Perhaps a hint of things to come

It's still a mystery how the Hittites and other Anatolian speakers ended up in the Near East. However, the leading theory is that their ancestors migrated from the steppes of Eastern Europe to western Anatolia via the Balkans sometime during the Copper Age.

Consider the qpAdm mixture models below, made possible thanks to some of the ancient samples published recently along with Skourtanioti et al. 2020. The key ancients are described in a text file available here.

TUR_Barcin_C
AZE_Caucasus_lowlands_LN 0.471±0.094
RUS_Vonyuchka_En 0.148±0.040
TUR_Barcin_N 0.381±0.069
chisq 12.874
tail prob 0.116261
Full output

TUR_Barcin_C
RUS_Vonyuchka_En 0.107±0.029
TUR_Buyukkaya_EC 0.893±0.029
chisq 12.107
tail prob 0.207331
Full output

I'd say it's quite clear now that TUR_Barcin_C harbors minor ancestry from the Pontic-Caspian (PC) steppe. The reason this isn't widely accepted yet is because demonstrating it convincingly hasn't been possible without a proximate Anatolian ancestry source for TUR_Barcin_C, precisely like TUR_Buyukkaya_EC.

Admittedly, though, the statistical fits in my models aren't all that great. I suspect the problem lies with RUS_Vonyuchka_En, which is likely to be a rather poor stand in for the people who brought steppe ancestry, and possibly early Anatolian speech, to western Anatolia.

So let's see what happens when I try a more proximate reference for the steppe ancestry in TUR_Barcin_C. How about Yamnaya_BGR, an individual of mixed Balkan and steppe origin from what is now Bulgaria?

TUR_Barcin_C
AZE_Caucasus_lowlands_LN 0.518±0.075
TUR_Barcin_N 0.203±0.056
Yamnaya_BGR 0.279±0.067
chisq 10.602
tail prob 0.225269
Full output

TUR_Barcin_C
TUR_Buyukkaya_EC 0.749±0.058
Yamnaya_BGR 0.251±0.058
chisq 9.687
tail prob 0.376414
Full output

That's a little better. Unfortunately, the problem now is that the models are anachronistic, because TUR_Barcin_C is about a thousand years older than Yamnaya_BGR. Clearly, we need more Copper Age samples from the western edge of the PC steppe, the eastern Balkans, and especially northwestern Anatolia.

The Principal Component Analysis (PCA) below effectively illustrates why my qpAdm models work. It was produced with Global25 data using the Vahaduo PCA tools freely available here. Note that TUR_Barcin_C is shifted away from the essentially perfect cline formed by AZE_Caucasus_lowlands_LN, TUR_Barcin_N and TUR_Buyukkaya_EC towards samples from ancient Eastern Europe, including Yamnaya_BGR.

See also...

Steppe invaders in the Bronze Age Balkans

An early Mitanni?

I've updated my Global25 datasheets with most of the ancients from the new Skourtanioti et al. paper. Here's a Principal Component Analysis (PCA) based on the data. It was produced with the Vahaduo PCA tools freely available here and the text file here.

Note that one of the Bronze Age females from Alalakh, labeled ALA019, appears to have ancestry from Turan and the Eurasian steppe. She may well have been a Mitanni of Indo-Aryan origin.

Interestingly, a Copper Age male from Arslantepe, ART038, belongs to Y-haplogroup R1b1a2 aka R1b-V1636. This is an unusual find, because R1b hasn't yet been reported in any Copper Age or earlier samples from outside of Europe and the Eurasian steppe.

As far as I can tell, this individual doesn't harbor any genome-wide ancestry from north of the Caucasus. However, R1b-V1636 is a rare lineage that is first attested in Eneolithic samples from the North Caucasus Piedmont steppe, so ART038's Y-chromosome might be the first evidence of the presence of steppe ancestry in Copper Age Anatolia.

I've also added most of the ancients from the new Agranat-Tamir et al. paper to the Gobal25 datasheets. The PCA below is based on the text file available here.

