March 19, 2018

Quickie: the pre-Indoeuropean evolution if ancient Iberians: from 'Sardinian' to 'Basque'

This may be needed as transition between the ancient Iberian genetic data of Valdiosera and Günther that I discussed two days ago and the modern Iberian genetic data that I'm planning to discuss very soon (just chewing on the data, because it is a bit perplexing in some aspects, but ref. Bycroft 2018 if you want to peek on it on your own). 

Fig. 1B from Valdiosera, Günther et al. 2018, annotated by me.

Just that: we see very clearly how ancient Iberians were at the beginning of Neolithic like modern Sardinians and by the time of Chalcolithic in some cases and at the Bronze Age everywhere, they had turned into something like modern Basques, i.e. more Paleoeuropean but not yet more Indoeuropean at all. 

Modern Spaniards/Iberians seem to be mostly that Basque-like Bronze Age base plus some Indoeuropean admixture from either the continent (Celts surely) or Italy (Romans no doubt). 

Maybe it is like stating the obvious but the obvious is not always obvious for everyone and understanding this will be handy when dealing with modern Iberian DNA and its structure.

March 17, 2018

Oldest known Iberian R1b-S116 (and DF27) is NOT at all Indoeuropean

This study is very interesting but it is very wrongly argued, maybe in an attempt to fit their findings with what has sadly become the mainstream current of "explanation" about the origins Y-DNA haplogroup R1b-S116 (also P312, etc.)

Cristina Valdiosera, Thorsten Günther et al. Four millennia of Iberian biomolecular prehistory illustrate the impact of prehistoric migrations at the far end of Eurasia. PNAS 2018. DOI:10.1073/pnas.1717762115

The issue is that they found the very first known carrier of R1b-S116 (and R1b-DF27, the main Iberian haplogroup) in an individual of the Bronze Age of Lower Rioja (Cueva de Los Lagos, Alhama de Cervera), belonging very clearly to the Central Iberian culture of Cogotas I, even if it is at its very northeast margin.

What is wrong? Well, the very title is wrong. It is nothing but an artifact produced by forced (supervised) results of Admixture within the simplistic 3-population model. Even then their result is in fact so weak that it immediately cried to me as "artifact" (noise or whatever you want to call it) and it is effectively nothing but that. 

And to demonstrate it is as simple as digging into the supplementary materials and look at the unsupervised Admixture run (dataset S03), whose optimal columns (lowest CV scores) are K=16-19 (all four are optimal, what is fine with me but makes explanation and understanding a bit more dense). 

As that unsupervised admixture is massive, with lots of global populations ancient and modern, I made a selection using only the four optimal K-values (K=16 to K=19, from left to right):

Click to expand (labels at bottom are mine)

And it is absolutely clear from K=16 to K=18 that there is not a speck of the Caucasus component which is absolutely universal in all the true Indoeuropean samples. There is a tiny speck of it in the K=19 column but there even Sardinians and some Anatolian Neolithic individuals have it at much greater values and thus cannot anymore be automatically interpreted as Indoeuropean marker, but just as extra Caucasus affinity present in some Neolithic-derived populations or individuals more than others since the very beginning of mainline (Vasconic) European Neolithic at the Aegean.

And this is it. Quod erat demonstrandum (Q.E.D): R1b-S116, at least in Iberia, has nothing to do with Indoeuropean expansion, nothing at all: it is absolutely clear that it is a pre-Indoeuropean thing. And it has been present in Lower Rioja since at least the Bronze Age.

Furthermore, when we look at the Central European Bell Beaker (Central BB) samples and compare them with their immediate chronological precursors of (definitely Indoeuropean) Corded Ware culture, we must admit that there is a decrease of the Caucasus component and an increase of the Vasconic Neolithic (light blue) element. This also speaks against the Indoeuropean "explanation" for the expansion of R1b-S116 into Central Europe, because the first known such ancient carriers are from the Bell Beaker period and not a moment earlier, and these clearly express an anti-Indoeuropean tendency in their autosomal genomes.

There is however a sizable Indoeuropean component in modern non-Basque Iberians, smaller than in most other European populations but very clear nevertheless. This must have arrived at later times: (1) with the Celts, who arrived to Catalonia at the end of the Bronze Age, later expanding into Central and Western Iberia, (2) with the Romans, (3) maybe also to some extent with the Germanic invaders of the late Roman period. None of these expansions seem particularly associated with R1b-S116, however the c. 1% R1a and the c. 8% J2 (with plausible Italo-Roman origin) should be related to it, along with an assortment of other haplogroups. 

For those willing to dig in the details, there is also a small treasure trove of other ancient Y-DNA, mostly I (which underlines the Paleoeuropean influence in Neolithic Iberia, regardless of whether this is local or was carried on from further East by the Neolithic settlers), as well as one instance of unspecific R1b, another of G and another of H.

