More ancient Scandinavians (Skoglund, Malmström et al. 2014)

A new paper has just appeared in Science which adds new ancient Swedish hunter-gatherer samples, as well as a new Gökhem2 Swedish farmer. Much lower quality data from the same archaeological sites were studied in 2012 by much the same team, but the new study has sequenced several new Pitted Ware individuals from Ajvide, as well as a  Mesolithic Swede.

The Swedish hunter-gatherers appear to be similar to those of Lazaridis et al. (2013) in that their ancestry is a mixture of both European hunter-gatherers like LaBrana1 and ~15% of something related to MA1, which seems quite close to the 19% of ANE ancestry for the older Motala hunter-gatherer also from Sweden. The finding of Y-haplogroup I2a1 also parallels the Motala hunter-gatherers, so everything seems quite consistent with the Mesolithic Swedes being genetically very close to the Pitted Ware Neolithic ones. However, there is one difference in that the new hunter-gatherers were ancestral for SLC24A5 while the Motala one was derived (this is the "skin lightening" allele that was curiously missing in both Iberia and Luxembourg hunter-gatherers).

The authors also find that the Iceman and Gökhem2 are a mixture of Basal Eurasians and something related to hunter-gatherers. A interesting new detail is that the Swedish farmer had more of the hunter-gatherer ancestry than the Iceman (the estimated difference in their non-Basal Eurasian ancestry is 77.2-56=21.2%) which seems reasonably close to the 16% difference in the related "Atlantic_Baltic" ancestry for the previous lower-quality Gok4 farmer and the Iceman I estimated in 2012.

Finally, the authors also study the genetic diversity of the Swedish hunter-gatherers:

The Scandinavian Neolithic hunter-gatherer group had significantly lower conditional nucleotide diversity (0.181±0.0015) compared to the Scandinavian Neolithic farmer group (0.201±0.0038, Figs 3A and S9). While the specific properties of ancient DNA may still affect comparisons with sequence data from modern-day individuals, the conditional nucleotide diversity in the hunter-gatherers was also lower than in any modern-day European and a Chinese population (22) analyzed using the same approach as for the ancient groups.

It is not easy to estimate nucleotide diversity with low coverage data (because you can't tell whether a sample is heterozygous in some position if you only have a handful of reads covering it), but the authors cleverly use the fact that they have multiple individuals from the hunter-gatherer population to estimate this. The low diversity in hunter-gatherers also parallels the finding of low genetic diversity in the Luxembourgeois Mesolithic hunter-gatherer, so it does seem that hunter-gatherers in Europe were a very low diversity population, which seems reasonable for people engaging in foraging (which does not allow for growth to large population numbers) and having ancestors who endured the Ice Age in Europe.

The last few months have been extremely generous in new ancient DNA studies and I hope that more stuff is coming this year as in 2013.

UPDATE: Also important (from the Independent):

“We see clear evidence that people from hunter-gatherer groups were incorporated into farming groups as they expanded across Europe. This might be clues towards something that happens also when agriculture spread to other parts of the world,” Dr Skoglund said.

Science DOI: 10.1126/science.1253448

Genomic Diversity and Admixture Differs for Stone-Age Scandinavian Foragers and Farmers

Pontus Skoglund, Helena Malmström et al.

Prehistoric population structure associated with the transition to an agricultural lifestyle in Europe remains contentious. Population-genomic data from eleven Scandinavian Stone-Age human remains suggest that hunter-gatherers had lower genetic diversity than farmers. Despite their close geographical proximity, the genetic differentiation between the two Stone-Age groups was greater than that observed among extant European populations. Additionally, the Scandinavian Neolithic farmers exhibited a greater degree of hunter-gatherer-related admixture than that of the Tyrolean Iceman, who also originated from a farming context. In contrast, Scandinavian hunter-gatherers displayed no significant evidence of introgression from farmers. Our findings suggest that Stone-Age foraging groups were historically in low numbers, likely due to oscillating living conditions or restricted carrying-capacity, and that they were partially incorporated into expanding farming groups.

Link

Europeans = Neolithic farmers, Mesolithic hunter-gatherers and "Ancient North Eurasians" (etc.)

A new preprint on the bioRxiv reports ancient DNA from a Mesolithic European hunter-gatherer from Luxembourg whose mtDNA was published a few years ago and a Neolithic European LBK farmer from Germany, as well as several Mesolithic hunter-gatherers from Sweden.

The Luxembourg sample is similar to the Iberian La Brana samples and the Swedish Mesolithic samples are similar to Swedish Neolithic hunter-gatherers. The LBK farmer is similar to Oetzi and a Swedish TRB farmer and to Sardinians. The authors also study the recently published Mal'ta Upper Paleolithic sample from Lake Baikal and find that it is part of an "Ancient North Eurasian" population that also admixed into West Eurasians on top of the Neolithic/Mesolithic mix.

