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Saturday, January 20, 2018

The case of Chalcolithic fortresses in the Northwestern Caucasus (Kozintsev 2017)

It's a pity that we still don't have any decent ancient DNA data from the North Caucasus and nearby steppes, apart from, of course, those few intriguing mitochondrial genomes from Maykop burials (see here). This leaves us guessing about the genetic origins of the people who lived in this region across the millennia, and thus their genealogical relationships to near and far ancient and modern-day populations, which might eventually prove pivotal in the search for the Proto-Indo-European homeland.

The most nagging questions to be solved are whether Yamnaya, and other closely related Eneolithic/Bronze Age steppe herder groups, sourced the greater part of their so called southern ancestry from the North Caucasus, and if so, from who exactly: groups indigenous to the region, or mixed populations with significant ancestry from, say, Transcaucasia (the Southern Caucasus) or even Mesopotamia?

To make matters worse, the archeology of the North Caucasus is fairly poorly understood. It's generally assumed that there was indeed a colonization of the Northwestern Caucasus by various peoples from the south, including Uruk migrants from Mesopotamia. But even if so, did they leave a lasting impact on the populations of the Caucasus and, subsequently, the steppes? Despite some strong opinions on the matter, particularly in the comments at this blog, no one can say for sure at this stage.

However, as far as I can see, a fascinating new archaeological paper by A.G. Kozintsev in Archaeology, Ethnology & Anthropology of Eurasia suggests that one such group of southern migrants, who built a fortress at Meshoko, in what is now Southern Russia, during the Chalcolithic, were overrun, and perhaps even wiped out, by people more culturally "archaic" and indigenous to the region. If true, and this wasn't an isolated incident, then for obvious reasons it might help to explain the lack of Mesopotamian- and South Caspian-specific uniparental markers amongst the Eneolithic/Bronze Age steppe herder groups, which is an issue that I have discussed at length in the past (see here, here and here). Below is the abstract from Kozintsev's paper. Emphasis is mine:

A multivariate method for assessing cultural changes at stratified sites is proposed. The variables are technological properties of ceramics, and occurrences of various categories of flint implements. The method is applied to stratigraphic sequences of Chalcolithic fortresses in the northwestern Caucasus dating to the late 5th–early 4th millennia BC: Meshoko and Yasenova Polyana. The properties of ceramics include hardness (assessed on the Mohs scale), wall thickness, and frequency of fragments tempered with calcium carbonate. For Meshoko, S.M. Ostashinsky’s data on the occurrence of implements made of high-quality colored flint, splintered pieces, and the total number of segments, points, inserts, scrapers, and perforators were used as well. Each parameter undergoes regular changes from the lower to the upper units of the sequence: ceramics progressively deteriorate, whereas flint industry becomes more and more sophisticated. These changes occur in parallel. Data were subjected to principal component analysis. The first principal component is regarded as a generalized measure of cultural change. The results support the view of the excavators: changes were caused by the interaction of two cultures differing in origin. The earlier culture, associated with the constructors of the Meshoko fortress, shows no local roots, and was evidently introduced from Transcaucasia. The one that replaced it was significantly more archaic (a few copper tools notwithstanding), and reveals local Neolithic roots. It alone can be termed the culture of ceramics with interiorpunched node decoration. The ceramics of Yasenova Polyana, too, indicate cultural heterogeneity and two occupation stages; but cultural changes are more complicated there, probably because the site existed longer, and more than two cultural components were involved.

A.G. Kozintsev, A Generalized Assessment of Cultural Changes at Stratified Sites: The Case of Chalcolithic Fortresses in the Northwestern Caucasus, Archaeology, Ethnology & Anthropology of Eurasia 45 (1) 2017, DOI: 10.17746/1563-0110.2017.45.1.062-075

See also...

Another look at the genetic structure of Yamnaya

Wednesday, January 17, 2018

Another look at the genetic structure of Yamnaya

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. This is easy to show with formal statistics (for instance, refer to the qpAdm output here) and illustrate with a decent Principal Component Analysis (PCA).

