Mitogenomes show Longobard migration was socially stratified and included females

antiquity-germanic-migrations

New bioRxiv preprint A genetic perspective on Longobard-Era migrations, by Vai et al. (2018).

Interesting excerpts (emphasis mine):

In this study we sequenced complete mitochondrial genomes from nine early-medieval cemeteries located in the Czech Republic, Hungary and Italy, for a total of 87 individuals. In some of these cemeteries, a portion of the individuals are buried with cultural markers in these areas traditionally associated with the Longobard culture (hereby we refer to these cemeteries as LC), as opposed to burial communities in which no artifacts or rituals associated by archaeologists to Longobard culture have been found in any graves. These necropolises, hereby referred as NLC, may represent local communities or other Barbaric groups previously migrated to this region. This extended sampling strategy provides an excellent condition to investigate the degree of genetic affinity between coeval LC and NLC burials, and to shed light on early-medieval dynamics in Europe.

lombard-hungary-czech
Geographical and genetic relationship between the newly sequenced individuals. (A) Location of the sampled necropolises. Here and through the other figures LC cemeteries are represented by a circle while NLC ones are indicated by a square. C) DAPC Scatterplot of the most supported K (7) highlighted by the kmeans analysis

Social rank

There is also no clear geographical structure between samples in our dataset, with individuals from Italy, Hungary and Czech Republic clustering together. However, the first PC clearly separates a group of 12 LC individuals found at Szólád, Collegno and Mušov from a group composed by both LC and NLC individuals. The same pattern is also found when pairwise differences among individuals are plotted by multidimensional scaling (…)

The presence in this group of LC sequences belonging to macrohaplogroups I and W, commonly found at high frequencies in northern Europe (e.g. Finland 32), suggests (although certainly does not prove) the existence of a possible link between these 12 LC individuals and northern Europe. The peculiarity of this group is strengthened by archaeological information from the Szólád cemetery, where 8 of the 12 individuals in this group originated, indicating that all these samples were found buried with typical Longobard artifacts and grave assemblages. We do not find the same tight association for the 3 samples from Collegno, where the 3 graves are indeed devoid of evident Germanic cultural markers; however they are not placed in a separate and marginal location—as for the tombs without grave goods found in Szólád —but among graves with wooden chambers and weapons. It is worth noting that weapon burials were quite scarce in 5th century Pannonia and 6th century Italy (e.g. Goths never buried weapons), and an increase in weapon burials started in Italy only after the Longobard migration. In this light, the individuals buried in this manner may have been members of the same community as well, but belonging to the lowest social level. This social condition could explain the absence of artifacts and could be related to mixed marriages, whose offspring had an inferior social rank. Finally, this group also includes an individual from the Musov graveyard. This finding is particularly interesting in light of the fact that the Musov necropolis has been only tentatively associated with Longobard occupation (see Supplementary Text for details), based on the presence of but a few archaeological markers.

Female migration

We hence estimated that about 70% of the lineages found in Collegno actually derived from the Hungarian LC groups, in agreement with previous archaeological and historical hypotheses. This supports the idea that the spread of Longobards into Italy actually involved movements of fairly large numbers of people, who gave a substantial contribution to the gene pool of the resulting populations. This is even more remarkable thinking that, in many studied cases, military invasions are movements of males, and hence do not have consequences at the mtDNA level. Here, instead, we have evidence of changes in the composition of the mtDNA pool of an Italian population, supporting the view that immigration from Central Europe involved females as well as males.

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Genomic analysis of Germanic tribes from Bavaria show North-Central European ancestry

antiquity-europe

New open access paper Population genomic analysis of elongated skulls reveals extensive female-biased immigration in Early Medieval Bavaria, by Veeramah, Rott, Groß, et al. PNAS (2018), published ahead of print.

First, a bit of context on the Bavarii:

Europe experienced a profound cultural transformation between Late Antiquity and the Middle Ages that laid the foundations of the modern political, social, and religious landscape. During this period, colloquially known as the “Migration Period,” the Roman Empire gradually dissolved, with 5th and 6th century historiographers and contemporary witnesses describing the formation and migration of numerous Germanic peoples, such as the Goths, Alamanni, Gepids, and Longobards. However, the genetic and social composition of groups involved and the exact nature of these “migrations” are unclear and have been a subject of substantial historical and archaeological debate

In the mid 6th century AD, the historiographer Jordanes and the poet and hagiographer Venantius Fortunatus provide the first mention of a group known as the Baiuvarii that resided in modern day Bavaria. It is likely that this group had already started to form in the 5th century AD, and that it emanated from a combination of the romanized local population of the border province of the former Roman Empire and immigrants from north of the Danube (2). While the Baiuvarii are less well known than some other contemporary groups, an interesting archaeological feature in Bavaria from this period is the presence of skeletons with artificially deformed or elongated skulls.

bavarii-pca
Procrustes-transformed PCA of ancient samples using pseudohaploid calls based on off-target reads using an imputed POPRES modern reference dataset. Blue, green, and red male or female symbols are ancient Bavarian individuals with normal, intermediate, and elongated skulls, respectively. Orange circles are Anglo-Saxon era individuals. Large circles are medians for regions, dots are individuals. CE, central Europe; EE, eastern Europe; NE, northern Europe; NEE, northeastern Europe; NEW, northwestern Europe; SE, southern Europe; SEE, southeast Europe; WE, western Europe. Percentage of variation explained by PCs 1 and 2 for modern populations only is 0.25% and 0.15%.

