Warriors from at least two different populations fought in the Tollense Valley battle

I can't get the genotype data from the Burger et al. paper. The lead authors, Joachim Burger and Daniel Wegmann, aren't replying to my emails.

But they were gracious enough to release the BAM files for each of their samples, and these files can be converted to genotype data. So I've included ten of the Tollense Valley warriors (DEU_Tollense_BA) in the Global25 datasheets (see here).

The claim in the paper that these warriors "represent an unstructured population" is absolutely false and extremely naive.

Below are a couple of Principal Component Analysis (PCA) plots produced with Vahaduo Global25 views. The samples are labeled according to their Y-chromosome haplogroups. To see interactive versions of the same plots, paste the Global25 coordinates from the text file here into the relevant fields here.

These warriors are not a single unstructured population, because they cover too much ground in the above plots for that to be possible. It's clear to me that they represent at least two different groups from Central Europe and surrounds.

Of course, this would be a lot easier to work out if Burger et al. cared to supply more information about each of the warriors, such as their attire, weapons, circumstances of death, and so on. It's a complete mystery to me why this wasn't included in the paper, and the authors are refusing to talk to me, so it's unlikely that I'll ever be able to get it from them.

In the absence of such crucial archeological and anthropological data, I don't want to speculate too much, and get overly creative, but here are a couple of possible scenarios to explain the ancient DNA results:

- this may have been a battle between two Central European armies, one rich in Y-haplogroup R1b and the other rich in Y-haplogroup I2a, as well as their allies or hired help, including warriors from Eastern Europe belonging to Y-haplogroup R1a

- or perhaps it was an invasion from the east by warriors rich in Y-haplogroup R1a, and it was a success, with the local armies, rich in Y-haplogroups R1b and I2a, losing the battle and suffering most of the casualties.

I'm sure that one day someone will attempt to undertake a decent multidisciplinary study of this epic battle, and we'll at least have a rough idea about what happened. Or not.

Citation...

Burger et al., Low Prevalence of Lactase Persistence in Bronze Age Europe Indicates Ongoing Strong Selection over the Last 3,000 Years, Current Biology, Available online 3 September 2020, https://doi.org/10.1016/j.cub.2020.08.033

See also...

Genetic and linguistic structure across space and time in Northern Europe

Low prevalence of lactase persistence in Bronze Age Europe (Burger et al. 2020)

Over at Current Biology at this LINK. Unfortunately, this is the long-awaited Tollense Valley battle paper. Despite the obvious presence of some very interesting genetic substructures among the Tollense Valley warriors (see here), the authors have the audacity to claim that these individuals represent a "single unstructured Central/Northern European population".

One of the warriors, labeled WEZ56, belongs to Y-haplogroup R1a and shows an exceedingly Balto-Slavic-like genome-wide genetic structure. But none of this is even mentioned in passing in the paper. Indeed, according to Burger at al., WEZ56 is best classified as belonging to R1, even though the R1a classification is quite secure based on the raw data that the authors posted online.

Be extremely wary of what you read in this paper, and anything else that these scientists have published in the past and will publish in the future. Below is the paper summary:

Lactase persistence (LP), the continued expression of lactase into adulthood, is the most strongly selected single gene trait over the last 10,000 years in multiple human populations. It has been posited that the primary allele causing LP among Eurasians, rs4988235-A [1], only rose to appreciable frequencies during the Bronze and Iron Ages [2, 3], long after humans started consuming milk from domesticated animals. This rapid rise has been attributed to an influx of people from the Pontic-Caspian steppe that began around 5,000 years ago [4, 5]. We investigate the spatiotemporal spread of LP through an analysis of 14 warriors from the Tollense Bronze Age battlefield in northern Germany (∼3,200 before present, BP), the oldest large-scale conflict site north of the Alps. Genetic data indicate that these individuals represent a single unstructured Central/Northern European population. We complemented these data with genotypes of 18 individuals from the Bronze Age site Mokrin in Serbia (∼4,100 to ∼3,700 BP) and 37 individuals from Eastern Europe and the Pontic-Caspian Steppe region, predating both Bronze Age sites (∼5,980 to ∼3,980 BP). We infer low LP in all three regions, i.e., in northern Germany and South-eastern and Eastern Europe, suggesting that the surge of rs4988235 in Central and Northern Europe was unlikely caused by Steppe expansions. We estimate a selection coefficient of 0.06 and conclude that the selection was ongoing in various parts of Europe over the last 3,000 years.

Burger et al., Low Prevalence of Lactase Persistence in Bronze Age Europe Indicates Ongoing Strong Selection over the Last 3,000 Years, Current Biology, Available online 3 September 2020, https://doi.org/10.1016/j.cub.2020.08.033

See also...