The Megiddo samples include a trio of interesting outliers dated to 1600-1500 BCE with significant ancestry from the steppe. One of these individuals is a male, I2189, who belongs to Y-haplogroup R and probably R1a. So he might also be of Indo-Aryan origin.

Another Megiddo male, S10768, belongs to R1b-M269 and probably shows a few per cent of steppe ancestry. I've already discussed how R1b and steppe ancestry may have ended up in the Bronze Age Near East in a couple of my previous posts:

R1b-M269 in the Bronze Age Levant

How did steppe ancestry spread into the Biblical-era Levant?

R-V1636: Eneolithic steppe > Kura-Araxes?

Seven thousand years of French prehistory (Brunel et al. 2020)

Over at PNAS at this LINK. I'm not sure why one of the Bell Beakers, CBV95, is modeled as 100% Yamnaya-like in the paper? I've had a preliminary look at this individual and he appears to be very similar to most Corded Ware samples from Germany, with about 75% Yamnaya-related steppe ancestry. I'll revisit this issue when the authors' genotype data are released, apparently within the next few days. Here's the paper abstract:

Genomic studies conducted on ancient individuals across Europe have revealed how migrations have contributed to its present genetic landscape, but the territory of present-day France has yet to be connected to the broader European picture. We generated a large dataset comprising the complete mitochondrial genomes, Y-chromosome markers, and genotypes of a number of nuclear loci of interest of 243 individuals sampled across present-day France over a period spanning 7,000 y, complemented with a partially overlapping dataset of 58 low-coverage genomes. This panel provides a high-resolution transect of the dynamics of maternal and paternal lineages in France as well as of autosomal genotypes. Parental lineages and genomic data both revealed demographic patterns in France for the Neolithic and Bronze Age transitions consistent with neighboring regions, first with a migration wave of Anatolian farmers followed by varying degrees of admixture with autochthonous hunter-gatherers, and then substantial gene flow from individuals deriving part of their ancestry from the Pontic steppe at the onset of the Bronze Age. Our data have also highlighted the persistence of Magdalenian-associated ancestry in hunter-gatherer populations outside of Spain and thus provide arguments for an expansion of these populations at the end of the Paleolithic Period more northerly than what has been described so far. Finally, no major demographic changes were detected during the transition between the Bronze and Iron Ages.

Brunel et al., Ancient genomes from present-day France unveil 7,000 years of its demographic history, PNAS, first published May 26, 2020 https://doi.org/10.1073/pnas.1918034117

See also...

The Boscombe Bowmen

Genetic continuity and change in prehistoric Ireland (Lara Cassidy Thesis)

Over at TARA at this LINK. Here's the abstract:

This thesis provides an initial demographic scaffold for Irish prehistory based on the palaeogenomic analysis of 93 ancient individuals from all major periods of the island's human occupation, sequenced to a median of 1X coverage. ADMIXTURE and principal component analysis identify three ancestrally distinct Irish populations, whose inhabitation of the island corresponds closely to the Mesolithic, Neolithic and Chalcolithic/Early Bronze Age eras, with large scale migration to the island implied during the transitionary periods. Haplotypic-based sharing methods and Y chromosome analysis demonstrate strong continuity between the Early Bronze Age and modern Irish populations, suggesting no substantial population replacement has occurred on the island since this point in time. The Mesolithic population shares high genetic drift with contemporaries from France and Luxembourg and shows evidence of a severe inbreeding bottleneck, apparent through runs of homozygosity (ROH). Substantial contributions from both Mediterranean farming groups and northwestern hunter-gatherers are evident in the Neolithic Irish population. Moreover, evidence for local Mesolithic survival and introgression in southwestern Ireland, long after the commencement of the Neolithic, is also implied in haplotypic-analysis. Societal complexity during the Neolithic is suggested in patterns of Y chromosome and autosomal structure, while the identification of a highly inbred individual through ROH analysis, retrieved from an elite burial context, strongly suggests the elaboration and expansion of megalithic monuments over the course of the Neolithic was accompanied in some regions by dynastic hierarchies. Haplotypic affinities and distributions of steppe-related introgression among samples suggest a potentially bimodal introduction of Beaker culture to the island from both Atlantic and Northern European sources, with southwestern individuals showing inflated levels of Neolithic ancestry relative to individualised burials from the north and east. Signals of genetic continuity and change after this initial establishment of the Irish population are also explored, with haplotypic diversification evident between both the Bronze Age and Iron Age, and the Iron Age and present day. Across these intervals selection pressures related to nutrition appear to have acted, with variants involved in lactase persistence and skin depigmentation showing steady increases in frequency through time.