Over the past couple of years I've come to the conclusion that this minor westerly input probably came from the Carpathian Basin (modern-day Hungary) or somewhere nearby, like the Balkans (see here).

However, this inference was based on just a handful of Neolithic samples from the Carpathian Basin. Now, thanks to Lipson et al. 2017, I have genotype data from tens of individuals from several different Neolithic and Copper Age cultures from the region. So let's revisit the issue by plugging these new samples into qpAdm, and also using the very latest qpAdm methods as described in scientific literature (with Ethiopia_4500BP as the base pright sample to 15 other ancient pright groups and individuals).

Below are the results, best to worst, sorted by taildiff. For comparison, I ran extra models with ancient populations from other parts of Europe and also West Asia. It's interesting and, I'd say, important to note that the West Asian reference groups produce amongst the worse statistical fits (bolded). What this suggests is that Yamnaya did not harbor extra West Asian ancestry on top of its CHG input. And, by the way, please note that I'm only using Yamnaya_Samara in these runs because I prefer UDG-treated, and thus higher quality, ancient samples.

CHG + EHG + Blatterhole_MN 0.465394061 > full output

CHG + EHG + Koros_HG 0.322245651 > full output

CHG + EHG + Germany_MN 0.321017025 > full output

CHG + EHG + Protoboleraz_LCA 0.315521424 > full output

CHG + EHG + Vinca_MN 0.292074267 > full output

CHG + EHG + Baden_LCA 0.255168297 > full output

CHG + EHG + Tisza_LN 0.246555616 > full output

CHG + EHG + ALPc_MN 0.220623346 > full output

CHG + EHG + Blatterhole_HG 0.219418173 > full output

CHG + EHG + Balaton_Lasinja_CA 0.211230222 > full output

CHG + EHG + Tiszapolgar_ECA 0.207527666 > full output

CHG + EHG + LBK_EN 0.182365613 > full output

CHG + EHG + TDLN 0.176675465 > full output

CHG + EHG + Koros_EN 0.15488361 > full output

CHG + EHG + Starcevo_EN 0.136365203 > full output

CHG + EHG + Armenia_EBA 0.127988891 > full output

CHG + EHG + Armenia_ChL 0.123057884 > full output

CHG + EHG + LBKT_MN 0.122780467 > full output

CHG + EHG + Tepecik_Ciftlik_N 0.110155019 > full output

CHG + EHG + Greece_N 0.105880232 > full output

CHG + EHG + Boncuklu_N 0.094240794 > full output

CHG + EHG + Anatolia_BA 0.069141519 > full output

CHG + EHG + Anatolia_ChL 0.067837662 > full output


CHG + EHG + Iran_ChL infeasible > full output

At the top of the list is Blatterhole_MN. Admittedly this is something of a surprise, considering the geographic distance between Blatterhole, Germany, and Samara, Russia. It's also an intriguing result because of the presence of Y-chromosome haplogroup R1b in both Blatterhole_MN and Yamnaya (see here).

However, this doesn't necessarily mean that Yamnaya harbors direct ancestry from Blatterhole_MN, or even any closely related group from North-Central Europe. 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. Indeed, when I let qpAdm vary the WHG ratio, by dropping Blatterhole_MN and adding Koros_EN and Koros_HG in its place, I get an even better fit.

CHG + EHG + Koros_EN + Koros_HG 0.612772624 > full output

And for comparison...

CHG + EHG + LBK_EN + WHG 0.551431774 > full output

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.

See also...

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

Saturday, January 13, 2018

Genetic maps featuring 67 ancient genomes and more than 3,000 present-day individuals

I've got some eye candy for you guys as we wait for 2018 to really get going. Below are three Principal Component Analyses (PCA) plots, or genetic maps, based on the ancient diploid dataset from Martiniano et al. 2017 (described in more detail here). Click on the images to download hi-res PDFs of each plot. The relevant datasheets are available here.