Abstract (emphasis mine):

Modern European genetic structure demonstrates strong correlations with geography, while genetic analysis of prehistoric humans has indicated at least two major waves of immigration from outside the continent during periods of cultural change. However, population-level genome data that could shed light on the demographic processes occurring during the intervening periods have been absent. Therefore, we generated genomic data from 41 individuals dating mostly to the late 5th/early 6th century AD from present-day Bavaria in southern Germany, including 11 whole genomes (mean depth 5.56×). In addition we developed a capture array to sequence neutral regions spanning a total of 5 Mb and 486 functional polymorphic sites to high depth (mean 72×) in all individuals. Our data indicate that while men generally had ancestry that closely resembles modern northern and central Europeans, women exhibit a very high genetic heterogeneity; this includes signals of genetic ancestry ranging from western Europe to East Asia. Particularly striking are women with artificial skull deformations; the analysis of their collective genetic ancestry suggests an origin in southeastern Europe. In addition, functional variants indicate that they also differed in visible characteristics. This example of female-biased migration indicates that complex demographic processes during the Early Medieval period may have contributed in an unexpected way to shape the modern European genetic landscape. Examination of the panel of functional loci also revealed that many alleles associated with recent positive selection were already at modern-like frequencies in European populations ∼1,500 years ago.

bavarii-admixture
Supervised model-based clustering ADMIXTURE analysis for ancient samples based on phased haplotypes for individual 1,000 bp loci from the 5-Mb neutralome. Analysis is based on the best of 100 runs for K = 8, but NC_EUR is the ancestry summed across 1000 Genomes CEU, 1000 Genomes GBR, and GoNL populations (i.e., it represents a northern/central European ancestry). Blue, green, and red male or female symbols are ancient Bavarian individuals with normal, intermediate, and elongated skulls, respectively.

There is no Y-DNA data to keep confirming the North-Central origin of certain modern European subclades in Central and South-Central Europe.

The potential Ostrogothic sample from Crimea was probably Hunnic, as the paper itself suggests, and both Ostrogoths and Gepids are known to have been allies of the Huns for a long time. It is also a well-known fact that East Germanic tribes migrated south- and eastward through eastern Europe, and then from the steppe westward.

Obviously, the PCA of a late Gepid sample – after a certain number of generations and admixture events with ‘local’ populations during the migrations – , and of a Crimean sample without a clear cultural identification, are of limited value today, until more samples are available.

Hence sadly no valid data yet to add to the debate of East Germanic nature, which mainly concerns its traditionally described origin in Scandinavia – i.e. close to North Germanic dialects – against a different origin (and dialectal branch) within Proto-Germanic territory.

NOTE. Just to be clear for future papers on Germanic tribes, I would expect East Germanic males to show either:
a) mainly R1b-U106, I1, and R1a-Z645 subclades, and to cluster closely to samples of Scandinavia during Antiquity, which would support a Scandinavian origin – a predominance of typically Scandinavian R1a-Z284 subclades would be more indicative of this origin, of course;
b) or mainly R1b-U106, R1b-P312, and I1 subclades and a PCA cluster close to West Germanic tribes, which would challenge its traditional dialectal identification.

I agree with the authors in that a few samples are able to describe certain migratory events, though, such as the emphasized female-biased long-distance migration in Bavaria, as well as the diverse ancestry of women versus men.

Related:

Germanic tribes during the Barbarian migrations show mainly R1b, also I lineages

antiquity-europe

New preprint at BioRxiv, Understanding 6th-Century Barbarian Social Organization and Migration through Paleogenomics, by Amorim, Vai, Posth, et al. (2018)

Abstract (emphasis mine):

Despite centuries of research, much about the barbarian migrations that took place between the fourth and sixth centuries in Europe remains hotly debated. To better understand this key era that marks the dawn of modern European societies, we obtained ancient genomic DNA from 63 samples from two cemeteries (from Hungary and Northern Italy) that have been previously associated with the Longobards, a barbarian people that ruled large parts of Italy for over 200 years after invading from Pannonia in 568 CE. Our dense cemetery-based sampling revealed that each cemetery was primarily organized around one large pedigree, suggesting that biological relationships played an important role in these early Medieval societies. Moreover, we identified genetic structure in each cemetery involving at least two groups with different ancestry that were very distinct in terms of their funerary customs. Finally, our data was consistent with the proposed long-distance migration from Pannonia to Northern Italy.

