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Sunday, February 17, 2019

On Maykop ancestry in Yamnaya

What Maykop ancestry in Yamnaya? There is none, or at least not enough worth discussing, except in one highly unusual female outlier from a burial in what is now eastern Ukraine. But apparently this is still up for debate? Well it shouldn't be.

To anyone with even a passing interest in the Yamnaya culture, it should be rather obvious that it formed during the tail end of the Eneolithic on the Pontic-Caspian steppe, as basically a direct offshoot of the earlier Repin culture, but perhaps also with significant influences from the earlier still Khvalynsk and Sredny Stog cultures. So why should its population history be much different from this?

It isn't, and this is fairly easy to demonstrate now despite the still rather poor sampling of Eneolithic remains from the Pontic-Caspian steppe.

Below is a series of qpAdm analyses in which I modeled several Yamnaya groups, as well as the closely related Afanasievo and Poltavka populations, exclusively and successfully as two- and three-way mixtures of a few Eneolithic singletons from various parts of the Pontic-Caspian steppe (obviously, I'd love to use homogeneous population sets instead, but, as per my point above, that's not possible yet). The models are sorted by their statistical fits, best to worst. Also note the large number and wide range of right pops or outgroups. I wanted to make sure that I wasn't missing anything.

Dereivka_I_I4110 0.324±0.035
Progress_Eneolithic_PG2004 0.676±0.035
chisq 6.797
tail prob 0.976979
Full output

Progress_Eneolithic_PG2004 0.638±0.038
Sredny_Stog_II_I6561 0.362±0.038
chisq 10.855
tail prob 0.818366
Full output

Progress_Eneolithic_PG2001 0.655±0.073
Sredny_Stog_II_I6561 0.345±0.073
chisq 12.676
tail prob 0.696277
Full output

Dereivka_I_I4110 0.324±0.038
Progress_Eneolithic_PG2004 0.676±0.038
chisq 12.895
tail prob 0.680437
Full output

Khvalynsk_Eneolithic_I0122 0.086±0.054
Sredny_Stog_II_I6561 0.221±0.070
Vonyuchka_Eneolithic_VJ1001 0.693±0.101
chisq 13.113
tail prob 0.593562
Full output

So, you might ask, is there any way to add Maykop to these models? Nope, it's pointless, because it doesn't improve the stats (for instance, see here, here and here). In other words, the situation is this: I already have awesome models, and I can't readily fit Maykop into my framework, so why do it? But if anyone out there wants to try, then by all means, and feel free to share the results with us in the comments.

Of course, the fact that most of these Yamnaya and Yamnaya-related populations are best modeled with somewhat different Eneolithic steppe singletons doesn't mean that they have radically different origins. In fact, they're all very closely related and they're basically like one Bronze Age steppe family. They just harbor somewhat different ratios of the same ancient ancestral components.

For the sake of being thorough, as per scientific literature, I pooled all of the above Afanasievo, Poltavka and Yamnaya samples into a Steppe_EMBA set and analyzed it with several genetically and geographically matching pairs of the Eneolithic singletons. This was one of the best fitting models, which I think is interesting, because the region roughly between the burial sites of these pairs of Eneolithic individuals was the home of the Repin culture.

North_Pontic_Eneolithic_I4110-I656 0.313±0.027
Progress_Eneolithic_PG2001-PG2004 0.687±0.027
chisq 15.378
tail prob 0.497157
Full output

Again, adding Maykop to this model makes no sense (see here, here and here). Clearly, I'd have to come up with a very different framework to successfully model Steppe_EMBA with a Maykop population. However, it's unlikely that such a model would make much sense in the context of various other types of genetic analyses and archeological data.

See also...