Warriors from at least two different populations fought in the Tollense Valley battle

The Balkan connection

The hot topic at the moment is social inequality in Bronze Age Europe, thanks to a new paper by Mittnik et al. at Science. The full article is sitting behind an exceedingly robust paywall here.

However, the genotype dataset from the paper is freely available at the Max Planck Society's Edmond data repository here. Below is my Principal Component Analysis (PCA) of ancient West Eurasian genetic variation featuring 41 of the highest quality ancients from the new dataset. Almost all of them are from the Lech Valley in the Bavarian Alps, covering the period from the Bell Beaker culture (BBC) to the Middle Bronze Age (MBA). Two of the samples are from a mass Corded Ware culture (CWC) burial in the more northerly Tauber Valley.

I've also highlighted other ancients on the plot associated with the BBC and CWC from present-day Netherlands and Germany, respectively. The relevant PCA datasheet can be downloaded here.

Social stratification in ancient Europe is a fascinating topic, and it's an issue that I've started looking at myself (see here). However, I can't see any correlation between the inferred social standing of the individuals from the Lech and Tauber valleys and their positions in my PCA.

Nevertheless, the PCA is interesting in that it highlights considerable genetic heterogeneity within the Lech Valley BBC population. Indeed, how is this heterogeneity even possible, if, as per Mittnik et al., ancient DNA "has shown that the spread of the BBC throughout continental Europe did not involve large-scale migrations"?

Below is another version of my PCA, but this time focusing on three males: Lech Valley Beakers UNTA58_68Sk1 and WEHR_1192SkA, as well as ALT_4 from the aforementioned mass CWC grave in the Tauber Valley. Note that UNTA58_68Sk1 and WEHR_1192SkA represent genetically the most southern and northern, respectively, Lech Valley BBC samples that had enough data to be run in my analysis. I chose to focus on males because they carry the Y-chromosome, which can be informative about male-mediated ancient population expansions.

The PCA outcomes for these individuals are generally in line with their results in other types of genetic analyses, including those based on formal statistics. For instance, compared to the other two, ALT_4 harbors excess early steppe herder ancestry, UNTA58_68Sk1 excess early European farmer ancestry, and WEHR_1192SkA excess European hunter-gatherer ancestry. Moreover...

- UNTA58_68Sk1 shows a non-local isotopic signature and belongs to Y-haplogroup G2a, a marker essentially missing from BBC populations north of the Alps, and is best modeled as a two-way mixture between Bronze Age populations from the Balkans and the Pontic-Caspian steppe (see here), which probably means that he was a migrant to the Lech Valley from south of the Alps

- importantly, UNTA58_68Sk1 is not an isolated case, at least in the sense that several other BBC individuals from Bavaria, Bohemia, Hungary and Poland show varying ratios of Balkan-related ancestry, although almost all of these people are women

- WEHR_1192SkA is very similar to Bell Beakers from the northern Netherlands with whom he shares the R1b-P312 Y-haplogroup, suggesting that he was part of a population that moved into the Lech Valley from potentially as far away as the North Sea coast

- although ALT_4 probably shares the R1b-L51 Y-haplogroup with WEHR_1192SkA and many other BBC and Bronze Age individuals from the Bavarian Alps and surrounds, this can't be used as evidence of significant local genetic continuity after the CWC period, especially considering the comparatively eastern genome-wide structure of ALT_4.

Of course, archeological data suggest that the BBC was influenced in some important ways by the Copper and Bronze Age cultures of the Balkans and Carpathian Basin. So much so, in fact, that Marija Gimbutas, author of The Civilization of the Goddess, believed that the BBC originated in the Balkans from a synthesis of the local Vucedol culture and the intrusive Yamnaya culture from the Pontic-Caspian steppe.

Considering the ancient DNA evidence, however, the main demographic center of the early BBC could not have been south of the Alps.

Rather, it appears that early BBC and even CWC groups from north of the Alps moved into the Balkans and Carpathian Basin, where they may have established contacts with the local elites. If so, this might explain the significant southern cultural influences on the BBC, but limited accompanying genetic impact. This scenario also has support from archeological data (for instance, see here).

See also...

Is Yamnaya overrated?

The Boscombe Bowmen

Single Grave > Bell Beakers

Is Yamnaya overrated?

Four years after the publication of the seminal ancient DNA paper Massive migration from the steppe is a source for Indo-European languages in Europe by Haak et al., we're still waiting for some of its loose ends to be finally tied up with new samples. In particular...

- if the men of the Corded Ware culture (CWC) were, by and large, derived from the population of the Yamnaya culture, then where are the Yamnaya samples with R1a-M417, the main CWC Y-haplogroup?