The important thing about these PCA is that none of the samples in the analyses are missing more than 1% of the ~188K markers used to compute the PCs, which means that I didn't have to resort to any type of projection to get things right. In other words, the relationships between the samples that you see on these plots are direct.

PCA are easy to read. The main thing to keep in mind is that the results are dependent on the samples in the analysis. For instance, note that the Indians (Gujaratis and Brahmins) cluster rather close to some Europeans on the West Eurasian plot, but much further from them on the Eurasian/American plot. Why? Because the addition of hundreds of East Eurasian individuals to the latter plot highlights the significant East Eurasian-related admixture in the Indians, and pulls them away from the Europeans, who generally have much less of this type of ancestry.

It's interesting, I think, that all of the ancients from burial sites from within the borders of present-day Europe (discussed in an earlier blog post here), cluster with present-day Europeans, or at least closest to us. See anything else interesting? Feel free to share it in the comments below.

If you're having trouble spotting certain individuals and/or populations, type the relevant individual or population ID in the PDF search box and click enter. The PDF will initially show you a box where the samples of interest are located; click on the box, and the PDF will zoom into the boxed area and highlight these samples, like this:

See also...

Who's your (proto) daddy Western Europeans?

Wednesday, January 10, 2018

Ancient mitogenomes from Sardinia and Lebanon (Matisoo-Smith et al. 2018)

Over at PLoS ONE at this LINK. Emphasis is mine:

Abstract: The Phoenicians emerged in the Northern Levant around 1800 BCE and by the 9th century BCE had spread their culture across the Mediterranean Basin, establishing trading posts, and settlements in various European Mediterranean and North African locations. Despite their widespread influence, what is known of the Phoenicians comes from what was written about them by the Greeks and Egyptians. In this study, we investigate the extent of Phoenician integration with the Sardinian communities they settled. We present 14 new ancient mitogenome sequences from pre-Phoenician (~1800 BCE) and Phoenician (~700–400 BCE) samples from Lebanon (n = 4) and Sardinia (n = 10) and compare these with 87 new complete mitogenomes from modern Lebanese and 21 recently published pre-Phoenician ancient mitogenomes from Sardinia to investigate the population dynamics of the Phoenician (Punic) site of Monte Sirai, in southern Sardinia. Our results indicate evidence of continuity of some lineages from pre-Phoenician populations suggesting integration of indigenous Sardinians in the Monte Sirai Phoenician community. We also find evidence of the arrival of new, unique mitochondrial lineages, indicating the movement of women from sites in the Near East or North Africa to Sardinia, but also possibly from non-Mediterranean populations and the likely movement of women from Europe to Phoenician sites in Lebanon. Combined, this evidence suggests female mobility and genetic diversity in Phoenician communities, reflecting the inclusive and multicultural nature of Phoenician society.

Matisoo-Smith E, Gosling AL, Platt D, Kardailsky O, Prost S, Cameron-Christie S, et al. (2018) Ancient mitogenomes of Phoenicians from Sardinia and Lebanon: A story of settlement, integration, and female mobility. PLoS ONE 13(1): e0190169.

See also...

Something unexpected from Mesolithic Sardinia

Wednesday, January 3, 2018

A genome from the first founding population of Native Americans (Moreno-Mayar et al. 2018)

Over at Nature at this LINK. By the way, when did Nature start adding those "Life Sciences Reporting Summaries" to its papers? I remember having a chat with Broad MIT/Harvard back in May about adding something like this to ancient DNA papers, especially in regards to data exclusions, right after my blog entry about the somewhat suspiciously missing Yamnaya males in Mathieson et al. 2017 (see here), and suddenly, here it is. Eh, probably a crazy coincidence, but a great move in any case. Below is the Moreno-Mayar et al. abstract and an Admixture graph from the paper:

Despite broad agreement that the Americas were initially populated via Beringia, the land bridge that connected far northeast Asia with northwestern North America during the Pleistocene epoch, when and how the peopling of the Americas occurred remains unresolved [1,2,3,4,5]. Analyses of human remains from Late Pleistocene Alaska are important to resolving the timing and dispersal of these populations. The remains of two infants were recovered at Upward Sun River (USR), and have been dated to around 11.5 thousand years ago (ka)6. Here, by sequencing the USR1 genome to an average coverage of approximately 17 times, we show that USR1 is most closely related to Native Americans, but falls basal to all previously sequenced contemporary and ancient Native Americans [1,7,8]. As such, USR1 represents a distinct Ancient Beringian population. Using demographic modelling, we infer that the Ancient Beringian population and ancestors of other Native Americans descended from a single founding population that initially split from East Asians around 36 ± 1.5 ka, with gene flow persisting until around 25 ± 1.1 ka. Gene flow from ancient north Eurasians into all Native Americans took place 25–20 ka, with Ancient Beringians branching off around 22–18.1 ka. Our findings support a long-term genetic structure in ancestral Native Americans, consistent with the Beringian ‘standstill model’9. We show that the basal northern and southern Native American branches, to which all other Native Americans belong, diverged around 17.5–14.6 ka, and that this probably occurred south of the North American ice sheets. We also show that after 11.5 ka, some of the northern Native American populations received gene flow from a Siberian population most closely related to Koryaks, but not Palaeo-Eskimos [1], Inuits or Kets [10], and that Native American gene flow into Inuits was through northern and not southern Native American groups1. Our findings further suggest that the far-northern North American presence of northern Native Americans is from a back migration that replaced or absorbed the initial founding population of Ancient Beringians.

Moreno-Mayar et al., Terminal Pleistocene Alaskan genome reveals first founding population of Native Americans, Nature, Published online: 03 January 2018, doi:10.1038/nature25173

Friday, December 29, 2017

Support this blog, buy a Haplotee

If you buy a Haplotee or any other DNAGeeks merchandise through this blog via this LINK, I'll get some cash.

Why is this important? Because 2018 is going to be a huge year for population genetics, and especially for ancient DNA, and if this blog is also going to be huge, then I'll need some money. So if you like this blog, or even if you hate it, but you like spending time here hating it, then buy a Haplotee. Or several.

Please note also that I've recently launched a genetic ancestry online store, which will be updated regularly with different tests throughout the year (see here). By purchasing tests from the store, you'll not only be helping to make this blog awesome, but also getting amongst the most accurate ancestry analyses available anywhere. Thank you for your support.

Monday, December 18, 2017

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

David W. Anthony has just posted a new paper at his page titled Archaeology and Language: Why Archaeologists Care about the Indo-European Problem (see here).

It's not only an interesting discussion about why the search for the Indo-European homeland is still such a big deal, but also a useful, almost up to date, summary of the fascinating stuff that ancient DNA has revealed about the genetic history of Europe, with a special focus on the origin of the Corded Ware people, who are generally accepted to be the first Indo-European-speaking population of Northern Europe.

Now, I say it's an almost up to date summary, because Anthony seems fairly certain that the Corded Ware people were descendants of the Yamnaya people, rather than just their close relatives. He uses archaeological and ancient DNA data to argue that Yamnaya migrants moved from the North Pontic steppe to the eastern Carpathian Basin (present-day Hungary), and then onto what is now southern Poland to give rise to the proto-Corded Ware population.

I probably would've said this was a highly plausible scenario before I saw the ancient DNA results from the latest preprint of Mathieson et al. 2017, an ancient genomics paper in the works focusing on Southeastern Europe (see here). But now that I've seen those results, I feel that Anthony's proposal might be outdated.

One of the samples in that preprint is from a pre-Yamnaya Eneolithic burial on the northern edge of North Pontic steppe, in what is now eastern Ukraine, labeled Ukraine_Eneolithic I6561. This individual not only strongly resembles the Corded Ware people in terms of genome-wide genetic structure, but also belongs to Y-haplogroup R1a-M417, which is a paternal marker probably no older than the Eneolithic and intimately associated with the Corded Ware expansion. Currently, as far as I can see, he's by far the most likely candidate in the ancient DNA record to belong to a proto-Corded Ware population.

