Y-chromosome haplogroup N phylogeny resolved

AJHG Volume 99, Issue 1, p163–173, 7 July 2016

Human Y Chromosome Haplogroup N: A Non-trivial Time-Resolved Phylogeography that Cuts across Language Families

Anne-Mai Ilumäe et al.

The paternal haplogroup (hg) N is distributed from southeast Asia to eastern Europe. The demographic processes that have shaped the vast extent of this major Y chromosome lineage across numerous linguistically and autosomally divergent populations have previously been unresolved. On the basis of 94 high-coverage re-sequenced Y chromosomes, we establish and date a detailed hg N phylogeny. We evaluate geographic structure by using 16 distinguishing binary markers in 1,631 hg N Y chromosomes from a collection of 6,521 samples from 56 populations. The more southerly distributed sub-clade N4 emerged before N2a1 and N3, found mostly in the north, but the latter two display more elaborate branching patterns, indicative of regional contrasts in recent expansions. In particular, a number of prominent and well-defined clades with common N3a3’6 ancestry occur in regionally dissimilar northern Eurasian populations, indicating almost simultaneous regional diversification and expansion within the last 5,000 years. This patrilineal genetic affinity is decoupled from the associated higher degree of language diversity.

Link

Chernykh on Eurasian metallurgy

Bell Beaker blogger points me to this excellent new review of the Eurasian Metallurgical Provinces scheme of Yevgeny Chernykh. I also include an abstract from an earlier study by the author.

Of interest:

The metallurgical contacts and character of interrelations between eastern and western parts we can observe in the Xinjiang among the materials of eastern focuses of the Circumpontic metallurgical province and later in the rich metal collections of the West-Asian and East-Asian steppe provinces. In this sphere extreme interest presents so called Seima-Turbino transcultural phenomenon: their impressive metal forms of eastern sources spreaded from the Western China up to Baltic Sea at the turn of the III and II millennium and in the early centuries of the II mill. BCE.

I have argued before that the Seima-Turbino phenomenon is associated with the spread of Finno-Ugrians into Europe. It would certainly be in accord with a recent thesis about Finno-Ugrians arriving to the Baltic after Indo-European speakers.

Metallurgical Provinces of Eurasia in the Early Metal Age: Problems of Interrelation

General chronological frame of the Early Metal Age (EMA) in Eurasia limited from IX/VIII up to turn II/I mill. BCE. The chronological scale of this investigation founded on the systematized date base of more than 3.5 thousand calibrated 14C analyses. EMA can be subdivided into five unequal in chronological sense periods. The Early Metal Age was the epoch clear domination of the western metallurgical centers – particularly up to III mill. BCE. In all probabilities the apogee of the western predominance was incarnated in the immense of the famous Scythian world, in the limits of the first millennium BCE – i.e. beyond the EMA. The eastern centers take up the initiative of westward pressing after collapse of the Scythian world.

Link

The “Steppe Belt” of stockbreeding cultures in Eurasia during the Early Metal Age

The stock-breeding cultures of the Eurasian “steppe belt” covered approximately 7-8 million square km2 from the Lower Danube in the West to Manchuria in the East (a distance of more than 8000 km). The initial formation of the “steppe belt’cultures coincided with the flourishing of the Carpatho-Balkan metallurgical province (V millennium BC). These cultures developed during the span of the Circumpontic metallurgical province (IV-III millennium BC). Their maturation coincided with the activity of the various centers of the giant Eurasian and East-Asian metallurgical provinces (II millennium BC). The influence of these stock-breeding nomadic cultures on the historical processes of Eurasian peoples was extremely strong. The collapse of the “steppe belt” occurred as late as the XVIIIth and XIXth centuries AD.

Link

Indo-Europeans preceded Finno-Ugrians in Finland and Estonia

According to an abstract of a Ph.D thesis (below). This would appear to work well with the dating of the signature Y-chromosome haplogroup of Finno-Ugrians. 

Bidrag till Fennoskandiens språkliga förhistoria i tid och rum (Heikkilä, Mikko)

My academic dissertation "Bidrag till Fennoskandiens språkliga förhistoria i tid och rum" ("Spatiotemporal Contributions to the Linguistic Prehistory of Fennoscandia") is an interdisciplinary study of the linguistic prehistory of Northern Europe chiefly in the Iron Age (ca. 700 BC―AD 1200), but also to some extent in the Bronze Age (ca. 1700―700 BC) and the Early Finnish Middle Ages (ca. AD 1200―1323). The disciplines represented in this study are Germanistics, Nordistics, Finnougristics, history and archaeology. The language-forms studied are Proto-Germanic, Proto-Scandinavian, Proto-Finnic and Proto-Sami. This dissertation uses historical-comparative linguistics and especially loanword study to examine the relative and absolute chronology of the sound changes that have taken place in the proto-forms of the Germanic, Finnic and Samic languages. Phonetic history is the basis of historical linguistics studying the diachronic development of languages. To my knowledge, this study is the first in the history of the disciplines mentioned above to examine the systematic dating of the phonetic development of these proto-languages in relation to each other. In addition to the dating and relating of the phonetic development of the proto-languages, I study Fennoscandian toponyms. The oldest datable and etymologizable place-names throw new light on the ethnic history and history of settlement of Fennoscandia. For instance, I deal with the etymology of the following place-names: Ahvenanmaa/Åland, Eura(joki), Inari(järvi), Kemi(joki), Kvenland, Kymi(joki), Sarsa, Satakunta, Vanaja, Vantaa and Ähtäri. 

My dissertation shows that Proto-Germanic, Proto-Scandinavian, Proto-Finnic and Proto-Sami all date to different periods of the Iron Age. I argue that the present study along with my earlier published research also proves that a (West-)Uralic language – the pre-form of the Finnic and Samic languages – was spoken in the region of the present-day Finland in the Bronze Age, but not earlier than that. In the centuries before the Common Era, Proto-Sami was spoken in the whole region of what is now called Finland, excluding Lapland. At the beginning of the Common Era, Proto-Sami was spoken in the whole region of Finland, including Southern Finland, from where the Sami idiom first began to recede. An archaic (Northwest-)Indo-European language and a subsequently extinct Paleo-European language were likely spoken in what is now called Finland and Estonia, when the linguistic ancestors of the Finns and the Sami arrived in the eastern and northern Baltic Sea region from the Volga-Kama region probably at the beginning of the Bronze Age. For example, the names Suomi ʻFinlandʼ and Viro ʻEstoniaʼ are likely to have been borrowed from the Indo-European idiom in question. (Proto-)Germanic waves of influence have come from Scandinavia to Finland since the Bronze Age. A considerable part of the Finnic and Samic vocabulary is indeed Germanic loanwords of different ages which form strata in these languages. Besides mere etymological research, these numerous Germanic loanwords make it possible to relate to each other the temporal development of the language-forms that have been in contact with each other. That is what I have done in my extensive dissertation, which attempts to be both a detailed and a holistic treatise.

ISABS 2013 abstracts

From the book of abstracts (pdf):

MITOCHONDRIAL DNA AND PHYLOGENETIC ANALYSIS OF PREHISTORIC NORTH AFRICAN POPULATIONS

North Africa is located at a crossroad between Europe, Africa and Asia and has been inhabited since the Prehistoric time. In the Epipaleolithic period (23.000 years to 10.000 years BP), the Western North Africa has been occupied by Mecha- Afalou Men, authors of the Iberomaurusian industry. The origin of the Iberomaurusians is unresolved, several hypotheses have been forwarded. With the aim to contribute to a better knowledge of the Iberomaurusian settlement we analysed the mitochondrial DNA (mtDNA) of skeletons exhumed from the prehistoric site of Taforalt in Morocco (23.000-10.800 years BP) and Afalou in Algeria (11.000 to 15.000 BP -Algeria). Hypervariable segment 1 of mtDNA from 38 individuals were amplified by Real-Time PCR and directly sequenced. Sequences were aligned with the reference sequence to perform the mtDNA classification within haplogroups. Phylogenetic analysis based on mitochondrial sequences from Mediterranean populations was performed using Neighbor-Joining algorithm implemented in MEGA program. mtDNA sequences from Afalou and Taforalt were classified in Eurasiatic and North African haplogroups. We noted the absence of Sub-Saharan haplotypes. Phylogenetic tree clustered Taforalt with European populations. Our results excluded the hypothesis of the sub-Saharan origin of Iberomaurusians populations and highlighted the genetic flow between Northern and Southern cost of Mediterranean since Epipaleolithic period.

DISCONTINUITY SCREENING OF THE EARLY FARMERS’ MT-DNA LINEAGES IN THE CARPATHIAN BASIN

Discontinuous mitochondrial (mt) haplotype data between Central-Europe’s first farmers and contemporary Europeans have been described before. Hungary was a key-area of the Neolithisation, in the route of Neolithisation following the River Danube, and that was also the birthplace of the Linear Pottery Culture, which later colonised Western and Northern Europe. Neolithic and post-Neolithic human remains as well as contemporary population of Hungary is involved in our project to gain information on their mt-haplotype pattern and especially on the frequency of Asian haplotypes in the Carpathian Basin. HVS-I sequences from nt15977 to nt16430 of Neolithic specimens with sufficient mtDNA preservation among an extended Neolithic collection were analysed for polymorphisms, identifying 23 different ones. A novel, N9a, N1a, C5, D1/G1a, M/R24 haplogroups were determined among the pre-industrial Hungarians. The presence of Asian haplotypes in the ancient populations must be taken into consideration when reconstructing the population history of Europe and Asia, so a survey of the recent Asian haplotype frequency in Europe is unavoidable. The ancient and recent haplotype pattern of Hungary is definitely worth further investigation to test a theory on the continuous population history of Europe, wheter genetic gaps between ancient and recent human populations of Europe were more likely to be detected. 