The authors' proposed model and admixture estimates:

It seems that the estimates go all the way to "almost pure" Early European farmer ancestry but "West European Hunter-Gatherer" and "Ancient North Eurasian" ancestry isn't found unmixed in any modern populations. The model seems to agree with Raghavan et al. that Karitiana are "Mal'ta"-admixed but also finds the most basal Eurasian ancestry in the European Neolithic farmer. The authors write:

The successful model (Fig. 2A) also suggests 44 ± 10% “Basal Eurasian” admixture into the ancestors of Stuttgart: gene flow into their Near Eastern ancestors from a lineage that diverged prior to the separation of the ancestors of Loschbour and Onge. Such a scenario, while never suggested previously, is plausible given the early presence of modern humans in the Levant25, African-related tools made by modern humans in Arabia26, 27, and the geographic opportunity for continuous gene flow between the Near East and Africa28

The Swedish/Luxembourg Mesolithic hunter-gatherers are all mtDNA-haplogroup U and Y-chromosome haplogroup I, so again no R1a/R1b in early European samples.

An interesting finding is that the Luxembourg hunter-gatherer probably had blue eyes (like a Mesolithic La Brana Iberian, a paper on which seems to be in the works) but darker skin than the LBK farmer who had brown eyes but lighter skin. Raghavan et al. did not find light pigmentation in Mal'ta (but that was a very old sample), so with the exception of light eyes that seem established for Western European hunter-gatherers (and may have been "darker" in European steppe populations, but "lighter" in Bronze Age South Siberians?), the origin of depigmentation of many recent Europeans remains a mystery. Ancient DNA continues to surprise at every turn.

UPDATE (4/4/2014): a new version of the preprint.

bioRxiv doi: 10.1101/001552

Ancient human genomes suggest three ancestral populations for present-day Europeans

Iosif Lazaridis et al.

Analysis of ancient DNA can reveal historical events that are difficult to discern through study of present-day individuals. To investigate European population history around the time of the agricultural transition, we sequenced complete genomes from a ~7,500 year old early farmer from the Linearbandkeramik (LBK) culture from Stuttgart in Germany and an ~8,000 year old hunter-gatherer from the Loschbour rock shelter in Luxembourg. We also generated data from seven ~8,000 year old hunter-gatherers from Motala in Sweden. We compared these genomes and published ancient DNA to new data from 2,196 samples from 185 diverse populations to show that at least three ancestral groups contributed to present-day Europeans. The first are Ancient North Eurasians (ANE), who are more closely related to Upper Paleolithic Siberians than to any present-day population. The second are West European Hunter-Gatherers (WHG), related to the Loschbour individual, who contributed to all Europeans but not to Near Easterners. The third are Early European Farmers (EEF), related to the Stuttgart individual, who were mainly of Near Eastern origin but also harbored WHG-related ancestry. We model the deep relationships of these populations and show that about ~44% of the ancestry of EEF derived from a basal Eurasian lineage that split prior to the separation of other non-Africans.

Link

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. 

A look at Y chromosomes of Romania via Count Dracula

In short: researchers tried to see whether they could identify a specific Y chromosome lineage associated with the House of Basarab in Romania, the most famous member of which is Vlad the Impaler, an inspiration for the mythical Count Dracula. To do this, they tested Basarab-surnamed individuals, as well as the general Romanian population.

The whole exercise was, in a sense, a failure, since it neither disclosed a Basarab-specific lineage, nor resolved the historical question about the origin of the House of Basarab (Vlach or Cuman). But, it gave us some wonderful new data on Romania that is, of course, quite welcome.

This seems like a good candidate for a future ancient DNA study, assuming of course, that Vlad and his family are still in their final resting place, and there are brave enough researchers to disturb them (j/k).

On a more serious note, the authors correctly state that even if the Basarab house was originally Turkic, they could still have carried West Eurasian chromosomes, since incoming Turkic groups in Europe were not purely Mongoloid like their more remote ancestors. On the other hand, I note that most of the Basarab-surnamed individuals belonged to E-V13, I-P37.2, J-M241 all of which are almost certainly native Romanian. If one of them carries the original chromosome, then the odds are in favor of a Romanian origin, although nothing short of ancient DNA work can resolve the issue, assuming that's possible.

Table S1 contains the new Romanian data, and Table S2 data from surrounding populations (Hungary, Bulgaria, Ukraine).

PLoS ONE 7(7): e41803. doi:10.1371/journal.pone.0041803

Y-Chromosome Analysis in Individuals Bearing the Basarab Name of the First Dynasty of Wallachian Kings

Begoña Martinez-Cruz et al.

