Global25 workshop 3: genes vs geography in Northern Europe

To produce the intra-North European Principal Components Analysis (PCA) plot below, download this datasheet, plug it into the PAST program, which is freely available here, then select all of the columns by clicking on the empty tab above the labels, and choose Multivariate > Ordination > Principal Components or Discriminant Analysis. This is what you should end up with...

I'd say that the result more or less resembles a geographic map of Northern Europe. Of course, if you're in the possession of your own personal Global25 coordinates, you can add yourself to this plot to check whether your position matches your geographic origin.

Please keep in mind, however, that the vast majority (>90%) of your ancestry must be from north of the Alps, Balkans and Pyrenees to obtain a sensible outcome. Also please ensure that all of the columns in the datasheet are filled out correctly, including the group column, otherwise your position on the plot will be skewed.

See also...

Global25 workshop 1: that classic West Eurasian plot

Global25 workshop 2: intra-European variation

Global25 workshop 4: a neighbour joining tree

Getting the most out of the Global25

Genetic ancestry online store (to be updated regularly)

The South Asian cline that no longer exists

Before the Indo-Europeans and Austroasiatics got to South Asia, probably well within the last 4,000 years, it's likely that all of the genetic variation in the region basically sat along a genetic cline devoid of any Bronze Age steppe and Southeast Asian ancestry, like the one in the Principal Component Analysis (PCA) below running from the Paniya to the "Indus Periphery" ancient sample Shahr_I_Sokhta BA2.

Note that almost all of the South Asian populations, including the Iron Age (IA) Swat Valley groups, are clearly peeling away from the said cline towards the Tajiks, in other words towards Central Asia. This is a reflection of the widespread presence of Sintashta-related steppe admixture among South Asians, especially those speaking Indo-European languages. Moreover, the Bangalis and Burushos are being pushed towards the top left of the plot as a result of East Asian-related ancestry. In the case of the former, this is largely due to gene flow from Austroasiatic groups.

It'll be interesting to see how ancient Harappans behave in this analysis. I'm betting that they'll be very similar to the Indus Periphery trio, although judging by the latest press report on the topic (see here), the Harappan samples from Rakhigarhi might be shifted much closer to the Paniya as a result of a higher ratio of indigenous South Asian ancestry.

The PCA is based on my Global25 test. If you're South Asian and in the possession of Global25 coordinates, you can add yourself to this plot using the datasheet available here. Plug the datasheet into the PAST program (freely available here), select all of the columns, and go Multivariate > Ordination > Principal Components (PCA).

Update 10/08/2018: I managed to almost reproduce my PCA with a graph based on D-stats of the form D(Mbuti,X)(Onge,Ganj_Dareh_N)/D(Mbuti,X)(Ganj_Dareh_N,Sintashta_MLBA). Admittedly, Gonur2_BA didn't want to cooperate by pushing slightly up and away from the ghost South Asian cline. But this may have been due to a lack of data or perhaps minor admixture (keep in mind that this sample is actually from Turkmenistan and not South Asia). However, combining all three of the Indus_Periphery individuals worked well enough. The relevant datasheet is available here.

See also...

Global25 workshop 1: that classic West Eurasian plot

Global25 workshop 2: intra-European variation

Global25 workshop 3: genes vs geography in Northern Europe

Global25 workshop 4: a neighbour joining tree

Getting the most out of the Global25

Genetic ancestry online store (to be updated regularly)

A Mycenaean and an Iron Age Iranian walk into a bar...

What do they have in common? The same type of Near Eastern ancestry? From Iran? Nope, that's a joke. Obviously, they share the same type of steppe ancestry. This probably has some very important linguistic implications.

The relevant Principal Component Analysis (PCA) datasheet is available here. Below are two pairs of formal mixture models that support my inferences from the PCA.

Mycenaean
Srubnaya_MLBA 0.266±0.029
Tepecik_Ciftlik_N 0.734±0.029
taildiff: 0.588000631
Full output

Mycenaean
Minoan_Lasithi 0.790±0.023
Srubnaya_MLBA 0.210±0.023
taildiff: 0.187709803
Full output

...