ANTHROPOLOGIC AND MITOCHONDRIAL DNA ANALYSIS OF A MEDIEVAL GRAVEYARD FROM SOPOT (CROATIA)

Anthropologic and DNA analysis of human remains recovered from a graveyard in ©opot near Benkovac (Croatia) dating to the 14th/15th century was conducted in order to reconstruct the origin and life conditions of the people populating the region at that time. The dynamics of the population represented in this graveyard are important for understanding Croatian history because the deceased individuals were buried according to pagan ritual which was uncommon in a post Christianization period. Human remains from a total of 31 graves were analyzed, in which 47 individuals were found (9 female, 23 male and 15 children). Average age at death for adults was lower than expected (for female 28.9, male 32.4 years), suggesting that the living conditions of these individuals were poor. In addition, 10 antemortem traumas were visible on 6 adults, which is a higher rate than expected, and indicates potential violence within the population group. Finally, mitochondrial DNA (mtDNA) analysis was performed on hypervariable regions one and two for 46 of the individuals. Due to the age and condition of the remains, only 19 of the samples yielded full sequence profiles. Haplogroup analysis was performed for these 19 individuals, with the majority of the results falling within the most common groups in present-day Croatia. However, examination of the lesscommon haplogroups suggested a possible migration of individuals from Asia. Collectively, the physical and molecular results from this study provide evidence to suggest that individuals recovered from this gravesite are not from the current indigenous population.

MATERNAL GENETIC PROFILE OF A NORTHWEST ALGERIAN POPULATION

The North African population gene pool based on mitochondrial DNA (mtDNA) polymorphisms has been shaped by the back-migration of several Eurasian lineages in Paleolithic and Neolithic times. Recent influences from sub-Saharan Africa and Mediterranean Europe are also evident. The presence of East-West and North- South haplogroup frequency gradients strongly reinforces the genetic complexity of this region. However, this genetic scenario is beset with a notable gap, which is the lack of consistent information for Algeria, the largest country in the continent. To fill this gap, we analyzed a sample of 240 unrelated subjects from a northwest Algeria cosmopolitan population. mtDNA sequences analysis was performed on the regulatory hypervariable segment I region (HVSI). Haplogroup diagnostic mutations were analyzed using PCR-RFLPs and/or SNaPshot multiplex reactions. Of all North African populations, Eurasian lineages are the most frequent in Algeria (80%) while sub-Saharan Africa origin accounts for the remaining (20%). Within them, the North African genetic component U6 and M1 count for 20%. Indeed, the U6 haplogroup, highly distributed in Northwestern African populations, show a high frequency in Algeria (11.83%), while, the M1 frequency (7.1%) raises an anomalous peak in its decreasing Northeast - Northwest gradient. Moreover, the high frequency of HV subgroups (38.33%) point to direct maritime contacts between the European and North African western sides of the Mediterranean. Besides, the most common western H subgroups, H1 (47.8%) and H3 (10.1%), represent 60% of H lineages. These frequencies and HV0 (7.5%) lie well within the observed Northwestern to Northeastern African decreasing gradients.

MATERNAL GENETIC VARIATION OF THE SLOVENIAN POPULATION IN A BROADER EUROPEAN CONTEXT AND COMPARED TO ITS PATERNAL COUNTERPART

Slovenia is a European country situated at the crossroads of main European cultural and trade routes. It is geographically more linked to Central Europe, but history draws it closer together to its ex-Yugoslavian, Southeast European (SEE) neighbors. Slovenian maternal heritage has not been analyzed since 2003 and our aim was to analyze SNP markers of 97 Slovenian mtDNAs in high resolution to see where this population fits according to its maternal genetic variation. We compared the Slovenian sample with the neighboring SEE populations, as well as with other published European population datasets. Also, we compared the obtained mtDNA variation results with the available Slovenian Y chromosome data to see how these two uniparental marker systems correspond to each other. In the PC plot based on mtDNA haplogroups frequencies, Slovenian population has an outlying position mostly due to the increased prevalence of J (14.4%) and T (15.4%) clade and especially because of the abundance and diversity of J1c samples in Slovenia, represented with 8 haplotypes and in a percentage of >11%. Although in an outlying position, Slovenian mtDNA variation still shows a certain degree of affinity to SEE. On the contrary, Slovenia’s paternal genetic heritage yielded results that correspond to the population’s geographic location and groups Slovenian population considerably closer to Central European countries, based on increased prevalence of Northern/Central European R1a-M198 and decreased frequency of Balkan-specific I2a2-M423. Such differences in maternal and paternal marker systems could indicate that Slovenian genetic variation was influenced by sex-biased demographic events.

AN ASIAN TRACE IN THE GENETIC HERITAGE OF THE EASTERN ADRIATIC ISLAND OF HVAR

The Island of Hvar is situated in the central eastern Adriatic, and its relatively small rural population has been reproductively isolated thought history. Therefore, founder effects, genetic drift and inbreeding have had significant role in the shaping of current genetic diversity of Hvar Islanders. We analyzed Y-chromosome SNP markers of 412 Hvar islanders in high resolution, with the aim to investigate the current paternal genetic diversity. We found a relatively high frequency (6.1%) of unrelated male samples belonging to the Q*-M424 haplogroup, which is unusual for European populations. Interestingly, a previous study showed 9 individuals from Hvar with mitochondrial haplogroup F, which is almost absent in Europe. Both findings could indicate a certain connection with Asian populations, where these haplogroups are most common. This might be a result of several migratory events in the history, one of which could be linked to the ancient Silk Road, the other a consequence of the arrival of the Slavs, following the Avars, to the eastern Adriatic in the 6th century or due to the expansion of the Ottoman Empire in 16th to 18th century. The presence of these rare mitochondrial and Y-chromosome lineages are an example of founder effect and random genetic drift which, in this small island with a high degree of isolation and endogamy, had a strong impact on shaping the genetic diversity of the population. 

GENETIC PORTRAIT OF THE BESERMYAN ETHNIC GROUP BASED ON MTDNA HAPLOGROUP STUDY

Besermyan are a small ethnic group living in the Volga-Ural region of Russia. They belong to Finno-Ugric language group, but speak a special dialect. There are some Bulgar-Chuvash borrowings in their adverb vocabulary that are absent in other dialects of the Udmurt language. Besermyan live in the northwestern part of modern Udmurtia in the Cheptsa basin. In 2002 their number was about three thousand. The Besermyan origin is a very interesting issue. There is a view that the endonym Besermyan (beserman) is derived from the Turkic word which means flMuslim« in Arabic. This hypothesis, along with their language, hints at the origin of this ethnic group; however the genetic portrait of Besermyan has not been described yet. In our study we used the data of mitochondrial DNA (mtDNA) HVSI sequencing from 98 Besermyans representing 10 villages in Udmurtia Republic of Russia. The prevalence of Western Eurasian mtDNA lineages (91.7%) over Eastern Eurasian ones (9.2%) was shown in the studied population which is consistent with the structure of mtDNA pool of Finno-Ugric ethnic groups of the Volga-Ural region. Some Eastern Eurasian lineages in Besermyan are represented by haplogroups D4b, A4b and Z1a which are also common in Udmurts. It is important to note though that the share of Western Eurasian component in Udmurts according to previous study by Bermisheva et al. (2002) is about 74.5% so mtDNA haplogroup distribution in Besermyans is closer to other Finno-Ugric people of the Volga-Ural region: Mordvins and Maris.

COSMOPOLITAN CENTRAL ASIA: TAJIK MTDNA TRACES THE EASTWEST MOVEMENT OF ANCIENT NOMADS 

Tajikistan is a country in the mountains of southeast Central Asia. Due to its isolation, mtDNA variation in the Tajiks has been fragmentary studied on a limited number of samples. In 1997 saliva samples were collected from unrelated Tajiks across Tajikistan. After long-term preservation DNA was extracted from 2 mm FTA discs. Due to degradation mtDNA was amplified using the primary and secondary PCRs with nested primers in the multiplex format. The origin of 91 mitochondrial genomes from Tajikistan traced from western Eurasia (62.6%), eastern Eurasia (25.3%), south Asia (11.0%), and North Africa (1.1%). Significant population structure in the distribution of these mtDNA lineages was revealed within the regional groups in Tajikistan. The mtDNA variation was compared between the Tajiks and 45 populations of Eurasia. Pairwise Fst comparisons and the correspondence analysis revealed non-significant differences between the Tajik and Uzbek populations. Although both nations speak languages belonging to different linguistic groups, this result corresponds to their cultural and economic proximity. Surprisingly, after the Uzbeks, the Tajik mtDNA pool most closely resembles to the Ossetians, an Indo-Iranian people from the North Caucasus. The Tajiks also display intensive gene flow and admixture with some other populations of Central Asia and the Iranian Plateau living along the centers and crossroads of the earliest civilizations and belonging to different linguistic groups including the Uyghur, Kazakh, Karakalpak, Turkmen, Pathans, Iranian Arabs, and Gilaki. This study demonstrates an impact of ancient nomad migrations and invasions on the distribution of mtDNA variation in Eurasia. 

ESHG 2013 abstracts

A couple of weeks before the ESHG 2013 conference, here are a few abstracts that caught my eye. Feel free to point to more interesting presentations in the comments section.

• J16.05 - Checking the hypothesis of a Balkan origin of the Armenians
• P17.5 - Y chromosome haplogroup analysis to estimate genetic origin of Balts
• J16.27 - Armenian Highland as a transition corridor for the spread of Neolithic agriculturists
• J16.14 - In Search of the Origin of Haplogroup J1-P58
• J16.03 - Y-chromosome haplogroup analysis in the Besermyan ethnic group
• P17.4 - Mitochondrial DNA Analysis of the Southeast European Genetic Variation Reveals a New, Local Subbranching in Hg X2
• P16.085 - Population diversity and history of the Indian subcontinent: Uncovering the deeper mosaic of sub-structuring and the intricate network of dispersals
• J16.43 - Ancient mtDNA diversity in Bulgaria
• P16.072 - Mitochondrial DNA diversity in medieval and modern Romanian population
• P16.012 - Frequency analysis of the CCR5-Delta32 allele in medieval and modern Romanian population
• J16.78 - The gene pool of Argyn in the context of generic structure of Kazakhs according to data on SNP-Y-Chromosome markers.

Evolutionary history of Uralic languages (Honkola et al. 2013)

Journal of Evolutionary Biology DOI: 10.1111/jeb.12107

Cultural and climatic changes shape the evolutionary history of the Uralic languages

T Honkola et al.

