Cystic fibrosis probably spread with expanding Bell Beakers

indo-european-uralic-bell-beaker-corded-ware-migrations

New paper (behind paywall) Estimating the age of p.(Phe508del) with family studies of geographically distinct European populations and the early spread of cystic fibrosis, by Farrell et al., European Journal of Human Genetics (2018).

Interesting excerpts (emphasis mine):

Our results revealed tMRCA average values ranging from 4725 to 1175 years ago and support the estimates of Serre et al. (3000–6000 years ago) [11], rather than Morral et al. (52,000 years ago) [6], but the latter figure was challenged by Kaplan et al. [26] because of disagreement with assumptions used in their calculations. In addition, the tMRCA values from western European regions reported herein refine the results of Fichou et al. [7] from a study of Breton CF patients in which the Estiage analysis suggested that the most common recent ancestor lived 115 generations ago. That tMRCA value, however, may have underestimated the age of p.(Phe508del) in Brittany due to consideration of all the haplotypes, even those that were reconstructed with ambiguities, as well as a potential bias associated with consanguinity due to including both haplotypes in homozygous families. In the more stringent Estiage analyses reported herein, those potential biases were avoided for all populations, leading to estimates of the oldest tMCRA values corresponding to the Early Bronze Age in western Europe, which is generally agreed to begin around 3000 BCE. This finding extends our results from a direct investigation of aDNA in teeth from Iron Age burials near Vienna around 350 BCE and allow us to conclude that p.(Phe508del) was present in that region long before then. More specifically, in the Austrian families studied, the Estiage data revealed a mean tMCRA value of 3575 years ago, which converts to 1558 BCE (Middle Bronze Age) [22].

Perhaps most remarkably, the estimated ages of p.(Phe508del) in the three western European regions (France, Ireland, and Denmark) were similar with closely overlapping 95% CI values. This observation is also in line with previously documented spatial autocorrelograms expressing genetic and geographical distance for these populations [24]. Such data provide more insight about the ancient origin of CF in our judgment—both when and where—and lead us to propose that CFTR p.(Phe508del) is derived from ancestors who lived in western Europe during the Bronze Age, as early as 2700 BCE, and that its relatively rapid dissemination occurred because of human migrations around the northwestern Atlantic trading routes [21] and then towards central and eastern Europe [22]. Diffusion from northwestern to central Europe in approximately 1000 years is consistent with the prominent Bronze Age migrations evident in the archeological record [21, 22] and from genomic studies of aDNA [27]. On the other hand, we are assuming a discrete origin of the principal CF-causing variant, but it is possible that p.(Phe508del) arose more than once or earlier, and then reached western Europe subsequently through Neolithic migrations.

cystic-fibrosis

[About Bell Beakers] (…) More specifically, their distinctive Bell Beaker pottery appeared and spread across western and central Europe beginning around 3000–2750 BCE and then disappeared between 2200 and 1800 BCE [22, 29]. Their migrations are linked to the advent of western and central European metallurgy, as they manufactured and traded metal goods, especially weapons, while traveling over long distances [30]. Most relevant to our study is the evidence that they migrated in a direction and over a time period that fits well with the pattern of tMRCA data we found for the p.(Phe508del) variant. Olalde et al. [29] have shown that both migration and cultural transmission played a major role in diffusion of the “Beaker Complex” and led to a “profound demographic transformation” of Britain after 2400 BCE. Moreover, the cultural elements that unite the widely distributed Beaker folk are so obvious that some have considered them a distinct ethnicity of Bronze Age people [33].

From our results, we propose the novel concept that large scale, long term west-to-east migrations of the Bell Beaker Europeans [22, 28–30] during the Bronze Age, could explain the dissemination of p.(Phe508del) in Europe and its documented northwest-to-southeast gradient [4].In fact, our tMRCA data show a temporal gradient also.

As you can see from the references, they consulted with Barry Cunliffe (or people accepting his theory), who is obsessed with Bell Beakers expanding Celtic languages from the British Isles. He is like the British equivalent of Danish scholar Kristian Kristiansen, and his obsession with Corded Ware = Indo-European (and Germanic = CWC Denmark), immutable no matter what genetic results might show.

The funny thing is, the interpretation of the paper is probably right. From what we can see in the data, it is quite possible that the disease spread with expanding Bell Beakers…only it spread from the East group in Hungary, i.e. from east to west. The regional difference in TMRCA and apparent west—east cline would point to the different expansions of affected lineages in the corresponding regions, and not to an origin in the British Isles.

