historical reasons). The heterozygosity may simply be a function then of the fact that southern Europe has been in greater contact with other regions of the world because of geographic proximity.

There is also a second pattern which has always elicited curiosity in me: why is it that the largest component of genetic variation in Europe separates north vs. south, as opposed to east vs. west? This does not seem to comport well with a model of expansion from southern refuges. Should not the west-east genetic variation of Ice Age Europeans who faced the tundra and ice be represented among modern populations as they expanded their range northward simultaneously? Something is wrong with the model.

First, it seems clear that a lot has changed since the Last Glacial Maximum. As recently as the late aughts authors were claiming that by ~20,000 years before the present the general shape of genetic variation we see around us had been set. I’d be willing to bet $5,000 dollars that that’s wrong. In the specific case of Europe there may be many explanations for the set of patterns we’re seeing. It may be that the original populations of the refuges were later replaced. Northern Europeans may be legitimate descendants of those groups, but the original patterns of genetic variation in southern Europe were washed away due to being overwhelmed by Neolithic populations from Anatolia. Or, it may be that modern people in the north of Europe descend from a group which moved laterally, and replaced and assimilated the original inhabitants of the continent.

There are many plausible models, and combinations of models. From what I have read people in the Reich lab are now attempting to construct a scenario for the ethnogenesis of Europeans analogous to that of South Asians. In other words, modern Europeans are a compound of the descendants of the Paleolithic hunter-gatherers with an intrusive population. The same lab seems to be positive that Indo-Europeans did have a substantial effect on genetics of South Asians. If so, then I see no reason why the same would not be so in Europe.

In any case, interesting times. We’ll know a lot more in exceedingly great detail soon enough (I’d be willing to bet money on that too!).

(Republished from Discover/GNXP by permission of author or representative)
 
• Category: Science • Tags: Anthropology, Europe, Paleolithic Europeans 
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Dienekes has a long post, the pith of which is expressed in the following:

If I had to guess, I would propose that most extant Europeans will be discovered to be a 2-way West Asian/Ancestral European mix, just as most South Asians are a simple West Asian/Ancestral South Indian mix. In both cases, the indigenous component is no longer in existence and the South Asian/Atlantic_Baltic components that emerge in ADMIXTURE analyses represent a composite of the aboriginal component with the introduced West Asian one. And, like in India, some populations will be discovered to be “off-cline” by admixture with different elements: in Europe these will be Paleo-Mediterraneans like the Iceman, an element maximally preserved in modern Sardinians, as well as the East Eurasian-influenced populations at the North-Eastern side of the continent.

This does not seem to be totally implausible on the face of it. But it seems likely that any “West Asian” component is going to be much closer genetically to an “Ancestral European” mix than they were to “Ancestral South Indians,” because the two former elements are probably part of a broader West Eurasian diversification which post-dates the separation of those groups from Southern and Eastern Eurasians. In other words, pulling out the distinct elements in Europeans is likely a more difficult task because the constituents of the mixture resemble each other quite a bit when compared to “Ancestral North Indians” vs. “Ancestral South Indians.”


The bigger issue which this highlights though is that the reality that many of these clustering methods are temporally sensitive. Given enough time a “hybrid” population is no longer a hybrid, but rather a new distinctive population which itself can be a “parent.” Recombination breaks apart the long range genetic physical associations which are the hallmarks of distinctive admixed ancestry on the genomic scale. That is why clustering methods easily generate a pure “South Asian” component. After at least ~3-4,000 years of continuous admixture the synthesis is now far less coarse, and the elements much more de facto miscible. And yet via other clustering techniques, such as principle components analysis, you get different results. The peculiar position of the “South Asian” individuals between Europeans and East Asians in direct proportion to their caste and regional origins becomes highly indicative of some sort of admixture event in different proportions as a function of geography and social context. The technique in Reconstructing Indian population history allowed for a resolution of this paradox by sifting through the variation and extracting out the ancestral components. The recent papers which came out on Australian Aboriginal genetics do something similar, in terms of making sense of somewhat puzzling results which are found when generating inferences from aggregate genomic variation.

Imagine how much more difficult the task would have been if the ancestral components were much closer! I suspect that’s what’s going on in Europe. I’m not privy to any big secrets, but I have heard of whispers of research groups using Sardinians as a “pure” outgroup to model the changing demographics of Europe since the arrival of agriculture. What David Reich stated at the conference was not particularly surprising to me in light of that possibility. Sardinia regularly pops out as a weird outlier in many analyses. One simple possibility here is that that’s simply a function of the fact that it’s an island, and therefore has diverged from mainland populations due to isolation from conventional village-to-village mate exchange. Another possibility, mooted by Dienekes, is that it may be a repository of European genetic variation from earlier periods, relatively unaffected by later perturbations due to demographic changes. The main reason that I can give some credit to Dienekes’ thesis has less to do with Sardinians than Basques. The French Basques in the HGDP are less atypical than the Sardinians, but in some runs they do lack a component which is most obviously classed as “West Asian,” and which other French have. In Dienekes’ own runs with a diverse array of Iberian populations this same distinction emerges.