Vlad III The Impaler, also known as Dracula, descended from the dynasty of Basarab, the first rulers of independent Wallachia, in present Romania. Whether this dynasty is of Cuman (an admixed Turkic people that reached Wallachia from the East in the 11th century) or of local Romanian (Vlach) origin is debated among historians. Earlier studies have demonstrated the value of investigating the Y chromosome of men bearing a historical name, in order to identify their genetic origin. We sampled 29 Romanian men carrying the surname Basarab, in addition to four Romanian populations (from counties Dolj, N = 38; Mehedinti, N = 11; Cluj, N = 50; and Brasov, N = 50), and compared the data with the surrounding populations. We typed 131 SNPs and 19 STRs in the non-recombinant part of the Y-chromosome in all the individuals. We computed a PCA to situate the Basarab individuals in the context of Romania and its neighboring populations. Different Y-chromosome haplogroups were found within the individuals bearing the Basarab name. All haplogroups are common in Romania and other Central and Eastern European populations. In a PCA, the Basarab group clusters within other Romanian populations. We found several clusters of Basarab individuals having a common ancestor within the period of the last 600 years. The diversity of haplogroups found shows that not all individuals carrying the surname Basarab can be direct biological descendants of the Basarab dynasty. The absence of Eastern Asian lineages in the Basarab men can be interpreted as a lack of evidence for a Cuman origin of the Basarab dynasty, although it cannot be positively ruled out. It can be therefore concluded that the Basarab dynasty was successful in spreading its name beyond the spread of its genes.

Link

Pre-Roman genetic structure has persisted in modern Basque populations

This is a fairly interesting study that paints a picture of continuity of genetic structure among Basques since pre-Roman times. I am not sufficiently familiar with either Basque history or geography to comment on this in detail, but the central conclusion that Basques differ from their neighbors in being more isolated and less cosmopolitan is something that I have also noticed in my own experiments (see for example the K12b population portraits, contrasting French_Basque and Pais_Vasco_1KG with other Iberian/French populations).

For those who know more, does the following scheme make sense?

Y-haplogroup frequencies, showing a preponderance of R-M269 related lineages and a strong showing of the the I-M26 lineage are shown below. The latter links Basques with Sardinians, as well as probably with Neolithic France.

Codes (from the paper): BIG, Bigorre; BEA, Béarn; CHA, Chalosse; ZMI, Lapurdi/Baztan; NLA,Lapurdi Nafarroa; SOU, Zuberoa; RON, Roncal and Salazar valleys; NCO, CentralWestern Nafarroa; NNO, North Western Nafarroa; GUI, Gipuzkoa; GSO, SouthWestern Gipuzkoa; ALA, Araba; BBA, Bizkaia; BOC, Western Bizkaia; CAN,Cantabria; BUR, Burgos; RIO, La Rioja; NAR, North Aragon.

The picture of continuity is further strengthened by ancient Basque Y-chromosomes, showing the same picture of R1b-majority/I minority as today. What we really need now is to bridge the gap between late antiquity and the Neolithic, and beyond to better understand the temporal sequence of settlement.

Mol Biol Evol (2012)doi: 10.1093/molbev/mss091

Evidence of pre-Roman tribal genetic structure in Basques from uniparentally inherited markers

Begoña Martínez-Cruz et al.

Basque people have received considerable attention from anthropologists, geneticists and linguists during the last century due to the singularity of their language and to other cultural and biological characteristics. Despite the multidisciplinary efforts performed to address the questions of the origin, uniqueness and heterogeneity of Basques, the genetic studies performed up to now have suffered from a weak study-design where populations are not analyzed in an adequate geographic and population context. To address the former questions and to overcome these design limitations, we have analyzed the uniparentally inherited markers (Y chromosome and mitochondrial DNA) of ∼900 individuals from 18 populations, including those where Basque is currently spoken and populations from adjacent regions where Basque might have been spoken in historical times. Our results indicate that Basque-speaking populations fall within the genetic Western European gene pool and they are similar to geographically surrounding non-Basque populations, and also that their genetic uniqueness is based on a lower amount of external influences compared to other Iberians and French populations. Our data suggest that the genetic heterogeneity and structure observed in the Basque region results from pre-Roman tribal structure related to geography and might be linked to the increased complexity of emerging societies during the Bronze Age. The rough overlap of the pre-Roman tribe location and the current dialect limits supports the notion that the environmental diversity in the region has played a recurrent role in cultural differentiation and ethnogenesis at different time periods.

Link

Serbian Y-chromosomes

Gene. 2012 Jan 31. [Epub ahead of print]

High levels of Paleolithic Y-chromosome lineages characterize Serbia.

Regueiro M, Rivera L, Damnjanovic T, Lukovic L, Milasin J, Herrera RJ.

