Wednesday, June 10, 2020

France, Like the Others (Brunel et al, 2020)

FINALLY.  After years and years and years of waiting for the curtain to be pulled back on ancient France, we FINALLY have a good initial bite on the sequence of genetic relationships across the Holocene.  Certainly we've had onesies and twosies and regional papers, but nothing as comprehensive.

For a broader out-take, see Bernard's comments.  Right now I'll focus on the French Beakers.

Even though we only have two Bell Beakers examined, they're interesting discussion material.  This man at Ciry-Salsogne (CBV95) was buried in supine-knees-drawn-up-looking-East configuration as the Yamanaya culture, and also had a very high proportion of similar ancestry.

The other Beaker from the Peirieres Dolmen (PEI2) had a lower percentage (~28%) of Yamanaya-like ancestry and also had a G2a Chromosome.

Via "La Sepulture campanifomre de Ciry-Salsogne" (Hachem et al, 2011)
Above you see how the knees fell to the side during decomposition.

Although we only have two Beakers in this paper (along with those previously reported), what is very apparent is that the Beaker (or Steppe) migration into France involved both men and women, introducing both Y-Chromosomes and mtdna mito-profiles not previously seen at any time during the Neolithic.  By the regular Bronze Age and Iron Age a situation exists in which the paternity of this geographical 'nation' had been almost completely superseded by those of the Steppe Cultures.



"The Transition: Before and After"  Snip from Figure S3-1





"Ancient genomes from present-day France unveil 7,000 years of its demographic history"
Brunel et al, PNAS June 9, 2020 117 (23) 12791-12798; first published May 26,2020 

"Genomic studies conducted on ancient individuals across Europe have revealed how migrations have contributed to its present genetic landscape, but the territory of present-day France has yet to be connected to the broader European picture. We generated a large dataset comprising the complete mitochondrial genomes, Y-chromosome markers, and genotypes of a number of nuclear loci of interest of 243 individuals sampled across present-day France over a period spanning 7,000 y, complemented with a partially overlapping dataset of 58 low-coverage genomes. This panel provides a high-resolution transect of the dynamics of maternal and paternal lineages in France as well as of autosomal genotypes. Parental lineages and genomic data both revealed demographic patterns in France for the Neolithic and Bronze Age transitions consistent with neighboring regions, first with a migration wave of Anatolian farmers followed by varying degrees of admixture with autochthonous hunter-gatherers, and then substantial gene flow from individuals deriving part of their ancestry from the Pontic steppe at the onset of the Bronze Age. Our data have also highlighted the persistence of Magdalenian-associated ancestry in hunter-gatherer populations outside of Spain and thus provide arguments for an expansion of these populations at the end of the Paleolithic Period more northerly than what has been described so far. Finally, no major demographic changes were detected during the transition between the Bronze and Iron Ages."

6 comments:

  1. Interesting. I would just add two provisos:
    1. The samples are autosomally analysed between four categories, two of which are archaic (Goyet & Villabruna) and two relatively contemporary (Yamnaya and Anatolia-N). If other categories closer to home had been used in the analysis (e.g. Corded Ware, Bulgarian Chalcolithic, Khvalynsk and Iberian Neolithic), they might have found no Yamnayan or Anatolian percentages at all.
    2. Yamnayan seems to be described as deriving from the Pontic Steppe. Most Yamnayan samples, I understood, were Caspian Steppe, with Pontic Steppe generally having a very different genetic profile.

    CBV95 (analysed as 100% Yamnayan) is striking though. It would be interesting to see whether other analysts come out with the same result, as I am not aware of any other samples in Western or Central Europe with no Anatolian or WHG component at all.

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  2. Davidski had a look at the two Beaker samples. Apparently the papers models were wrong.

    The R1b sample has 70% Yamnaya-like ancestry not 100% as reported in the paper.
    The G2a sample has 0% Yamnaya-like ancestry not 28% as reported in the paper.

    Which fits perfectly with their burials. The G2a sample had standard Neolithic burial, the R1b sample had a standard Indo European burial.

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    1. Interesting. This seems to make a bit more sense.

      The stark difference in the results of the two models does make you wonder about their reliability though. Although I suppose these results might vary, depending on which Yamnayan samples are used for the comparison.

      To test the point I made above, I replicated the analysis on a batch of P312 Bell Beaker samples from just up the road (Southern Germany) and came out with similar results to the NE France Bell Beakers - Yamnaya Dnieper 51%, Anatolia Neolithic 38%, Villabruna 10%, GoyetQ2 1%.

      However, when you replace Goyet with something more relevant (Danish Neolithic), you get very different results - Yamnaya Dnieper 12%, Anatolia Neolithic 16%, Villabruna 1%, Danish Neolithic 71%. This is suggestive perhaps of an alternative phenomenon - Bell Beakers migrating into Central Europe from the maritime North, rather than the continental steppic East.

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  3. Moreover, as you know, the G2a guy is in Southwest France and the R1b guy is in Northeast France. Which once again fits perfectly with their DNA profiles.

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  4. I've enjoyed your recent posts btw. They are very cool insights Bell Beaker.

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  5. For me this is interesting:

    "Finally, no major demographic changes were detected during the transition between the Bronze and Iron Ages."

    What does this imply regarding the Hallstatt Expansion ? France surely had a relatively large population during the Bronze Age, maybe a million or more. If Celtic Languages came Purely, Only from Hallstatt, how did they manage to change a Million peoples language without any major demographic change somewhere in this region ?

    So if Gaulish developed out of Bronze Age Locals why not then Insular Celtic as well ?



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