CASSIDY, LARA, A Genomic Compendium of an Island: Documenting Continuity and Change across Irish Human Prehistory, Trinity College Dublin.School of Genetics & Microbiology. GENETICS, 2018

Update 24/05/2020: Apparently the thesis has been embargoed until 24/5/2023. It's still marked as open access, but the link to the PDF now leads to a login page.

See also...

Commoner or elite?

A significant finding

At least five individuals from Neolithic burial sites in what is now Ukraine harbor ancestry that is normally associated with much later steppe populations. Labeled UKR_N_admixed in the plot below, these samples were part of the Mathieson et al. 2018 dataset and most were radiocarbon dated to well before 5,000 BCE. An interactive version of the plot is available here.

Their unusual ancestry probably explains why they form a cluster that appears to be pulling away from the ancient European hunter-gatherer cline towards the part of the plot home to RUS_Progress_En (from the Progress-2 Eneolithic burial site in the North Caucasus piedmont region). But, of course, there's more to this. For instance, consider the formal statistics-based qpAdm mixture models below:

UKR_N_admixed
RUS_Progress_En 0.083±0.021
UKR_N 0.917±0.021
chisq 7.461
tail prob 0.589238
Full output

UKR_N_admixed
RUS_Progress_En 0.172±0.021
SRB_Iron_Gates_HG 0.332±0.024
UKR_Meso 0.495±0.035
chisq 9.255
tail prob 0.321282
Full output

UKR_N_I1738
RUS_Progress_En 0.196±0.035
SRB_Iron_Gates_HG 0.414±0.039
UKR_Meso 0.390±0.056
chisq 7.913
tail prob 0.442006
Full output

Ergo, as much as a quarter of the genome of individual I1738, dated to 5473-5326 calBCE, might be derived from a population very similar to RUS_Progress_En. This is a big deal, because it's still widely believed that this type of ancestry didn't exist until the Eneolithic, and that it didn't spread significantly until the migrations of steppe pastoralists associated with the Early Bronze Age Yamnaya culture.

I'm confident, nay, certain, that my findings will be confirmed directly with more Neolithic samples from present-day Ukraine and surrounds.

See also...

Understanding the Eneolithic steppe

Ancient DNA vs Ex Oriente Lux

Mixed marriages on the early Eneolithic steppe

Of horses and men #2

Fascinating stuff courtesy of Fages et al. at the Journal of Archaeological Science: Reports (emphasis is mine):

Abstract: The domestication of the horse and the development of new equestrian technologies have had a far-reaching impact on human history. Disentangling the respective role that horse males and females played during this process is, however, difficult based on iconography and osteological data alone. In this study, we leveraged an extensive ancient DNA time-series to determine the molecular sex of 268 horses spread across Eurasia and charted the male:female sex ratio through the last 40,000 years. We found even sex ratios in the Upper Palaeolithic and up until ~3900 years BP. However, we identified a striking over-representation of horse males in more recent osseous assemblages, which was particularly magnified in funerary contexts but also significant in non-ritual deposits. This suggests that the earliest horse herders managed males and females alike for more than one thousand years after domestication at Botai, but that the human representation and use of horses became gendered at the beginning of the Bronze Age, following the emergence of gender inequalities in human societies.

...