Someone may ask, which is then the origin and means of expansion of R1b-S116, if not Indoeuropean? Good question to which I don't have yet a well defined answer. But my tentative explanation is that it should be related to two ultimately related processes within Western European "Neolithic" (Late Neolithic and Chalcolithic): 
  1. The well documented phenomenon of increase, in most areas at least, of the Paleoeuropean component time passes, this may be to some extent because of simple absorption of local subneolithic "hunter-gatherers" but it probably also produced different subpopulations within the Western Neolithic and in some cases we do see these peripheral "Second Neolithic" groups expanding at the expense of the "First Neolithic" peoples. This is most clear in Central Europe with the expansion of Funnelbeaker cultures from, probably, Denmark and nearby areas of Low Germany. In fact Michelsberg culture and its close relative in France Seine-Oise-Marne basically wipe out the first farmers of LBK (Linear Pottery) at what I usually describe as the Chalcolithic but is often described as Middle or Late Neolithic in other sources.
  2. Clearly Bell Beaker had something to do: we see their impact in Germany, Britain and Ireland and one could argue that Cogotas I is somehow derived from the Bell Beaker of Ciempozuelos, although in this I'm going to remain neutral and a bit skeptic until more evidence shows up. 
But what seems very apparent tome is that R1b-S116 should have expanded from somewhere in France, probably towards the South. And we do need better genetic studies, including archaeogenetic ones, on the Hexagon before we can jump to conclusions. France is not the most affected area by Bell Beaker, so I am cautious about attributing too much weight to only Bell Beaker and I would rather think on a complex succession of expansions associated to various cultures. 

Of great interest here should be the ill-known but fascinating Artenacian culture, which expanded in all West France and Belgium from a core at Dordogne before the BB period and coincident with the Corded Ware expansion in Central Europe. Like Bell Beaker folk, they were adept at bowmanship but their area is not densely affected by Bell Beaker later on (although there is indeed a scatter of findings). I do wonder if somehow Bell Beaker is derived from Artenac, even if it is clearly not the same thing. Food for thought.

Update (March 18): small steppe-like noise appears in diverse Iberian samples since the Late Neolithic/Chalcolithic.

This has arisen in the discussion below (h/t to MZ): when the supervised (forced assignment to rigid three populations) is used, the appearance of "steppe" ancestry is found here and there also before the Bronze Age. As we see above, this is not real: it does not happen in the unsupervised model at all but mere "noise" or "artifact" produced by the excessive simplicity of the three populations model.

This does not make the three populations model "wrong": it is still approximately right but "evidence" produced  ONLY from rigidly applying this model is not evidence of anything, just a hint to be confirmed or rejected via wider analysis at best.

Most interesting video-conference on Luwians, Troy and the Sea Peoples

All archaeogenetics and no archaeology makes people go mad. So let's spice this a bit with this absolutely enticing video of a conference by Dr. Eberhard Zangger, which I have watched thrice already, twice tonight alone.

I love the general outline of the exposition even if I know some details, like the outline of Lower Troy are controversial. 

I also did pose the following questions as commentary to the video:
  1. How can the professor be so sure that all ancient Western Anatolian nations were Luwian and not from other diverse ethnicities? How that they were the only ones in the last Sea Peoples' wave? Just the same we see some non-Greeks in the Greek side of the Trojan war, I would expect some non-Luwians in the Trojan side as well, assuming the Trojans were Luwians and not Tyrsenians or something else. 
  2. What about the Phrygians who show up in Anatolia, West and East (Armenians) after the Bronze Age collapse, out of nothing (they seem to originate in an obscure Paeonian tribe, the Bryges)? Not a single mention of them: I guess they would blurr the nice "Luwian" homogeneity. 
  3. What about the Greeks (Danaoi, Denesh) and their Pelasgian (Peleset, Philistine) neighbors and often allies (Achilles himself and his Myrmidons were that)? They seem also involved in that late Sea Peoples wave and there is coincidence of cultural Hellenization (and not Luwianization) of Cyprus precisely in that period of the late Sea Peoples' attacks against Syria, Egypt and whatever else. Let's not forget that the Egyptians speak of the foreign peoples making a COALITION in their "islands", and I would say that this coalition involved peoples from all the Aegean, and not just the Asian side of it (although very good point about Evans' racism and his horrible influence on Aegean studies). 
But please don't let my nit-pickiness wrong what I think is a great conference dealing with a topic that has been way too neglected and even purposely ignored. There is a lot of good stuff in the video.

By the way, this is the Wikipedia map of Luwian inscriptions (unsure of what exactly the German legend says, "early" and "late" maybe?, but it's definitely about Luwian inscriptions):

Credit: Hendrik Tammen (CC-license)

March 16, 2018

Ancient DNA from the Balkans

This study has been for several months around but I have not discussed until now and is well worth a mention.

Ian Mathieson et al., The Genomic History Of Southeastern Europe. BioRXiv (pre-pub) 2017. doi:10.1101/135616

There is a lot of ancient autosomal DNA from the region but it basically says one thing: everything was almost exactly as expected from archaeology. The Karanovo-Gumelnita people, famed for inventing the Bronze Age a whole millenium earlier than anyone else, and nearby related cultures, were within the mainstream (Vasconic) Neolithic genetic grouping. This changed however with the kurgan invasion expressed primarily in the Ezero culture, which I've been told should be considered direct precursors of Thracians. But the change is not something radical: more genetic affinity with the steppe is visible than before and more generalized through all samples. 