Keep in mind also that not a single instance of R1a-M417 has yet been found among a wide range of prehistoric individuals from the Carpathian Basin. On the other hand, Olalde et al. 2017 (see here) did manage to catch one Early Bronze Age (EBA) Bell Beaker from the region belonging to R1b-Z2103, which is the paternal marker currently most strongly associated with Yamnaya.

Below is a map of Central and Eastern Europe ca. 3000-2000 BCE from Anthony's paper, edited by me to show the burial location of Ukraine_Eneolithic I6561. If we assume that his descendants or close relatives were the proto-Corded Ware population, then looking at this map, it seems unlikely to me that they would've taken the Carpathian Basin route before expanding into Northern Europe. Rather, I'd say that they would've fanned out across the north directly from the steppe, perhaps along those northward-pointing river valleys? And I suspect that they may have still been a pre-Yamnaya group as they migrated out of the steppe, just as Yamnaya was forming somewhere to the east.

But hey, Anthony might be right, and I might be way off. Indeed, perhaps Anthony based his theory, to an extent, on soon to be published Yamnaya samples from the Carpathian Basin? If such genomes have been sequenced, and at least one belongs to R1a-M417, then it's game over as far as the origin of the Corded Ware people is concerned, and I'll welcome the surprise.

See also...

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

Friday, December 15, 2017

Watch the red arrows naysayers

Here's a map from yesterday's presentation by Italian archaeologist Massimo Vidale at the MPI-SHH Jena Cross Roads conference on South Asia. He was focusing on the skeletal remains from the protohistoric, and likely early Indo-Aryan, cemeteries at Udegram and Gogdara in the Swat Valley, modern-day Pakistan. Source: Twitter.

And this is my own map from back in August (see here) summarizing what ancient DNA (both published and otherwise...nudge, nudge) is telling us about the early Indo-European, including Indo-Aryan, expansions across Eurasia.

Remarkably similar, aren't they? And obviously I'm not just talking about the use of ellipses and red arrows by the authors of both maps (probably a coincidence, but perhaps not if Prof. Vidale reads this blog).

Keep in mind also that last year Prof. Vidale sent samples from the Swat Valley cemeteries to the ancient DNA lab at Harvard for testing and analysis (see here). So if these samples yielded endogenous DNA (wink, wink), then he probably knew the results when he drew up his map.

See also...

Best of Davidski on South Asian population history

The beast among Y-haplogroups

Descendants of ancient European (fair?) maidens in Central Asia's highlands

Friday, December 1, 2017

Descendants of ancient European (fair?) maidens in Central Asia's highlands

Several South Central Asian populations have a reputation for producing individuals who look surprisingly European, even the lighter shade sort of European from Eastern and Northern Europe. This is especially true of the Pamiri Tajiks, and that's unlikely to be a coincidence, because these people probably do harbor a lot of ancient Eastern European ancestry.

My own estimates, using various ancestry modeling methods, suggest that Pamiri Tajiks derive ~50% of their genome-wide genetic ancestry from populations closely related to, and probably derived from, Eneolithic/Early Bronze Age pastoralists from the Pontic-Caspian steppe of Eastern Europe, such as the Sredny Stog and Yamnaya peoples. Below is a simple Admixture graph using the mostly Yamnaya-derived Iron Age Sarmatians from Pokrovka, Russia, in far Eastern Europe, to illustrate the point. Note that Sarmatians were East Iranic-speakers, which is what Pamiri Tajiks are. The relevant graph file is available here.

But, some of you might retort, this is all just statistical smoke and mirrors, and what it really shows is that these so called Europeans came from Central Asia or even India.

Not so, because my models can't be twisted any which way, and they have strong support from uniparental marker data.

