Map of pre-Corded Ware culture (>2900 BCE) instances of Y-haplogroup R1a (updated)

Below is a map showing the global distribution of Y-chromosome haplogroup R1a prior to the expansions of the R1a-rich Corded Ware culture (CWC) people and their descendants across Europe and Asia from around 2900 BCE. I'll be updating this map regularly and using it to help me narrow down the options for the place of origin of R1a, and also to counter the misinformation about this topic that has appeared in print and online over the years, including in many scientific publications and popular websites such as Wikipedia.

Incredibly, as far as I know, there are just six reliably called instances of R1a in the now ample Eurasian ancient DNA record dating to the pre-CWC period. To put this into perspective, consider that R1a is today the most common Y-haplogroup in much of Europe and Asia. How did that happen I wonder? However, please note that I chose to base the map only on samples sequenced with the capture and shotgun methods, rather than the PCR method, which is susceptible to producing contaminated results and no longer used in major ancient DNA studies.

See also...

Y-haplogroup R1a and mental health

The Poltavka outlier

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

Ancient island hopping in the western Mediterranean (Fernandes et al. 2019 preprint)

Over at bioRxiv at this LINK. Here's the abstract, emphasis is mine:

A series of studies have documented how Steppe pastoralist-related ancestry reached central Europe by at least 2500 BCE, while Iranian farmer-related ancestry was present in Aegean Europe by at least 1900 BCE. However, the spread of these ancestries into the western Mediterranean where they have contributed to many populations living today remains poorly understood. We generated genome-wide ancient DNA from the Balearic Islands, Sicily, and Sardinia, increasing the number of individuals with reported data from these islands from 3 to 52. We obtained data from the oldest skeleton excavated from the Balearic islands (dating to ~2400 BCE), and show that this individual had substantial Steppe pastoralist-derived ancestry; however, later Balearic individuals had less Steppe heritage reflecting geographic heterogeneity or immigration from groups with more European first farmer-related ancestry. In Sicily, Steppe pastoralist ancestry arrived by ~2200 BCE and likely came at least in part from Spain as it was associated with Iberian-specific Y chromosomes. In Sicily, Iranian-related ancestry also arrived by the Middle Bronze Age, thus revealing that this ancestry type, which was ubiquitous in the Aegean by this time, also spread further west prior to the classical period of Greek expansion. In Sardinia, we find no evidence of either eastern ancestry type in the Nuragic Bronze Age, but show that Iranian-related ancestry arrived by at least ~300 BCE and Steppe ancestry arrived by ~300 CE, joined at that time or later by North African ancestry. These results falsify the view that the people of Sardinia are isolated descendants of Europe's first farmers. Instead, our results show that the island's admixture history since the Bronze Age is as complex as that in many other parts of Europe.

Fernandes et al., The Arrival of Steppe and Iranian Related Ancestry in the Islands of the Western Mediterranean, bioRxiv, posted March 21, 2019, doi: https://doi.org/10.1101/584714

Update: Another preprint on a similar theme by Marcus et al. has appeared at bioRxiv (see here).

Abstract: Recent ancient DNA studies of western Eurasia have revealed a dynamic history of admixture, with evidence for major migrations during the Neolithic and Bronze Age. The population of the Mediterranean island of Sardinia has been notable in these studies -- Neolithic individuals from mainland Europe cluster more closely with Sardinian individuals than with all other present-day Europeans. The current model to explain this result is that Sardinia received an initial influx of Neolithic ancestry and then remained relatively isolated from expansions in the later Neolithic and Bronze Age that took place in continental Europe. To test this model, we generated genome-wide capture data (approximately 1.2 million variants) for 43 ancient Sardinian individuals spanning the Neolithic through the Bronze Age, including individuals from Sardinia's Nuragic culture, which is known for the construction of numerous large stone towers throughout the island. We analyze these new samples in the context of previously generated genome-wide ancient DNA data from 972 ancient individuals across western Eurasia and whole-genome sequence data from approximately 1,500 modern individuals from Sardinia. The ancient Sardinian individuals show a strong affinity to western Mediterranean Neolithic populations and we infer a high degree of genetic continuity on the island from the Neolithic (around fifth millennium BCE) through the Nuragic period (second millennium BCE). In particular, during the Bronze Age in Sardinia, we do not find significant levels of the "Steppe" ancestry that was spreading in many other parts of Europe at that time. We also characterize subsequent genetic influx between the Nuragic period and the present. We detect novel, modest signals of admixture between 1,000 BCE and present-day, from ancestry sources in the eastern and northern Mediterranean. Within Sardinia, we confirm that populations from the more geographically isolated mountainous provinces have experienced elevated levels of genetic drift and that northern and southwestern regions of the island received more gene flow from outside Sardinia. Overall, our genetic analysis sheds new light on the origin of Neolithic settlement on Sardinia, reinforces models of genetic continuity on the island, and provides enhanced power to detect post-Bronze-Age gene flow. Together, these findings offer a refined demographic model for future medical genetic studies in Sardinia.

Marcus et al., Population history from the Neolithic to present on the Mediterranean island of Sardinia: An ancient DNA perspective, bioRxiv, posted March 21, 2019, doi: https://doi.org/10.1101/583104

See also...

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

An exceptional burial indeed, but not that of an Indo-European

Not too many people have been buried sitting on wagons. The most famous case is that of an Early Bronze Age man who, considering his injuries, may have died in a high-speed crash - high-speed for its time anyway - on the Pontic-Caspian steppe in Eastern Europe.