Turkmenistan_IA
Namazga_CA 0.528±0.040
Srubnaya_MLBA 0.472±0.040
taildiff: 0.561330411
Full output

Turkmenistan_IA
Dzharkutan1_BA 0.530±0.037
Srubnaya_MLBA 0.470±0.037
taildiff: 0.485083377
Full output

But seriously, what's the direct link between populations like Tepecik_Ciftlik_N/Minoan_Lasithi and Namazga_CA/Dzharkutan1_BA, except some exceedingly distant farmer ancestry from the Fertile Crescent?

See also...

An early Iranian, obviously

Graeco-Aryan parallels

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

An early Iranian, obviously

Today, the part of Asia between the Caspian Sea and the Altai Mountains, known as Turan, is largely a Turkic-speaking region. But during the Iron Age it was dominated by Iranian speakers. Throughout this period it was the home of a goodly number of attested and inferred early Iranic peoples, such as the Airya, Dahae, Kangju, Massagetae, Saka and Sogdians.

Indeed, the early Iron Age Yaz II archaeological culture, located in southwestern Turan, is generally classified as an Iranian culture, and even posited to have been the Airyanem Vaejah, aka home of the Iranians, from ancient Avestan literature.

That's not to say that Iranian speakers weren't present in this part of the world much earlier. They probably were, and it's likely that we already have their genomes (see here). But the point I'm making is that Turan can't be reliably claimed to have been an Iranian realm until the Iron Age.

Ergo, any ancient DNA samples from Turan dating to the Iron Age, as opposed to, say, the Bronze Age, are very likely to be those of early Iranian speakers. One such sample is Turkmenistan_IA DA382 from Damgaard et al. 2018.

Below is a screen cap of the "time map" from homeland.ku.dk, with the slider moved to 847 BC, showing the location of the burial site where the remains of DA382 were excavated. The site is marked with the Z93 label because DA382 belongs to the Eastern European-derived Y-chromosome haplogroup R1a-Z93. Interestingly, his burial was located in close proximity to archaeological sites associated with the above mentioned and contemporaneous Yaz II culture.

DA382 didn't get much of a run in the Damgaard et al. paper, and little wonder because the authors also analyzed 73 other ancient samples. So let's take a close look at this individual's genetic structure to see whether there's anything particularly Iranian about it.

Damgaard et al. did mention that DA382 was partly of Middle to Late Bronze Age (MLBA) steppe origin. And indeed, my own mixture models using qpAdm confirm this finding with very consistent results and strong statistical fits. Here are a couple of two-way examples...

Turkmenistan_IA
Namazga_CA 0.528±0.040
Srubnaya_MLBA 0.472±0.040
taildiff: 0.561330411
Full output

Turkmenistan_IA
Dzharkutan1_BA 0.530±0.037
Srubnaya_MLBA 0.470±0.037
taildiff: 0.485083377
Full output

The fact that the MLBA Srubnaya samples from the Pontic-Caspian steppe can be used to model DA382's ancestry (alongside Bronze and Copper Age populations from Turan) with such ease shouldn't be surprising, considering the he belongs to R1a-Z93, which is the dominant Y-haplogroup in the Srubnaya and all other closely related MLBA steppe peoples.

Now, Srubnaya is generally regarded to be the proto-Iranian archaeological culture. How awesome is that considering those qpAdm fits? But, admittedly, this is just an inference, even if a robust one, based on genetic, archaeological and historical linguistics data. So apart from the fact that DA382 comes from Iron Age Turan, an Iranian-speaking realm, is there any other way to link him directly to Iranians?

Well, he's very similar in terms of overall genetic structure to some of the least Turkic-admixed Iranian speakers still living in Turan, and might well be ancestral to them.