Many South Central Asian groups, and especially Indo-European-speakers, like the Tajiks, show moderate to high frequencies of two Y-chromosome haplogroups typical of Bronze Age Eastern Europeans: R1a-M417 and R1b-M269. This is old news to the regular visitors here and its implications are obvious, so if you still think that these haplogroups expanded from South Central Asia to Eastern Europe, rather than the other way around, then please update yourself (for some pointers, see here and here).

And now, courtesy of Peng et al. 2017, we also have a much better understanding of ancient European influence on the maternal gene pool of Pamiri groups (see here). The paper doesn't specifically cover the topic of European admixture in South Central Asia, but it nevertheless demonstrates it unequivocally.

Below are a couple of phylogenetic trees from the paper featuring a wide range of mitochondrial DNA (mtDNA) sequences shared between Europeans and Central and South Asians; quite a few of these lineages are rooted in Eastern Europe, as shown by both modern-day and ancient DNA, so they strongly imply gene flow, and indeed considerable maternal gene flow, from Eastern Europe deep into Asia.

Worthy of note are the lineages belonging to such relatively young (likely post-Neolithic) haplogroups as U5a1a1, U5a1d2b, U5a2a1, and U5b2a1, all of which have already been found in ancient remains from the Pontic-Caspian steppe.

I'm no longer wondering whether there were massive population movements from Eastern Europe to South Central Asia during the metal ages. It's a given that they happened, and I'm now looking forward to learning about the details from ancient DNA. For instance, what was the ratio of men to women amongst these migrants? And how fair were they exactly?

See also...

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

Ancient herders from the Pontic-Caspian steppe crashed into India: no ifs or buts

R1a-rich ancient Siberians may have been as blond as today's Northern Europeans

Tuesday, November 28, 2017

The ancient genomics revolution (Skoglund & Mathieson 2017 preprint)

Two former Harvard scientists Pontus Skoglund and Iain Mathieson are working on a new review paper on the wide range of scientific breakthroughs provided by ancient genomics over the past decade. The preprint is available at Dropbox here. There's also a thread about the preprint at Mathieson's Twitter account here.

I've read through it a couple of times, especially the parts about Europe, and haven't been able to spot any major problems; the authors obviously chose their words very carefully, and their geography is beyond reproach. [Edit: first problem spotted, see here]

Now, you might think that geography is easy, but apparently not when it comes to the location of the Pontic-Caspian steppe. Recent media articles have claimed that it's located in West Asia, and, I kid you not, even that it's hilly (for instance, see here), while scientists from Max Planck and other supposedly high brow places seem to think that it's in Central Eurasia (see here). Nope, as Skoglund and Mathieson correctly point out, it's actually located in (far) Eastern Europe, while Central Eurasia is generally posited to be further to the east. From the preprint (emphasis is mine):

Anatomically modern humans were widely distributed in Europe by at least 42,000-45,000 BP (3; 41). The oldest genomic data from a modern human in Europe is the Oase 1 individual from present-day Romania dated to 37,600-41,600 BP. This individual, which had a direct Neanderthal ancestor in the past four to six generations, did not contribute detectable ancestry to later Upper Paleolithic populations (24). During the Upper Palaeolithic, a major transformation ~30,000-35,000 years ago was likely associated with the replacement of the Aurignacian with the Gravettian culture in western Europe(28). As the Last Glacial Maximum (LGM) came to an end and the ice sheets receded, Europe was repopulated, possibly from southern European and central Eurasian refugia (28). Another transformation may have taken place during an interstadial warm period ~14.5 kya, replacing the original recolonizers with a population that would come to form the Mesolithic populations of Europe (28; 93). These Mesolithic populations were outside the genetic diversity of present-day Europe (114; 131) and themselves display a clinal structure, with an east-to-west cline (32; 37; 38; 47; 57; 62; 72; 78; 112; 130). The origin of this cline is not clear, although it plausibly reflects two or more major sources of ancestry in the post-LGM or post-14.5kya expansions.

Starting from the southwest around 8,500 BP, the Mesolithic ancestry of Europe was largely replaced (29; 38; 42; 130; 131) as a new type of ancestry related to that found in Neolithic northwest Anatolia (73; 87) and, ultimately, to early farming populations of the Levant and Northern Iran (11; 56) expanded throughout Europe. This ancestry rapidly reached the extreme edges of Europe, with direct evidence of its presence in Iberia at 7300 BP (86), in Ireland at 5100 BP (14) and in Scandinavia at 4900 BP (131). This “Anatolian Neolithic” ancestry was highly diverged relative to the “hunter-gatherer” ancestry of the populations that previously inhabited Europe (F ST ~ 0.1, similar to the divergence between present-day European and East Asian populations) (73; 132). Across Europe, its appearance was closely linked in time and space to the adoption of an agricultural lifestyle, and it now seems established that this change in lifestyle was driven, at least in part, by the migration. However, the Anatolian Neolithic migrants did not replace the hunter-gatherer populations. Over the next 4000 years, the two populations merged, and by 4500 BP, almost all European populations were admixed between these two ancestries, typically with 10-25% hunter-gatherer ancestry (29; 38; 42; 50; 62; 71; 73; 130; 131). Across Europe, this “resurgence” of hunter-gatherer ancestry (10) was independent–driven by local hunter-gatherer populations who lived in close proximity to farming groups (7; 62; 72; 130).

The next substantial change is closely related to ancestry that by around 5000 BP extended over a region of more than 2000 miles of the Eurasian steppe, including in individuals associated with the Yamnaya Cultural Complex in far-eastern Europe (1; 38) and with the Afanasievo culture in the central Asian Altai mountains (1). This “steppe” ancestry is itself a mixture between ancestry that is related to Mesolithic hunter-gatherers of eastern Europe and ancestry that is related to both present-day populations (38) and Mesolithic hunter-gatherers (46) from the Caucasus mountains, and also to the populations of Neolithic (11), and Copper Age (56) Iran. Steppe ancestry appeared in southeastern Europe by 6000 BP (72), northeastern Europe around 5000 BP (47) and central Europe at the time of the Corded Ware Complex around 4600 BP (1; 38). These dates are reasonably tight constraints, because in each case there is no evidence of steppe ancestry in individuals immediately preceding these dates (47; 72). Gene flow on the steppe was extensive and bidirectional, as shown by the eastward flow of Anatolian Neolithic ancestry–reaching well into central Eurasia by the time of the Andronovo culture ~3500 BP (1)–and the westward flow of East Asian ancestry–found in individuals associated with the Iron Age Scythian culture close to the Black Sea ~2500 BP (143).

Copper and Bronze Age population movements (14; 78 Martiniano, 2017 #8761; 85; 112), as well as later movements in the Iron Age and Historical period (70; 119) further distributed steppe ancestry around Europe. Present-day western European populations can be modeled as mixtures of these three ancestry components (Mesolithic hunter-gatherer, Anatolian Neolithic and Steppe) (38; 57). In eastern Europe, further shifts in ancestry are the result of additional or distinct gene flow from Anatolia throughout the Neolithic and Bronze Age in the Aegean (42; 51; 55; 72; 87), and gene flow from Siberian-related populations in Finland and the Baltic region (38).

And I really like this part; sounds ominous for the Out-of-India (OIT) crowd, doesn't it? Hopefully we won't have to wait too long for the relevant paper from Harvard, which, I can assure you, is coming sooner or later.

There are no published ancient DNA studies from South- or Southeast Asia. However, data from neighboring regions provides clues to the population history of this region. In particular, present-day South Asian populations share ancestry with Neolithic Iranian (11) and Steppe (56) populations. This strongly suggests Neolithic or Bronze Age contact between South Asia and west/central Eurasia, although only direct ancient DNA evidence from the region will resolve the timing and structure of this contact.


Pontus Skoglund and Iain Mathieson, Ancient genomics: a new view into human prehistory and evolution, preprint 2017

See also...

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

Who's your (proto) daddy Western Europeans?

Ancient herders from the Pontic-Caspian steppe crashed into India: no ifs or buts