It's likely that this guy was one of the very first wagon-drivers in human history, because his four-wheeled wooden model is dated to 3336-3105 calBCE, which makes it the oldest wagon discovered thus far. His genotype data, under the label Steppe Maykop SA6004, were published recently along with Wang et al. 2019.

Early wagons are very important for a couple of reasons: they revolutionized human transport and warfare, and they're often closely associated with the prehistoric expansions of Indo-European languages.

So I'm pretty sure that many of you must be thinking right now that wagon-driver SA6004 was an early Indo-European, or even a Proto-Indo-European! I bet that's what Wang et al. thought too, considering the conclusion in their paper. But, alas, the chances of this are slim to none.

Steppe Maykop samples show rather peculiar genetic structure considering their geographic origin, with a large proportion of their ancestry deriving from a source closely related to western Siberian hunter-gatherers (aka West_Siberia_N in the ancient DNA record). Indeed, SA6004 basically looks like a 50/50 mix between West_Siberia_N and Piedmont_Eneolithic. Here's a map with all of the relevant details.

Thus, clearly, the Steppe Maykop population wasn't ancestral or even directly related to the steppe and steppe-derived groups generally regarded to have been Indo-European speaking, such as those associated with the Yamnaya, Corded Ware, and Bell Beaker cultures. That's because these groups lack any discernible West_Siberia_N-related ancestry.

It also wasn't ancestral or directly related to any present-day or currently sampled ancient Indo-European speaking populations, again because these populations basically lack West_Siberia_N-related ancestry.

On the other hand, Yamnaya, Corded Ware and other closely related groups show an exceptionally strong genetic relationship with Indo-European speakers, especially those from across Northern Europe, which experienced massive migrations from the Pontic-Caspian steppe during the late Neolithic period, and hardly anything from elsewhere since then.

Case in point, the samples from Wang et al. labeled Yamnaya Caucasus were recovered from the same area of the Pontic-Caspian as their Steppe Maykop samples, and yet, take a look at this linear model based on outgroup f3-statistics. Steppe Maykop does show high genetic affinity to Indo-European speakers (no doubt mediated via its Piedmont_Eneolithic-related ancestry), but, unlike Yamnaya Caucasus, it also shows unusually high affinity for a West Eurasian population to Native Americans and Siberians. The relevant datasheet is available here.

So the only way that the Steppe Maykop population was Indo-European-speaking, was if it inherited its Indo-European speech from its Piedmont_Eneolithic-related ancestors. And even if it was Indo-European-speaking, it probably spoke an extinct Indo-European language not closely related to any extant Indo-European languages. In other words, the possibility that Steppe Maykop passed on its language to Yamnaya, along with its wagons, is close to zero. More likely, Yamnaya stole a few wagons from Steppe Maykop, and the rest is history.

See also...

The Steppe Maykop enigma

On Maykop ancestry in Yamnaya

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

Maykop: a multi-ethnic layer cake?

Let's speculate about the linguistic affinities of the currently available ancient populations from the Caucasus and surrounds. I put together a series of outgroup f3-stats to help things along. They're available for download here.

Maykop
Georgian 0.258224
Abkhasian 0.257899
Latvian 0.257376
Swedish 0.257301
Turkish_Trabzon 0.256996
Basque_Spanish 0.256589
Chechen 0.256514
Icelandic 0.256418
Norwegian 0.256325
Lezgin 0.256272
Irish 0.256227
Tabasaran 0.256092
Italian_Bergamo 0.25605
English_Cornwall 0.256032
Polish_East 0.255991
Scottish 0.255955
Adygei 0.255913

Steppe_Maykop
Latvian 0.261845
Russian_North 0.26145
Estonian 0.260355
Finnish 0.260211
Lithuanian 0.260072
Udmurd 0.259804
Ingrian 0.259663
Surui 0.259637
Vepsa 0.259608
Karelian 0.259532
Karitiana 0.259482
Russian_West 0.259397
Russian_Central 0.259274
Wichi 0.259106
Saami 0.258982
Komi 0.258945
Icelandic 0.258854
Swedish 0.258814
Mordovian 0.258604
Irish 0.25859

Eyeballing the stats might be enough to get a general impression about what they mean, but to understand them properly it's necessary to get technical with something like PAST3 (see here). That's because f3-stats pick up shared genetic drift from all drift paths, and don't especially focus on more recently shared ancestry. This can often lead to confusing outcomes.

Below are a few examples of linear models based on my f3-stats. Note that many Indo-European speakers, especially from Northern Europe, are foremost attracted to ancient samples from the Pontic-Caspian steppe. On the other hand, non-Indo-European speakers, from such far flung locations as the Caucasus and Iberia, show relatively stronger affinity to ancient samples from Anatolia and the Caucasus. Moreover, Uralic speakers show elevated affinity to ancient hunter-gatherer samples from Eastern Europe and Siberia. Makes sense, right?

Based on these and other data, I'd say that Maykop and the culturally related Steppe Maykop were something of a multi-ethnic polity, with many near and far related languages spoken by its people, including perhaps Kartvelian, Northwest Caucasian, Yeniseian and Indo-European. But it seems to me that Proto-Indo-European was spoken by steppe foragers turned pastoralists just outside of the Maykop zone. And I'm quite sure that after the Maykop collapse various early Indo-European groups pushed across the Caucasus and deep into the Near East. Just take a look at the f3-stats and linear model for Hajji_Firuz_BA to see what I mean.

See also...

An exceptional burial indeed, but not that of an Indo-European

The Steppe Maykop enigma

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