The time period around ~3900 years ago marked a drastic shift in male:female sex ratios inferred from excavated remains, after which the horse osteological record comprises approximately four males for every female (Fig. 2). This over-representation of horse males was maintained when disregarding those animals excavated from ritual burial sites (77/25 ~ 3.08 males for every female) and even more pronounced in the animal bones found in funerary contexts (66/14 ~ 4.71 males for every female). This indicates that the status of male and female horses dramatically changed during the Bronze Age period. This is in line with archaeozoological evidence from the Late Bronze Age cemeteries of the Volga-Ural region associated with the Sintashta, Potapovka and Petrovka cultures, that suggest a domination of male horses in funerary rates (Kosintsev, 2010). Interestingly, this pattern somehow mirrors that observed in humans, for whom a clear binary gender structure ubiquitous across all funerary practices, clothing, personal ornaments and representations is not observed during the Neolithic but became the norm from the transition between the Neolithic and the Bronze Age onwards (Robb and Harris, 2018). In addition, the prevalence of male horses in funerary contexts throughout the past three millennia is in line with archaeological evidence from burial sites (Bertašius and Daugnora, 2001, Taylor, 2017) and suggests that stallions (or geldings) were more prized for sacrificial rituals. This is possibly due to symbolic attributes then-associated with masculinity, mounted warriors and chariotry, such as power, protection and strength (Frie, 2018). In particular, petroglyph images associated with vehicles, characterized by two wheels with spokes, became typical by the late third – early second millennium BCE (Jacobson-Tepfer, 2012). They are generally associated with male warriors and the emergence of mobile warfare (Anthony, 2007) or ritual needs, in particular the passage to the after-life land (Jones-Bley, 2000). This suggests an essential ideological role of stallions and their use in elite warfare and ritual practices (Drews, 2004, Kelekna, 2009, Novozhenov and Rogozhonskiy, 2019).

...

Future research should focus on assessing the molecular sex of horses from Early and Middle Bronze Age Pit Grave and Catacomb cultures, which do show evidence for social inequality, but for which sex inequalities remain to be investigated.

Fages et al., Horse males became over-represented in archaeological assemblages during the Bronze Age, Journal of Archaeological Science: Reports Volume 31, June 2020, 102364, https://doi.org/10.1016/j.jasrep.2020.102364

See also...

Of horses and men

Inferring the linguistic affinity of long dead and non-literate peoples: a multidisciplinary approach

The mystery of the Sintashta people

Understanding the Eneolithic steppe

Archeologist David Anthony has teamed up with Harvard's David Reich Lab to work on a paper about the Eneolithic period on the Pontic-Caspian steppe.

A couple of other labs are also preparing papers on similar topics, and they've already sequenced and analyzed many of their ancient samples (for instance, see here). However, I don't have a clue when these papers will be published. My guess is that we'll have to wait a year or so.

Needless to say, knowing what happened on the Pontic-Caspian (PC) steppe and surrounds during the Eneolithic is crucial to understanding the origins of the present-day European gene pool. It's also likely to be highly relevant to the debate about the location of the Proto-Indo-European (PIE) homeland.

In this blog post I'll explain what I've learned about the Eneolithic peoples of the PC steppe based on already published data.

If we ignore Steppe Maykop samples, the currently available Eneolithic individuals from the eastern part of the PC steppe form an essentially perfect cline in my Principal Component Analysis (PCA) of ancient West Eurasian genetic variation.

The cline runs from the Mesolithic hunter-fishers of the Eastern European forest zone to those of the Eneolithic sites of Progress 2 and Vonyuchka in the North Caucasus foothills. Let's call this the Khvalynsk cline, because three of the samples are from a burial site in the Volga River valley associated with the Khvalynsk culture. The relevant datasheet is available here.

The reason that these samples form the cline is because they carry different ratios of admixture related to Caucasus hunter-gatherers (CHG) from what is now Georgia. Moreover, the Khvalynsk individuals appear to be relatively recent mixtures between sources rich and poor in this type of ancestry.