Quantitative phylogenetic methods have been used to study the evolutionary relationships and divergence times of biological species, and recently, these have also been applied to linguistic data to elucidate the evolutionary history of language families. In biology, the factors driving macroevolutionary processes are assumed to be either mainly biotic (the Red Queen model) or mainly abiotic (the Court Jester model) or a combination of both. The applicability of these models is assumed to depend on the temporal and spatial scale observed as biotic factors act on species divergence faster and in smaller spatial scale than the abiotic factors. Here, we used the Uralic language family to investigate whether both ‘biotic’ interactions (i.e. cultural interactions) and abiotic changes (i.e. climatic fluctuations) are also connected to language diversification. We estimated the times of divergence using Bayesian phylogenetics with a relaxed-clock method and related our results to climatic, historical and archaeological information. Our timing results paralleled the previous linguistic studies but suggested a later divergence of Finno-Ugric, Finnic and Saami languages. Some of the divergences co-occurred with climatic fluctuation and some with cultural interaction and migrations of populations. Thus, we suggest that both ‘biotic’ and abiotic factors contribute either directly or indirectly to the diversification of languages and that both models can be applied when studying language evolution.

Link

Thesis of Oleg Balonovsky

is available here as pdf. Lots of interesting information, and a few striking maps. Hopefully, the fact that it's all in Russian won't be much of a problem in this day and age.

I will highlight a few pieces of information. First, a distribution of Y-chromosome haplogroups in Russian groups:

Notice:

• N1c-Tat is a general feature of the Russians, but N1b-P43 is only really found at any significant frequency in the northern groups.
• A strong contrast of E-M78 between central (present) and northern (absent) groups, consistent with a late introduction of this haplogroup in easternmost Europe.
• South-Central-North decreasing frequency of R1a; now, it's not clear how R1a came to be in Russians: some of it may be legacy of its initial entry into Europe from the east, other could be of historical import, and may have even arrived during the Slavic expansion from Central Europe. The pattern probably is the reverse of the high frequency of N1, indicating increasing importance of Finno-Ugric substratum in the north.
• Fairly interesting that of the two likely "Balkan" haplogroups E-M78 and I-P37, the former is modal in central region, the latter in southern one. The absence of both in "deep Asia" suggests a late introduction, as mentioned before, but when?

Also of interest a haplotype analysis within R1a1a-M198:

My most immediate observation is the set of mainly Indian highly divergent haplotypes on the left. There has been (well-deserved) excitement about recent Y-SNP progress within this haplogroup, but we should not neglect the occurrence of outliers/relics in our reconstruction of a haplogroup's history. I'd love to see those few Indian haplotypes SNP-tested using the currently available SNPs, or even used to develop new SNPs for this important Eurasian haplogroup.

Genomewide structure of populations from European Russia (Khrunin et al. 2013)

Notice:

1. The intermediate position of Estonians between Balts and Finns
2. The intermediate position of some Russian groups between Komi and the main body of Europeans.

PLoS ONE 8(3): e58552. doi:10.1371/journal.pone.0058552

A Genome-Wide Analysis of Populations from European Russia Reveals a New Pole of Genetic Diversity in Northern Europe

Andrey V. Khrunin et al.

Several studies examined the fine-scale structure of human genetic variation in Europe. However, the European sets analyzed represent mainly northern, western, central, and southern Europe. Here, we report an analysis of approximately 166,000 single nucleotide polymorphisms in populations from eastern (northeastern) Europe: four Russian populations from European Russia, and three populations from the northernmost Finno-Ugric ethnicities (Veps and two contrast groups of Komi people). These were compared with several reference European samples, including Finns, Estonians, Latvians, Poles, Czechs, Germans, and Italians. The results obtained demonstrated genetic heterogeneity of populations living in the region studied. Russians from the central part of European Russia (Tver, Murom, and Kursk) exhibited similarities with populations from central–eastern Europe, and were distant from Russian sample from the northern Russia (Mezen district, Archangelsk region). Komi samples, especially Izhemski Komi, were significantly different from all other populations studied. These can be considered as a second pole of genetic diversity in northern Europe (in addition to the pole, occupied by Finns), as they had a distinct ancestry component. Russians from Mezen and the Finnic-speaking Veps were positioned between the two poles, but differed from each other in the proportions of Komi and Finnic ancestries. In general, our data provides a more complete genetic map of Europe accounting for the diversity in its most eastern (northeastern) populations.

Link

Medieval signal of Swedish (?) admixture in Finland

I took the FIN (Finnish), GBR (British), and CDX (Chinese Dai) samples of the 1000 Genomes Project, each of which has a sample size of 100 in order to investigate the signal of East-West Eurasian admixture in Finns. While neither Britons nor Dai could be imagine of having contributed to Finns directly, they ought to make useful proxies of a NW European population lacking recent East Eurasian ancestry, and an East Eurasian population lacking recent West Eurasian ancestry respectively.

In the following, I will assume a generation length of 29 years and a sample birthyear of 1980 as in previous experiments.

First, the 1-reference analysis of FIN using GBR produced an admixture proportion lower bound of 37.4 +/- 5.1 percent.

The corresponding analysis of FIN using CDX produced an admixture proportion lower bound of 4.4 +/- 1.0 percent.

The 2-ref admixture test with {GBR,CDX} reported success:

Test SUCCEEDS (z=2.76, p=0.0057) for FIN with {GBR, CDX} weights

But, the decay rates were inconsistent, a situation which might occur when major admixture from different sources took place at different times. In particular, the one using CDX corresponded to 65.57 +/- 8.36 generations, and the one using GBR to 25.48 +/- 4.93 generations.

In calendar dates, Finns are estimated to have mixed with an East Eurasian CDX-like population between 170BC-320AD and with a NW European GBR-like population between 1100-1380AD.

The central date of the latter estimate is 1,240AD, which corresponds quite closely to the beginning of Swedish rule and is in the middle of the 13th. century, between the time when Finland was initially claimed for western Christendom (12th c.) and the time when the conflict between Sweden and Russia was settled (14th c.).

An estimate of the admixture time for Finns

Using a similar procedure as in my recent post on the Baltic (Update II), I used 15 FIN individuals from the 1000 Genomes together with 12 Nganasans from Rasmussen et al. (2010) as reference populations, and 15 other FIN individuals to estimate admixture LD in a rolloff analysis. Three outlier Nganasan individuals (GSM558800, GSM558802, GSM558807) were removed.

The estimated time of admixture is 86.095 +/- 10.187 generations, or 2500 +/- 300 years. It corresponds rather well to the beginning of the Iron Age in northern Europe.

As I mention in my previous post, there is evidence for intrusive cultures (Battle Axe and Seima Turbino) converging on the area from different directions during the preceding Bronze Age. If the above date is accurate, it will suggest a rather late admixture event between the Europeoid and Siberian elements of Finns. The former may have included both the descendants of Mesolithic European hunter-gatherers and intruders from Central Europe (Corded Ware/Battle Axe); the latter may have included both Comb Ceramic and the descendants of the Seima Turbino metallurgists.

The Indo-European invasion of the Baltic

In some recent posts, I showed that South Asian populations (North Indian Brahmins, South Indian Brahmins) can be seen as mixtures of West Eurasian and South Indian populations, but also that West Eurasians (Bulgarians, Greeks, Armenians, and French) can be seen as mixtures of South Asian and Sardinian populations.

This may seem strange, but can be explained if we understand how f3-statistics and rolloff actually work. These methods do not require pure or unadmixed ancestral populations, but exploit allele frequency differences in the reference populations together with either (i) allele frequencies in the mixed population, in the case of f3-statistics, or (ii) admixture linkage disequilibrium in the mixed population, in the case of rolloff.

If a and b are allele frequencies in two ancestral populations A and B that mix, then:

• The frequency of a will shift towards b if A experiences gene flow from B
• The frequency of a will randomly shift if A experiences gene flow from an "outgroup" population
• The frequency of a will shift towards b if A experiences gene flow from a third population that is geographically and genetically intermediate between A and B

An application to the Europe-South Asia cline

I took the following set of populations, and calculated all 1,365 possible f3-statistics:

"FIN30"         "Lithuanians"   "Russian"       "Pathan"        "Balochi"       "North_Kannadi" "Polish_D"      "Russian_D"     "Mixed_Slav_D"  "Bulgarian_D"   "Serb_D"        "Ukrainian_D"   "Belorussian"   "Bulgarians_Y"  "Ukranians_Y"

In the following table, I report the lowest Z-scores for each target population (third column). So, for example, Polish_D can be seen as a mixture of Lithuanians and Balochi. Only negative scores are indicative of admixture. I highlight in bold the significant negative scores (Z less than -3)


Lithuanians North_Kannadi FIN30 0.001606 0.000259 6.193 280043
Ukrainian_D Belorussian Lithuanians 0.00078 0.000299 2.614 268493
Lithuanians North_Kannadi Russian -0.002738 0.000248 -11.045 279965
North_Kannadi Polish_D Pathan -0.006959 0.000229 -30.344 280220
North_Kannadi Bulgarians_Y Balochi -0.003636 0.000246 -14.781 281604
Pathan Ukrainian_D North_Kannadi 0.033802 0.000623 54.237 271858
Lithuanians Balochi Polish_D -0.001171 0.000178 -6.581 279519
Lithuanians Pathan Russian_D -0.001829 0.000166 -11.026 280658
Lithuanians Pathan Mixed_Slav_D -0.001715 2e-04 -8.594 277635
Lithuanians Balochi Bulgarian_D -0.001247 0.000313 -3.979 272342
Lithuanians Balochi Serb_D -0.00091 0.000377 -2.416 270807
Lithuanians Balochi Ukrainian_D -0.002222 0.000358 -6.211 270399
Lithuanians Balochi Belorussian -0.000897 0.00027 -3.325 273076
Balochi Polish_D Bulgarians_Y -0.001198 0.000185 -6.481 279632
Lithuanians Balochi Ukranians_Y -0.001727 0.000187 -9.236 278677

It is clear, that what I have described holds here: European populations appear like mixtures of Lithuanians and South Asians; conversely, South Asian populations appear like mixtures of Europeans and North Kannadi.

