viernes, 20 de abril de 2018

Muestras antiguas de ADN: Haplogrupo R1b-U152



Oldest Steppe Bell Beakers: Saxony-Anhalt, Germany


We now have confirmation that there was a genetic distinction between Steppe Bell Beaker and Iberian Bell Beaker, with only the former having steppe ancestry and belonging almost entirely to haplogroup R1b-L11. A tip of the cap to posters "Alan" and "rms" for insisting on that point for many years. One of the major distinguishing factors between the two groups has always been the difference in burial rites. Steppe Bell Beaker buried their dead in single graves while Iberian Bell Beaker continued the Neolithic practice of collective burials. In September 2015 I postulated that if there was a difference between the two populations (we had none from Iberia), radiocarbon dating of single graves may lead us to some important information about the origin of L11. Since we now have radiocarbon dates of single grave Steppe Bell Beaker R1b-P312 samples, I pulled together all Bell Beaker dates from single graves that used bone/collagen samples and avoided charcoal samples affected by what called the “old wood” effect. To my delight, some new radiocarbon dates have come to light and are likely to drastically alter our view of Steppe Bell Beaker. Without a doubt, the oldest dates come from the area of Saxony-Anhalt, Germany. See the spreadsheet below:

Earliest Radiocarbono Tested Bell Beakers - Sigle Grave, Bone/Collagen Only

After throwing out two Dutch dates that Lanting classified as “too old” possibly due to contamination, and two French dates because of very large standard deviations (130+ years), the top eight oldest dates are from three sites in Saxony-Anhalt, Germany. Of note is the sample from Bleckendorf. Some publications classify him as Yamnaya and some as Bell Beaker. This is what Harrison and Heyd had to say about this burial:

In this transformation, under the impact of ideas
originating in the Yamnaya culture, different processes
were taking place together, and their mutual interactions
are more complicated than one might expect. It is
obvious that cultural assimilation by indigenous people
of an ideological ‘Package’ was important; but so too
was the arrival of individual people from the steppes
and Pontic area. Their significance derives from their
social rank, and the archetype is the single burial from
Bleckendorf, Lkr. Aschersleben-Staßfurt (Saxony-Anhalt)
in Germany (Behrens 1952) (Fig. 49). We do not
know if this man journeyed farther to the west than
anyone else, yet his equipment and burial rite was
typical for the Yamnaya culture. An early tanged knife,
a copper awl, bone hammerhead pin, and a decorated
beaker accompanied the skeleton in a deep pit. The
radiocarbon determination places it around the 27th
century BC (14C: 4080±20 bp [KIA-162]; 1-Sigma:
2850–2500 BC: J. Müller 1999). The nearest parallels
are found in Moldavia at the Dnestr River and in the
Ukraine.


Yes, this sample had a Corded Ware beaker, but if we consider pottery making as a female craft, his wife could very well have been a Corded Ware woman. His male prestige item is a copper dagger in the Yamnaya/Bell Beaker style instead of a Corded Ware axe. The Yamnaya/Bell Beaker classification puts him squarely in the L23 conversation. This is not very far-fetched when you consider that twenty miles away and, one or two generations later we have the ninth oldest date… none other than the Kromsdorf R-M343 sample! The Kromsdorf cemetery also had an R-M269 sample that was not radiocarbon dated. Since individual SNPs were called, not much more is known about their genetics. Saxony-Anhalt samples continue to dominate until we get to our eighteenth oldest sample RISE563. He is our oldest R-P312 (and R-U152) and also the first sample found south of the Danube.

While this does not mean that Saxony-Anhalt is the "ground zero" expansion point for L11, it would help explain a lot of what we know about L11 so far, namely:

1. Steppe Bell Beaker’s non-steppe ancestry needs a population with Western Hunter-Gatherer (WHG) matching that of Globular Amphora Culture (GAC) or the Funnelbeaker Culture.
2. Bell Beaker samples from Rhenish Bell Beaker (Netherlands and Britain) have more steppe ancestry than other Steppe Bell Beaker samples.
3. The great diversity of Y-DNA groups in Csepel and Vucedol, both in the form of L23 and non-R1b. If L11 took this route, some may have stayed behind while the rest kept moving. Perhaps an early escape from the Great Hungarian Plain can be traced through tumuli as far west as Slovakia and the Austrian Burgenland. Tracing Lockenringe is another option.
4. The founder effects (L2 in the Bell Beaker East Group and L21 in Britain) almost calls for a centralized P312 or L11-only group with no other haplogroups, namely Z2103 nor R1a and certainly not non-R haplogroups.
5. A place where U106 was not too far to the east, at least not far enough so that it could not appear (without R1a) meaningful numbers just as the Bell Beaker Culture was starting to fade.
6. The lack of R1b in Corded Ware samples. These early dates make it so that R1b is not needed in Corded Ware.

So we have a very early Yamnaya/Bell Beaker man in Bleckendorf, Saxony-Anhalt, we have a very early R-M343+ man in Kromsdorf, Saxony-Anhalt and we have two later L11+ Bell Beaker samples from Quedlinburg, Saxony-Anhalt (I0805 and I0806). So, that raises the question... was Saxony-Anhalt the main expansion area for L11 and/or P312?

Fuentes

1.- Mapa, comentarios y hoja de cálculo elaboradas por Richard Rocca.

No hay comentarios:

Publicar un comentario