Yamnaya: home-grown

Big deal of 2018: Yamnaya not related to Maykop

Yamnaya isn't from Iran just like R1a isn't from India

Wednesday, February 13, 2019

Ancient Caucasus open analysis and discussion

The following samples from the recent Wang et al. paper on the genetic prehistory of the Caucasus are now in the Global25 datasheets:

Catacomb MK3003
Catacomb RK4001
Catacomb RK4002
Catacomb SA6003
Darkveti-Meshoko I1722
Darkveti-Meshoko I2055
Darkveti-Meshoko I2056
Kubano-Tersk BU2001
Kubano-Tersk GW1001
Kubano-Tersk LYG001
Kubano-Tersk MK5009
Kubano-Tersk PG2002
Kubano-Tersk RK1003
Kubano-Tersk_Late KBD001
Kubano-Tersk_Late KBD002
Kura-Araxes_Kaps ARM001
Kura-Araxes_Kaps ARM002-003
Kura-Araxes_Velikent VEK007-009
Lola NV3001
Maykop OSS001
Maykop_Late MK5001
Maykop_Late MK5004
Maykop_Late SIJ001
Maykop_Late SIJ002
Maykop_Late SIJ003
Maykop_Novosvobodnaya I6266
Maykop_Novosvobodnaya I6267
Maykop_Novosvobodnaya I6268
Maykop_Novosvobodnaya I6272
North_Caucasus_MBA KDC001
North_Caucasus_MBA KDC002
Progress_Eneolithic PG2001
Progress_Eneolithic PG2004
Steppe_Maykop AY2001
Steppe_Maykop AY2003
Steppe_Maykop SA6001
Steppe_Maykop SA6004
Steppe_Maykop_o IV3002
Steppe_Maykop_o SA6013
Vonyuchka_Eneolithic VJ1001
Yamnaya_Caucasus RK1001
Yamnaya_Caucasus RK1007
Yamnaya_Caucasus SA6010
Yamnaya_Caucasus ZO2002

A lot of people don't seem to be aware of this, but the links are always the same for all of the datasheets, even after major updates:

Global 25 datasheet (scaled)

Global 25 pop averages (scaled)

Global 25 datasheet

Global 25 pop averages

Feel free to analyze the data in any way you wish and share your findings in the comments. Did the authors miss anything?

See also...

Big deal of 2018: Yamnaya not related to Maykop

Saturday, February 9, 2019

Blast from the past: Matters of basic geography

I'm re-posting this article from 2017 for the benefit of some Science News journalists, who are apparently having major problems dealing with basic geography. That's because they think that the Yamnaya culture was located in Asia rather than Eastern Europe. Take my advice and don't read Science News whatever you do. It might rot your brain.


The steppe north of the Black Sea in Ukraine has basically always been considered part of Europe, and just over 100 years ago some guy with a map decided that the steppe between the eastern coast of the Black Sea in Russia and the Ural River in western Kazakhstan should also be Europe.

So nowadays, right or wrong, it's generally accepted that the entire steppe region west of the Ural River, known as the Pontic-Caspian steppe, is in Eastern Europe. Here's a map courtesy of Wikipedia showing how the official boundary between Eastern Europe and Asia has shifted since the 18th century.

But this decision wasn't entirely arbitrary, because the current boundary between Eastern Europe and Asia by and large follows several major geographic barriers, including the Caucasus Mountains, the Caspian Sea and the Ural Mountains. It'd be hard to argue that these barriers haven't had a profound impact across the ages on the character of Europe and its people, and this has probably been known for well over a couple hundred years.

For instance, if we're to trust the most common interpretations of the works of ancient geographers like Hecataeus and Herodotus, then their worlds in some important ways resembled the typical Principal Component Analysis (PCA) of West Eurasian genetic variation. And it seems that they had a pretty good idea where both the strong continental boundaries and fuzzy areas were located.

Below, on the geographic map inspired by Herodotus, Europa or Europe is delineated from much of Asia by the Black Sea, the Caucasus Mountains and the Caspian Sea, while on the genetic map, most European and Asian populations form two, more or less parallel, clusters fairly cleanly separated by empty space (this was first noted in Lazaridis et al. 2013). Indeed, this empty space is the work of the Black Sea, the Caucasus Mountains and the Caspian Sea acting as rather effective barriers to gene flow between Eastern Europe and Asia (see Yunusbayev et al. 2012).