All of this reminds us that clustering methods give us great insights into how populations are related to each other, but they don’t tell us about the details of how that relatedness came to be. It makes a great difference if an element is the outcome of relatively recent (<10,000 years) hybridization events, as opposed to having deeper roots. For example, admixture between Polynesians and Melanesians brings together two components, whatever their own prior origins, diverged on the order of 50,000 years before the present. And yet if the two groups mentioned earlier are correct than the Melanesian component itself must be decomposed into two fractions, one of which is much closer to the Polynesians than the other, our understanding of the past changes.

As I implied earlier today I think the era of wild hypothesis generation in the area of the settling of Europe over the last 10,000 years is coming to the end. The combination of more powerful analytic techniques and the emergence of ancient DNA samples with which to calibrate, peg, and check, inferences from those techniques, will probably clarify our understanding of the past to a great extent.

Image credit: yomi955

(Republished from Discover/GNXP by permission of author or representative)
 
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I decided to take the Dodecad ADMIXTURE results at K = 10, and redo some of the bar plots, as well as some scatter plots relating the different ancestral components by population. Don’t try to pick out fine-grained details, see what jumps out in a gestalt fashion. I removed most of the non-European populations to focus on Western Europeans, with a few outgroups for reference.

Here’s a table of the correlations (I bolded the ones I thought were interesting):

W Asian NW African S Europe NE Asian SW Asian E Asian N European W African E African S Asian
W Asian * -0.01 -0.18 0.04 0.81 0.59 -0.64 0.39 0.2 0.04
NW African * * 0.19 -0.16 0.23 -0.09 -0.19 0.26 0.67 -0.11
S European * * * -0.38 -0.03 -0.27 -0.42 -0.11 -0.02 -0.36
NE Asian * * * * -0.06 0.5 0.26 -0.04 -0.1 -0.07
SW Asian * * * * * 0.21 -0.62 0.74 0.59 -0.13
E Asian * * * * * * -0.27 0.08 0 0.14
N European * * * * * * * -0.34 -0.28 -0.31
W African * * * * * * * * 0.86 -0.04
E African * * * * * * * * * -0.07
dodenorthdodsouthdodswasiandodwestscatternorthwestscattersouthnorthscattersouthwestscatterwestasiansouthwest

(Republished from Discover/GNXP by permission of author or representative)
 
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444px-Ole_Henrik_Magga_closeup
Ole Magga, Norwegian politician

ResearchBlogging.org On this blog I regularly get questions about the Sami (Lapp*). That’s because I often talk about Finnish genetics, have readers such as Clark who are of part-Sami origin, and, the provenance and character of the Sami speak to broader questions about the emergence of the modern European gene pool. More precisely questions about the Sami are relevant to the broader nature of the Finnic presence in Europe, and their relationship to other Baltic and northern populations. Are these people “indigenous” to Europe, or relatively newcomers (prehistoric Magyar or Turks).? These questions are prompted by the peculiarity of their languages (as well as the physical appearance of some of the Sami). With Basque they are the only living non-Indo-European European languages whose origins are prehistoric (Magyar and Turkish were arrivals within the last 1,000 years).**

Because of affinities to other Uralic languages which are found in Central Siberia it has often been conjectured that the Finns, Sami, and Estonians are relative newcomers to Norden from that region. This has some equivocal support from Y chromosomal lineages. On the other hand, there are those who argue that the Finnic peoples were present in the north of Europe before the arrival of Indo-European speakers (often these are Finnish nationalists). This has some support from maternal lineages. Naturally, some have been tempted to synthesize these two genetic lines of evidence, and the linguistic affinities, to argue that Finns are a hybrid population of Asiatic men and Paleolithic European women! But we need to go further than uniparental markers, the direct male and female ancestral lines. We need to look across the broader swath of the genome. It just happens that a new paper was published in The European Journal of Human Genetics on autosomal Sami affinities to other populations, A genome-wide analysis of population structure in the Finnish Saami with implications for genetic association studies:

The understanding of patterns of genetic variation within and among human populations is a prerequisite for successful genetic association mapping studies of complex diseases and traits. Some populations are more favorable for association mapping studies than others. The Saami from northern Scandinavia and the Kola Peninsula represent a population isolate that, among European populations, has been less extensively sampled, despite some early interest for association mapping studies. In this paper, we report the results of a first genome-wide SNP-based study of genetic population structure in the Finnish Saami. Using data from the HapMap and the human genome diversity project (HGDP-CEPH) and recently developed statistical methods, we studied individual genetic ancestry. We quantified genetic differentiation between the Saami population and the HGDP-CEPH populations by calculating pair-wise FST statistics and by characterizing identity-by-state sharing for pair-wise population comparisons. This study affirms an east Asian contribution to the predominantly European-derived Saami gene pool. Using model-based individual ancestry analysis, the median estimated percentage of the genome with east Asian ancestry was 6% (first and third quartiles: 5 and 8%, respectively). We found that genetic similarity between population pairs roughly correlated with geographic distance. Among the European HGDP-CEPH populations, FST was smallest for the comparison with the Russians (FST=0.0098), and estimates for the other population comparisons ranged from 0.0129 to 0.0263. Our analysis also revealed fine-scale substructure within the Finnish Saami and warns against the confounding effects of both hidden population structure and undocumented relatedness in genetic association studies of isolated populations.

They had 352 Sami samples, and looked at ~38,000 SNPs. For the questions they’re focusing on 38 K SNPs seems fine. That’s enough to smoke out inter-population variation. In their paper they compared the Sami to the HGDP populations using standard techniques. Assuming 7 ancestral populations in the data set, this what ADMIXTURE popped out:

ejhg2010179f2

There is a definite “eastern” affinity among the Sami. Interestingly, it is broken down into a major and minor component. The major one is what is found among the Han, while the minor one resembles Native Americans. The natural interpretation for this is that what one is seeing is the shadow of the circumpolar northern Eurasian populations which spanned eastern Europe to Siberia. In comparison with other European populations the Sami affinity with Russians is clear, though interestingly they lack the “blue” component which peaks in northwest South Asian populations, which the Russians have, and Sardinians and French Basque lack.

samieigenTo the left you see a PCA which breaks out the top two components of genetic variation for the data set. The two axes seem to be roughly west-east, north-south. Whatever ancient affinities the Sami may have with Southern Europeans via mtDNA haplogroup U5, it is not evident in the total genome content. The position of the Sami between Russians and Orcadians (from north of Scotland) is probably attributable to the fact that the Sami share much genetically with other Scandinavians, who are closer to British populations than the Russians are.

I’m not sure these analyses really shed any light on the on the questions I mentioned earlier. The authors themselves note that the “eastern” component of the ancestry in the Sami is probably very old, so they may be an ancient stabilized hybrid population, mostly indigenous with a non-trivial exogenous element. That does not tell us whether Finnic languages are indigenous to Europe, or whether they are indigenous to Central Siberia (indigenous here is in reference to the Indo-European languages). Additionally, there is the matter that for such fine-grained questions the HGDP sample is suboptimal as reference populations. Dienekes Pontikos points this out:

It is unfortunate that they included Native American HGDP populations, but did not include the most relevant published data on Siberians that I first used to study population structure across north Eurasia here and here and here.

Hence, they discover a “Native American”-like component in Saami, which in all likelihood can be further resolved into Siberian-specific components utilizing the Rasmussen et al. dataset.

The “closest approximation” to the East Eurasian component in Saami in the HGDP panel are the Yakuts, but finer-scale analysis (see my previous posts) reveals that the Yakuts are made up almost entirely of an Altaic-specific component tying them to Turkic, Mongol, and Tungusic populations, while the eastern component in European Finns, Vologda Russians and Chuvashs has relationships with Central Siberians such as Kets, Selkups, and Nganasans, all of which are missing in this paper.

Below is a re-edited ADMIXTURE plot from Dienekes:

ADMIXTURE15

Note: There are many ways to spell Sami. They used two a’s, but I find that confusing, so I just used one in my text.

Citation: Maki-Torkko, Elina, Aikio, Pekka, Sorri, Martti, Huentelman, Matthew J, & Camp, Guy Van (2010). A genome-wide analysis of population structure in the Finnish Saami with implications for genetic association studies European Journal of Human Genetics : 10.1038/ejhg.2010.179

* Apparently “Lapp” is considered derogatory among Norwegians, though Finnish Sami refer to themselves as lappalainen. I will use Sami to avoid irritating Norwegian terminology police.

** I am implicitly excluding much of European Russia west of the Urals, but so be it.

(Republished from Discover/GNXP by permission of author or representative)
 
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Razib Khan
About Razib Khan

"I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. If you want to know more, see the links at http://www.razib.com"