Interesting excerpts:

Since the adults were almost all non-local, it is tempting to suggest that we may be observing the historically described fara during migration. Regardless, this group appears to be a unit organized around one high-status, kin-based group of predominantly males, but also incorporating other males that may have some common central/northern European descent. The relative lack of adult female representatives from Kindred SZ1, the diverse genetic and isotope signatures of the sampled women around the males and their rich graves goods suggests that they may have been acquired and incorporated into the unit during the process of migration (perhaps hinting at a patrilocal societal structure that has been shown to be prominent in Europe during earlier periods).

The remaining part of this community for which we have genomic data (N=7) is composed of individuals of mainly southern European genetic ancestry that are conspicuously lacking grave goods and occupy the southeastern part of the cemetery, with randomly oriented graves with straight walls. While the lack of grave goods does not necessarily imply that these individuals were of lower status, it does point to them belonging to a different social group. Interestingly, the strontium isotope data suggest that they may have migrated together with the warrior-based group from outside Szólád, but barriers to gene flow were largely been maintained.

longobards-pca-szolad-collegno
Genetic structure of Szólád and Collegno. (A) Procrustes Principal Component Analysis of modern and ancient European population (faded small dots are individuals, larger circle is median of individuals) along with samples from Szólád (filled circles), Collegno (filled stars), Bronze Age SZ1 (filled grey circle), second period CL36 (grey star), two Avar-period samples from Szólád (yellow circles), Anglo-Saxon period UK (orange circles) and 6th Century Bavaria (green circles). Szólád and Collegno samples are filled with colors based on estimated ancestry from ADMIXTURE. Blue circles with thick black edge = Kindred_SZ1 , blue stars with thick black edge = Kindred_CL1 , stars with thick green edge = Kindred_CL2 . NWE = northwest Europe, NE = modern north Europe, NEE = modern northeast Europe, CE =central Europe, EE = eastern Europe, WE =western Europe, SE = southern Europe, SEE = southeast Europe, HUN = modern Hungarian, HBr = Hungarian Bronze Age, Br = central, northern and eastern Europe Bronze age.

Evidence for Migrating Barbarians and “Longobards”

Our two cemeteries overlap chronologically with the historically documented migration of Longobards from Pannonia to Italy at the end of the 6th century. It is thus intriguing that we observe that central/northern European ancestry is dominant not only in Szólád, but also in Collegno. Based on modern genetic data we would not expect to see a preponderance of such ancestry in either Hungary or especially Northern Italy. While we do not yet know the general genomic background of Europe in these geographic regions just before the establishment of Szólád and Collegno, other Migration Period genomes from the UK and Germany show a fairly strong correlation with modern geography (while also possessing a similar central/northern European ancestry component to that found in Szólád and Collegno). Going further back in time, Late Bronze Age Hungarians show almost no resemblance to populations from modern central/northern Europe, especially compare to Bronze Age Germans and in particular Scandinavians, who, in contrast, show considerable overlap with our Szólád and Collegno central/northern ancestry samples. Coupled with the strontium isotope data, our paleogenomic analysis suggest that the earliest individuals of central/northern ancestry in Collegno were probably migrants while those with southern ancestry were local residents. Our results are thus consistent with an origin of barbarian groups such as the Longobards somewhere in Northern and Central Europe east of the Rhine and north of the Danube. Thus our results cannot reject the migration, its route, and settlement of “the Longobards” described in historical texts.

We note however that whether these people identified as “Longobard” or any other particular barbarian people is impossible to assess. Modern European genetic variation is generally highly structured by geography 22,32 , even at the level of individual villages 33 . It is, therefore, surprising to find significant diversity, even amongst individuals with central/northern ancestry, within small, individual Langobard cemeteries. Even amongst the two family groups of primarily central/northern ancestry, who may have formed the heart of such migration, there is clear evidence of admixture with individuals with more southern ancestry. If we are seeing evidence of movements of barbarians, there is no evidence that these were genetically homogenous groups of people.

longobards-admixture-szolad-collegno
Model-based ancestry estimates from Admixture for Szólád (B) and Collegno (C) using 1000 Genomes Project Eurasian and YRI populations to supervise analysis. Note that high contamination was identified in CL31 and is shown with a triangle in the (A) and overlaid with a pink hue in the (C).

From the supplementary material:

The haplogroups detected in the samples show a prevalence of R1b (55.3%), which is the most common sub-haplogroup in western Europe, with a peak in the Iberian Peninsula and in the British islands and a west-east gradient in central Europe. A consistent percentage of haplotypes belongs to the I haplogroup (26.4%), both in the I1a and, more abundantly, in I2a2 sub-haplogroups. They are particularly frequent in the northern Balkans with a westward gradient in central and western Europe, with some lineages belonging to I2a2a1b particularly common in the Germanic region.

germanic-tribes
Relative and absolute haplogroup frequencies: COL = Collegno; SZO = Szólád; CEU = Central European from Utah; FIN = Finnish; GBR = Britons; IBS = Iberians; SAR = Sardinians; TSI = Tuscans

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