However, on the genetic map, the Iranic Scythians of the Asian steppes straddle my somewhat arbitrary red line separating Europa and Asia, and this is echoed on the Herodotus map by Iranic and related peoples like the Massagetae and Issedones, who inhabit the seemingly undefined part of the world between Europa and Asia east of the Caspian Sea (Mare Caspium).

Nothing really ground breaking, but pretty cool stuff.

On a related note, I've seen the term "mainland Europe" used recently in at least one of the big ancient DNA papers to describe the part of Europe west of the Pontic-Caspian steppe. It seems that the authors wanted to underline the fairly stark genetic difference that existed between most of Europe and the steppe just prior to the expansion of Yamnaya and related steppe herder groups that initiated the formation of the present-day European gene pool.

I can see why they did this, but to my mind they got things backwards. That's because the term mainland implies the opposite of island and/or peninsula, and of course the part of Europe west of the Pontic-Caspian steppe is a relatively narrow strip of land surrounded by water, so it's a peninsula. Let's visualize these two models on a map of Europe courtesy of Wikipedia:

I understand that my model might result in heart palpitations for some readers, especially those from Western Europe, who generally see their part of Europe as core Europe, but I feel that it makes good sense from a purely geographic POV.

See also...

Max Planck scientists: on a mission against geography

Genetic borders are usually linguistic borders too

Thursday, February 7, 2019

A Bell Beaker superhighway

Below is a density heat map of Bell Beaker pottery finds from a recent paper titled Der Glockenbecher in Europa - eine Karteirung (The mapping of the Bell Beaker in Europe). It's freely available as part of a series of new archeological papers on the Bell Beaker phenomenon at the Journal of Neolithic Archeology (see here).

Particularly eye catching, at least for me, is the trail of high density clusters that runs from the Carpathian Basin to the North Sea, especially in the context of recent online discussions about the potential geographic origins of the non-Iberian, or Yamnaya-related, Beakers with significant steppe ancestry. I'm guessing that this was something of a Beaker superhighway back in the day.

By itself, the heat map is probably very favorable to the rather popular idea nowadays that the Yamnaya-related Beakers originated in the Carpathian Basin. Their ancestors, for instance, may have been Yamnaya groups that arrived from the Pontic-Caspian steppe via the Balkans, and their ethnogenesis may have been sparked by the cultural impulses that were streaming into the region from across Europe, perhaps from as far away as Iberia. The descendants of these early, potentially Yamnaya-derived, Beakers may then have moved en masse to the North Sea region and beyond via the aforementioned superhighway.

However, fortunately, we now also have quite a bit of ancient DNA data to throw into such debates. Note that I added the following labels to the map: Beaker The Netherlands, Beaker Mittelelbe-Saale, Beaker Bohemia, and Beaker Hungary. These are the currently sampled Beaker populations from along the so called superhighway, and you can see how they cluster compared to each other in my Principal Component Analysis (PCA) of ancient West Eurasian genetic variation.

Clearly, what we're dealing with here is not just a series of well settled sites, or a heavily populated trade route, but also a busy migration trail, because of the significant overlap in the PCA between almost all of the Beaker populations.

Interestingly, though, most of the gene flow appears to have gone from the northwest to the southeast, because the Dutch Beakers hardly overlap with the other groups, and arguably form the tightest cluster, suggesting that they're the most genetically homogeneous and unadmixed of these Beakers. Indeed, they're also genetically very similar to the earlier nearby Corded Ware groups from Germany and Scandinavia, so it's unlikely that they derive from recent migrants to Northern Europe. On the other hand, the Hungarian Beakers from the Carpathian Basin are by far the most dispersed of the lot, which certainly means that they're the least genetically homogeneous and probably the most admixed.

Note also that some of them do clearly "pull" towards the Dutch Beakers, suggesting that they might harbor significant ancestry from as far north as the shores of the North Sea.

See also...