For instance, below is a Principal Component Analysis (PCA) featuring a wide range of ancient and present-day West Eurasian samples. Note that, in line with the qpAdm models, DA382 clusters about half-way between the populations of the MLBA steppe and pre-Kurgan expansion Turan, and amongst present-day Yaghnobi and Pamiri Tajiks. In fact, he clusters at the apex of a southeast > northwest cline made up of Tajiks that appears to be pulling towards Europeans.

Needless to say, Tajiks, especially Pamiri Tajiks, also pack a lot of Srubnaya-related ancestry. I've talked about this plenty of times at this blog (for instance, see here). But what happens if I try to model Pamiri and Yaghnobi Tajiks with DA382?

Tajik
Turkmenistan_IA 0.892±0.023
Han 0.108±0.023
taildiff: 0.794566182
Full output

Wow, it's an awesome fit! My mind's made up: DA382 was probably an Iranian speaker and, more specifically, an Eastern Iranian speaker. Who disagrees and why? Feel free to let me know in the comments (unless you're banned, in which case, f*ck off).

See also...

A Mycenaean and an Iron Age Iranian walk into a bar...

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

New PCA featuring Botai horse tamers, Hun and Saka warriors, and many more...

"The Homeland: In the footprints of the early Indo-Europeans" time map

Click HERE to view the interactive time map, and give it some time to load if you're on a slow connection. Use the slider tool to explore different time periods from 6385 BC to 1 BC. It's still a work in progress, so feel free to let the author, Mikkel Nørtoft, know if anything should be added, tweaked and/or generally improved.

Below is a screen cap of the map with the slider moved to 3618 BC. Note the sheep in the North Pontic steppe and the wheels just west of it. Wink, wink, nudge, nudge...

See also...

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

Friendly Yeniseian steppe pastoralists

For most people the Proto-Indo-European (PIE) homeland debate isn't just about language, but also, or even more so, about things like ancestry, politics, racism, and ethnic pride.

I don't want to get into all the dirty details in this post, but, for instance, many of those who argue vehemently against a steppe homeland seem to really hate the idea that their ancestors were, at some level, dominated by a bunch of sheep and cow herders from an obscure part of Eastern Europe. Why? I'm pretty sure because they find this humiliating.

Hence, PIE homeland debates are generally very emotional and often degenerate into shouting matches. So what would happen if we assumed that those sheep herders weren't Indo-Europeans? Let's say, for the sake of argument, that they spoke extinct Yeniseian languages.

Well, nothing really...

We still have them expanding in a big way out of the Pontic-Caspian steppe. And the fact that their impact was mostly male mediated, especially at the two ends of its range, in Iberia and India, suggests that they weren't just friendly pastoralists looking for new grazing fields.

In fact, in India, steppe ancestry, including Y-chromosome haplogroup R1a, is much more pronounced in the upper castes than in the rest of society. But who knows what that means, right? Maybe those friendly "Yeniseian" steppe pastoralists just got lucky or something?

But that's OK, perhaps this will always remain a mystery? In any case, does anyone know if there's any sort of Yeniseian substrate in Celtic or Mycenaean? Haha.

See also...

"Heavily sex-biased" population dispersals into the Indian Subcontinent (Silva et al. 2017)

Migration of the Bell Beakers—but not from Iberia (Olalde et al. 2018)

Steppe admixture in Mycenaeans, lots of Caucasus admixture already in Minoans (Lazaridis et al. 2017)

Ahead of the pack

Eurogenes Blog January 2018 (see here):

Yamnaya and other similar Eneolithic/Bronze Age herder groups from the Eurasian steppe were mostly a mixture of Eastern European Hunter-Gatherers (EHG) and Caucasus Hunter-Gatherers (CHG). But they also harbored minor ancestry from at least one, significantly more westerly, source that pulled them away from the EHG > CHG north/south genetic cline.

...

It's interesting and, I'd say, important to note that the West Asian reference groups produce amongst the worst statistical fits (in bold text). What this suggests is that Yamnaya did not harbor extra West Asian ancestry on top of its CHG input.

...

Rather, Blatterhole_MN is simply the best proxy in this analysis for the non-CHG/EHG ancestry in Yamnaya, and the important question is why?

