Tuesday, December 6, 2016

"Once Upon a Time in the West" DNA (Roth, 2016)

Here's a doctoral thesis by Christina Roth which includes quite a bit of Iberian mtdna.  The most interesting aspect of this paper concerns Beakerfolk maternal lines which presents an interesting situation.

The publish date is 2016 at the University of Mainz website.  She has been a co-author of several of the large DNA papers in the last year or so.  I believe this is includes a large amount of unpublished data, but I don't have time to look at it closely.  You can dig in at page 134.

"The two Bell Beaker groups [North and South Mesetas] show significant differences on haplogroup level to Chalcolithic non-Bell Beaker from the Southern Meseta and all Early and Late Neolithic groups with strong genetic hunter-gatherer background...They are clearly separated from all other Chalcolithic groups in PCA, cluster analysis, and MDS...Furthermore, AMOVA supports – though not significant – separation of Bell Beaker and non-Bell Beaker groups (see table 21, p.104). The Fisher-test with superordinate groups supports significant differences between Chalcolithic Bell Beaker and non-Bell Beaker groups as well (see table 14, p.92). Genetic differences between the two Bell Beaker groups are low but not significant while higher and mostly significant FST values to the Chalcolithic groups of the Southern Meseta and East Spain can be observed (see table 16, p.94)"


"The genetic distinctness of the Southern Meseta Bell Beaker and non-Bell Beaker groups can even be observed on the same sites: Camino de las Yeseras and Humanejos provided both, non-Bell Beaker and Bell Beaker individuals."

This is weird...

"A common feature that is shared between the two Bell Beaker groups [in the Mesetas] and that separates them from other Chalcolithic groups is the low amount of haplogroup H and the presence of haplogroup U5a, which was – apart from the Bell Beaker groups – only found in one Late Neolithic individual from Portugal and the Portuguese Chalcolithic site of Perdigões."  (remember a U5b Phoenician..)

and weirder...

"The only new haplogroup found in the Bell Beaker dataset was the sub-Saharan lineage of haplogroup L1b in the Southern Meseta."

Christina Roth then continues with some interesting interpretation.  In total, this part of the paper is maybe 10 pages or so, but the whole thing looks like a good read when time comes available.

"Once upon a time in the West : paleogenetic analyses on Mesolithic to Early Bronze Age individuals from the Iberian Peninsula" Christina Roth.  Mainz : Univ. 236 Seiten.  [Link]

Abstract: While the amount of ancient Iberian genetic data has increased over the last years, few studies have focused on population dynamic processes beyond the immediate period of the Neolithic transition. In this study, the Iberian dataset was enlarged by SNP-based haplogroup information for 249 new Mesolithic to Early Bronze Age individuals and 187 reproduced HVR I sequences. These new data allow confident insights into post-Neolithisation population dynamic processes on the Iberian Peninsula and make it possible to compare the development of Iberian and Central European groups over a time span of about 4,000 years.
The results of this study reveal a strong genetic regionalization of Iberian groups throughout the Neolithic and partially in the Chalcolithic. A considerable amount of hunter-gatherer maternal heritage persisted during the Iberian Early Neolithic. The greatest amount of “Neolithic” lineages/haplogroups (HV, J, K, N1a, T2, V, and X) has been found in Northeast Spain and Aragón, suggesting these regions were the main entrance for Neolithic lineages into the Iberian Peninsula, while the amount of mitochondrial hunter-gatherer influence increases with growing distance from these regions, pointing to various forms of Neolithic transitions on the Iberian Peninsula. In some areas genetic continuity between Early and Late Neolithic seems highly likely (Ebro Valley) while other regions show large genetic differences to the preceding period (Central Portugal, Northern Meseta). Central Iberian Bell Beaker groups are genetically distinct to most other Chalcolithic groups.
Although a substantial number of Early Neolithic Iberian individuals share direct sequence hits to contemporary individuals of the Central European Linear pottery culture, the amount of hunter-gatherer mitochondrial heritage is considerably greater in all regions of the Iberian Peninsula than in Central Europe. No genetic connection between Iberian and Central European Bell Beakers or the Corded Ware culture could be found. When focusing on the distribution of sub-clades of haplogroup H, differences between the Iberian Peninsula and the groups from other parts of Europe were recognizable. In the Iberian samples set only sub-haplogroups H1 and H3 could be identified. While H1 was present in all Early and Later Neolithic groups from Central and Western Europe, H3 shows strong Western European affinities and is not detectable in Central Europe before the Middle Neolithic. While no strong differences in sub-haplogroup H variability among Iberian groups of different epochs could be detected, a clear shift between Central Europe´s Early and Middle Neolithic is recognizable.


  1. So, it sounds like the proto-Bell Beaker people must pick up H in Iberia by taking local wives and then drag it all over Western Europe as they expand following ethnogenesis in Iberia as European Bell Beakers.