The Boscombe Bowmen

Single Grave > Bell Beakers

Dutch Beakers: like no other Beakers

Monday, February 4, 2019

The tracer dye

Remember that Wang et al. preprint at bioRxiv on the genetic prehistory of the Greater Caucasus? Well, it's just been published at Nature Communications under a new title: Ancient human genome-wide data from a 3000-year interval in the Caucasus corresponds with eco-geographic regions.

The authors also re-worked a few other parts of the manuscript, including the abstract and figures, but most of it looks pretty much the same as the bioRxiv version from May 2018. It's hard for me to believe that this process took more than half a year, so I'm guessing this is just how long it takes sometimes to get a paper into this journal.

In any case, the supplementary information includes a Peer Review File (see here) with a couple of interesting comments in regards to the Proto-Indo-European (PIE) homeland debate. Emphasis is mine:

Reviewer no 2: This hypothesis about the Caucasus source of Proto-Indo-European has been advanced also for slightly other reasons by David Reich and Kristian Kristiansen, so I think it should be elaborated here by the authors and they should marshall their new results to add whatever support they can. However, this hypothesis should rest on showing a sustained admixture between Maikop and Yamnaya to serve as a bridge to Yamnaya from the Caucasus (because the authors accept Yamnaya as connected to later PIE.) It is difficult to see in the results presented here a sustained gene flow from Maikop into Yamnaya, that would sustain this hypothesis. On lines 410 and 432 the authors preferred to see the Anatolian Farmer genes that appeared in Yamnaya as flowing from southeastern Europe, with a 20% WHG component, not from Maikop, without the WHG component. If most of the c. 15% Anatolian Farmer found in Yamnaya came from the west, it leaves very little room for gene flow into Yamnaya from Maikop. If the 3% WHG that makes the difference between a western and Caucasian source of Anatolian Farmer is strongly supported by their data, that makes a Caucasian origin of PIE less likely because it reduces gene flow from Maikop into the steppes. In fact it suggests that very little south-to-north gene flow occurred during the Maikop period (except into 2 individuals from a distinct, small, local genetic group different from Maikop and Yamnaya). This is puzzling and unexpected, but also it fails to support the bridge that seems to be needed.

Reply: We’re afraid that this might be a misunderstanding. There is indeed very limited gene flow between the Caucasus and the steppe groups (apart from the examples highlighted). However, we have based our PIE-related speculations on the observation that the CHG/Iranian (green) ancestry component is increasing already during the Eneolithic north of the Caucasus. This led us to propose that this might be the actual ‘tracer dye’ of an early PIE spread, which could then also accommodate the spread of PIE south of the mountain range where this ancestry component also rises in frequency resulting in a relatively homogenised dual ancestry (Anatolian + Iranian farming-related ancestry) in Chalcolithic times (see also brown arrow in Figure 2).

A misunderstanding? Perhaps, but my impression from reading both the preprint and paper was that the authors really wanted Maykop as the source of Indo-European languages on the Pontic-Caspian steppe, even if they didn't spell this out explicitly. So I'm not surprised by the peer reviewer's line of inquiry.

I think what actually happened was that the authors got it in their heads long ago that the PIE homeland was south of the Caucasus, simply because that's what they saw when they looked at the spread, across space and time, of some exceedingly broad and very ancient genome-wide genetic components, especially one such component with roots in the Caucasus and surrounds that was found both in Yamnaya and Hittite samples. And they penciled in Maykop, probably because of archeological data, as the most likely vector for the spread of this potential PIE "tracer dye" onto the steppe.

But obviously that didn't work out once they had a good look at their ancient DNA from the Caucasus, and it seems that they couldn't come up with a coherent alternative theory. Little wonder, considering that their ancient DNA showed a profound genetic differentiation between the Eneolithic/Bronze Age populations of the Caucasus and the Pontic-Caspian steppe, especially in terms of paternal ancestry, which is crucial in linguistics debates.

Whatever. I've already said way too much on this topic, so I'm now moving on. But I'm certainly looking forward to the genotype data from this paper. Analyzing it is going to be a hoot.