Related

Mitogenomes from the middle of the Merovingian period in the Lorraine region

herange-burial

Investigating the kinship between individuals deposited in exceptional Merovingian multiple burials through aDNA analysis: The case of Hérange burial 41 (Northeast France), by Deguilloux et al. Journal of Archaeological Science: Reports (2018) 20:784-790.

Interesting excerpts (emphasis mine):

The Merovingian period in Northeast France (developing from 440/450 to 700/710 CE; Legoux et al., 2004) represents [a case of multiple burial], where a large majority of the types of deposits encountered consists of individual burials. In this context, whereas hundreds of individual burials are known, the syntheses recently conducted have enabled the inventory of only six multiple burials (Lefebvre and Lafosse, 2016). These observations naturally raised questions about the exceptional circumstances that led the members of the community to set up such unusual burials. The archaeological site of Hérange, excavated in 2014 (Lorraine, Grand Est region; Fig. S1), holds a key position in the debate surrounding the interpretation of multiple burials during the Merovingian period since it contains one of these rare multiple burials: burial 41, which was dated through archaeological material to the period 530–640 CE.

(…) The biological analysis of the human remains recovered in the second burial (“burial 41”) enabled the demonstration of the combined presence of a woman of approximately 40 years old (A) and three immature individuals, including a 4–5-year-old child (B), a 14–16-year-old teenager (C) and a 2,5–3-month-old infant (D) (Lefebvre and Lafosse, 2016) (Fig. 1). Since rare multiple burials described for the Merovingian period in Northeast France mainly contained two or rarely three deceased, the discovery of a burial grouping four individuals reinforced its exceptional nature. (…) Intriguingly, great care was observed in the treatment of the dead, as illustrated through a special arrangement of the deceased in the grave (Fig. 1). Indeed, the woman A occupied a central position in the grave, with her left arm covering part of the body of child D, her right arm covering the torso of child B and her right hand covering the legs of children B and C. Several arguments, such as the close contact or the imbrication of the bones of individuals A, B and C, have attested to the simultaneity of their deposits in the burial (Lefebvre and Lafosse, 2016).

mitochondrial-distribution-merovingian
Geographic distribution of the extant European individuals sharing mitochondrial haplotypes with the Hérange human remains.

Interestingly, studies have demonstrated an important chronological homogeneity for the rare multiple burials discovered for the Merovingian period in the Lorraine region (Lefebvre and Lafosse, 2016). The collected data support the existence of an epiphenomenon arisen around the middle of the Merovingian period and that may have linked the multiple burials to (i) a funerary “fashion trend” for a special group of the community, (ii) an increase in cases of violence or (iii) an epidemic crisis linked to infectious disease. In other Lorraine sites, none of the available indices permitted the specification of the cause of death for the individuals recovered in these specific burials. The deceased could well have died of natural causes, violent acts or infectious diseases that had left no visible evidence on the skeletal.

merovingian-y-chromosome
Nuclear data (Y chromosome SNPs and nuclear STRs) typed on the four Hérange human remains (STRs alleles shown in grey were not fully replicated).

The aDNA analyses conducted on the four individuals discovered in the exceptional multiple burial 41 from Hérange (Lorraine) have demonstrated strong biological links between three individuals. Notably, we could propose that the woman A was the mother of the two immatures B and D deposited just besides her whereas she was not genetically closely related to the teenager C deposited along her legs. Consequently, we propose that the special arrangement of the deceased in the grave clearly reflected the degree of biological links between the deposited individuals. In Hérange, the bereaved were well aware of kinship among the deceased, wanted to express this close linkage through their relative location within the burial, and intentionally arranged body positions consequently. In conclusion, the collected archaeological, archaeo-anthropological and genetic data suggest that the special setup of the multiple burial 41 in the Hérange necropolis and the great care in the treatment of the dead, could be explained by the contemporaneous death of the four related individuals. Data gathered for other archaeological sites from the region or in Germany suggested an epidemic crisis (plague epidemic?) during the middle of the Merovingian period that may explain the contemporaneous death of related individuals living in close contact and easily sharing pathogens.

mitogenomes-merovingian

Reported mtDNA haplogroups include U* for samples A, B, and D, and H for sample C.

Related:

Oldest bubonic plague genome decoded in Srubna ca. 3800 YBP

New open access paper from the Max Planck Institute: Analysis of 3800-year-old Yersinia pestis genomes suggests Bronze Age origin for bubonic plague, by Spyrou et al., Nature Communications (2018) 9:2234.