This does not mean that the populations that appear unadmixed (FIN30, Lithuanians, North_Kannadi, and Serbs) are in fact so, for at least two reasons:

1. The f3 statistic confirms, but does not reject the presence of admixture; in particular, it fails to find real admixture in highly drifted populations
2. The f3 statistics exploits allele frequency correlations between populations: but the North Kannadi and Lithuanians/Finns occupy opposite ends of the studied cline, so their lack of signal of admixture may be due to the non-existence of populations that are even more unadmixed than themselves.

In the case of South Indians, we are completely sure that this is the case. Reich et al. (2009) managed to show this not because there are any unadmixed Ancestral South Indians (ASI) left, but because they exploited the existence of the Onge, an isolated group from the Andaman Islands that was a sister group to the ASI. So, we can be fairly sure that southern Indians themselves have West Eurasian-like admixture, even the ones that are at the end of the West Eurasia-South India cline on its southern end.

The problem is: there is no isolated group of unadmixed Europeans left in existence that might serve a similar proxy function as the Onge did for South Asians.

Enter Pickrell et al. (2012) to the rescue. In that paper, the authors studied admixture in the Khoe-San of South Africa. Now, many of the Khoe-San sub-groups appeared to be admixed, but the "Juj'hoan North" population appeared to be at the "end of the cline": it's impossible to detect admixture in them using alelle frequency differences, because, quite simply, there are no populations that are less unadmixed than them: they're as pure descendants of "Ancestral Bushman" as exist on the earth today.

But, the clever thing is, that we don't have to detect admixture only using allele frequency differences, but also using admixture LD, i.e., by exploiting the correlation between linkage disequilibrium (the co-inheritance of physically separated markers on a chromosome) and allele frequency differences between populations. Pickrell el al. were able to do this not by conjuring up a more unadmixed population than the "Juj'hoan North" one available to them, but by splitting up that population, and using one half to find allele frequency differences, and the other half to detect admixture LD.

Admixture LD signal in Lithuanians

Using the aforementioned idea, I set out to see whether Lithuanians, who occupy the European end of the Europe-South Asia cline present such a signal of admixture LD. I used the Lithuanian_D sample from the Dodecad Project and the Balochi HGDP sample as reference populations (to calculate allele frequency differences), and the Behar et al. (2010) Lithuanians for admixture LD. There were only ~300k SNPs usuable in this set, but sufficient to detect the signal of admixture LD:

The admixture time estimate is 200.350 +/- 61.608 generations, or 5,810 +/- 1790 years. This is not very precise, probably because of the small number of SNPs and individuals used, but it certainly points to the Neolithic-to-Bronze Age for the occurrence of this admixture. The date is certainly reminiscent of the expansion of the Kurgan culture out of eastern Europe, or, the later Corded Ware culture of northern Europe.

So, it may well appear that at least some of the people participating in these groups of cultures, were indeed influenced by the Indo-Europeans as they expanded from their West Asian homeland. These intruders mixed with eastern Europeans who vacillated during the late Neolithic between a northern Europeoid pole akin to Mesolithic hunter gatherers from Gotland and Iberia, and a widely dispersed Sardinian-like population that is in evidence at least in the Sweden-Italian Alps-Bulgaria triangle. The gradual appearance of non-mtDNA U related lineages in Siberia and Ukraine is most likely related to this phenomenon.

It would seem that the Proto-Indo-Europeans mixed with different substrata in the four directions of their expansion: Sardinian-like people in southern Europe, Lithuanian-like people in northern Europe, South Indian-like people in South Asia, and East Eurasians in Siberia and east central Asia. Extant groups are descendants of divergent Neolithic population groups, brought closer together (genetically) because of variable admixture with the PIE population and its early offshoots.

Conclusion

There are mutual signals of admixture across a Europe-South Asia cline: Europeans appear to be mixed with South Asians, and South Asians appear to be mixed with Europeans. The simplest explanation for this pattern involves expansion of a third, geographically and genetically intermediate population that affected both Europe and South Asia. We can use the signal of admixture LD to prove that this expansion affected some of the most unadmixed populations in Europe (e.g., Lithuanians), just as it did the most unadmixed populations of India (e.g., Dravidians).

It will be interesting to use these techniques to study signals of admixture in other "end of the line" populations such as Sardinians, South Indians, etc.

UPDATE I (rolloff analysis of Poles):

I have carried out rolloff analysis of my 25-strong Polish_D sample using Lithuanians and Pathans as references:

The signal is fairly distinct, and corresponds to 149.296 +/- 38.783 generations or 4330 +/- 1120 years. I am guessing that either the different reference population (Pathans vs. Balochi), or, more likely the increased number of target individuals (25 vs. 10) have contributed to the narrowing down of the uncertainty. It will be interesting to explore this signal further with more population pairs.

UPDATE II (rolloff analysis of Finns):

I have also used the 1000 Genomes Finnish sample (FIN) in a similar manner as Lithuanians, using 15 individuals to estimate allele frequency differences, and 15 ones for admixture LD, and using the Pathans as a South Asian reference population. There is a clear signal of admixture:

This dates to 104.967 +/- 14.797 generations, or 3,040 +/- 430 years. Finland came under the influence of both Europeans (and likely Indo-Europeans) during the Bronze Age period (a mixture of Battle Axe with local Comb Ceramic seems to have occurred), as well as likely non-European (and likely Uralic) intrusions during the same time frame, as part of the Seima-Turbino phenomenon. It will be interesting to repeat this analysis with an East Eurasian reference population to isolate potential signals of admixture dating to either the Comb Ceramic or Seima-Turbino episodes of migration.

(Note; added Oct 14): I carried out rolloff analysis using Nganassans as suggested in the above paragraph here.

UPDATE III (rolloff analysis of Ukrainians):

I have used the Yunusbayev et al. sample of Ukrainians, and estimated its admixture time using Lithuanians and Balochi as reference populations:

The admixture time estimate is 191.078 +/- 35.079 generations, or 5,540 +/- 1,020 years. It seems very similar to that in Lithuanians, with a smaller standard error, perhaps on account of either the larger number of SNPs or larger number of individuals.

It is tempting to associate this admixture signal with the Maikop culture which appeared at around this time. Assuming that North_European/West_Asian (or Lithuanian-like and Balochi-like) gene pools existed north and south of the Pontic-Caspian-Caucasus set of geographical barriers, then the Maikop culture which shows links to both the early Transcaucasian culture and those of Eastern Europe would have been an ideal candidate region for the admixture picked up by rolloff to have taken place. There are, of course, other possibilities.

UPDATE IV (rolloff analysis of Lithuanians with Pathan reference):

I repeated the first analysis of this post, but this time, I used Pathans, rather than Balochi as a reference population:

The admixture time estimate of 217.501 +/- 51.170 generations, or 6,310 +/- 1,480 years appears to be similar with the original estimate of 5,810 +/- 1790 years, so it does not appear that the use of Balochi or Pathan as a reference population much affects this result.

East to West across Eurasia

A couple more interesting abstracts from the DNA in Forenscics 2012.


Genetic journey of the N1c haplogroup
Pamjav H, Nemeth E, Feher T, Volgyi A

Binary and Y-STR polymorphisms associated with the NRY region of the human Y chromosome preserve the paternal genetic legacy that has persisted to the present, permitting inference of human evolution, population migration and demographic history.The NRY region of the Y chromosome acts much like mtDNA to reveal the structure among human populations and possiblyto infer the order and timing of their descents. In the present study, we have investigated the originof haplogroup N1c-Tat phylogeographic structure and the genetic relationship of Eurasianpopulations by examining STR variation in a large number of individuals. We have identified 54samples as the haplogroup N1c-Tat from 5 population groups (N=632). To place the results into awider geographic context, we included 209 samples from published sources and 296 samples from the FTDNA public database into the phylogenetic analysis. According to previous studieshaplogroup N-M231 is of East Asian ancestry. Our results suggest that N1c-Tat mutation probably originated in South Siberia 8-9 thousand years ago and had spread through the Urals into the European part of present-day Russia. Its distribution is not fully correlated with the spread of Uralic languages. Turkic-speaking ethnic groups in South Siberia have high N1c-Tat presence and STR variance, while the N1c-L550 subgroup largely occurs among non-Uralic-speaking Europeanpopulations. Only the European N1c-Tat (xL550) subgroup can be linked to the spread of Finno-Ugric languages from the Kama-Urals area ~6,000 years ago. The subgroup N1c-L550 cannot be considered Finno-Ugric origin and its carriers might have been assimilated by Indo-European groups, resulting in their spread across Europe in historical times with Vikings and Balto-Slavs. Based on the present study Buryats were dominated by a young, about 800-years old N1c-Tat cluster, which suggest that this ethnic group could be a relatively recent admixture of Mongolian conquerors with a Paleo-Siberian population groups.

Of course these ages should be taken with a grain of salt because it is unclear how they were derived (i.e., whether the "evolutionary mutation rate" was used). Hopefully, someone will treat the  subject of N1c ages with Y-SNPs that do not have the problem of saturation that affects microsatellites. This is an interesting test case, because a ~3-fold change in ages will have important consequences for our understanding of the spread of Finno-Ugric languages into Europe: an earlier date would associate them with the Comb Ceramic, while a later, Bronze Age date would associate them with the Seima-Turbino phenomenon.

Huns in Bavaria? Genetic analyses of an artificially deformed skull from an early medieval cemetery in Burgweinting (Regensburg, Germany)

Schleuder R, Wilde S, Burger J, Grupe G, Forster P, Harbeck M

The morphological examination of an early medieval burial site in Burgweinting, which is dated to the end of the 5th century, revealed one female with an artificially, circularly deformed skull, a practice that is thought to be associated with the arrival of Nomads of the Eurasian steppe, particularly the Huns.    

Individuals with such artificial cranial deformations also can be found in other Late Roman and Early Medieval cemeteries in Europe mostly in the Carpathian basin but only as few isolated cases in Western Europe, where mostly women show such deformations.  

Regarding the artificial cranial deformations it is unclear whether a foreign custom was taken over by Germanic tribes or whether the individuals were members or descendants of Eurasian nomads.  

With the help of the find of Burgweinting, we exemplarily investigated this question.To identify the possible foreign origin of this female with alleged “Asian” skull deformation we sequenced the HVRI and HVRII region of the mitochondrial DNA.  

Our results show that the ancestry of a woman with artificially deformed skull can be linked to an at least partly Asian origin. So this indicates that at least some of the few individuals with skull deformation had not adopted the costume but can be seen as former members or descendants of the hunnish tribal community.   

It will be worthwhile if geneticists can co-operate with physical anthropologists and/or archaeologists more broadly in cases where morphology, or burial customs indicate that a possibly heterogeneous population exists at that site. The above is a good example of that synergy in action.

East Eurasian-like ancestry in Northern Europe (part 3)

(This is the third part of the series. See part 1 and part 2.)

In the first two parts of the series, I showed that northern European populations show hints of East Eurasian ancestry when compared against Sardinians. I used Dai, Han, and Karitiana as reference populations for East Eurasia. In the current post, I extend this analysis by using HGDP Papuans and the Onge (Reich et al. 2009) from the Andaman Islands.

The f4 statistics using Karitiana, Papuan, and Onge populations can be found in this spreadsheet.

Below, you can see that they are all near perfectly correlated with each other.

The visual appraisal is confirmed when we calculate the correlation coefficients:

The fact that all three populations track the same signal is strong evidence for the direction of gene flow: from Asia into northern Europe. If the signal was present in only one of the three populations, then it could conceivably be an artefact of gene flow in the opposite direction (from northern Europeans to the affected population). But, the fact that all three populations show the same pattern would require northern European-like admixture in the Andaman Islands, Papuan New Guinea and South America, which does not appear very parsimonious.

While the signals from the three populations are correlated, their intensity varies. The Z-scores provide a measure of this intensity. The mean Z-scores using a Karitiana, Papuan, and Onge reference across all populations are respectively -17.7, -8.0, and -6.0.

While I did not include the Han reference of part 1 in this analysis, inspection of the f4 statistics (which can be obtained at the bottom of that part), suggests that the Z-scores become more significant when using an Onge, Papuan, Han, and Karitiana reference in that order. For example, for the Finnish_D population, they are: -10.037, -13.2949, -23.9305, and -27.764 respectively.

It thus appears that the element contributing East Eurasian-like ancestry in northern Europeans was derived from the northern spectrum of East Eurasians; the Karitiana may live in South America today, but they trace their ancestors to northern Eurasia, having entered the Americas c. 15ka.

In my opinion, the signal has been formed by a superposition of a few factors:

1. The fact that Y-haplogroup R, the main lineage in modern northern Europeans has a common origin (Y-haplogroup P) with haplogroup Q, the main lineage in modern Amerindians, and many Siberians. We can hypothesize that the population that brought R into Europe was intermediate genetically across the Caucasoid-Mongoloid spectrum. In West Eurasia, this population admixed with the Palaeo-West Eurasians (Y-haplogroups IJ, G, and possibly LT), and contributed their DNA primarily to the northern Europeoids.
2. Other population movements of more regional impact, such as Y-haplogroup N, which affected mainly Uralic, Baltic, and East Slavic populations, as well as elements from the mixed West/East Eurasian mtDNA contact zone that ancient DNA analysis has revealed in Eastern Europe and Siberia.

The raw dumps of fourpop output for Papuan and Onge reference can be found here.

East Eurasian-like admixture in Northern Europe (part 2)

This is a continuation of my earlier post. Please refer to it for the methodology. A new part 3 can be found here.

I have repeated the experiment with a much larger set of populations:

English_D, British_D, Ukranians_Y,  Karitiana, Spaniards, Sardinian,  Serb_D, Mordovians_Y, Irish_D,  French, Finnish_D, Chuvashs_16,  Romanian_D, N_Italian_D, French_Basque,  Austrian_D, Russian_D, Hungarians_19,  Kent_1KG, German_D, Belorussian,  Tuscan, Lithuanian_D, Orkney_1KG,  Dutch_D, TSI30, Ukrainian_D,  Bulgarians_Y, Bulgarian_D, Russian,  Swedish_D, Pais_Vasco_1KG, French_D,  Castilla_Y_Leon_1KG, Lithuanians, San,  Polish_D, Romanians_14, Orcadian,  Cornwall_1KG, Valencia_1KG, North_Italian,  FIN30, Norwegian_D, CEU30

I used Sardinians as the Caucasoid reference population, Karitiana for Mongoloids, and San for Africans. The latter two were chosen because they live at maximally opposite corners of the Earth (South America vs. South Africa).

A first plot of the f4 statistics used for f4 regression ancestry estimation is seen below:

Clearly, some evidence of a cline is present, but several populations appear to deviate from it. In order to get the cleanest possible cline, I carried out the following greedy procedure: I calculate the correlation coefficient of this set, and iteratively remove one population that leads to the maximum improvement of the correlation, until no further improvement takes place. The following populations were removed with this procedure:

Spaniards, Serb_D, Romanian_D, N_Italian_D, Tuscan, TSI30, Bulgarians_Y, Bulgarian_D, Castilla_Y_Leon_1KG, Romanians_14, Valencia_1KG

This seems to make sense, as all these are southern European populations. Note that their removal does not mean that they do not partake in the same phenomenon as northern Europeans: they also exhibit Karitiana-shift relative to the Sardinians, but there are probably other confounding factors that make them fall "off-cline". Including them would diminish the clarity of the cline for Northern European populations. The regression of the remaining populations can be seen on the right:

f4 regression ancestry estimation results are shown on the left. These appear to be much higher than was the case with the Han and Dai in the previous experiment.

I can't say that I've made any obvious mistakes, but these admixture proportions are substantial, and call for an explanation. Whatever their true levels, I am fairly confident on at least a few points:

First, it is evident that northern Europeans have higher levels of this element than southern Europeans; the latter are not altogether deficient in it, but they fall "off-cline", making estimation of their admixture proportions more difficult.

Second, within northern Europe, there is a fairly clear east-west cline of diminishing Amerasian-like admixture. The minimum occurs in Sardinians and secondarily in Southwest Europe. Romance, Celtic, and Germanic populations all have less of it than Balto-Slavic and Uralic ones. And, some populations of northeastern Europe seem to have a noticeable excess of it.

The groups with the most Amerasian-like admixture possess Y-haplogroup N, a clear trace of eastern ancestry that is not shared by most Europeans. The arrival of this haplogroup, either with Comb Ceramic of the Baltic Neolithic or later with Seima Turbino Bronze Age expansions is probably responsible for the local excess in Northeastern Europe. The Chuvash are, of course, a Turkic population but of Finno-Ugrian genetic origin.

But, the presence of this element even in Western Europe cannot be explained on the basis of typically Mongoloid elements which are almost completely lacking there. If Mesolithic Europeans were themselves Asian-shifted, then this would account for the presence of the element, but not necessarily for its clinal manifestation. The double (north-south and east-west) cline indicates every sign of an intrusive element. So, for the time being, I will propose that this is associated with late (e.g., Copper and Bronze Age) phenomena, such as the northern stream of the Bronze Age Indo-European invasion of Europe.

This may be due to the

• (i) northern Indo-European groups picking up some native east European or Siberian elements as they made their way into Europe, 
• or (ii), more likely, in my opinion, that the Y-haplogroup R1 group of people, whose closest relatives are in Central/South Asia (R2) , and whose more distant relatives (Q) are in Siberia and the Americas, were from the beginning an "intermediate population" between West and East Eurasia. The R1 group of people in its R1b and R1a varieties first appear in Europe during the Copper Age, and they are lacking in early Neolithic sites.

Eight years ago, and in a totally different context, I wrote:

Similarly, 9 out of 10 Basques are descended from a man who has also fathered 9 out of 10 Kets from Siberia and 9 out of 10 Maya Indians from America. That man, founder of haplogroup P thus has descendants who belong to two of the major human races (or three, if Amerindians are considered as separate from Asian Mongoloids)   

... 

In conclusion, human continental populations form groups of genetic and phenotypic similarity, and these groups can be considered races in the phenetic sense. However, these groups are not monophyletic, hence in the cladistic sense they should not be considered as valid taxa. Since the principle of common descent is generally applied in modern systematics (or at least it should!), I think it's best not to recognize human subspecies. 

If these data pan out, it may be revealed that the European branch of the Caucasoids is actually a product of admixture too, with at least two of its constituent elements being the "Palaeo-West Eurasians" (Y-haplogroups G, IJ, possibly LT) and the "Neo-NW Eurasians" (Y-haplogroups N1 and R1), with the "Neo-Afrasians" (Y-haplogroup E1b1b) forming a third element.

(A raw dump of fourpop output can be found here).

Visualizing admixture differences with ACD tool

Vaêdhya has created a new ACD tool that allows one to visualize differences between sets of populations in terms of admixture components. He also posts two examples of the application of his tool on data generated by myself in the Dodecad Project, as well as by the Harappa Project.

 I have speculated about the origins of Indo-Iranians before, noting that the evidence links even the Kurds with a "South Asian" component; in subsequent higher-resolution analysis, such as the K12b, it appeared that this component was related to the Gedrosia component. In any case, the evidence is clear about the links of different Iranian and Indo-Aryan groups, so it is nice that this can be made evident with the ACD tool and data from the Harappa Project. Notice the excess of the Baloch (~Gedrosia) component in Kurds and Iranians in contradistinction to the Indo-European Armenians and Semitic Assyrians. It is fairly clear to me that the Iranian ancestral homeland is to be sought to the east, with the Bactria-Margiana Archaeological Complex (BMAC) being a good candidate for its location.

In a second plot, Vaêdhya uses Dodecad data to contrast patterns of differences in Northeastern Europe. Here, too, the patterns are clear, with Finns, and secondarily Russians showing an excess of Siberian ancestry relative to Poles. This is, no doubt, due to the Finnic element, which links Finns, and the Uralic substratum in Russians with Siberia. A second contrast is between Finns and Russians/Poles. The latter have more of the Caucasus component, a probable legacy of the Bronze Age Indo-European invasion of Europe. A final contrast is the higher Atlantic_Med element in Poles, which suggests an excess of early Neolithic farmer ancestry, or, admixture with West European populations such as Germans and others who possess more of this component than Slavs.

AAPA 2012 abstracts (part 1)

Here are some interesting abstracts from the 81st Annual Meeting of the American Association of Physical Anthropologists.


Maternal marks of admixture in Cape Coloreds of South Africa.
KRISTINE G. BEATY1, DELISA L. PHILLIPS1, MACIEJ HENNEBERG2 and MICHAEL H. CRAWFORD1.

Previous studies of genetic diversity have suggested that the Cape Coloureds of South Africa are a highly admixed population with genetic roots from indigenous African groups including Khoisans, and the later arrival of Bantu speaking Xhosa farmers. Further genetic contributions came during European colonization of South Africa, which added to the inclusion of largely male European markers to the gene pool. Slaves from Indonesia, Malaysia, Madagascar and India are also thought to have contributed to the genetic makeup of this ethnic group. This study examines the maternal contribution of each of these groups to the genetic diversity of the Cape Coloreds through sequencing of the hypervariable region I of the mitochondrial DNA and through restriction fragment length polymorphism.
A total of 123 individuals were examined for this study. High frequencies of haplogroups L1 and L2 were found at 81.3 percent in this group (100 of the 123 individuals), which indicates that this group has a large African contribution to its mitochondrial makeup. Restrictions of the major European haplogroups identified nine individuals, 7.3 percent of the sample, belonged to haplogroups I and J. Five individuals (4.1 percent of the sample) belonged to the superhaplogroup M, indicating that Asian slaves did contribute to the maternal gene pool. The majority of maternal lineages in this Cape Coloured sample are African in origin, with some European influence and a small contribution from Asian maternal lineages.

Ancient DNA reveals the population origin of the Eastern Xinjiang.
SHIZHU GAO2, HONGJIE LI1, CHUNXIANG LI1 and HUI ZHOU1,3.

Connecting with the Turpan Basin, the Eurasia steppe and the Gansu Corridor, the Eastern region of Xinjiang has played a significant role in the history of human migration, cultural developments, and communications between the East and the West. The population origin, migration and integration of this region have attracted extensive interest among scientists.
In order to research the population origin and movement of the Eastern Xinjiang, genetic polymorphisms studies of the Hami population were conducted. The Hami site is located in the East of Tian-Moutain in Xinjiang, dating back to the Bronze-early Iron Age. Archaeological studies showed that the culture of the Hami site possessed features from both the East and the West. Ancient mtDNA analysis showed that A, C, D, F, G, Z and M7 of the Eastern maternal lines, and W, U2e, U4, and U5aof the Western maternal lines were identified. Tajimas’D test and mismatch distribution analysis show that the Hami population had experienced population expansion in recent time. The demographic analysis of haplogroups suggests that the populations of the Northwest China, Siberia and the Central Asia have contributed to the mtDNA gene pool of the Hami population.
Our study reveals the genetic structure of the early population in Eastern Xinjiang, and its relationships with other Eurasian populations. The results will provide valuable genetic information to further explore the population origin and migration of Xinjiang and Central Asia.

Analysis of Chuvash mtDNA points to Finno-Ugric origin.
ORION M. GRAF1, STEPHEN M. JOHNSON1, JOHN MITCHELL2, STEPHEN WILCOX3, GREGORY LIVSHITS4 and MICHAEL H. CRAWFORD1.

A sample of 92 unrelated individuals from Chuvashia, Russia was sequenced for hypervariable region-I (HVR-I) of the mtDNA molecule. These data have been verified using RFLP analysis of the control region, revealing that the majority exhibit haplogroups H (31%), U (22%), and K (11%), which occur in high frequencies in western and northern Europe, but are virtually absent in Altaic or Mongolian populations. Multidimensional scaling (MDS) was used to examine distances between the Chuvash and reference populations from the literature. Neutrality tests (Tajima’s D (-1.43365) p<0.05, Fu’s FS (-25.50518) p<0.001) and mismatch analysis, which illustrates unimodal distribution, all suggest an expanding population.
The Chuvash speak a Turkic language that is not mutually intelligible to other extant Turkish groups, and their genetics are distinct from Turkic-speaking Altaic groups. Some scholars have suggested that they are remnants of the Golden Horde, while others have advocated that they are the products of admixture between Turkic and Finno-Ugric speakers who came into contact during the 13th century. Earlier genetic research using autosomal DNA markers indicated a Finno-Ugric origin for the Chuvash. This study examines uniparental mitochondrial DNA markers to better elucidate their origins. Results from this study maintain that the Chuvash are not related to Altaic or Mongolian populations along their maternal line, thus supporting the “Elite” hypothesis that their language was imposed by a conquering group —leaving Chuvash mtDNA largely of Eurasian origin. Their maternal markers appear to most closely resemble Finno-Ugric speakers rather than Turkic speakers.

An ancient DNA perspective on the Iron Age “princely burials” from Baden-Wurttemberg, Germany.
ESTHER J. LEE1, CHRISTOPH STEFFEN1, MELANIE HARDER1, BEN KRAUSE-KYORA1, NICOLE VON WURMB-SCHWARK2 and ALMUT NEBEL3.

During the Iron Age in Europe, fundamental social principles such as age, gender, status, and kinship were thought to have played an important role in the social structure of Late Hallstatt and Early Latene societies. In order to address the question of kinship relations represented in the Iron Age “princely burials” that are characterized by their rich material culture, we carried out genetic analysis of individuals associated with the Late Hallstatt culture from Baden-Wurttemberg, Germany. Bone specimens of thirty-eight skeletal remains were collected from five sites including Asperg Grafenbuhl, Muhlacker Heidenwaldle, Hirschlanden, Ludwigsburg, and Schodeingen. Specimens were subjected to DNA extraction and amplification under strict criteria for ancient DNA analysis. We successfully obtained mitochondrial DNA (mtDNA) control region sequences from seventeen individuals that showed different haplotypes, which were assigned to nine haplogroups including haplogroups H, I, K, U5, U7, W, and X2b. Despite the lack of information from nuclear DNA to infer familial relations, information from the mtDNA suggests an intriguing genetic composition of the Late Hallstatt burials. In particular, twelve distinct haplotypes from Asperg Grafenbuhl suggest a heterogeneous composition of maternal lineages represented in the “princely burials”. The results from this study provide clues to the social structure reflected in the burial patterns of the Late Hallstatt culture and implications on the genetic landscape during the Iron Age in Europe.

Genetic snapshot from ancient nomads of Xinjiang.
HONGJIE LI1, SHIZHU GAO2, CHUNXIANG LI1, YE ZHANG1, WEN ZENG3, DONG WEI3 and HUI ZHOU1,3.

Nomads of the Eurasian steppes are known to have played an important role in the transfer commodities and culture among East Asia, Central Asia, and Europe. However, the organization of nomadic societies and initial population genetic composition of nomads were still poorly understood because of few archaeological materials and written history.
In this study, the genetic snapshot of nomads was emerged by examining mitochondrial DNA and Y-chromosome DNA of 30 human remains from Heigouliang (HGL) site in the eastern of Xinjiang, which dated 2000 years ago and associated to the nomadic culture by archaeological studies. Mitochondrial DNA analysis showed that the HGL population included both East Eurasian haplogroups (A, C, D, G, F and Z) and West Eurasian haplogroups (H, K, J, M5 and H). The component of Eastern haplogroups is dominant. The distribution frequency and Fst values of Eastern haplogroups indicated the HGL population presented close genetic affinity to the nearby region modern populations of Gansu and Qinghai, while those of western haplogroups showed similar with Mongolia and Siberia populations. The results implied various maternal lineages were introduced into the HGL population. Regarding the Y chromosomal DNA analysis, nearly all samples belonged to haplogroup Q which is thought to be the mark of the Northern Asian nomads. We identified paternal kinship among three individuals at the same tomb by Y-STR marker.
Combined with archaeological and anthropological investigations, we inferred that the gene flow from the neighboring regions was possibly associated with the expansion of Xiongnu Empire.

Vikings, merchants and pirates at the top of the world: Y-chromosomal signatures of recent and ancient migrations in the Faroe Islands.
ALLISON E. MANN1, EYDFINN MAGNUSSEN2 and CHRISTOPHER R. TILLQUIST1.

The Faroe Islands are a small archipelago in the North Atlantic Ocean. With a current population of approximately 48,000 individuals and evidence of high levels of genetic drift, the Faroese are thought to have remained highly homogeneous since the islands were settled by Vikings around 900CE. Despite their geographic isolation, however, there is historical evidence that the Faroese experienced sporadic contact with other populations since the time of founding. Contact with Barbary pirates in the seventeenth century is documented in the Faroes; there is also the possibility of modern migrations to work in the highly productive fishery. This study set out to distinguish the signal of the original founders from later migrants. Eleven Y-chromosomal STR markers were scored for 139 Faroese males from three geographically dispersed islands. Haplotypes were analyzed using Athey's method to infer haplogroup. Median-joining networks within haplogroups were constructed to determine the phylogenetic relationships within the Faroese and between likely parental populations—Danish, Irish, and Norwegians. Dispersal patterns of individuals around Faroese haplogroups suggest different times of haplotype introduction to the islands. The most common haplogroup, R1a, consists of a large node with a tight network of neighbor haplotypes, such that 68% of individuals are one or two mutational steps away. This pattern may represent the early founder event of R1a in the Faroes. Other distributions, especially of non-Scandinavian haplotypes, document more recent introductions to the islands. The overall pattern is one of a strong founder effect followed by minor instances of later migrations.

Date estimates for major mitochondrial haplogroups in Yemen.
DEVEN N. VYAS1, VIKTOR ČERNÝ2, ALI AL-MEERI3 and CONNIE J. MULLIGAN1.