See also...

PIE Urheimat poll: two or three options left

Big deal of 2018: Yamnaya not related to Maykop

R-V1636: Eneolithic steppe > Kura-Araxes?

Friday, February 1, 2019

The Boscombe Bowmen

I'm thinking that the Boscombe Bowmen site in Wiltshire, southern England, might be a valuable case study of how the Bell Beaker population, and thus also the present-day western European gene pool, came to be.

Dated to 2500–2140 BCE, this isn't an especially early Bell Beaker grave, but its inventory is intriguing. It includes seven All-Over-Cord (AOC) beakers and one Cord-Zoned-Maritime (CZM) beaker.

Maritime beakers are quintessential Bell Beaker gear, and they're named as such because most of them have been recovered from sites along the Atlantic and Mediterranean coasts. However, strictly speaking, AOC beakers aren't Bell Beaker artifacts. Rather, their origin is said to be in the Single Grave culture, which is, of course, the northwestern European variant of the Corded Ware culture.

Genotype data for two samples from the Boscombe cemetery were analyzed in and published along with last year's Olalde et al. Beaker paper. In tune with the archeological data, one of these individuals came out very Corded Ware-like, with a lot of steppe ancestry, and the other rather southern, with among the lowest level of steppe ancestry for a Beaker dated to later than ~2500 BCE.

To take a closer look at their genetic affinities, I put together the graph below based on a couple of D-stats of the form D(Mbuti,X)(Yamnaya_Samara)/D(Mbuti,X)(Barcin_N,WHG). The bowmen are labeled I2416 and I2417, and the relevant datasheet is available here.

Considering these results, I2416 and I2417 may have been migrants, or the descendants of migrants, from such relatively far flung places as, say, what are now northern Germany and western France, respectively. [Edit: as per the comments below, these individuals are probably third-degree relatives, which makes it unlikely that they're migrants to the region, although it's still possible that their recent ancestors may have been migrants]

Note also that almost all of the populations are basically sitting between the two bowmen. This indeed suggests to me that the cultural processes and resulting population mixtures that took place at the Boscombe site also played out across the width and breadth of the Beaker realm, giving rise to heterogeneous Beaker groups almost everywhere within it and, eventually, the present-day western European gene pool.

Most of the Scandinavians, as well as the closely related British Anglo-Saxons, are slightly pulled above the red trend line by their excess genetic affinity to Western European Hunter-Gatherers (WHG). This phenomenon appears to date back to at least 2275-2032 BCE, because Nordic_LN:RISE98 is clearly affected by it and dated to this period.

My guess is that Single Grave populations from what is now Denmark and surrounds harbored much higher levels of WHG-related ancestry than the more easterly Corded Ware (aka Battle-Axe) Scandinavian groups, and they passed this onto present-day Scandinavians. Nordic_LN:RISE98, although from a burial site in what is now southern Sweden, might well be of Danish Single Grave origin.

See also...

Single Grave > Bell Beakers

Dutch Beakers: like no other Beakers

Hungarian Yamnaya > Bell Beakers?

Tuesday, January 22, 2019

Hungarian Yamnaya predictions

About ten thousand ancient burial mounds still stand in the Carpathian Basin and surrounds. Many of these kurgans or tumuli show direct archeological links with the highly mobile Yamnaya culture of the Pontic-Caspian steppe to the east, and may have been built by Yamnaya migrants.

The testing of ancient DNA from the remains in these burials is important, because the results are likely to be informative about the profound genetic, cultural and linguistic changes that took place in what is now Hungary and the Balkans during the Copper and Bronze Ages.

But, alas, probably to the disappointment of some readers, my great prediction is that they're not going to be overly relevant to what happened at this time in Northern and Western Europe, and won't upend the current consensus that the Corded Ware culture (CWC) was the main vector for the spread of steppe ancestry and Indo-European languages into these parts of the continent.

