Ancient DNA from the Balkans

This study has been for several months around but I have not discussed until now and is well worth a mention.

Ian Mathieson et al., The Genomic History Of Southeastern Europe. BioRXiv (pre-pub) 2017. doi:10.1101/135616

There is a lot of ancient autosomal DNA from the region but it basically says one thing: everything was almost exactly as expected from archaeology. The Karanovo-Gumelnita people, famed for inventing the Bronze Age a whole millenium earlier than anyone else, and nearby related cultures, were within the mainstream (Vasconic) Neolithic genetic grouping. This changed however with the kurgan invasion expressed primarily in the Ezero culture, which I've been told should be considered direct precursors of Thracians. But the change is not something radical: more genetic affinity with the steppe is visible than before and more generalized through all samples. 

Fig. 1-D - Supervised ADMIXTURE plot, modeling each ancient individual (one per row), as a mixture of
populations represented by clusters containing Anatolian Neolithic (grey), Yamnaya from Samara (yellow), EHG (pink) and WHG (green).  (click to expand)

Well, it is not exactly everything what is as expected, if we consider Polish Globular Amphorae culture, which I would have expected to be at least somewhat steppary, Indoeuropean, already but were not. Thus it seems I have to concede on this culture and its precursors being still part of the Vasconic Neolithic. This makes Indoeuropean penetration into Central-North Europe a much more sudden episode and one directly tied to Corded Ware culture and nothing else. It must have been perceived by its victims like a massive catastrophe, because it was a huge area which they conquered and to a large extent colonized in a very short span of time.

Lots of R1b in Epipaleolithic Balkans

Most interesting anyhow is the huge hoard of ancient Y-DNA R1b in the Iron Gates region (Lepenski Vir) before the Neolithic. This not only demonstrates, again, that this haplogroup is Paleoeuropean, at least in part, but, quite intriguingly makes earlier findings on modern data suggesting a possible origin or R1b-M269 in or near modern Serbia (Morelli 2010 and Myres 2010) at least somewhat plausible. However none of the Iron Gates R1b is described as R1b-M269 and in some cases it is excluded that it could be this sublineage. 

Thus the issue of the ultimate origins of this key lineage remains open, but let me underline that these Iron Gate individuals belonged to the WHG grouping, as did Villabruna (so far the oldest R1b carrier kown) and that they breach this way the assumed haplogroup homogeneity I2 conceived on merely Central and Northern European samples. Just as happened with mtDNA U haplogroup homogeneity when mtDNA H was detected by several independent studies of Iberian ancient DNA. It is normal to expect more diversity towards the south for several reasons but maybe the most critical of them is just average temperature, which makes the southern lands naturally more fertile (notably so for crops domesticated in the Middle East) and easier to inhabit. 

This trend was only broken in the Middle Ages when the heavy plough allowed the improved exploitation of deep Oceanic soils, being useless in the Mediterranean region of shallow soils however. It was only then when the center of European development moved from south to north, to Belgium specifically, where it remains till present day. So let's take Southern Europe a bit seriously, please.

Negligible genetic flow in Slavic expansion to the Balcans

A new genetic study comes to confirm what most of us already knew: that Southern Slavs don't show any significant signature of immigration from the core Slavic area North and NE of the Carpathian Mountains that can be attributed to the so-called Slavic migrations of the Dark Age.

Alena Kushniarevich et al., Genetic Heritage of the Balto-Slavic Speaking Populations: A Synthesis of Autosomal, Mitochondrial and Y-Chromosomal Data. PLoS ONE 2015. Open access → LINK [doi:10.1371/journal.pone.0135820]

Abstract

The Slavic branch of the Balto-Slavic sub-family of Indo-European languages underwent rapid divergence as a result of the spatial expansion of its speakers from Central-East Europe, in early medieval times. This expansion–mainly to East Europe and the northern Balkans–resulted in the incorporation of genetic components from numerous autochthonous populations into the Slavic gene pools. Here, we characterize genetic variation in all extant ethnic groups speaking Balto-Slavic languages by analyzing mitochondrial DNA (n = 6,876), Y-chromosomes (n = 6,079) and genome-wide SNP profiles (n = 296), within the context of other European populations. We also reassess the phylogeny of Slavic languages within the Balto-Slavic branch of Indo-European. We find that genetic distances among Balto-Slavic populations, based on autosomal and Y-chromosomal loci, show a high correlation (0.9) both with each other and with geography, but a slightly lower correlation (0.7) with mitochondrial DNA and linguistic affiliation. The data suggest that genetic diversity of the present-day Slavs was predominantly shaped in situ, and we detect two different substrata: ‘central-east European’ for West and East Slavs, and ‘south-east European’ for South Slavs. A pattern of distribution of segments identical by descent between groups of East-West and South Slavs suggests shared ancestry or a modest gene flow between those two groups, which might derive from the historic spread of Slavic people.

This is most evident in the identity-by-descent (IBD) analysis:

Fig 4. Distribution of the average number of IBD segments between groups of East-West Slavs (a), South Slavs (b), and their respective geographic neighbors.

The x-axis indicates ten classes of IBD segment length (in cM); the y-axis indicates the average number of shared IBD segments per pair of individuals within each length class.

For non-acquainted: shorter segments (left) indicates older relatedness, now very fragmented by repeated chromosome recombination, while longer segments (right) indicate more recent one, which had less time to be chopped into pieces.



The authors explain:

The presence of two distinct genetic substrata in the genomes of East-West and South Slavs would imply cultural assimilation of indigenous populations by bearers of Slavic languages as a major mechanism of the spread of Slavic languages to the Balkan Peninsula. Yet, it is worthwhile to add here evidence from the analysis of IBD segments: the majority of Slavs from Central-East Europe (West and East) share as many IBD segments with the South Slavs in the Balkan Peninsula as they share with non-Slavic populations residing nowadays between Slavs (Fig 4A and 4B; Table G in S1 File). This even mode of IBD sharing might suggest shared ancestry/gene flow across the wide area and physical boundaries such as the Carpathian Mountains, including the present-day Finno-Ugric-speaking Hungarians, Romance-speaking Romanians and Turkic-speaking Gagauz. A slight peak at 2–3 cM in the distribution of shared IBD segments between East-West and South Slavs (Fig 4A and 4B) might hint at shared “Slavonic-time” ancestry, but this question requires further investigation.

Another graph of interest is surely the Principal Component Analyses of the three types of genetic markers:

Fig 2. Genetic structure of the Balto-Slavic populations within a European context according to the three genetic systems.

a) PC1vsPC3 plot based on autosomal SNPs (PC1 = 0.53; PC3 = 0.26); b) MDS based on NRY data (stress = 0.13); c) MDS based on mtDNA data (stress = 0.20). We focus on PC1vsPC3 because PC2 (S1 Fig) whilst differentiating the Volga region populations from the rest of Europeans had a low efficiency in detecting differences among the Balto-Slavic populations–the primary focus of this work.

In the mtDNA graph (c) it is hard to discern any pattern, as the various studied populations seems to form rings of eccentricity around the Balcans, probably because no Western Europeans are present in this particular PCA. 

However in the autosomal (a) and Y-DNA (b) figures more defined patterns do emerge. Quite apparently in all three graphs, South Slavs appear as strictly Balcanic. 

More interesting is probably the relative position of Russian and Baltic speakers: the first showing very notable diversity almost representative of the whole East European region and again indicative of assimilation rather than replacement being the main drive in Russian ethnic expansion, at least in the North. 

Balto-Slavic peoples appear intermediate between Russians and Finns (and overlapping Estonians) in the Y-DNA graph and somewhat extreme in the autosomal graph, something that comes as no surprise, as they seem the best preserved vessel of Eastern Paleoeuropeans. Curiously a few Sorbian individuals also tend to that same extreme, what may well be a reason to increase interest on the study of this forgotten and neglected Slavic minority of Eastern Germany. Their Y-DNA is, also intriguingly, most similar to that of Swedes, rather than to their geographic neighbors or ethno-linguistic relatives.

Other Western Slavs, form two clear distinct sub-clusters: with Czechs being notably more Western than Poles and Slovaks, who tend to cluster with mainline Russians and Ukrainians instead. One can of course think that this Polish-Slovak-Ukranian-Russian cluster could be the demic or genetic core of the Slavic cluster. However I can't but wonder how much of that clustering, as well as the differences shown by Czechs and Sorbians should be attributed to older periods like those of Corded Ware Culture, Eastern Bell Beaker, etc.

Ancient mtDNA from Romania

Quantity over quality series.