Abstract

Whether present-day European genetic variation and its distribution patterns can be attributed primarily to the initial peopling of Europe by anatomically modern humans during the Paleolithic, or to latter Near Eastern Neolithic input is still the subject of debate. Southeastern Europe has been a crossroads for several cultures since Paleolithic times and the Balkans, specifically, would have been part of the route used by Neolithic farmers to enter Europe. Given its geographic location in the heart of the Balkan Peninsula at the intersection of Central and Southeastern Europe, Serbia represents a key geographical location that may provide insight to elucidate the interactions between indigenous Paleolithic people and agricultural colonists from the Fertile Crescent. In this study, we examine, for the first time, the Y-chromosome constitution of the general Serbian population. A total of 103 individuals were sampled and their DNA analyzed for 104 Y-chromosome bi-allelic markers and 17 associated STR loci. Our results indicate that approximately 58% of Serbian Y-chromosomes (I1-M253, I2a-P37.2, R1a1a-M198) belong to lineages believed to be pre-Neolithic. On the other hand, the signature of putative Near Eastern Neolithic lineages, including E1b1b1a1-M78, G2a-P15, J1-M267 and J2-M172 and R1b1a2-M269 accounts for 39% of the Y-chromosome. Furthermore, an examination of the distribution of Y-chromosome filiations in Europe indicates extreme levels of Paleolithic lineages in a region encompassing Serbia, Bosnia-Herzegovina and Croatia, possibly the result of Neolithic migrations encroaching on Paleolithic populations against the Adriatic Sea.

Link

Armenian Y-chromosomes revisited (Herrera et al. 2011)

Armenian Y-chromosomes have been a largely ignored since the publication of the classic Weale et al. (2001) paper a decade ago. The Armenian DNA Project has largely covered the void during the intervening years, but it is nice that the topic is revisited by academics.

Armenia is sandwiched between Anatolia, the Fertile Crescent, the Iranian plateau, the Caucasus, and the Black and Caspian seas, making the study of Armenian Y-chromosomes extremely interesting for the student of Eurasian prehistory.

Gene flow from the surrounding regions may have affected the Armenian population over historical time, but the remoteness of the Armenian highlands, coupled with the national church -- which distinguished Armenians from both the Orthodoxy of the Roman Empire, the Zoroastrianism of the Persians, and, later the Islam of Arabs and Ottomans -- may have prevented it.

My comments on the paper will follow below once I read it.

UPDATE I: The paper spends a lot of time on analysis of Y-STR variance; my opinion of Y-STRs as a tool for inferring past population movements is, to put it mildly, low. When Bahamian Y-STR variance is higher than African one, and E-V13, one of the youngest European Y-haplogroups (in terms of Y-STR variance) turns up in Spain in one of the earliest ancient DNA samples, it goes without saying that the burden of proof is on those who wish to continue to talk about Neolithic or other population movements to make the assumptions of their models clearer. Nonetheless, there is still some utility in Y-STRs, so I reproduce some tree diagrams from the paper (top left), and link to the supplementary info that has a collection of haplotypes that may be useful to genealogists.

From the paper:

However, owing to the contentions associated with the current calibrations of the Y-STR mutation rates,32,34,35,41 as well as the limitations of the assumptions utilized by the methodologies for time estimations, the absolute dates generated in this study should only be taken as rough estimates of upper bounds.

Indeed. We are at the point where Y-STRs are at the end of their utility, but the replacement technology of extensive Y-chromosome sequencing has not quite arrived in an economical way yet.

UPDATE II: I will have some additional thoughts on Y-chromosome distribution in the third update, but, for the time being, the two most important "nuggets" of information are: (i) the unusual haplogroup frequencies in Sasun (high R2 and T), which may be due to a founder effect, but it would be interesting if Armenian historians could find some explanation for their occurrence there, and (ii) the occurrence of R-M269*(xL23) in Ararat Valley. I invite more knowledgeable readers to comment on the issue; the haplotypes are in Table 2 of the supplement.

UPDATE III: The ubuiquity of haplogroup G2a in Neolithic Europe, coupled with the absence of other prominent present-day European haplogroups, has important implications about European discontinuity.

But, it also has implications about West Asian discontinuity. The Neolithic in Europe arrived by all accounts from either of two principal areas: Anatolia or the Levant. Today, in Anatolia and the Levant, we see a set of haplogroups of which haplogroup J is the most important and ubiquitous one. Haplogroup R1b is also quite frequent in Armenia, the east Caucasus, Anatolia, and Iran, but its frequency drops dramatically to the east and south. And, there is a whole assortment of other haplogroups with varying frequency.

Why didn't all these non-G2a haplogroups participate in the early Neolithic colonization of Europe? It could very well be that a very small founder population crossed the Aegean into Europe, one that happened to be G2a-dominated. But, that is ultimately not very satisfying: if there was plenty of J and R1b in West Asia at the time of the Neolithic expansion, why are these haplogroups so conspicuous in their absence -at least so far- from Neolithic Europe?

The case of haplogroup J is particularly problematic. If we had to guess, by looking at present-day distribution, which lineage tracks population movements from the Near East to Europe, there is simply no better candidate: every map of this haplogroup, and especially of its J2a sublineage shows an unambiguous pattern of radiation, with a core area consisting of Southern Italy, Greece, Anatolia, West Asia, Mesopotamia and the northern parts of the Levant. All these regions are crucial to the story of the Neolithic, so the absence of J in Neolithic Europe is perplexing.