Fig. 1-D - Supervised ADMIXTURE plot, modeling each ancient individual (one per row), as a mixture of
populations represented by clusters containing Anatolian Neolithic (grey), Yamnaya from Samara (yellow), EHG (pink) and WHG (green).
  (click to expand)

Well, it is not exactly everything what is as expected, if we consider Polish Globular Amphorae culture, which I would have expected to be at least somewhat steppary, Indoeuropean, already but were not. Thus it seems I have to concede on this culture and its precursors being still part of the Vasconic Neolithic. This makes Indoeuropean penetration into Central-North Europe a much more sudden episode and one directly tied to Corded Ware culture and nothing else. It must have been perceived by its victims like a massive catastrophe, because it was a huge area which they conquered and to a large extent colonized in a very short span of time.

Lots of R1b in Epipaleolithic Balkans

Most interesting anyhow is the huge hoard of ancient Y-DNA R1b in the Iron Gates region (Lepenski Vir) before the Neolithic. This not only demonstrates, again, that this haplogroup is Paleoeuropean, at least in part, but, quite intriguingly makes earlier findings on modern data suggesting a possible origin or R1b-M269 in or near modern Serbia (Morelli 2010 and Myres 2010) at least somewhat plausible. However none of the Iron Gates R1b is described as R1b-M269 and in some cases it is excluded that it could be this sublineage. 

Thus the issue of the ultimate origins of this key lineage remains open, but let me underline that these Iron Gate individuals belonged to the WHG grouping, as did Villabruna (so far the oldest R1b carrier kown) and that they breach this way the assumed haplogroup homogeneity I2 conceived on merely Central and Northern European samples. Just as happened with mtDNA U haplogroup homogeneity when mtDNA H was detected by several independent studies of Iberian ancient DNA. It is normal to expect more diversity towards the south for several reasons but maybe the most critical of them is just average temperature, which makes the southern lands naturally more fertile (notably so for crops domesticated in the Middle East) and easier to inhabit. 

This trend was only broken in the Middle Ages when the heavy plough allowed the improved exploitation of deep Oceanic soils, being useless in the Mediterranean region of shallow soils however. It was only then when the center of European development moved from south to north, to Belgium specifically, where it remains till present day. So let's take Southern Europe a bit seriously, please.

Ancient genomes of SE Asia

Just a quick mention because I have such a long queue of stuff from Europe that I really have no time to look but very shallowly onto this study, which looks extremely interesting. Credit for the reference to Kristiina.

Hugh McColl, Fernando Racimo, Lasse Vinner, Fabrice Demeter et al., Ancient Genomics Reveals Four Prehistoric Migration Waves into Southeast Asia, BioRXiv (pre-pub) 2018. doi:10.1101/278374


Two distinct population models have been put forward to explain present-day human diversity in Southeast Asia. The first model proposes long-term continuity (Regional Continuity model) while the other suggests two waves of dispersal (Two Layer model). Here, we use whole-genome capture in combination with shotgun sequencing to generate 25 ancient human genome sequences from mainland and island Southeast Asia, and directly test the two competing hypotheses. We find that early genomes from Hoabinhian hunter-gatherer contexts in Laos and Malaysia have genetic affinities with the Onge hunter-gatherers from the Andaman Islands, while Southeast Asian Neolithic farmers have a distinct East Asian genomic ancestry related to present-day Austroasiatic-speaking populations. We also identify two further migratory events, consistent with the expansion of speakers of Austronesian languages into Island Southeast Asia ca. 4 kya, and the expansion by East Asians into northern Vietnam ca. 2 kya. These findings support the Two Layer model for the early peopling of Southeast Asia and highlight the complexities of dispersal patterns from East Asia.

March 2, 2018

Two big issues with Olalde 2018 (Indoeuropean Bell Beaker speculation)

"Just for being published in Nature it does not mean it is necessarily wrong" (popular saying).

Iñigo Olalde et al., The Beaker Phenomenon And The Genomic Transformation Of Northwest Europe. doi:10.1101/135962 (pre-pub version, no way I'm spending 1/3 of my monthly income on this, in case you're willing to waste your money, it's been recently published in Nature)

Issue 1: All comparisons are made between Anatolia Neolithic or other Early Neolithic in some cases and Yamna or Corded Ware.  Late Neolithic is not used nor, critically, is Hunter-Gatherer populations or anything related. 

This means that everything will be much more Yamna-like than it should, just because Yamna are 50% HG, while Early Neolithic are very low in this component. 

This is very apparent in the PCA:

It's junk-in: junk-out.

Issue 2: there is a huge sampling gap precisely where ancient mtDNA (and modern Y-DNA) tells us that the origin of the modern West-Central European genetics should be: in France and nearby areas like the Basque Country, West Germany. Sure: they sample some Eastern French sites but see "issue 1" above.

Nuff said.