The important thing to understand about the Yamnaya expansion into the Carpathian Basin is that it mostly stopped at the Tisza River. It's true that some archeological cultures west of the Tisza, such as Mako and Vucedol, do show fairly strong Yamnaya influences, but they can't be regarded as part of the Yamnaya colonization of Central Europe. Below is a slightly modified map from Heyd 2011 to illustrate my point.

In fact, four early Yamnaya period samples from one of the few kurgans west of the Tisza have already been published along with the Olalde et al. 2018 paper on the Bell Beaker culture (BBC). And one of these samples, labeled I5117, even represents a male buried in a Yamnaya-like pose. But this is how three of these individuals cluster in my Principal Component Analysis (PCA) of ancient West Eurasian genetic variation.

They sit firmly among other Copper Age and Neolithic samples from west of the Pontic-Caspian steppe. In other words, they show practically zero Yamnaya-related or steppe ancestry. Moreover, both of the males belong to Y-haplogroup G2a-L91, which is yet to be found in any samples from the Copper and Bronze Age steppe.

That's not to suggest, however, that the spread of the Yamnaya culture into the Carpathian Basin was a cultural process with little or no genetic impact. It probably wasn't, because five samples labeled "Yamnaya Hungary" were featured in the Wang et al. 2018 preprint on the genetic prehistory of the Greater Caucasus, and judging by their PCA and ADMIXTURE results (in the figure below from the said preprint) they're not very different from most Yamnaya samples, such as those from far to the east in Kalmykia or Samara.

But the point I'm making is that not every one of the ten thousand kurgans and tumuli in the Carpathian Basin and surrounds was built by newcomers from the steppe, and, thus, my other prediction is that a fair proportion of the Yamnaya-related burial mounds, especially west of the Tisza, might contain remains without any steppe ancestry.

As far as I know, the Y-haplogroups of the aforementioned Yamnaya Hungary samples haven't yet been reported anywhere. But there are three ancients in the Mathieson et al. 2018 paper on the genetic prehistory of southeastern Europe that are probably highly informative about what we can expect in this context, because based on their archeology and ancestry, they're likely to be closely related to the Hungarian Yamnaya population. They are:

Balkans_BronzeAge I2165: Y-hg I2a-L699 3020-2895 calBCE

Vucedol_Croatia I3499: Y-hg R1b-Z2103 2884-2666 calBCE

Yamnaya_Bulgaria Bul4: Y-hg I2a-L699 3012-2900 calBCE

That's not much to work with, you might say. Perhaps, but keep in mind that R1b-Z2103 has now been reported in Yamnaya samples from Ciscaucasia, Kalmykia, and Samara, while I2a-L699 in a Yamnaya singleton from Kalmykia. Thus, a lot of outcomes are still possible, but some are more likely than others. So I'm expecting most Hungarian Yamnaya males to belong to R1b-Z2103 and I2a-L699, or perhaps even the other way around!

However, in line with my great prediction, I don't expect to see any R1a-M417 or R1b-L51, the two most common Y-halogroups among present-day Europeans living north and west of the Balkans. And I think that if these markers do actually show up, then they'll be represented by nowadays rare or even extinct lineages that aren't very important to the peopling of Europe. Any thoughts? Feel free to share them in the comments.

See also...

Hungarian Yamnaya > Bell Beakers?

Single Grave > Bell Beakers

Dutch Beakers: like no other Beakers

Saturday, January 19, 2019

Dutch Beakers: like no other Beakers

In my last two blog posts I tried to explain why the so called Bell Beakers of Bronze Age Europe cannot be confidently derived in any significant way from the Yamnaya population of the Carpathian Basin, and are more likely to have been an offshoot, in varying degrees, of the Single Grave or Corded Ware people of the Lower Rhine region (see here and here).

To help drive my message home, below is a series of new Principal Component Analysis (PCA) plots that illustrate the unique position of Dutch Beakers from the Lower Rhine relative to the Corded Ware population of Germany and all the other Beaker groups sampled to date. The relevant datasheet is available here.