I also marked a Maykop cline on the plot. This cline is made up of individuals associated with the Maykop and Steppe Maykop cultures from the Caucasus Mountains and nearby parts of the PC steppe, respectively. The Maykop culture is dated to the Early Bronze Age (EBA) period, but the PC steppe was still part of the Eneolithic world at the time.

The Maykop cline is more complicated than the Khvalynsk cline, because some of the Maykop individuals carry genetic components that the others lack. These genetic components are closely related to the aforementioned CHG, as well as Anatolian Neolithic farmers (ANF) and Western Siberian hunter-gatherers (WSHG).

Note that the two clines intersect, but this isn't because any of the Khvalynsk cline samples harbor Maykop-related ancestry. It's largely because the Steppe Maykop individuals carry high levels of Vonyuchka-related ancestry.

So unless we're dealing here with a remarkable string of coincidences, then the Vonyuchka hunter-fisher must be a decent proxy for the people who spread significant levels of CHG-related ancestry north of the Caucasus.

The important question, therefore, is where and when exactly did this population form? And it's a question that the authors of the aforementioned upcoming papers should be aiming to answer comprehensively.

In my view, it was the result of interactions between the hunter-fishers of the North Caucasus and the southernmost parts of the PC steppe during the Neolithic period, perhaps around 6,000 BCE, just before significant ANF-related ancestry spread across the Caucasus during the Eneolithic. That's because the Progress 2/Vonyuchka samples lack ANF-related ancestry, or at least an obvious signal of it, and are dated to ~4,200 BCE. And when I say Neolithic in this context, I don't mean the Near Eastern type of Neolithic with well developed farming, but rather the local type of Neolithic still based on hunting and fishing.

Now, obviously, the people of the Corded Ware and Yamnaya cultures were the children of the Eneolithic PC steppe. So you might be wondering how they fit into all of this. I still don't know, and apparently neither do the scientists at Harvard (see here). However, I'd say that the Maykop cline isn't relevant to this question. The Khvalynsk cline might be relevant, but even if it is, this doesn't necessarily mean that the Yamnaya people are by and large derived from the Khvalynsk people.

Here's the same PCA plot as above, but this time with early Corded Ware and Yamnaya samples also highlighted. Note that, apart from a few outliers, they form a rather tight cluster that is shifted slightly away from the Khvalynsk cline, but probably not in the direction of the Maykop cline.

A couple of the Yamnaya outliers are shifted towards the "eastern" end of the Khvalynsk cline, and thus near the Progress 2/Vonyuchka samples. This isn't surprising because these Yamnaya individuals are from burial sites close to the North Caucasus and probably harbor significant levels of local ancestry.

The most extreme Yamnaya outlier, from a site in what is now Ukraine, is clearly shifted towards the Maykop cline, and even towards the Caucasus Maykop cluster. However, this is a female with no grave goods and she may have been a foreign bride or captive, possibly from a late Maykop settlement. It's also possible that her 3095-2915 calBCE dating is wrong.

I'm pretty sure that when we find out why the Yamnaya cluster is so deliberately shifted away from the Khvalynsk cline, we'll also discover how the early Corded Ware and Yamnaya populations formed. For now, I strongly suspect that this has something to do with gene flow from the western edge of the PC steppe and the ethnogenesis of the Sredny Stog culture, which was located just west of the Khvalynsk culture.

By and large, the PC steppe is still seen by historical linguists and archeologists as the most sensible place to put the PIE homeland.

However, a theory that the PIE homeland was located somewhere south of the Caucasus, and that instead the PC steppe was the late or nuclear PIE dispersal point, has gained popularity in recent years, largely thanks to the apparent lack of PC steppe ancestry in a handful of samples from Hittite era Anatolia. In this scheme, the Maykop culture took PIE into Eastern Europe and the Yamnaya culture subsequently spread late/nuclear PIE from the PC steppe, while Proto-Anatolian, the ancestor of Hittite, was introduced into Anatolia from the east along with Maykop-related ancestry.

This is possible, in the sense that almost anything is possible, but it doesn't strike me as the most parsimonious interpretation of the facts.