Interesting excerpts from the paper and supplementary materials (emphasis mine):

Here, we analyse material from the Mikhailovsky II burial site, which was excavated in 2015 and is one of numerous kurgan cemeteries identified in the Samara Oblast. It consists of seven kurgan burials, and is chronologically associated to the ‘Pokrovka’ phase (3,900-3,750 BP) of the ‘Srubnaya’ culture (3,850-3,150 BP) (radiocarbon dates produced in this study provided in Supplementary Table 6), also referred to as the ‘proto-Srubnaya’ that is considered the earliest phase of the LBA in the Samara Oblast. All sex and age groups were represented in this cemetery. We analysed nine individuals buried in three kurgans and identified two individuals buried in the same kurgan (see Supplementary Figure 1) to be positive for Y. pestis. According to anthropological analysis these were a 30-40 year-old male (RT5) and 35- 45 year-old female (RT6).

After its divergence from Y. pseudotuberculosis, Y. pestis acquired its high pathogenicity and distinct niche mainly by chromosomal gene loss16 as well as the acquisition of two virulence-associated plasmids, pMT1 and pPCP11,17,18. Throughout this process, one of the most crucial evolutionary adaptations related to its pathogenicity was its ability to colonise arthropods, a phenotypic/functional gain mediated by a combination of chromosomal and plasmid loci19,20. These genetic changes are central to the most common “bubonic” form of the disease, where bacteria enter the body via the bite of an infected flea, travel via the lymph to the closest lymph node and replicate while evading host defences. Recent ancient genomic investigations of Y. pestis have identified its earliest known variants in Eurasia during the Late Neolithic/Bronze Age period (LNBA) that show genetic characteristics incompatible with arthropod adaptation. These strains, therefore, have been considered incapable of an efficient flea-based transmission2; however, the alternative early-phase transmission could have provided an independent means of arthropod dissemination2,3,21. To date, the earliest evidence of a Y. pestis strain with signatures associated with flea adaptation has been reported during the Iron Age through shotgun sequencing of an ~2900-year-old genome from Armenia (strain RISE397), though at a coverage too low (0.25-fold) to permit confident phylogenetic positioning2. Although the mechanism by which the LNBA lineage caused human disease is unclear, its frequency in Eurasia during the Bronze Age2,3 and its phylogeographic pattern that mimics contemporaneous human migrations are noteworthy3.

population-srubna-pca
Population genetic analysis to infer the ancestry of RT5. b Principal component analysis (PCA) of modern-day western Eurasian populations (not shown) and projected ancient populations (n = 82, see population labels), including the newly sequenced RT5 individual from Samara and c estimation of ancestral admixture components using ADMIXTURE analysis (K= 12) (see Supplementary Methods)

The central steppe region seems to have played a significant role as a migration corridor during the entire Bronze Age, and as such, it likely facilitated the spread of human-associated pathogens, such as Y. pestis, across Eurasia. Here, we explore additional Y. pestis diversity in that region by isolating strains from LBA Samara, in Russia. We identify a Y. pestis lineage contemporaneous to the LNBA strains with genomic variants consistent with flea adaptation. This reveals the co-circulation of two Y. pestis lineages during the Bronze Age with different properties in terms of their transmission and disease potentials.

A recent study has suggested that flea-adapted Y. pestis, along with its potential to cause bubonic plague in humans, likely originated around 3000y BP2. Contrary to such conclusions, the lineage giving rise to our Y. pestis isolates (RT5 and RT6) likely arose ~4000 years ago (Supplementary Tables 6 and 9), and possessed all vital genetic characteristics required for flea-borne transmission of plague in rodents, humans and other mammals. (…)