The Dutch Beakers don't exactly sit between the Corded Ware and the other Beaker samples, but generally at the apex of their clusters, suggesting to me that they're not a mixture between Corded Ware and one or more of the other Beaker groups, but rather, as per my recent argumentation, a genetically homogeneous, relatively unique and thus long-standing Corded Ware-related population that may have contributed significant gene flow to the other Beaker groups.

Please note also that all of these outcomes can be confirmed with various types of formal statistics. I know this because I've done it.

See also...

Late PIE ground zero now obvious; location of PIE homeland still uncertain, but...

Wednesday, January 16, 2019

Single Grave > Bell Beakers

I've been studying in detail the genetic substructures within the Bell Beaker population with formal statistics and Principal Component Analyses (PCA). As far as I can see, among the two most homogeneous, and thus least likely to be recently admixed, Beaker groups are the Dutch Beakers and also the Dutch and British Beaker males belonging to Y-haplogroup R1b-P312. This, of course, makes good sense, because both the Dutch and British Beakers are so called Rhenish Beakers.

The results are also in line with the observation that the Dutch Beakers are the quintessential Beakers in terms of physique, with three quarters or more sporting exceedingly brachycephalic, planoccipital skulls (like this).

Moreover, these two Beaker groups are among the most Yamnaya-like Beakers, with almost as much Yamnaya-related ancestry as the Corded Ware culture samples from Germany (~60% vs ~70%). As a result, in my PCA of ancient West Eurasian genetic variation the Dutch Beakers form a more or less continuous, west to east cline with these and other Corded Ware individuals that runs all the way to the Yamnaya cluster.

In the same PCA, the R1b-P312 Dutch and British Beaker males form a tight cluster at the apex of a Beaker cline that stretches to European Neolithic groups with no steppe ancestry. The only Beaker who is positioned clearly east of the Dutch/British R1b-P312 Beaker cluster is from Hungary, and in all likelihood he harbors recent Yamnaya ancestry because his Y-haplogroup is the Yamnaya-specific R1b-Z2103.

These findings potentially have important implications for the origins of the Dutch Beakers and the Beakers who dominated much of Central and Western Europe during the Bronze Age, and these are:

- the Dutch Beakers are unlikely to be the result of a recent migration from afar into what is now The Netherlands and surrounds, but rather the descendants, by and large, of the earlier local Single Grave (and thus Corded Ware) populations

- the R1b-P312 lineages in the Dutch and British Beakers probably derive from Single Grave R1b-P312, which suggests that R1b-P312 was common among some clans within the Corded Ware culture

- the spread of most of the Yamnaya-related or steppe ancestry and quintessential Beaker physique across the Beaker world and into Western Europe can probably be blamed on the massive expansions of Beakers from what is now The Netherlands and surrounds (ie. the Lower Rhine region)

- late Yamnaya groups contributed some ancestry to eastern Beaker groups, such as those in the Carpathian Basin, but the Dutch Beakers acquired their high level of Yamnaya-related ancestry from their Single Grave predecessors, who, in turn, acquired it from their proto-Corded Ware ancestors from the steppe.

Admittedly, I find the discussion about the origin of the Bell Beaker cultural package somewhat confusing. For all I know, it might have come from Iberia, the Carpathian Basin, or even North Africa. But this post isn't about that, it's about the homeland of the classic Beaker warrior male, with his R1b-P312, Corded Ware-like genome-wide genetic structure and brachycephalic skull. I'm almost certain now that this was the Lower Rhine region.

See also...

Hungarian Yamnaya > Bell Beakers?

Dutch Beakers: like no other Beakers

Late PIE ground zero now obvious; location of PIE homeland still uncertain, but...

Friday, January 11, 2019

Hungarian Yamnaya > Bell Beakers?

Ever since the publication of the Olalde et al. Beaker paper (see here), there's been a lot of talk online about Hungarian Yamnaya as the most likely source of the Yamnaya-related, R1b-P312-rich northern Bell Beakers who went on to dominate much of Central and Western Europe during the Bronze Age.