Even before ancient DNA, it was known that the Maykop culture colonized parts of the PC steppe, at least for a short time, and probably had contacts with the Yamnaya people and/or their antecedents. But it was generally seen as the vector for Caucasian and other non-Indo-European influences in PIE.

Moreover, not only were the Maykop and Yamnaya populations of fundamentally different genetic origins, but apparently the Yamnaya people didn't absorb any perceptible Maykop ancestry as they expanded into the North Caucasus region at the tail end of the Maykop period.

That's really difficult to explain if we assume that these groups were close linguistic relatives, and much easier to reconcile with the assumption that they were derived from different worlds culturally and linguistically.

Another important question is what happened to the Steppe Maykop people, because right now it looks like they vanished almost without a trace, essentially as if they were pushed out or even erased by the Yamnaya expansion. If they were indeed pushed out or erased, then it's likely that their language was as well.

As for the lack of PC steppe ancestry in Hittite era Anatolians, I honestly can't see this is as a significant obstacle to a PIE homeland on the steppe, especially if we consider that the most widely accepted Indo-European phylogenies show the Anatolian family as the most basal node.

In the opinion of the vast majority of experts, it's the most basal node because the Proto-Anatolian speakers were the first to leave the PIE homeland. And if they were indeed the first to leave the homeland, then why should we expect their descendants to harbor significant ancestry from the homeland? In my view, such an assumption would contradict the most widely accepted Indo-European phylogenies.

See also...

The Caucasus is a semipermeable barrier to gene flow

Aesch25

During the early 3rd Millennium BC much of Central and Northern Europe was being infiltrated by pioneer herders, often young men, from the east associated with the Corded Ware culture (CWC).

In some important ways, this expansion may have been very similar to the European colonization of the more remote parts of the Americas during the 16th and 17th centuries.

For instance, the European newcomers weren't always able to dominate the indigenous peoples, and, sometimes, instead of trying to impose their culture on them, they accepted theirs.

I suspect that Aesch25, an ancient sample from the recent Furtwängler et al. paper on the social and genetic structure of the prehistoric populations of the Swiss Plateau, represents a similar case.

Aesch25 wasn't buried with grave goods so he wasn't given a cultural context in the said paper. However, dated to 2864-2501 calBC, he's the earliest individual in this part of Europe with the originally Eastern European Y-haplogroup R1b-M269 and a CWC-like genome-wide genetic structure.

Indeed, the other fourteen samples from the same burial site, dated to more or less the same period as Aesch25, are overwhelmingly of local Neolithic farmer origin.

In any case, irrespective of his cultural affiliation and life story, Aesch25 represents an important data point in the search for the homeland of the so called Bell Beakers who spread across much of Europe during the Copper Age. That's because most Bell Beaker males belong to R1b-M269 and are very similar to Aesch25 in terms of overall genetic structure, apart from an excess of Neolithic farmer ancestry.

My view is that the Bell Beakers were an offshoot of the Single Grave culture (SGC), the westernmost variant of CWC. Of course, the SGC was centered on what is now northwestern Germany and surrounds, and didn't reach into the Swiss Plateau. However, in all likelihood it was founded by men closely related to Aesch25.

Below is a Principal Component Analysis (PCA) based on Global25 data featuring Aesch25 and several other individuals from the Furtwängler et al. paper. To view an interactive version of the plot, copy paste the data from the text file here into the relevant field here, then press Add to PCA. Also, you should copy paste each population separately to make sure that they don't form one grouping in the PCA key.

Aesch25 can easily pass for a CWC individual from what is now Germany (DEU_CWC_LN). On the other hand, the CWC samples from the Swiss Plateau (CHE_CWC_LN) are clearly shifted "south" relative to the German CWC cluster, which suggests that they harbor more Neolithic farmer ancestry. Indeed, they all belong to Y-haplogroup I2, which is especially closely associated with Middle Neolithic European farmers.