Moreover, our analysis of the previously published Iron Age RISE397 strain from modern-day Armenia2 revealed its close relationship to RT5 and RT6 (Supplementary Fig. 4). Note that the modern 0.PE2 and 0.PE7 lineages, which are known to possess all genomic characteristics that confer adaptation to fleas19, fall ancestral to RT5 (Fig. 2b) and RISE397 (Supplementary Fig. 4), but are more derived than the LNBA lineage. Our phylogenetic and dating results thus suggest that 0.PE2 and 0.PE7 also originated during the Bronze Age, with their mean divergence here estimated to 4474 (HPD 95%: 3936–5158) and 5237 (HPD 95%: 4248–6346) years BP, respectively, based on the Bayesian skyline model (Supplementary Table 9). While these lineages may have been confined to sylvatic rodent reservoirs during the EBA, the possibility that they co circulated among human populations contemporaneously with the LNBA lineage should be considered. Although the places of origin of 0.PE2 and 0.PE7 are not known, today, their strains are isolated from modern-day China and the Caucasus region. In terms of their disease potential, both 0.PE2 and 0.PE7 possess pMT1 plasmids with fully functional ymt genes, but 0.PE2 strains lack pPCP144, and though frequently recovered from sylvatic rodent reservoirs, their virulence in humans is not known. On the other hand, the more basal 0.PE7 contains pPCP12 and has previously been associated with human bubonic plague12. It is, therefore, tempting to hypothesise that efficient flea adaptation in Y. pestis, as well as the potential for bubonic disease, might have evolved earlier than 5000 years ago.

plague-clade-tree
Maximum Clade Credibility tree. The MCC tree was produced using TreeAnnotator of BEAST v1.88 and is a product of demographic analysis based on the Coalescent Skyline model, summarizing 27,001 trees. The tree was visualized in FigTree v1.4.2 (http://tree.bio.ed.ac.uk/software/figtree/). It is presented in a temporal scale between 6,000 and 0 yBP, and the mean divergence dates of major Y. pestis lineages are indicated on each corresponding node.

It seems possible that already in the Bronze Age, with the establishment of transport and trade networks, the interconnectivity between Europe and Asia that is also reflected in the ancient human genomes, likely contributed to the spread of infectious disease. Similarly, the abundant trade routes of the medieval period are considered the main conduit for plague’s movement between Asia and Europe8,12. Our current data suggest a more complex model, where at least two human-associated lineages (LNBA and RT5) with different transmission potentials were established in Eurasia during the Bronze Age (Fig. 2b, c).

The haplogroup of RT5 is R1a1a1b-Z645 (most likely Z93, only with coverage of 1-fold), mtDNA U2e2a.

See also materials from the Max Plank Institute.

Related:

Copenhagen group: Germanic and Balto-Slavic from Bell Beaker; Indo-Anatolian homeland in the Caucasus

invasion-from-the-steppe-yamnaya

Article of general knowledge in Der Spiegel, Invasion from the Steppe, with comments from Willerslev and Kristiansen, appeared roughly at the same time as the Damgaard et al. Nature (2018) and Science (2018) papers were published.

NOTE. You can read the article (in German) from Kristiansen’s Academia.edu account.

Excerpts translated from German (emphasis mine):

On the Y-DNA data

Particularly striking is the genetic signature from the steppe on the Y chromosome. From this the researchers conclude that the majority of migrants were males. Kristian Kristiansen, chief archaeologist in the Willerslev team, also has an idea of ​​how this could be explained: “Maybe it’s a rite of initiation, as it was spread among the steppe peoples,” he says.

The younger sons of the Yamnaya herders, who were excluded from the succession, had to seek their fortune on their own. As part of a solemn ritual, they threw themselves to wolves’ skins and then swarmed in warlike gangs to buy their own herds by cattle-stealing.

(…)

An ally that they seem to have brought from their homeland may also have contributed to the genetic success of the steppe people: Yersinia pestis, the plague bacterium. Its genes were found by researchers from the Max Planck Institute in Jena – and apparently it emerged exactly at the same time as the Yamnaya thrust began.

About the Hittites

(…) And yet now, where Asia and Europe meet geographically, there is no trace of the Yamnaya genes. The wander-loving people from the Pontic-Caspian steppe apparently found neither the way across the Balkans nor through the Caucasus mountains.

Now the researchers are puzzled: How can it be that a language goes on a walk, without the accompanying speakers coming along? Is it possible that the Indo-European seeped into Anatolia, much like the English language spread today without the need for Englishmen?

Archaeologist Kristiansen does not believe it. The researchers would find it hard to reconsider their theories, he says: “Especially the first chapter of the story has to be rewritten.”

He suspects that there was a predecessor of the Yamnaya culture, in which a kind of Proto-Proto-Indo-European was spoken. And he also has a suspicion, where this people could have drifted around: The Caucasus, says Kristiansen, was their homeland. But that remains unproven: “There’s another hole left,” he admits.

invasion-yamnaya-steppe
Spread of Indo-European languages

About the Botai

The study of [the Botai] genome revealed that it was genetically radically different from the members of the Yamnaya culture. The Botai, it seems, consistently avoided any contact with their neighbors – even though they must have crossed the territory of the Botai on their migratory waves.