Certainly, this is still possible, and we might find out soon if it's true because several Hungarian Yamnaya samples are apparently about to be published. But I wouldn't bet the proverbial farm on it just yet.

The most Yamnaya-like Beaker in the Olalde et al. dataset and ancient DNA record to date is from the Szigetszentmiklós burial site, which is indeed in present-day Hungary. But this individual, labeled I2787, is dated to just 2457–2201 calBCE, which isn't an early date for a Beaker and probably a couple hundred years past the proto-Beaker time frame.

Moreover, he belongs to Y-haplogroup R1b-Z2103, a paternal marker most closely associated in the ancient DNA record with eastern Yamnaya groups. And he doesn't exactly look like a classic northern Beaker, because he doesn't have a brachycephalic head with an exceedingly flat occiput (like this).

So I'd say that this is either an acculturated Beaker of recent Yamnaya origin, or perhaps the son of a Yamnaya father and Beaker mother. Below are several qpAdm mixture models that I ran to explore the latter possibility. They look very solid.

Beaker_Bavaria 0.442±0.045
Yamnaya_Samara 0.558±0.045

chisq 8.562
tail prob 0.73982
Full output

Beaker_Czech 0.441±0.045
Yamnaya_Samara 0.559±0.045

chisq 10.009
tail prob 0.61513
Full output

Beaker_The_Netherlands 0.576±0.062
Yamnaya_Samara 0.424±0.062

chisq 11.469
tail prob 0.489238
Full output

The idea that I2787 is a Beaker with recent Yamnaya ancestry isn't an original one. It was put forth very eloquently and convincingly months ago by the Bell Beaker Blogger himself:

Szigetszentmiklós Cemetery (Santa's Six Foot Elves)

I2786 is another Beaker male from the Szigetszentmiklós site who shows excess Yamnaya-related ancestry compared to most other Beakers. Again, it's likely that this individual harbors recent Yamnaya ancestry, because his Y-haplogroup is I2a-M223, which has been recorded in eastern Yamnaya alongside R1b-Z2103.

So my gut feeling for now is that Hungarian Yamnaya samples will mostly belong to Y-haplogroups R1b-Z2103 and I2a-M223, rather than R1b-P312, and thus they won't fit the bill in any obvious way as the population that may have given rise to northern Beakers.

One of the oldest individuals in the ancient DNA record belonging to R1b-P312 is I5748, a Beaker dated to 2579–2233 calBCE from the Oostwoud-Tuithoorn burial site in what is now West Frisia, The Netherlands.

Interestingly, this part of Northwestern Europe was home to the Single Grave population shortly before I5748 was alive. And the Single Grave culture is a variant of the Corded Ware culture. So can anyone tell me if there's any evidence that I5748 and his kind were relative newcomers to West Frisia, from, say, somewhere in the direction of the Carpathian Basin? If not, then what are the chances that northern Beakers are by and large the descendants of the Single Grave people?

In fact, there's not much difference in terms of genome-wide genetic structure between the Beakers from the Oostwoud-Tuithoorn site and Corded Ware people from what is now Germany. The Principal Component Analysis (PCA) below illustrates this well. But, you might say, Corded Ware males by and large belong to Y-haplogroup R1a-M417. Yep, but this doesn't mean that R1b-P312 wasn't common in some Single Grave clans.

At this stage, I don't have a clue where the northern Beakers might have come from, and unfortunately I don't have any inside information about the Y-haplogroups of Hungarian Yamnaya. I don't even know if any Single Grave samples are being analyzed. But I'll leave you with this map from a recent paper by French archeologist and Beaker expert Olivier Lemercier (see here). To me it suggests rather strongly that northern Beakers developed from the synthesis of Corded Ware newcomers to Western Europe and indigenous Western Europeans. As far as I can tell, that's what the paper basically argues as well.

See also...

Single Grave > Bell Beakers

Dutch Beakers: like no other Beakers

Late PIE ground zero now obvious; location of PIE homeland still uncertain, but...