- if the men of the Bell Beaker culture (BBC) were also, by and large, derived from the population of the Yamnaya culture, then where are the Yamnaya samples with R1b-P312, the main BBC Y-haplogroup?

- and, most crucially, if R1b-L51, which includes R1b-P312, and is nowadays by far the most important Y-haplogroup in Western Europe, arrived there from the Pontic-Caspian steppe, then why hasn't it yet appeared in any of the ancient DNA from this part of Eastern Europe or surrounds, except of course in samples that are too young to be relevant?

I'm certainly not suggesting that, in hindsight, the said paper now looks fundamentally flawed. In fact, I'd say that it has aged remarkably well, especially considering how fast things are moving in the field of ancient genomics.

But those loose ends really need tying up, one way or another. It's now time.

So someone out there, please, let us know finally if you have the relevant Yamnaya samples. And if you don't, that's OK too, just tell us what you do have. Indeed, it'd be nice know a few basic details about the thousands of samples that have been successfully sequenced in various labs and are waiting to be published. A lot of people would appreciate it.

See also...

Corded Ware as an offshoot of Hungarian Yamnaya (Anthony 2017)

Hungarian Yamnaya > Bell Beakers?

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

Not Bell Beaker, not Corded Ware, but...the SGBR complex

I'd be very grateful if someone could explain to me what this new paper at the Proceedings of the Prehistoric Society journal was actually about.

Citation...

Furholt, Martin, Re-integrating Archaeology: A Contribution to aDNA Studies and the Migration Discourse on the 3rd Millennium BC in Europe, Proceedings of the Prehistoric Society, Published online: 10 June 2019, DOI: https://doi.org/10.1017/ppr.2019.4

See also...

Open thread: What are the linguistic implications of Olalde et al. 2019?

I was going to write a huge post on the linguistic implications of the latest batch of ancient DNA from Iberia courtesy of Olalde et al. 2019, and then I thought better of it. Admittedly, I don't know enough about the languages of prehistoric Iberia to say anything really useful on the topic. So instead here's an open thread to bounce around a few ideas in the comments.

Just briefly, this is what Olalde et al. say in the abstract of their paper about the relationship between ancestry from the Pontic-Caspian steppe and languages in Iron Age Iberia:

We reveal sporadic contacts between Iberia and North Africa by ~2500 BCE and, by ~2000 BCE, the replacement of 40% of Iberia’s ancestry and nearly 100% of its Y-chromosomes by people with Steppe ancestry. We show that, in the Iron Age, Steppe ancestry had spread not only into Indo-European–speaking regions but also into non Indo-European–speaking ones, and we reveal that present-day Basques are best described as a typical Iron Age population without the admixture events that later affected the rest of Iberia.

However, in the paper it's revealed that "Indo-European regions" actually refers to a Celtic-speaking part of northern Iberia. And it's quite possible that Celts moved into this area from outside of Iberia only during the Iron Age. In other words, the speakers of Indo-European languages here may not have been the descendants of any of the people with steppe ancestry who came to Iberia by ~2000 BCE.

So I'm probably not alone in thinking that the question of the linguistic affinities of these early migrants with steppe ancestry to Iberia (mostly associated with the Bell Beaker culture or BBC) remains open, especially since they evidently had such a profound genetic impact on the later non Indo-European-speaking populations of eastern and southern Iberia. Could they have been the speakers of unattested Indo-European languages, as well as Proto-Iberian and Proto-Basque? If not, why not?

Below is a Principal Component Analysis (PCA) of West Eurasian genetic variation. I highlighted some of the ancient samples from Olalde et al., as well as Basques and other present-day Iberians. The Basques form a tight cluster with most of the Copper, Bronze and Iron Age Iberians, and, unlike the other present-day Iberians, they basically look like an Iberian population from the metal ages. The relevant datasheet is available here.

This is nothing new and very much in line with the results in Olalde et al., but I wanted to emphasize the point that Basques were not just a group that experienced an extreme founder effect in R1b-P312, which is a Beaker-specific Y-chromosome lineage. Rather, they're still very similar to Iberian Beakers in terms of overall genetic structure. So where did they get their language?

See also...

Celtic probably not from the west

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

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

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?

Dutch Beakers: like no other Beakers

In my last two blog posts I tried to explain why the so called Bell Beakers of prehistoric 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...

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 Late Neolithic and 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...

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 Late Neolithic and 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_Hungary_I2787
Beaker_Bavaria 0.442±0.045
Yamnaya_Samara 0.558±0.045
chisq 8.562
tail prob 0.73982
Full output

Beaker_Hungary_I2787
Beaker_Czech 0.441±0.045
Yamnaya_Samara 0.559±0.045
chisq 10.009
tail prob 0.61513
Full output

Beaker_Hungary_I2787
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...