And, the story has other complications. From the current paper:

The relative expansion times for haplogroup J2-M172 (Table 4) generally correspond with those yielded for R1b-M343, with the exception of Greece and Crete, which, unlike haplogroup R1b-M343, are slightly older than the dates yielded for several of the Near Eastern groups as well as the four Armenian populations.

As mentioned above, I don't give much weight on Y-STR evidence, but observations such as the above certainly add to the feeling of unease that something is not quite right with the default picture of prehistory.

Another observation on the Armenian population, is its very low frequency of haplogroup R1a1. Proponents of the Kurgan model of Indo-European dispersals sometimes associate this haplogroup with the Proto-Indo-European community, and it is strange why -if their ideas are right- Armenia is so lacking in this haplogroup, like its Caucasian neighbors. Why would these hypothetical migrants make such a huge impact in faraway India and barely a dent in nearby Armenia?

Finally, the occurrence of some I2, E-V13, and, perhaps, J2b in Armenia may point to Balkan contacts. But, when did these contacts occur? Are they traceable to the migration of Phrygians to Anatolia, according to the Herodotean account of Armenian origins, or can they be attributed to later contacts with Greeks or other Europeans?

The veil of mystery seems to be raised even higher by every new study: we may be less certain of what really happened today than in the days of happy ignorance, ten years ago. Ultimately it is new data, like the ones included in this paper, that will make every piece of evidence fit, and the grand puzzle of the history of Eurasia will be revealed in all its glory.

European Journal of Human Genetics , (16 November 2011) | doi:10.1038/ejhg.2011.192

Neolithic patrilineal signals indicate that the Armenian plateau was repopulated by agriculturalists

Kristian J Herrera, Robert K Lowery, Laura Hadden, Silvia Calderon, Carolina Chiou, Levon Yepiskoposyan, Maria Regueiro, Peter A Underhill and Rene J Herrera

Abstract
Armenia, situated between the Black and Caspian Seas, lies at the junction of Turkey, Iran, Georgia, Azerbaijan and former Mesopotamia. This geographic position made it a potential contact zone between Eastern and Western civilizations. In this investigation, we assess Y-chromosomal diversity in four geographically distinct populations that represent the extent of historical Armenia. We find a striking prominence of haplogroups previously implicated with the Agricultural Revolution in the Near East, including the J2a-M410-, R1b1b1*-L23-, G2a-P15- and J1-M267-derived lineages. Given that the Last Glacial Maximum event in the Armenian plateau occured a few millennia before the Neolithic era, we envision a scenario in which its repopulation was achieved mainly by the arrival of farmers from the Fertile Crescent temporally coincident with the initial inception of farming in Greece. However, we detect very restricted genetic affinities with Europe that suggest any later cultural diffusions from Armenia to Europe were not associated with substantial amounts of paternal gene flow, despite the presence of closely related Indo-European languages in both Armenia and Southeast Europe.

Link

Sardinian continuity against a backdrop of European discontinuity

Ancient DNA research from Europe has tended to paint a picture of substantial population discontinuity. In a Neolithic sample from Derenburg, neither of the two major Y-chromosome haplogroups prevalent in Central-Northern Europe, R1 and I were found. The Tyrolean Iceman belongs to haplogroup G2a4, a minor lineage in modern-day Europeans. In a Neolithic site from the French south, Treilles, haplogroups G2 and I2 were found, the major R1 lineage again being absent. Megalithic mtDNA from France complements that from the Linearbandkeramik in suggesting a picture of discontinuity, or, at least, substantial change, in the occupation of Europe since the Neolithic. An upcoming study suggest that mtDNA haplogroup X2 did not arrive in Central Europe with the early LBK Neolithic, but with the later Bell Beaker folk. The picture of discontinuity, at least for the Mesolithic-Neolithic transition is supported from Scandinavia, as well as Luxembourg. To cap it all off, a pair of unexpected results from Hungary and Ukraine stretch the contact zone of West/East Eurasian populations well to the west of what has already been determined by ancient DNA work in the Tarim basin and Siberia.


There is, however, one population that stands as an outlier against the backdrop of discontinuity: Sardinians. Ghirotto et al. inferred population continuity in Sardinian mtDNA at least until the Bronze Age. Stories about the Tyrolean Iceman, confirmed in the NOVA TV documentary suggest that a 5,000-year old denizen of Central Europe was genetically closest to Sardinians. A study of craniofacial variation confirms population continuity in Sardinia since the Neolithic, with the population of peninsular Italy gradually diverging, consistent with the Iceman findings. Substantial frequencies of Y-haplogroups G and I are found in modern Sardinian newborns, the same two haplogroups detected in Neolithic southern France at Treilles. And, a study of European genetic isolates finds Sardinians to be lacking in some European polymorphic sites, suggesting a degree of genetic isolation compared to mainland Europeans; this is consistent with my own finding that Sardinians are maximally "western" along the east-west Eurasian axis.

Two cryptic bits of revealed information suggest that a major event may have happened in Europe. In an ICHG 2011 talk, David Reich revealed that his lab has unpublished work of ancient admixture in Europe and that "Europeans are anciently mixed just like South Asians." A blog post by Ewen Callaway suggests that Zink's Tyrolean Iceman investigators are asking "whether he and his kin died out and were replaced by migrants from elsewhere, such as the Middle East."

In the absence of concrete data, it is difficult to interpret such hints of things to come. But the idea of an episode of admixture in Europe from the East that would leave a South Asian-like cline of diminishing West Asian ancestry is supported by admixture studies of West Eurasians, showing that the Near-East to Atlantic-Baltic vector captures the principal aspect of variation in this region.


Interestingly, a "West Asian" ancestral component centered on the South Caucasus region has an Fst distance of 0.028 with the main European "Atlantic-Baltic" component, and of 0.058 with a "Southern" component present at non-trivial amount in southern populations from both sides of the Mediterranean and the Near East.

The possibility of a major east-west population movement into Europe that left Sardinians least affected is intriguing. At K=7 Sardinians have almost none of the "West Asian" ancestral component and most of the "Southern" one in Europe. This appears to be consistent with a population that was least affected by population movements from the northern parts of West Asia.

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


In a roundabout manner, the Caucasus and its environs may soon reclaim their position as the fons gentium that Blumenbach, more than two centuries ago, ascribed to them. More than one century ago, Italian anthropologist Giuseppe Sergi, proposed a model of the double origin of Europeans, supposing that the Mediterraneans of southern Europe (a branch of the "Eurafricans") were invaded by peoples from the east, the "Eurasiatics." Naturally, the ideas of Blumenbach and Sergi cannot be adopted today in their entirety, but they do well to remind us that inklings of truth can be found in the most unexpected of places.


And, when one reads this quote from Carleton Coon's classic 1939 synthesis The Races of Europe (section "The western Mediterranean Islands")... "Sardinia and Corsica were peopled at the beginning of the Neolithic by a race of short-statured, dolichocephalic, low-vaulted, brunet Mediterraneans, coming probably from several quarters, including the adjacent European coasts, North Africa, and the eastern Mediterranean. Subsequent immigrations of other Mediterranean peoples have affected the racial composition of these islands but little." ... one is inclined to say "Dr. Coon, you were right!"

Y-chromosome, mtDNA, and autosomal DNA from Treilles (5,000 years ago, Neolithic France)

The paper is behind a paywall, but there is plentiful raw genetic data in the online supplement. I'll probably have much more to say on this when I read it, but here's the groundbreaking part:

Most of this sample belonged to haplogroup G2a-P15 with some I2a-P37.2 also represented.

G2a was also one of the haplogroups represented in a small sample from Neolithic Central Europe. I think we can now safely say that G2a may have been the main Neolithic link that ties the farmers that went north across the Balkans to Central Europe, and those that followed the western, maritime route to the Western Mediterranean. The unambiguous West Asian origin of this lineage should put to rest any ideas about Neolithic farmers in the Western Mediterranean being descended from indigenous Mesolithic foragers.

I-P37.2 is also quite interesting, as it is tied to the Balkans, but also modern Southwestern Europe (it is especially frequent in Sardinia in its derived M26+ form). ISOGG tells me that:

I2-M438 et al includes I2* which shows some membership from Armenia, Georgia and Turkey; I2a-P37.2, which is the most common form in the Balkans and Sardinia. I2a1-M26 is especially prevalent in Sardinia. I2b-M436 et al reaches its highest frequency along the northwest coast of continental Europe. I2b1-M223 et al occurs in Britain and northwest continental Europe. I2b1a-M284 occurs almost exclusively in Britain, so it apparently originated there and has probably been present for thousands of years.

If these aren't signals of a maritime pioneer colonization that followed the maritime route along the Mediterranean and Atlantic, I don't know what is.

What is absent is also quite interesting as what is present. The absence of E1b1b is consistent with my theory about the Bronze Age Greek expansion of that haplogroup in Europe that has been tied to the historical Greeks of the West Mediterranean.

R-M269 which, because of its apparent young Y-STR age has been tied by some to either the Mediterranean or Central European Neolithic is conspicuous absently from both at the moment. It may yet surface in a Neolithic context, but its absence this late from a region where, today, it is abundant only adds to its mystery. The absence of J2 is equally mysterious, as this is another putative Neolithic lineage which has failed to appear so far in a Neolithic context, while its J1 sister clade did make an appearance in much later aboriginals from the Canary Islands.

UPDATE I: Interestingly, some French researchers had noted a littoral distribution of haplogroups I, J, G in the Finistère, on the Atlantic side.

UPDATE II: I was reviewing my Ancient Y-chromosome studies compendium and one thing starts to become clear: how many of the earliest samples we have were dominated by 1-2 haplogroups, whereas there is a plethora of haplogroups in most modern populations: Treilles, Krasnoyarsk, Xiaohe, Pengyang all belonged to a single haplogroup, while Yangtze China to several lineages, all of which were in the O haplogroup.

Look at the MDS plot of the Y-chromosome and mtDNA from Treilles:

The Y-chromosome is an extreme outlier compared to modern groups, probably because of its heavy G2a domination, whereas the mtDNA from Treilles appears just like a normal and unexceptional Mediterranean-type population.

Perhaps the modern Caucasus where particular ethnic groups are dominated by particular Y-haplogroups is a good analogy for prehistoric man, with many different groups with their signature haplogroups kept disjoint patrilineal gene pools before beginning to merge in late prehistorical and historical times.

UPDATE III: A poster at dna-forums as well as Ken Nordtvedt both agree that the I2a haplotypes belong to I-M26, a haplogroup that is modal in the SW Mediterranean, reaching very high frequencies in Sardinia. This may be consistent with the great biological continuity since the Neolithic in Sardinia, continuity which is also evident on the mtDNA. It also shows why the inference of pre-Neolithic I2a in Sardinia was flawed because of the use of the evolutionary mutation rate, while the origin and expansion of I-M26 in "genealogical rate" years becomes 5-7ky, consistent with the Neolithic origin of that haplogroup and the ancient DNA presence in Neolithic France.

UPDATE IV: Table S4 lists (in %) shared mtDNA lineages between Treilles and modern populations. The top ones are: Welsh (17.391), Cornish (16.667), Central Greeks (14.286), Bulgarians (12.5). Several Italian groups as well as South Tyrol Ladins and Germans are also greater than 10%.

UPDATE V: The G2a median joining network shows that the Treilles haplotypes are disjoint from those that dominate the North Caucasus, with clear links to the Middle East, Central/East Mediterranean regions, as well as the South Caucasus.

UPDATE VI: Some more good news: "The ancient DNA Lacan is now extracting from skeletons across France and Spain, Haak says, should provide more “piece[s] of the enormous puzzle we are trying to put together.”

PNAS doi: 10.1073/pnas.1100723108

Ancient DNA reveals male diffusion through the Neolithic Mediterranean route

Marie Lacan et al.

The Neolithic is a key period in the history of the European settlement. Although archaeological and present-day genetic data suggest several hypotheses regarding the human migration patterns at this period, validation of these hypotheses with the use of ancient genetic data has been limited. In this context, we studied DNA extracted from 53 individuals buried in a necropolis used by a French local community 5,000 y ago. The relatively good DNA preservation of the samples allowed us to obtain autosomal, Y-chromosomal, and/or mtDNA data for 29 of the 53 samples studied. From these datasets, we established close parental relationships within the necropolis and determined maternal and paternal lineages as well as the absence of an allele associated with lactase persistence, probably carried by Neolithic cultures of central Europe. Our study provides an integrative view of the genetic past in southern France at the end of the Neolithic period. Furthermore, the Y-haplotype lineages characterized and the study of their current repartition in European populations confirm a greater influence of the Mediterranean than the Central European route in the peopling of southern Europe during the Neolithic transition.

Link

Y chromosomes of Arbereshe from Calabria

From the paper:

The Arbereshe are one of the largest linguistic minorities in Italy. They are the result of complicated movements of Albanians around the end of the 15th and beginning of the 16th century, often linked to the invasion of the Balkans by the Ottoman Empire. Despite that, it is generally agreed that most of the immigrants started moving from the south of Albania (Toskeria), with, very often, intermediate steps in Greece, particularly in the Peloponnese (Zangari 1941). Further evidence is provided by linguistic research, according to which Arberisht, the language spoken by Arbereshe, is part of the Tosk dialect group of Albanian, a language originally spoken in Toskeria (Babiniotis 1998).

On the sample:

The Arbereshe Y-chromosome variation was investigated by sampling individuals from different villages of the Pollino area (Calabria) who bear one of the founding surnames of the population. The genotyping was performed using 12 microsatellites (STRs) and 31 unique event polymorphisms (UEPs), defining, respectively, haplotypes and haplogroups. The Italian and Balkan genetic backgrounds were explored using the large amount of data provided by recent Y-chromosome studies in the two peninsulas and by literature data on STRs from forensic research.

Comparison of Y-haplogroup frequency and diversity between Albanians from Tirana and Arbereshe from Calabria (from Table III):

The presence of F*(xG,I,J,K) in Albanians is interesting as this occurs in Romania and Bosnia Herzegovina (all groups), and in South Apulia, It could potentially be haplogroup H and may reflect a Gypsy element that was not present when the Arbereshe moved to Italy from the Balkans.