Yemen occupies a key location as the first stop for anatomically modern humans on a theoretical southern migration route out of Africa. If modern humans did pass through Yemen during the first migrations out of Africa and if they left modern-day descendants, we would expect to see deep divergences in the Yemeni mitochondrial gene tree. Alternatively, if modern humans passed through Yemen but did not leave modern-day descendants or if Yemen was not on the path of these ancient migrations, we would expect more recent dates to be associated with Yemeni mitochondrial haplogroups.
Using 44 previously sequenced mitochondrial genomes as well as 24 newly sequenced mitochondrial genomes from samples collected throughout Yemen, several methods were used to estimate divergence dates of major Yemeni haplogroups including L2, M, R0a and HV. Specifically, phylogenetic trees were generated using MrBayes and maximum likelihood methods. Bayesian and ρ statistic based methods were used to estimate dates of Yemeni haplogroups and these dates were compared with each other, previously published dates for these haplogroups, approximate dates of climatic change that might be expected to correlate with population expansions, and estimates based on archaeological and paleontological evidence for the first migrations out of Africa. These comparisons are intended to cover the range of possible haplogroup divergence dates with respect to the history of early modern humans in southern Arabia.

ICHG 2011 abstracts are online

You can search here. I will update this entry with any interesting abstracts I've identified and my early comments on them, if any.

UPDATE:

I will add abstracts to this entry one by one, with the newer ones added to the top of the post.

Demographic histories of African hunting-gathering populations inferred from genome-wide SNP variation.

S. Soi et al.

Africa is the geographic origin of anatomically modern humans; it is also home to a third of all modern languages, including four major language families: Niger-Kordofanian, Afro-Asiatic, Nilo-Saharan, and Khoesan. Despite the importance of African populations for studying human origins and the complexity of demographic and linguistic relationships among African populations, genome-wide analyses of sub-Saharan variation have been sparse. To address this deficiency, we used Illumina 1M-Duo SNP arrays to genotype samples (N=697) from 44 sub-Saharan populations, which we supplemented with published data sets. Principal components analysis (PCA) and linear regression were used to assess the statistical effect of geography and linguistics on the partitioning of genetic variation. As ascertainment bias can distort the allele frequency spectrum, we examined patterns of linkage disequilibrium (LD), haplotype sharing, and identity by descent (IBD) to understand the demographic relationship among populations. To affirm that LD-based analyses were robust to ascertainment bias, we assessed the rank correlation of estimates of effective population size from the rate of LD decay within populations and estimates of population size based on the variance of microsatellite repeat lengths from previously published data (Spearman’s ρ=0.782, p=0.011). Additionally, the presence of long IBD tracts between individuals indicates recent common ancestry. Thus, we used the GERMLINE algorithm to infer IBD tracts between individuals in hunting-gathering populations and neighboring agriculturalist and pastoralist populations. To infer the time to most recent common ancestor and test demographic models while accounting for the confounding effects of migration and changes in population sizes, we employed Approximate Bayesian Computation (ABC) using summaries of haplotype frequency, diversity and sharing within and between populations. We report, for the first time, evidence for recent common ancestry of Ethiopian hunter-gatherers and the Kenyan Sanye/Dahalo, who speak a language with remnant clicks, with click-speaking eastern African Khoesan populations. This work supports archaeological and linguistic studies that indicate that the distribution of Khoesan speaking populations may have extended as far north as Ethiopia.

Not very surprising to me, as I detected a contribution of the "Palaeo_African" component (which has one of its peaks in San) in East Africans.

Comparative study of the Y chromosome diversity in some ethnic groups living in Iran and populations of the Middle East.

L. Andonian et al.

Background: The main goal of this study is to conduct a population genetic study of: a) Armenians living in Iran, in the context of general Armenian population; and b) Iranian Azeris, one of the biggest ethno-linguistic communities, in comparison with other Turkic-speaking populations of the Middle East (from eastern Turkey, Azerbaijan Republic and Turkmenistan). Methods: Buccal cells of 89 Armenian males from central Iran, the descendants of Armenians forcibly moved to Iran in the beginning of 17th century CE, and 105 Turkic-speaking Azeri males from north-west Iran (Tabriz) were collected by mouth swabs. The samples were screened for 12 Single Nucleotide (SNP) and 6 microsatellite markers on the non-recombining portion of the Y chromosome. The results of genetic typing were statistically analyzed using Arlequin software. Results: Iranian Armenians display a moderate level of genetic variation and are genetically closer to Western Armenians which is in agreement with historical records. Iranian Azeris demonstrate much weaker genetic resemblance with Turkmens (as putative source population) than with their geographic neighbors. Conclusion: Political, religious and geographic isolation had moderate influence on the genetic structure of modern Iranian Armenians during the last four centuries, which is expressed in lower diversity of their patrilineal genetic legacy. The imposition of Turkic language to the populations of north-west Iran was realized predominantly by the process of elite dominance,i.e. by the limited number of invaders who left weak traces in the patrilineal genetic history of Iranian Azeris.

A direct characterization of human mutation.

J. X. Sun et al.

Mutation and recombination provide the raw material of evolution. This study reports the largest study of new mutations to date: 2,058 germline mutations discovered by analyzing 85,289 Icelanders at 2,477 microsatellites. We find that the paternal-to-maternal mutation rate ratio is 3.3, and that the mutation rate in fathers doubles between the ages of 15 to 45 whereas there is no association to age in mothers. Strong length constraints apply for microsatellites, with longer alleles tending to mutate more often and decrease in length, whereas shorter alleles tending to mutate less often and increase in length. Based on these direct observations of the microsatellite mutation process, we build a model to estimate key parameters of evolution without calibration to the fossil record. The sequence substitution rate per base pair is estimated to be 1.84-2.21×10-8 per generation (95% credible interval). Human-chimpanzee speciation is estimated to be 3.92-5.91 Mya, challenging views of the Toumaï fossil as dating to >6.8 Mya and being on the hominin lineage since the final separation of humans and chimpanzees.

This microsatellite based estimate of human-chimp speciation contrasts with a recent SNP-based estimate of 7 million years.

Genetic structure of Jewish populations on the basis of genome-wide single nucleotide polymorphisms.

N. M. Kopelman

The Jewish population forms a genetically structured population, due to historical migrations and diverse histories of the various Jewish communities. Discerning the ancestry and population structure of different Jewish populations is important for understanding the complex history of the Jewish communities as well as for research on the genetic basis of disease. Using >500,000 genome-wide single-nucleotide polymorphisms, we investigated patterns of population structure in 438 samples from 30 Jewish populations in the context of additional samples from non-Jewish populations. The collection of Jewish populations studied incorporates a variety of populations not previously included in other genomic population structure studies of Jewish groups (e.g. NM Kopelman et al. 2009 BMC Genet 10:80; G Atzmon et al. 2010 AJHG 86:850-859; DM Behar et al. 2010 Nature 466:238-242; SM Bray et al. 2010 PNAS 107:16222-16227; JB Listman et al. 2010 BMC Genet 11:48). We identify fine-scale population structure within the Jewish samples, including notable distinctions separating Ashkenazi, Mizrahi, Sephardi, and North African populations. Additionally, we identify distinctions within major regional groups, including a separation among the North African populations of Libyan, Moroccan, and Tunisian Jewish samples and a separation among the Mizrahi populations of Bukharan, Georgian, Iranian, and Iraqi Jewish samples. These results supply enhanced information regarding Jewish population structure, providing a basis for further detailed analysis of the genetic history of Jewish populations.

Hopefully the wealth of this new Jewish and non-Jewish data will be made publicly available.

LD patterns in dense variation data reveal information about the history of human populations worldwide.

S. Myers et al.

A detailed understanding of population structure in genetic data is vital in many applications, including population genetic analyses and disease gene mapping, and relates directly to human history. However, there are still few methods that directly utilize information contained in the haplotypic structure of modern dense, genome-wide variation datasets. We have developed a set of new approaches, founded on a model first introduced by Li and Stephens, which fully use this powerful information, and are able to identify the underlying structure in large datasets sampling 50 or more populations. Our methods utilize both Bayesian model-based clustering and principal component analyses, and by using LD information effectively, consistently outperform existing approaches in both simulated and real data. This allows us to infer ancestry with unprecedented geographical precision, in turn enabling us to characterize the populations involved in ancient admixture events and, critically, to precisely date such events. We applied our new techniques to combined data for 30 European populations sampled by us, or publicly available, and the worldwide HGDP data. We find almost all human populations have been influenced by mixture with other groups, with the Bantu expansion, the Mongol empire and the Arab slave trade leaving particularly widespread genetic signatures, and many more local events, for example North African (Moroccan) admixture into the Spanish that we date to 834-1394AD. Dates of admixture events between European groups and groups from North Africa and the Middle East, seen in multiple Mediterranean countries, vary between 800 and 1700 years ago, while Greece, Croatia and other Balkan states show signals of admixture consistent with Slavic migration from the north, which we date to 600-1000AD. At the finest scale, we are able to study admixture patterns in data gathered by a project (POBI) examining people within the British Isles. Our approaches reveal genetic differences between individuals from different UK counties, and show that the current UK genetic landscape was formed by a series of events in the millennium following the fall of the Roman Empire.

Existing methods (see comments below) for dating historical admixture events differ from each other by a factor of two, and they all assume a 2-population model. Hopefully the research described here will be an improvement, especially if it is encapsulated in an easy-to-use piece of software. It will definitely be interesting to see the evidence for Slavic admixture in the Balkans, which probably corresponds somewhat to the "East European" component discovered in the Dodecad Project which differentiates Balkan populations from their Italian and West Asian neighbors.

Evidence for extensive ancient admixture in different human populations.

J. Wall et al.

We generated whole-genome sequences from four Biaka pygmies and analyzed them along with the publicly available genomes of 69 individuals from a range of different ethnicities. We scanned each of the 73 genomes for regions with unusual patterns of genetic variation that might have arisen due to ancient admixture with an ‘archaic’ human group. While a majority of the most extreme regions were really misalignment errors, we did find hundreds of regions that likely introgressed in from archaic human ancestors, and we estimate the amount and the timing of these ancient admixture events. These regions were found in the genomes of both sub-Saharan African and non-African populations. While Neandertals are a natural source population for ancient admixture into non-Africans, the source for ancient admixture into sub-Saharan African populations is less obvious.

Wall and Hammer have been arguing for archaic admixture for years, and there's a good chance they finally found the "smoking gun" here. I've argued before that Homo sapiens was not the only species in Africa at the time of its emergence, due to the great ecological diversity of the continent, and the long adaptation of humans there. We are unlikely to ever be able to find and sequence Paleolithic non-sapiens Homo from tropical Africa, but the signal is there to be discovered in modern African hunter-gatherers.