MX265, from Singen in southwest Germany, is the only sample in the Furtwängler et al. dataset that belongs to Y-haplogroup R1a. This is a somewhat unexpected outcome, because R1a is, overall, the most common Y-haplogroup in CWC males (see here).

Another surprise is that this individual is dated to just 763-431 calBC, which is a period that overlaps with the Hallstatt and La Tene cultures in Central Europe. Considering that these cultures are often associated with early Celts, was this person perhaps the speaker of a long lost Celtic language?

See also...

Single Grave > Bell Beakers

Dutch Beakers: like no other Beakers

Hungarian Yamnaya > Bell Beakers?

Hungarian Yamnaya predictions

The Battle Axe people came from the steppe

Corded Ware cultural and genetic complexity (Linderholm et al. 2020)

Open access at Scientific Reports at this LINK. Although very useful and broadly accurate, I'm really not sure what to make of this paper yet, especially in regards to its more nuanced inferences. I'll need to look at the genotype data at some point. Worthy of note is that most of the Corded Ware males sampled by the authors belong to Y-haplogroup R1b-M269, rather than R1a-M417, which is the dominant Y-haplogroup in previously published Corded Ware samples. From the paper:

During the Final Eneolithic the Corded Ware Complex (CWC) emerges, chiefly identified by its specific burial rites. This complex spanned most of central Europe and exhibits demographic and cultural associations to the Yamnaya culture. To study the genetic structure and kin relations in CWC communities, we sequenced the genomes of 19 individuals located in the heartland of the CWC complex region, south-eastern Poland. Whole genome sequence and strontium isotope data allowed us to investigate genetic ancestry, admixture, kinship and mobility. The analysis showed a unique pattern, not detected in other parts of Poland; maternally the individuals are linked to earlier Neolithic lineages, whereas on the paternal side a Steppe ancestry is clearly visible. We identified three cases of kinship. Of these two were between individuals buried in double graves. Interestingly, we identified kinship between a local and a non-local individual thus discovering a novel, previously unknown burial custom.

...

The PCA revealed that despite geographical proximity there is a distinct genetic separation between CWC and BBC individuals from southern Poland. The genetic variation of CWC individuals from southern Poland overlaps with the majority of previously published CWC individuals from Germany while the eight published CWC individuals from the Polish lowland [10,11] more closely resemble BBC individuals (Fig. S21). This fact is not unexpected if we consider the CWC communities in Polish lowlands as representatives of north-western parts of the CWC world called as the Single-Grave culture (see supplementary information). The genetic variation of BBC individuals from south-eastern Poland overlaps with the broad variation of BBC individuals from Central Europe (Bohemia, Moravia, Germany, south-western Poland and Hungary) (Fig. S22) which corresponds well with archaeological data.

Linderholm, A., Kılınç, G.M., Szczepanek, A. et al. Corded Ware cultural complexity uncovered using genomic and isotopic analysis from south-eastern Poland. Sci Rep 10, 6885 (2020). https://doi.org/10.1038/s41598-020-63138-w

See also...

The Battle Axe people came from the steppe

Is Yamnaya overrated?

Single Grave > Bell Beakers

Latest on Sintashta-Petrovka chariots (Lindner 2020)

Open access at Antiquity at this LINK. As far as I can tell, several individuals from the graves analyzed in this paper are in my ancient DNA dataset and the Global25 datasheets. Sample I1064 from the Kamennyi Ambar 5 cemetery comes to mind. Here's the abstract:

In Eastern Europe, the use of light vehicles with spoked wheels and harnessed horse teams is first evidenced in the early second-millennium BC Sintashta-Petrovka Culture in the South-eastern Ural Mountains. Using Bayesian modelling of radiocarbon dates from the kurgan cemetery of Kamennyj Ambar-5, combined with artefactual and stratigraphic analyses, this article demonstrates that these early European chariots date to no later than the first proto-chariots of the ancient Near East. This result suggests the earlier emergence of chariots on the Eurasian Steppe than previously thought and contributes to wider debates on the geography and chronology of technological innovations.

See also...

The mystery of the Sintashta people