Haplogroup I shows similar frequencies, but:

I-M170 is the most common Balkan haplogroup (Pericic et al. 2005a,b) and the second most frequent Arbereshe clade. Nevertheless, analysis of its network reveals unexpected results: most of the Arbereshe I-M170 haplotypes are not included in the Balkan cluster (Figure 3), but are located in the long branches containing mainly Italian chromosomes. Comparisons with literature data (Semino et al. 2000; Barac et al. 2003, Rootsi et al. 2004) show that the core haplotype of the Balkan cluster (16-14-15-13-31-24-11-11-13; locus order as above) is consistent with the almost Balkan exclusive I2a (formerly I1b) clade. The proposed interpretation of the Arbereshe as a proxy of the founder Albanian population leads us to hypothesize that the I2a clade was less common in the southern Balkans 500 years ago than nowadays. The very tight shape of the I2a cluster in the network suggests a very recent expansion of this haplogroup in the southern Balkans. Furthermore, I2a is still rare in

mountain populations such as the Albanians of Kosovo (Pericic et al. 2005a,b) and in a randomly selected Arbereshe sample from Rootsi et al. (2004).

This is an interesting finding in the light of recent evidence for selection in Y-haplogroup I.

The situation with J2 is also quite interesting as this is rarer in Arbereshe (3%) than Albanians (17%):

The scarcity of J2 chromosomes in the Arbereshe sample (1/40) is very difficult to explain, given that they are very common in both the Italian peninsula and the southern Balkans. Literature data on J2 indicate that most of the haplotypes included in the Balkan (B) cluster of the network (Figure 3) have an STR configuration consistent with the J2-M12 sub-clade (Di Giacomo et al. 2004; Semino et al. 2004; Cruciani et al. 2007). In contrast, most of the haplotypes in the other clusters agree with the STR configuration given for the J2-M67 clade, with its sub-clade J2-M92 (Di Giacomo et al. 2004). It is unconvincing to attribute the rarity of J2 in the Arbereshe to random sampling or to the effect of genetic drift. Furthermore, the Arbereshe sample analysed by Semino et al. (2004) also completely lacks the typically Balkan J2-M12 chromosomes. If we interpret our Arbereshe sample as representative of the founding Albanian population, we may hypothesize that the J2 haplogroup was considerably less diffuse in the southern Balkans five centuries ago than today.

What we can conclude from this study is that the founding Albanian population was J2- and I2a- lite compared to modern Albanians. The source for the I2a seems to be either the Albanization of people from the West Balkans and/or selection, although it would be difficult to see a massive increase in frequency in only five centuries. The I2a-deficiency of the Arbereshe also gives support to the theory that the Albanians are relatively recent arrivals from the northeast; this theory has been upheld in the past on the basis of the (i) their historical obscurity until the last millennium, and (ii) the paucity of native sea terms and Greek loanwords in Albanian, which is difficult to explain if Albanians always occupied their current location on the Adriatic.

The source of J2 is less clear, and could be either the Albanization of Greeks (the only Balkan population with a sizeable J2 frequency) or remnants of Muslim Anatolians from Ottoman times. However, modern Albanians belong mainly to clade J2b, while Anatolians belong to J2a. Thus, I tend to dismiss the Anatolian connection.

The low frequency of R1*x(R1a1) in the Arbereshe, together with the high E1b1b1a frequency are quite convincing of the Balkan origins of this population.

Ann Hum Biol. 2010 Jun 22. [Epub ahead of print]

Linking Italy and the Balkans. A Y-chromosome perspective from the Arbereshe of Calabria.

Boattini A, Luiselli D, Sazzini M, Useli A, Tagarelli G, Pettener D.

Abstract

Background: The Arbereshe are an Albanian-speaking ethno-linguistic minority who settled in Calabria (southern Italy) about five centuries ago. Aim: This study aims to clarify the genetic relationships between Italy and the Balkans through analysis of Y-chromosome variability in a peculiar case study, the Arbereshe. Subject and methods: Founder surnames were used as a means to identify a sample of individuals that might trace back to the Albanians at the time of their establishment in Italy. These results were compared with data of more than 1000 individuals from Italy and the Balkans. Results: The distributions of haplogroups (defined using 31 UEPs) and haplotypes (12 STRs) show that the Italian and Balkan populations are clearly divergent from each other. Within this genetic landscape, the Arbereshe are characterized by two peculiarities: (a) they are a clear outlier in the Italian genetic background, showing a strong genetic affinity with southern Balkans populations; and (b) they retain a high degree of genetic diversity. Conclusion: These results support the hypothesis that the surname-chosen Arbereshe are representative of the Y-chromosome genetic variability of the Albanian founder population. Accordingly, the Arbereshe genetic structure can contribute to the interpretation of the recent biological history of the southern Balkans. Intra-haplogroup analyses suggest that this area may have experienced important changes in the last five centuries, resulting in a marked increase in the frequency of haplogroups I2a and J2.

Link