Validating the authenticity of the pedigrees of Chinese Emperor CAO Cao of 1,800 years ago.

H. Li

Deep pedigrees are of great value for studying the Y chromosome evolution. However, the authenticity of the pedigree information requires careful validation. Here, we validated some deep pedigrees in China with full records of 70-100 generations spanning over 1,800 years by comparing their Y chromosomes. The present clans of these pedigrees claim to be descendants of Emperor CAO Cao (155AD-220AD). Haplogroup O2-M268 is the only one that is enriched significantly in the claimed clans (P=9.323×10-5, OR=12.72), and therefore, is most likely to be that of the Emperor. Moreover, our analysis showed that the Y chromosome haplogroup of the Emperor is different from that of his claimed ancestry of the earlier CAO aristocrats (Haplogroup O3-002611). This study offers a successful showcase of the utility of genetics in studying the ancient history.

This is probably the oldest attested Y-chromosome lineage currently available. Confucius next? It will be interesting to know how many likely Cao descendants there are today, as a control on the rate with which a socially-selected lineage can grow.

Exceptions to the "One Drop Rule"? DNA evidence of African ancestry in European Americans.

J. L. Mountain et al.

Genetic studies have revealed that most African Americans trace the majority (75-80%, on average) of their ancestry to western Africa. Most of the remaining ancestry traces to Europe, and paternal lines trace to Europe more often than maternal lines. This genetic pattern is consistent with the "One Drop Rule,” a social history wherein children born with at least one ancestor of African descent were considered Black in the United States. The question of how many European Americans have DNA evidence of African ancestry has been studied far less. We examined genetic ancestry for over 77,000 customers of 23andMe who had consented to participate in research. Most live in the United States. A subset of about 60,000 shows genetic evidence of fewer than one in 16 great-great-grandparents tracing ancestry to a continental region other than Europe. They are likely to consider themselves to be entirely of European descent. We conducted two analyses to understand what fraction of this group has genetic evidence of some ancestry tracing recently to Africa. We first identified individuals whose autosomal DNA indicates that they are predominantly of European ancestry, but who carry either a mitochondrial (mt) DNA or Y chromosome haplogroup that is highly likely to have originated in sub-Saharan Africa. Of the 60,000 individuals with 95% or greater European ancestry, close to 1% carry an mtDNA haplogroup indicating African ancestry. Of approximately 33,000 males, about one in 300 trace their paternal line to Africa. We then identified the subset of these European Americans who have estimates of between 0.5% and 5.0% of ancestry tracing to Africa. This subset constitutes about 2% of this set of individuals likely to be aware only of their European ancestry. The majority (75%) of that group has a very small estimated fraction of African ancestry (about 0.5%), likely to reflect African ancestry over seven generations (about 200 years) ago. We estimate that, overall, at least 2-3% of individuals with predominantly European ancestry have genetic patterns suggesting relatively deep ancestry tracing to Africa. This fraction is far lower than the genetic estimates of European ancestry of African Americans, consistent with the social history of the United States, but reveals that a small percentage of “mixed race” individuals were integrating into the European American community (passing for White) over 200 years ago, during the era of slavery in the United States.

Hopefully this was not done with 23andMe's "Ancestry Painting" that grossly overestimates European ancestry with even East Africans and South Asians often getting >90% "European". The search for non-white ancestry seems to be a favorite pastime of many people who test at 23andMe, so this could potentially bias the results; on the other hand, I've encountered many, many more people who are seeking that illusive Amerindian ancestor of family lore, so, perhaps this is not as big of a problem for the detection of African ancestry.

Estimating a date of mixture of ancestral South Asian populations.

P. Moorjani

Linguistic and genetic studies have shown that most Indian groups have ancestry from two genetically divergent populations, Ancestral North Indians (ANI) and Ancestral South Indians (ASI). However, the date of mixture still remains unknown. We analyze genome-wide data from about 60 South Asian groups using a newly developed method that utilizes information related to admixture linkage disequilibrium to estimate mixture dates. Our analyses suggest that major ANI-ASI mixture occurred in the ancestors of both northern and southern Indians 1,200-3,500 years ago, overlapping the time when Indo-European languages first began to be spoken in the subcontinent. These results suggest that this formative period of Indian history was accompanied by mixtures between two highly diverged populations, although our results do not rule other, older ANI-ASI admixture events. A cultural shift subsequently led to widespread endogamy, which decreased the rate of additional population mixtures.

I have previously highlighted that ROLLOFF, the method used by these authors produces age estimates that are about half the age of HAPMIX and StepPCO. As of this writing, ROLLOFF does not seem to be available for independent evaluation, so it is not entirely clear to me whether it, or the older methods, are right. It would be great if this issue is dealt with in the publication arising from this research.

Another issue that must be dealt with is the spurious inference that Ancestral North Indians are more closely related to Europeans than to West Asians in the previous publication on the ANI/ASI division, an inference that was an artifact of unequal sample sizes between Adygei and CEU.

Synthesis of autosomal and gender-specific genetic structures of the Uralic-speaking populations.

K. Tambets et al.

The variation of uniparentally inherited genetic markers - mitochondrial DNA (mtDNA) and non-recombining part of Y chromosome (NRY) - has suggested somewhat different demographic scenarios for the spread of maternal and paternal lineages of North Eurasians, in particular those speaking Uralic languages. The west-east-directed geographical component has evidently been the most important factor that has influenced the proportion of western and eastern Eurasian mtDNA types among Uralic-speakers. The palette of maternal lineages of Uralic-speakers resemble that of geographically close to them European or Western Siberian Indo-European and Altaic-speaking neighbours. However, the most frequent in North Eurasia NRY type N1c, that is a common patrilineal link between almost all Uralic-speakers of eastern and western side of the Ural Mountains, is rare among Indo-European-speakers, with a notable exception of Latvians, Lithuanians and North Russians. In this study the information of genetic variation of uniparentally inherited markers in Uralic-speaking populations from 13 Finno-Ugric and 3 Samoyedic speakers is combined with the results of their genome-wide analysis of 650 000 SNPs (Illumina Inc.) to assign their place in a landscape of autosomal variation of North Eurasian populations and globally. The genome-wide analysis of the genetic profiles of studied populations showed that the proportion between western and eastern ancestry components of Uralic-speakers is concordant with their mtDNA data and is determined mostly by geographical factors. Interestingly, among the Saami - the population which is often considered as a genetic outlier in Europe - the dominant western component is accompanied by about one third of the eastern component, making the Saami genetically more similar to Volga-Finnic populations than to their closest Fennoscandian-East Baltic neighbors. The high frequency of pan-northern-Eurasian paternal lineage N1c among Saami cannot explain this phenomenon alone - genetic ancestry profiles of autosomes of other Finnic- and Baltic-speaking populations, who share the high N1c with the Saami, do not show a considerable eastern Asian contribution to their genetic makeup.

This study seems to include more Northern Eurasian references, but we will have to wait and see how its components are defined. Notice the slight discrepancy between its eastern Saami estimate (1/3) and that of the following study (22%), which is probably an artefact of the different range of samples used.

Population genetics of Finland revisited - looking Eastwards.

K. Rehnström et al.

We have previously reported that the genetic structure within Finland correlates well both with geography and known population history. While these studies have quantified the genetic distances between Finland and European neighbours to the south and the west, the influence of the Eastern and the Northern populations have not been described using genome-wide tools. Here we investigated the degree of Asian ancestry in Northern Europe. We also studied the genetic ancestry of geographic and linguistic neighbours of Finns, using genome-wide SNP data in a dataset comprising over 2200 individuals. First we quantied the proportions of European (represented by HapMap CEU) and Asian (HapMap CHB/JPT) genetic ancestry. Within Finland, the average Asian ancestry proportion varied from 2.5% in the Swedish speaking Finns to 5.1% in Northern Finland. The Saami population, being the indigenous inhabitants of Northern Finland, showed a surprisingly high proportion of Asian genetic ancestry (17.5%). We therefore hypothesize that, as genetic sharing between individuals in Northern Finland and Saami are higher than in other parts of the country, the Asian genetic ancestry in Finland could partly be through admixture with the Saami. Using a model-based estimation of individual ancestry, three ancestral populations provided a best fit for the combined Finnish and Saami dataset. Particularly, one of these ancestral populations was predominant in the Saami (average 78%), and higher in Northern Finland (average 14%) compared to the rest of the country (average 4%). Despite the fact that Finns are the closest relatives of the Saami of all populations included in this study, in general, our results show that language and genetics are only weakly related. The Finns are more closely related to most Indo-European speaking populations than to linguistically related populations such as the Saami. These analyses are currently being extended to sequence level variation using genome-wide sequence data for 100 Finns as part of the 1000 Genomes project, and 200 further individuals from the North-Eastern Finnish subisolate of Kuusamo. These 200 individuals provide good power to identify founder haplotypes within this isolate. Next, we aim to investigate the power to extend the imputation of haplotypes to the rest of Northern Finland as well as to the rest of the country.

It is unfortunate that these researchers used HapMap populations to study admixture in Finns; the Chinese are, especially, not a very good proxy for the East Eurasian element in the Finnish population. There are much data available on North Eurasian populations at this point, so I find the continued use of HapMap populations puzzling; hopefully this will be remedied when this research finds itself in the journals.

The current Dodecad estimate of East Eurasian admixture in the 1000 Genomes FIN population is 5.9%, the bulk of which is "Northeast Asian", a component which peaks in Nganasan, Chukchi, and Koryak, and is also well-represented in Central Siberia among Selkups. I don't have 5 Swedish-speaking Finns to report an average yet, but the ones I have are in the ~2-4% "Northeast Asian" range.

I also ran a quick test of FIN together with CEU and CHB and ~186k SNPs I am currently considering for the next version Dodecad v4 of my ancestry analysis. At K=2, FIN is 3.7% Asian, which seems consistent with the authors reporting the highest Asian ancestry of 5.1% in northern Finland, and also shows how the use of CHB as an Asian reference underestimates the degree of Eastern Eurasian admixture.