Considering also the presence at the top of the list of Koros_HG (which includes Hungary_HG I1507), Germany_MN and Vinca_MN, the likely answer is its high ratio of Western European Hunter-Gatherer (WHG) ancestry.

...

So is the missing piece of the Yamnaya puzzle a population with roughly equal ratios of Early Neolithic (EN) and WHG ancestries from the Carpathian Basin or surrounds? Quite possibly. But let's wait and see what happens when I add the ancient groups from the Balkans and North Pontic steppe from the forthcoming Mathieson et al. 2018 to this analysis.

And now Wang et al. May 2018 (see here).

In principal component space Eneolithic individuals (Samara Eneolithic) form a cline running from EHG to CHG (Fig. 2D), which is continued by the newly reported Eneolithic steppe individuals.

...

However, PCA results also suggest that Yamnaya and later groups of the West Eurasian steppe carry some farmer related ancestry as they are slightly shifted towards ‘European Neolithic groups’ in PC2 (Fig. 2D) compared to Eneolithic steppe.

...

Importantly, our results show a subtle contribution of both Anatolian farmer-related ancestry and WHG-related ancestry (Fig.4; Supplementary Tables 13 and 14), which was likely contributed through Middle and Late Neolithic farming groups from adjacent regions in the West. A direct source of Anatolian farmer-related ancestry can be ruled out (Supplementary Table 15).

...

We find that Yamnaya individuals from the Volga region (Yamnaya Samara) have 13.2±2.7% and Yamnaya individuals in Hungary 17.1±4.1% Anatolian farmer-related ancestry (Fig.4; Supplementary Table 18)– statistically indistinguishable proportions. Replacing Globular Amphora by Iberia Chalcolithic, for instance, does not alter the results profoundly (Supplementary Table 19). This suggests that the source population was a mixture of Anatolian farmer-related ancestry and a minimum of 20% WHG ancestry, a profile that is shared by many Middle/Late Neolithic and Chalcolithic individuals from Europe of the 3 rd millennium BCE analysed thus far.

Strikingly similar, don't you think? However, I'm not implying that they copied me. The point I'm making is that I predicted this outcome ahead of anyone else, and was able to demonstrate it without some of the key ancient samples that Wang et al. had access to. Indeed, kudos to them for finding and successfully sequencing those all important new Eneolithic steppe samples.

Moreover, these results mean that it's no longer plausible to argue that the Yamnaya population, by and large, formed due to recent gene flow from south of the Caucasus, let alone from what is now Iran, into the Pontic-Caspian steppe. Obviously, this is a major problem for anyone arguing that the Proto-Indo-European (PIE) homeland may have been located somewhere south of the Caucasus, such as Paul Heggarty of the Max Planck Institute for the Science of Human History (for instance, see here). But hey, never mind the facts when you have an awesome theory, right?

See also...

Yamnaya: home-grown

Genetic borders are usually linguistic borders too

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

Genetic borders are usually linguistic borders too

Note the awesome correlation between the two maps below. The first map is mine. I posted it on this blog almost a year ago (see here). The second map is from the recent Wang et al. preprint (see here). Also note that the Steppe and Caucasus clusters as defined by Wang et al. are rich in Y-haplogroups R1 and J, respectively (see here).

Very cool indeed. But I'm still scratching my head and wondering why Wang et al. entertained the possibility in their conclusion that Indo-European languages diffused into the steppe from south of the Caucasus? That's because, as a rule, human genetic borders also represent linguistic borders, and major linguistic families are strongly associated with Y-haplogroups (for instance, see here).

See also...

Matters of geography

Likely Yamnaya incursion(s) into Northwestern Iran

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

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

A strange thing sometimes happens in population genetics: highly capable and experienced researches come up with stupid ideas and push them so hard that, despite all the evidence to the contrary, they become accepted as truths. At least for a little while.