Willerslev assumes that the art of keeping horses from the Yamnaya steppe nomads was adopted from these peoples, and then they developed it further. At some point, the Botai could then have itself become doomed by its groundbreaking innovation: While the descendants of the Yamnaya spread over half of Eurasia, the Botai disappeared without leaving a trace.

Even more interesting than the few words that set the Copenhagen group’s views for future papers (such as the expected Maykop samples with EHG ancestry) is the artistic sketch of the Indo-European migrations, probably advised by the group.

A simple map does not mean that all members of the Danish workgroup have changed their view completely, but I would say it is a great improvement over the previous “arrows of migration” (see here), and it is especially important that they show a more realistic picture of ancient migrations to general readers.

NOTE. Especially absurd is the identification of the ‘Celtic’ expansion with the first Bell Beakers in the British Isles (that idea is hold by few, such as Koch and Cunliffe in their “Celtic from the West” series). Also inexact, but not so worrying, are the identification of ‘Germanic’ in Germany/Únětice, or the spread of ‘Baltic’ and ‘Slavic’ directly to East Europe (i.e. I guess Mierzanowice/Nitra -> Trzciniec), which is probably driven by the need to assert a close connection with early Iranians and thus with their satemization trends.

Also, as we know now thanks to Narasimhan et al. (2018), there is no need to support that convoluted west arrow (representing CWC) from West Yamna to Central Europe, and then to East Yamna, since the Proto-Indo-Iranian community – represented by the Steppe MLBA cloud that later expanded Indo-Aryan and Iranian languages – has a more direct connection with the in situ admixture of Poltavka/Abashevo within the Volga-Ural region.

I think we can keep this from the article:

Their results, as well as those of the competition labs at Harvard University and Jena’s Max Planck Institute for the History of Humanity, leave no doubt: Yes, the legendary herdsmen in the Pontic-Caspian steppe really existed. They belonged to the so-called Yamnaya culture, and they spread, as linguists had predicted, in massive migrations towards Central Europe and India – a later triumph for linguists.

This can be added to a recent comment by de Barros Damgaard:

The project has been an extremely enriching and exciting process. We were able to direct many very different academic fields towards a single coherent approach. By asking the right questions, and keeping limitations of the data in mind, contextualizing, nuancing, and keeping dialogues open between scholars of radically different backgrounds and approaches, we have carved out a path for a new field of research. We have already seen too many papers come out in which models produced by geneticists working on their own have been accepted without vital input from other fields, and, at the other extreme, seen archaeologists opposing new studies built on archaeogenetic data, due to a lack of transparency between the fields.

Data on ancient DNA is astonishing for its ability to provide a fine-grained image of early human mobility, but it does stand on the shoulders of decades of work by scholars in other fields, from the time of excavation of human skeletons to interpreting the cultural, linguistic origins of the samples. This is how cold statistics are turned into history.

Related:

Ancient DNA study reveals HLA susceptibility locus for leprosy in medieval Europeans

danemark-medieval

Open access Ancient DNA study reveals HLA susceptibility locus for leprosy in medieval Europeans, by Krause-Kyora et al., Nature Communications (2018)

Abstract:

Leprosy, a chronic infectious disease caused by Mycobacterium leprae (M. leprae), was very common in Europe till the 16th century. Here, we perform an ancient DNA study on medieval skeletons from Denmark that show lesions specific for lepromatous leprosy (LL). First, we test the remains for M. leprae DNA to confirm the infection status of the individuals and to assess the bacterial diversity. We assemble 10 complete M. leprae genomes that all differ from each other. Second, we evaluate whether the human leukocyte antigen allele DRB1*15:01, a strong LL susceptibility factor in modern populations, also predisposed medieval Europeans to the disease. The comparison of genotype data from 69 M. leprae DNA-positive LL cases with those from contemporary and medieval controls reveals a statistically significant association in both instances. In addition, we observe that DRB1*15:01 co-occurs with DQB1*06:02 on a haplotype that is a strong risk factor for inflammatory diseases today.

danes-leprosy-positive
Relationship of 53 medieval leprosy-positive Danes to contemporary Europeans. Principal component analysis plot for 53 medieval St. Jørgen individuals in relation to European population samples from the 1000 Genomes project. (CEU, Northern Europeans from Utah; GBR, British in England and Scotland; IBS, Iberian population in Spain; TSI, Tuscans in Italy; FIN, Finnish in Finland)

The study shows mtDNA haplogroups comparable to those of northern Europeans today, and findings in general indicate no major genome-wide changes in the Danish population structure in the past 1000 years.

