Genetic study Capturing the fusion of two ancestries and kinship structures in Merovingian Flanders

Tautalus

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Ethnic group
Portuguese
Y-DNA haplogroup
I2-M223 / I-FTB15368
mtDNA haplogroup
H6a1b2
Significance
The extent and impact of Early Medieval population movements on the establishment of trade and cultural networks across the North Sea have been the subject of debate for centuries. Analyzing ancient genomes from the Flemish coast, we find two distinct ancestry groups merging in a Late Merovingian community: the major group with a dense network of distant relationships among individuals and genetic affinity to populations around the North Sea coast and the minor group representing likely continental Gaulish ancestry of unrelated individuals from various inland sources. We also find evidence of local continuity suggesting that similarly to Britain, the Early Medieval population movements had a long-term impact and were integral to the formation of the Flemish population.

Abstract
The Merovingian period (5th to 8th cc AD) was a time of demographic, socioeconomic, cultural, and political realignment in Western Europe. Here, we report the whole-genome shotgun sequence data of 30 human skeletal remains from a coastal Late Merovingian site of Koksijde (675 to 750 AD), alongside 18 remains from two Early to Late Medieval sites in present-day Flanders, Belgium. We find two distinct ancestries, one shared with Early Medieval England and the Netherlands, while the other, minor component, reflecting likely continental Gaulish ancestry. Kinship analyses identified no large pedigrees characteristic to elite burials revealing instead a high modularity of distant relationships among individuals of the main ancestry group. In contrast, individuals with >90% Gaulish ancestry had no kinship links among sampled individuals. Evidence for population structure and major differences in the extent of Gaulish ancestry in the main group, including in a mother–daughter pair, suggests ongoing admixture in the community at the time of their burial. The isotopic and genetic evidence combined supports a model by which the burials, representing an established coastal nonelite community, had incorporated migrants from inland populations. The main group of burials at Koksijde shows an abundance of >5 cM long shared allelic intervals with the High Medieval site nearby, implying long-term continuity and suggesting that similarly to Britain, the Early Medieval ancestry shifts left a significant and long-lasting impact on the genetic makeup of the Flemish population. We find substantial allele frequency differences between the two ancestry groups in pigmentation and diet-associated variants, including those linked with lactase persistence, likely reflecting ancestry change rather than local adaptation.

In PNAS it is not an open access article
https://www.pnas.org/doi/10.1073/pnas.2406734121

But the pdf can be downloaded here :
https://lirias.kuleuven.be/retrieve/766284
 
Map and PCA of the samples
mVvdiN8.png


Haplogroups of the samples (from the supplementary information)
ia4Mexa.png
 
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All three E members are E-V13, of which two are brothers. That makes more than 10 % E-V13 for the whole sample.
 
In relation to the 28 males with assigned y haplogroup the distribution is 18 R1b, 7 I1 and 3 E.

ZtHdO8x.png

I1 individuals have predominant North Sea ancestry.
The only E-V13 individual with estimated ancestry has a predominant North Sea ancestry also.
Interestingly R-U106 is associated with an individual with predominant North Sea ancestry and also with individuals with predominant Gaulish ancestry.
v1Upyfk.png
 
Interesting that the Gaulish samples have both R1b-DF19 (typical Celtic) and R1b-U106. I suppose that is because they are of Belgic origin and Belgic tribes have long been presumed to be of mixed Celtic and Germanic descent.

It would be great if someone could check for deeper clades for the various Y-haplogroups. I am also looking forward to the K12b coordinates.
 
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Interesting that the Gaulish samples have both R1b-DF19 (typical Celtic) and R1b-U106. I suppose that is because they are of Belgic origin and Belgic tribes have long been presumed to be of mixed Celtic and Germanic descent.

It would be great if someone could check for deeper clades for the various Y-haplogroups. I am also looking forward to the K12b coordinates.