    1. Interesting way to look at it. I'm not really sure what to think.

    2. It's possible, Andrew, assuming that BB peoples are the main vector and is not something more complex (involving also Megalithism, Funnelbeaker, etc.) Anyhow, remember that H was also present in Epipaleolithic Karelia, and not just Iberia (and France, at least if we consider Neolithic data from Gurgy as possibly "aboriginal") and that the spread of mtDNA H in Europe is particularly concentrated all over the coasts, not just in the BB areas but also in the Baltic, etc. So IMHO H1 (and associated lineages) may have double origins in what regards to Neolithic-plus, one to the SW and another to the North, while instead H3 (and whatever associated lineages) seems instead almost restricted to the Southwest. Complexity may be the name of the game: I fail to see any simple answer for now.

    3. On second thought, after reading and pondering the thesis a bit, I fail to see any serious chance of Iberian BB being carriers of mtDNA H or in general a more HG-rich mtDNA pool: Central Portugal (a key Atlantic civilizational hub, but also the "Beaker People" of the Plateau) actually show a tendency to greater "Neolithic" DNA. So I would look for some populations further north as the source, for instance in modern France. Or is it around Westfalia? Michelsberg culture remains a big mystery and they did wipe out the LBK from Central Europe and Northern France (SOM), even probably pushing southwards until Artenacians stopped them and pushed them back to the Rhine. So I'm leaning for somewhere between Pyrenees and Rhine or Helgoland Bight, which incidentally is also where we *should* find the origins of both Western European R1b sublineages.

      Not sure if should "swear" against Bell Beaker at Bell Beaker Blog, probably not, but I'm quite tempted and thinking it's a bit of a smokescreen and that other more specific cultures and groups area actually more central to this development, with BB being rather a side issue or secondary vector, affecting maybe (in terms genetic) only some areas like the British Islands.

      It's something about the coalescing of Atlantic, HG-influenced, cultures but not so decidedly just BB.

  2. Bellbeakerblogger.
    thank you. Kudos and would love to pay you a beer.

    "awn as well. A most interesting
    12 Discussion of population genetic results
    fact that was revealed by the statistical analyses was the genetic relation of both Bell Beaker
    groups to the Central Portuguese Neolithic and Chalcolithic data as well as the African
    lineage detected in one Bell Beaker individual. Both Portuguese Estremadura and Northern
    Africa play an important role in the archaeological debate on the origin of the Bell Beaker
    phenomenon (BOKBOT 2005; KUNST 2005; TUREK 2012)."

  3. Wow, this thesis is extremely informative (at least if you do care about ancient mtDNA, because there's also those who just want to dismiss the largest ancient DNA dataset we do have). It's too large to discuss not just here but even at my blog (where I'll make an entry right away anyhow, with some selected and annotated graphs) but some highlights:

    1. HGW (Iberian hunter-gatherers) are clearly distinct from HGC (Central European HGs) at the very least in their mtDNA pool (on autosomal DNA we only have one Iberian sample so far).

    2. In fig. 23 we can see how this results in different "zones" or "stripes" of admixture in Iberia and Central Europe, the difference is basically on which HGs are the farmers admixing with, mostly with the local ones quite apparently (although central and eastern HGs are hard to consider as separate groups, be it in the PCA or in the cluster analysis, so it's possible that where one reads HGC, another reads HGE or a mixture of both).

    3. Blätterhöhle is a most curious German population, because it tends not to HGC but to HGW (Iberian HGs). This is the Westfalian site where farmers and hunter-gatherers were documented living side by side, the question is: why do those late HGs look (in mtDNA at least) like the Iberian ones and not the Central European ones?, that may be an important clue.

    4. I don't see clear the role of Portuguese or Iberian BB in the expansion of mtDNA H and possibly other related genetics. At the Chalcolithic, Central Portugal moves from a HG tendency to a "farmer" tendency. The only areas where I would expect therefore to find the kind of mtDNA that makes a "modern" West European pool would therefore be further North, possibly somewhere in France (Artenacian culture, Breton Megalithism or whatever) or maybe even, considering the Blätterhöhle issue, in Westfalia and generally speaking in the Michelsberg or Funnelbeaker cultural groups. The key is somewhere in Atlantic Europe but it hides very well from scrutiny.

    5. Overall we see in Iberia the pattern I would have expected and that is, long-term, the opposite of what we see in Central Europe: an increase of "Neolithic" genetic influence over time but irregularly (stronger in the West and Center, weaker in the East and South, not appreciable in the North). Why? I can't say for sure but seemingly Bell Beaker and the Chalcolithic in general is associated with greater "Neolithic" mtDNA and is those areas with less strong Beaker and Megalithic influence (East and SE), the ones that seem to retain greater HG mtDNA frequencies. The North (Northern Plateau excluded) seems to remain even less affected but the sequence ends with the late Neolithic, so I have to resort to my own data to infer this (and with some doubts, because there'd be a Chalcolithic "Neolithization", later reversed or only affecting some specific areas).

    1. Thanks for your comments. Good analysis BTW. For point #4, I have to admit this is a bit perplexing.

  4. BTW, my take on the matter if you're interested: took me half day, so you better are ;)

    → http://forwhattheywereweare.blogspot.com/2017/01/extensive-ancient-iberian-mtdna-analysis.html