It's obvious now, thanks to full genome sequencing and ancient DNA, that Y-chromosome haplogroup R1a cannot be native to India. It arrived there rather recently from the Eurasian steppe, in all likelihood during the Bronze Age, probably as the Indus Valley Civilization (IVC) was collapsing or, perhaps, just after it had collapsed.

But for quite a few years this was something of a taboo, even politically incorrect, narrative, and it was vehemently rubbished by many Indians, including Indian scientists, and their western academic sympathizers.

Indeed, a whole series of papers came out, often in high brow scientific journals, claiming that R1a originated in South Asia, and that it spread from there to Europe. This, it was also claimed, was the final nail in the coffin of the so called Aryan Invasion Theory (AIT), because R1a was often described as the "Aryan" haplogroup.

I wasn't impressed by any of this nonsense. I said so here and elsewhere, to the great annoyance of those who believed, against all reason and logic, that the Indo-Aryans, and even Indo-Europeans, were indigenous to India. Here's a taste of some of my work on the topic going back to 2013.

South Asian R1a in the 1000 Genomes Project

Children of the Divine Twins

The Poltavka outlier

Looking back, it's all a bit rough, but very cool nonetheless. However, I was often accused of being biased, unscientific and even bigoted and racist as a result of offering such commentary and research. Make no mistake, my detractors were seething that I would dare to question what was apparently a scientific reality, and they wanted to shut me up. It was a nasty experience, but it now feels great to be vindicated.

Certainly, nowadays, no objective person who, more or less, knows their stuff would argue that the vast majority of the R1a in India doesn't ultimately derive from the Pontic-Caspian steppe in Eastern Europe.

But otherwise things haven't changed all that much since then. For instance, despite a whole heap of ancient DNA data being available from Eastern Europe and West Asia, there's a widely accepted idea that the Early Bronze Age (EBA) Yamnaya culture formed on the Pontic-Caspian steppe as a result of migrations from what is now Iran.

This is not true. It can't be true, because it's contradicted by all of the data. I've tried to explain this on several occasions, but generally to no avail.

Yamnaya =/= Eastern Hunter-Gatherers + Iran Chalcolithic

Another look at the genetic structure of Yamnaya

Likely Yamnaya incursion(s) into Northwestern Iran

Thus, the Yamnaya people and culture were indigenous to Eastern Europe, and basically formed as a result of the amalgamation of at least three different populations closely related to Eastern European Hunter-Gatherers (EHG), Caucasus Hunter-Gatherers (CHG), Early European Farmers (EEF) and Western European Hunter-Gatherers (WHG). They did not harbor any significant ancestry from what is now Iran; at least not from within any reasonable time frame.

However, me communicating this fact has resulted in some rather strange and unsavory reactions from a number of individuals who appear to have a big emotional investment in this issue. They become frustrated and even angry when I try to explain to them that there's no sense in looking for the genetic origins of Yamnaya in Iran, much like the people who argued with me when I tried to reason with them that R1a wasn't native to India. Here's an example from a recent blog post (for the full conversation scroll down to the comments here).

Heh, here we go again with the accusations of bias, scientific impropriety and whatnot. Ironically, the poor chap just couldn't comprehend that he never had an argument to begin with, quite obviously due to his own bias in regards to this topic. Well, at least he didn't call me a racist.

In a recent preprint, Wang et al. correctly characterized Yamnaya as, by and large, a mixture of populations closely related to EHG, CHG, EEF and WHG (see here), with no obvious input from what is now Iran. Sounds familiar, right?

They also discovered that, during the Chalcolithic and Bronze Age, the Caucasus and nearby steppes were mainly home to three quite distinct populations: 1) Steppe groups, including Eneolithic steppe and Caucasus Yamnaya, 2) Caucasus groups, including Kura-Araxes and Maykop, and 3) Steppe Maykop, which they classified as part of 1. These populations were all separated by clear genetic and cultural borders, with significant and unambiguous mixture from the Caucasus cluster only in a couple of Steppe Maykop outliers and one Yamnaya outlier from what is now Ukraine.