FTDNA did the samples as far as it goes. E.g. 2 of the 3 E being confirmed E-V13, the third is a brother of one of the confirmed, which makes 3 confirmed. But they couldn't go much more downstream. If you want to check for a specific branch, I would recommend to go into FTDNA Discovery and look out for it.
But as you can see from the E-V13 guys, the coverage is not that great for most of them.
 
This is the detailed path for the Y-HG’s already assigned in the study.
IDY-HGBranchDetailed Y-HG Path
KOS006R1b-L257R-U106M269>L23>L51>P310>L151>U106>Z2265>BY30097>Z18>FGC79182>Z17>Z372>S5695>L257
KOS009R1b-S497R-U106M269>L23>L51>P310>L151>U106>Z2265>BY30097>FTT8>Z381>Z156>S497 (Z306)
KOS010R1b-M269
KOS015R1b-FGC17465R-U106M269>L23>L51>P310>L151>U106>Z2265>BY30097>FTT8>FGC3861>Z8053>S1855>FGC17471>FGC17465
KOS016R1b-S4268R-DF19M269>L23>L51>P310>L151>P312>DF19>DF88>FGC11833>S4281>S4268
KOS017R1b-S4268R-DF19M269>L23>L51>P310>L151>P312>DF19>DF88>FGC11833>S4281>S4268
KOS024R1b-L151
KOS026R1b-P312
KOS032R1b-ZP139R-U106M269>L23>L51>P310>L151>U106>Z2265>BY30097>Z18>FGC79182>Z17>Z372>Y38140>ZP91>BY41788>ZP139 (S7015)
KOS039R1
WPK001AR1b
WPK002R1b-Y1232??
WPK005R1b-L47R-U106M269>L23>L51>P310>L151>U106>Z2265>BY30097>FTT8>Z381>Z301>L48>L47
OLV021R1b
OLV072R1b
OLV051R1b
OLV055R1b
OLV056R1b
KOS002I1I1-M253
KOS007I1-Y15155I1-M253M253>DF29>Z58>Z59>CTS8647>Z61>Z60>Z140>Z141>Z2535>L338>FT456763>Y15155 (A1944)
KOS012I1I1-M253
OLV038I1I1-M253
OLV065I1I1-M253
OLV054I1I1-M253
OLV050I1I1-M253
KOS005E-Z1919E-V13M35>V68>M78>PF2179>Z1919>L618>CTS1975>V13
KOS011E-V13E-V13M35>V68>M78>PF2179>Z1919>L618>CTS1975>V13
OLV058EE-V13 ?

Place in the phylogenetic tree for the R1b-U106 individuals.

u2Iq5pe.png



The sample with 100% Gaulish (KOS009) ancestry belongs to the Z381 branch.

UmWjqtb.png
 
I downloaded the BAM files for samples KOS006 (100% North Sea Ancestry) and KOS009 (100% Gaulish Ancestry) from
https://www.ebi.ac.uk/ena/browser/view/PRJEB70768

And converted them to raw data with with WGSExtract
mUmmocv.png


I uploaded it to Gedmatch with the recommended format (combined file of all SNP’s).

The individual KOS006 has the kit number ZJ2996184.

For the individual KOS009 I received the message HTZ percentage out of range/Fails HTZ ratio test. The problem apparently is that the percentage of heterozygous alleles (different versions inherited of a genomic marker from each biological parent) is not consistent across a genome. This probably occurred because the tests carried out by the study did not adequately score a very large number of SNPs or “imputed” them with two possible values instead of omitting them from the results file.
The bam file for KOS009 had 3 GB, much smaller than the file for KOS006 that had 12 GB.

For KOS006 these are the results of Dodecad K12b
1JY1qkh.png


I found strange that the individual had such a high SSA value, but then I checked the page Genetic analysis of Early Medieval Germanic tribes and there are some individuals with similar results.

Although I was unable to test KOS009 in Gedmatch, I was able to test it with Admixture studio.
ewjg6R0.png

You can compare them with results from Iron Age Gauls here
https://www.eupedia.com/genetics/ancient_gaul.shtml#Iron_Age
 
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