Montserrat Hervella et al. Ancient DNA from South-East Europe Reveals Different Events during Early and Middle Neolithic Influencing the European Genetic Heritage. PLoS ONE 2015. Open access → LINK [doi:10.1371/journal.pone.0128810]

Abstract

The importance of the process of Neolithization for the genetic make-up of European populations has been hotly debated, with shifting hypotheses from a demic diffusion (DD) to a cultural diffusion (CD) model. In this regard, ancient DNA data from the Balkan Peninsula, which is an important source of information to assess the process of Neolithization in Europe, is however missing. In the present study we show genetic information on ancient populations of the South-East of Europe. We assessed mtDNA from ten sites from the current territory of Romania, spanning a time-period from the Early Neolithic to the Late Bronze Age. mtDNA data from Early Neolithic farmers of the Starčevo Criş culture in Romania (Cârcea, Gura Baciului and Negrileşti sites), confirm their genetic relationship with those of the LBK culture (Linienbandkeramik Kultur) in Central Europe, and they show little genetic continuity with modern European populations. On the other hand, populations of the Middle-Late Neolithic (Boian, Zau and Gumelniţa cultures), supposedly a second wave of Neolithic migration from Anatolia, had a much stronger effect on the genetic heritage of the European populations. In contrast, we find a smaller contribution of Late Bronze Age migrations to the genetic composition of Europeans. Based on these findings, we propose that permeation of mtDNA lineages from a second wave of Middle-Late Neolithic migration from North-West Anatolia into the Balkan Peninsula and Central Europe represent an important contribution to the genetic shift between Early and Late Neolithic populations in Europe, and consequently to the genetic make-up of modern European populations.

Table 2. Haplotype (ht) and haplogroup (hg) mtDNA distribution resulting of the analysis of 62 ancient individuals from Romania.

Please notice that, contrary to what the abstract says, I do not consider that Boian-Maritza and derived cultures belong to any second wave from Anatolia but rather to the wider Danubian (LBK-derived) Central European macro-culture. There was indeed a second wave from Anatolia (Halaf-related, it seems) but it mostly affected Greece, Macedonia and Serbia (Vinca, Dimini and related cultures). It briefly affected Bulgaria and Wallachia as well but this Danubian Boian-Maritza wave from the North neutralized its influence. 

Gumelnita (Karanovo-Gumelnita) culture is particularly remarkable as civilization center of ancient Europe before the Kurgan (Indoeuropean) invasions. They were strongly involved in the earliest development of bronze metallurgy known to date (oddly enough considered "late Neolithic" in this study).

Rather than thinking that these cultures (Boian →→ Gumelnita) had a major effect on European genetics, I'd say that they reflect greater degree of "Europeanization", if anything. Anyhow the key marker here is (as usual) mtDNA H but in no case (except one Late Bronze individual) is H1, so we are rather talking of other less influential sublineages.

Montenegro was part of the Dolmenic Megalithic phenomenon

Just read a most interesting article, with many beautiful images at Old European culture blog: the excavation of a tumulus at Danilovgrad showed it was not a Bronze Age Indoeuropean/Kurgan thing but a true dolmen (trilithon) and many centuries older than expected: c. 2400 BCE. 

There are thousands of similar tumuli awaiting excavation, most in the same rich area of Central Montenegro. This finding puts the Balcanic country (and probably also neighboring regions of the Western Balcans) fully within the Dolmenic Megalithic tradition in the late Copper Age. 

Also an intriguing bronze artifact was part of the grave goods, as well as zig-zag decorated pottery.

Everything you wanted to know about Balcan and Carpathian Neolithic

Prolific researcher Esther Bamfy recently uploaded to her academia.edu page this most interesting publication, which, even if it is not "recent", has a load of information on the Neolithic of the Balcans, which is crucial to understand that of Europe in general.

Various authors. A SHORT WALK THROUGH THE BALKANS:THE FIRST FARMERS OF THE CARPATHIAN BASIN AND ADJACENT REGIONS. Proceedings of the Conference held at the Institute of Archaeology UCL on June 20th - 22nd, 2005. Freely available at academia.edu → LINK.

The collection is pretty much exhaustive but the paper that most caught my attention was the one by J.K. Koszlowski, titled "Western Anatolia, the Aegean Basin and the Balcans in the Neolithisation of Europe", which underlines that, contrary to pop culture ideas, often making headway into flawed genetic or linguistic studies, the first European Neolithic of Greece (Thessaly and Argolid) can't be related to Western Anatolia, where there was no such Neolithic yet but probably arrived, maybe via Cyprus, by sea.

This is coincident with what I wrote months ago at PPNB ancient mtDNA and its legacy.

But all 18 papers are very much worth reading anyhow, take a look.