Clearly, this leaves no room for any migrations from what is now Iran to the steppe that would potentially give rise to Yamnaya. In other words, the main genetic ingredients for what was to become Yamnaya were already on the steppe well before Yamnaya, during the Eneolithic, and it's quite likely that they were indigenous to the region.

However, interestingly, Wang et al. did appear to try to save the link between Yamnaya and Iran by referring to the CHG-related ancestry in Yamnaya as "CHG/Iranian". I'm not surprised because most of these authors are associated with the Max Planck Institute for the Science of Human History (MPI-SHH), which is currently pushing a proposal that the Proto-Indo-European (PIE) homeland was located in what is now Iran and surrounds (see here). So, obviously, they need to somehow show a relationship between Yamnaya and Iran, because Yamnaya and the closely related Corded Ware archaeological complex are generally seen as early Indo-European cultural horizons. Good luck with that.

Actually, let me make it clear once and for all that I couldn't care less where the very first Indo-European words were uttered. It's just something that I find interesting. I rather doubt that this was within the borders of present-day Iran, and I explained in some detail why in a post almost two years ago (see here). But if someone manages to prove that the PIE homeland was indeed located partly or wholly within what is now Iran, that's OK. I won't be emotionally traumatized as a result.

However, obviously, this will have to be done with the assumption in mind that Yamnaya and Corded Ware became Indo-European-speaking almost purely via linguistic transmission, with hardly any associated gene flow. It's possible, I guess. But then there's almost 200 years of scholarship based on linguistics and archaeological data that generally agrees in favor of the Pontic-Caspian steppe as the PIE homeland.

On a related note, I also couldn't care less whether the Aryan Invasion Theory (AIT) reflects what really happened during the Indo-Europeanization of South Asia, or if it's more appropriate to call it the Aryan Migration Theory (AMT). I'll accept whatever an objective analysis of all of the relevant data shows when we have enough of it to make an informed judgment.

However, currently, I see nothing in the data that would prevent the AIT from being true. To me, the profound impact that the Bronze Age steppe peoples obviously had on South Asia, and especially on the Indo-European-speaking Indian upper castes, suggests that, overall, an invasion-like scenario is quite plausible. But I might be wrong, and so what if I am?

See also...

Yamnaya: home-grown

Ahead of the pack

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

Of horses and men

Y-HT-1 is today by far the most common Y-chromosome haplogroup in domesticated horse breeds. According to Wutke et al. 2018, this is probably the result of artificial, human induced selection for this lineage, initially on the Eurasian steppe during the Iron Age, and then subsequently in Europe during the Roman period (see here).

However, during the Bronze and Iron Ages, before Y-HT-1 reached fixation, another very important Y-haplogroup in domesticated horses was its older sister clade Y-HT-4.

Indeed, it's likely that both Y-HT-1 and Y-HT-4 first dominated the domesticated horse gene pool during the Bronze Age, probably because they happened to have been present in the horse population exploited by the early Indo-Europeans. This was missed, or at least not directly discussed by Wutke et al., but I'd say it's a fairly obvious conclusion that can be drawn from their data, especially if we consider the fact that horses are the most important animal in the Indo-European pantheon.

Thus, the story of Y-HT-1 and, up to a point, Y-HT-4 is probably very similar to that of two human Y-haplogroups, R1a-M417 and R1b-M269. Both of these lineages also rose to prominence rather suddenly during the Eneolithic and Bronze Age, in all likelihood because they were present amongst early Indo-European-speaking males (see here).

Below is a map of the earliest reliably called and dated instances of Y-HT-1, Y-HT-4, R1a-M417 and R1b-M269 in the ancient DNA record. Not surprisingly, all of the points on the map are located on or very close to the Pontic-Caspian steppe, which is generally accepted to have been the Proto-Indo-European homeland. Fascinating stuff.

See also...

Central Asia as the PIE urheimat? Forget it

Cultural hitchhiking and competition between patrilineal kin groups may have led to the post-Neolithic Y-chromosome bottleneck (Zeng et al. 2018)

Was Ukraine_Eneolithic I6561 a Proto-Indo-European?