The paper may be of interest for earlier migrations:

rs3135388-t-allele-frequency-leprosy

Discovered via Iain Mathieson:

Related:

Mixed haplogroups R1a, R1b, I, in collective burials of early Medieval Bavarians

antiquity-europe

New paper (behind paywall) Family graves? The genetics of collective burials in early medieval southern Germany on trial, by Rott. Päffgen, Haas-Gebhard, Peters, & Harbecka, J Arch Sci (2018) 92: 103–115.

Abstract:

Simultaneous collective burials appear quite regularly in early medieval linear cemeteries. Despite their relatively regular occurrence, they are seen as extraordinary as the interred individuals’ right to be buried in a single grave was ignored for certain reasons. Here, we present a study examining the possible familial relationship of early medieval individuals buried in this way by using aDNA analysis of mitochondrial HVR-I, Y-STRs, and autosomal miniSTRs. We can show that biological relatedness may have been an additional reason for breaking the usual burial custom besides a common cause of death, such as the Plague, which is a precondition for a simultaneous burial. Finally, with our sample set, we also see that signs of interaction between individuals such as holding hands which are often interpreted by archeologists as signs of biological or social relatedness, do not always reflect true genetic kin relationships.

Most of the burials studied are from the mid-6th and early 7th century, and all are from collective burials:

Of the simultaneous burials nine graves are proven or potential (due to contemporaneity) Plague burials (Feldman et al., 2016; Harbeck et al., 2013) and one grave is attributed to interpersonal violence against the background of the early medieval feud system (Schneider, 2008). The remaining simultaneous and the two successive burials did not reveal hints on their individuals’ cause of death.

The distribution of lineages includes R1b, R1a, and I (one family each) in Altenerding-Klettham, and T, R1b, and R1a (two families) in Aschheim-Bajuwarenring.

bavaria
Map of Upper Bavaria showing the location of the sites investigated. Both Aschheim and Altenerding are located north-east of the Bavarian capital Munich (black star). The two sites are approximately 20 km apart from each other. The map is based on maps taken from here and here (Wikimedia Commons).

There were, for example:

A father and son R1a in a “warrior grave”:

Showing traces of perimortal sharp traumata (AE 888), both men seem to have died in succession of a physical conflict (Sage, 1984). It must remain open, whether this conflict was executed as a blood vengeance in connection with the medieval feud system (Schneider, 2008; Steuer, 2008) or any other kind of interpersonal violence. Attacks and interpersonal violence are also often believed to be a precondition for individuals being buried together.

It has been assumed that burials of several men with weaponry, so-called “warrior graves”, are burials which reflect the early medieval feud system (Schneider, 2008; Steuer, 2008) in the very sophisticated but implausible assumption, that women and children might have been spared in those conflicts. While feuds were actually struggles between familiae, friends and servants of a particular family could be also involved, which would explain the deposition of nonrelated individuals in such burials.

Two children, half-siblings, one of haplogroup R1b, in a shared coffin.

A non-genetic family of an elderly man of haplogroup I and a child being protected:

The early medieval concept of familia not only comprised the (biological) nuclear family and individuals certainly entered a family clan by marriage. This leaves room for any possible social (i.e. non-genetic) relation that may have allowed these two individuals to be buried in a common grave.

It is tempting for me to hail the mixed genetic pool among late Germanic tribes found in recent genetic studies, as I have done for Proto-Balto-Slavic territory and Iberia.

It is indeed possible that the mostly R1b-L11 and I1 subclades seen in late medieval West Germanic-speaking populations (and in modern West Germanic speakers) are in fact the result of later internal migratory flows and founder effects.

However, Bavarians – like the recently studied Lombards (with a predominance of R1b and I lineages), and especially Goths (apparently showing ‘eastern’ ancestry) – occupied territories of mixed ‘Barbarian’ populations after the invasion of the Huns and their allies, and settled near Slavs and Avars.

EDIT (18 MAR 2018). We should add here for this southern Germanic territory the Merovingian burials (ca. 7th c.) from Ergolding, with 3 samples of haplogroup R1b, and 2 samples of G2a, published by Vanek, Saskova, & Koch (2009).

Earlier, expanding Proto-Germanic tribes may not show this variable admixture and haplogroups we are seeing right now, though.

Related: