From about 3100 BC and for the next two to three centuries, GAC communities migrated from the Vistula River drainage basin into the area between the Carpathians and the Dnieper, more thoroughly than any of their central European predecessors: they crossed to the eastern bank of the Dnieper, they appeared in the Carpathian basin, and they came into close contact (probably ‘face to face’) with communities of the Yamna culture (Szmyt 2013).
GAC appeared into the forest-steppe and steppe zone west of the Dnieper ca. 3000–2900 BC, including areas between the Southern Buh and Sinyukha rivers, on the Inhul River, and also on the Dniester–Danube region. At the same time, the Trypillia culture was disintegrating into many regional groups in the forest-steppe and southern forest region between the Prut and the Dnieper (see §V.6. North Pontic area). Close interaction in this area is evidenced by mixed grave inventories in at least two parts of the north-western Pontic area, namely the Middle Dnieper and the Siret–Prut–Dniester area, with Yamna settlements showing atypical clay vessels more or less corresponding to GAC style (Szmyt 2013).
Nevertheless, even in the zone of greater migration exchange along the Prut, it is usually possible to draw a line separating the distribution of synchronous settlements, e.g. with GAC settlements occupying territories west of the area, between the Prut and Siret rivers, and Yamna occupying their eastern bank, between the Prut and Dniester. In the steppe zone, contacts in form of adopted pottery ornamentation by Yamna settlers are still less clear, which supports a clear differentiation of both groups (Szmyt 2013).
Figure 27. Burial schemes of pit graves found in the Lower Danube region during the Eneolithic according to Frînculeasa, Preda, and Heyd (2015).
After 3000–2900 BC, the majority of pit–graves west of the Black Sea belong to the domination and assimilation of peoples characterised by the Yamna funeral standard (Figure 27), in which the buried—both primary and secondary—were lying supine with the legs bent up in the knees, usually orientated on the west–east direction, in rectangular or sometimes chamber-like grave–pits covered by wooden beams. Poor inventories are the rule (contrasting with previous north Pontic steppe cultures, see IV.2.3. Kurgans), and spiral silver hair rings are the most defining items. Male burials are prevalent, and ochre staining or deposition of lumps is common. Pottery of local origin is rarer than before, and when it appears it is represented by cord-decorated beaker vessels, such as in Coţofeni III pottery ca. 3000–2800 BC (Frînculeasa, Preda, and Heyd 2015). During this late phase, Yamna appears firmly settled in the forest-steppe further north, where they were previously only occasionally found. Larger bands are therefore seen expanding in all directions (Suppl. Fig. 9).
Most Yamna burials in the west Pontic area have radiocarbon dates ca. 2880–2580 BC. Only a small proportion of sites at the Lower Danube shows later dates, with a dilution of the wider Pit-Grave phenomenon. This third stage of pit–graves shows a re-appearance of individuals buried contracted to the side or in extended body position as secondary burials in the mounds. This trend appeared perhaps under the influence of the Catacomb Grave culture or further to the east, or locally at the Lower Danube. This is a period when southeast and central European cultures like Coţofeni, Baden, Ezero A, Globular Amphora and TRB communities were transforming and splitting into successive archaeological cultures, such as Glina, Schneckenberg, Livezile, Makó/Kosihý–Čaka, Ezero B, or Corded Ware proper (Frînculeasa, Preda, and Heyd 2015).
The beginning of the western early Yamna complex is linked to the arrival of a novel set of deeply interlinked social, economic, and ideological innovations. Its five components (Figure 28) play the crucial roles, one due to the next (Frînculeasa, Preda, and Heyd 2015):
1. Subsistence economy based on specialised breeding and herding of cattle only, which leads to the increased use of secondary products in which milk and overall protein-enriched diet supplemented by game and fish (and very low ratio of starch and carbohydrates, as seen in neglectable caries frequency) have an importance in subsequent changes in peoples’ physical appearance and stature (with old anthropometric studies showing that they might have been some inches taller in average than their neighbours).
2. This new economy triggers a higher human mobility: the overall westward migration is a consequence of the ever-lasting search for green pastures for their stock. This mobility may have increased the exchange network, forwarding technical innovations like ‘Caucasian metallurgy’ of shaft–hole axes, tanged daggers, and previous metal hair rings.
3. Both the new economy and mobility triggered a novel way-of-life, with different land uses and understanding of territory. Peoples become true pastoralists leading a highly mobile way of life, and some segments become true nomads, which alters the social organisation and thus norms, morale, values, symbols and terms, altering the Weltanschauung and ideology, as well as religion, which become tradition.
4. A pit–grave under a kurgan becomes a standard in the Yamna custom-set, with its homogenisation reflecting the emerging unifying social norms. Its powerful symbolism is seen as a high landmark, the ‘pyramids of the steppe’, a monumental and dominant architectural element over ancestor graves (quasi-temples) in an otherwise flat and monotonous ‘sea of grass’, creating real or virtual ancestry and lineage, and being a sign of possession, and probably claiming territory, as well as delineating the oecumenes of pastoral groups, forming orientation points on the transhumance routes.
5. One key technological innovation made all this possible: the widespread acceptance of the transport complex of wheel and wagon, allowing herders to enter and exploit the deep waterless steppes (the largest part of the steppes) for their stock animals. It also allowed pastoralists to live in these regions with their families for the longer part of the year, with all their possessions, without the need to keep a base-camp close to a water course.
Figure 28. Scheme of interlinked socio-economic-ideological innovations forming the Yamnaya, modified from Frînculeasa, Preda, and Heyd (2015). Images used, from top to bottom and left to right: Cattle on the Puszta of Hrotobagy, by Adrian and Marianne Stokes (Wikimedia); still image from the documentary “Equus: Story of the Horse” (CBC); Bronzezeit keltische Hügelgräber, by Gerhard Beuthner (1930); reconstruction of primary burial (feature 2, Grave 1) of the Hajdúnánás-Tedej-Lyukashalom kurgan by Viktor Szinyei, modified from Pospieszny (2015). Center image: reconstruction of wagon after A.N. Gej (1993), from Novotitorovka wagon burial at Ostannii, kurgan I, burial 150.
Yamna settlements spread initially west- and southward into the Danube valley. A real current of immigration is noticed from ca. 2950 BC, being the first primary example of large-scale migration in later prehistory, with foreign people flooding over east and east-central European lowlands. More than 500 tumuli and more than 1000 graves have been already studied in this area (Heyd 2012).
A rapid decline in human activities peaked in Central Europe between 4000–3000 BC and recovered only after 3000 BC, accelerating after 2500 BC. This decline has been related to adaptation processes during climatic changes (Kolář et al. 2016; Gardner 2002) – which might have helped the expansion of Yamna settlers into scarcely populated areas closer to a more Atlantic-dominated climate zone.
The area recovered after 3000 BC with a more humid climate that favoured grassland productivity (Harrison and Heyd 2007), at the same time as the horse, the wheel, and pastoralist societies expanded into these areas. Their migration seems not to have been a traumatic event. There might have been local conflicts and raids, but there are signs of interaction with contemporary societies, as well as exchange of ideas, innovations and material culture (Heyd 2012).
The main settlement areas of west Yamna migrants were confined to the steppe habitat, and therefore Yamna settlers (initially) did not occupy, push away, or expel locally settled farming societies. West Yamna tumuli are radiocarbon dated ca. 3000–2500 BC (3100/2900–2500/2475 cal. BC), and contacts with other archaeological cultures confirm that they belong to the first half of the 4th millennium. Distinct from the close contacts between south-eastern European steppes and Pontic–Caspian steppes from earlier periods, it is quite likely that the “infiltration” of small Yamna migrants had begun in the decades, even centuries before the real current of immigration, i.e. at the end of the 4th millennium, as an extension of the north Pontic roaming area (Frînculeasa, Preda, and Heyd 2015).
The massive Yamna migration in south-east Europe is said to have been well organised, either in loose family alliances (the most likely scenario) or in clans, in any case with a clear leadership and structure (Heyd 2012). There was possibly more than one wave of migrations, with cultural differences noted north and south of the Balkans. At least one migration wave seems to have come from the north Pontic steppes, due to the presence of wagons (or parts of wagons) and stelae—characteristic of the Kemi-Oba and neighbouring zones of the Southern Buh–Lower Don steppe—in burial mound cemeteries of Yamna settlements (Kaiser and Winger 2015).
Important settlement areas included (Heyd 2011):
· The first large concentration of Yamna tumuli and burials appeared in the grass and bush-land typical of the steppe-like vegetation and environment, continuous from the north Pontic to the west Pontic area, up to the Dobruja (south of the Danube delta) and north-east Bulgaria.
· The second large concentration, the Tarnava-Rast group, appeared to the west in south-western Romania, on the plains and terraces divided by the lower Danube River. Migrants pushed west, appearing west of the Iron Gates in Jabuke, but the largest number of migrants ended up in the central Carpathian basin.
· Another province was formed by the Upper Thracian Plains south of the Varna Bay, in the Balkan uplands (Kovachevo-Troyanovo), within the region of the Ezero culture (Anthony 2007). It is more influenced by the Mediterranean, and tumuli are widespread, especially in the area between the Maritza and Tundza rivers.
· The Prut–Siret region of well-drained hill and flatlands show tumuli and burials backing onto the eastern Carpathians, in a number smaller than most other western provinces. More than distant nomadic settlements, these settlers formed part of a much wider, expanding Yamna group that was originally located further to the east and north-east. This is reflected by the gradually increasing number of tumuli and graves up to their source territories in the Dniester River and the north Pontic steppe
The westernmost group, third in size, lies in the Great Hungarian Plain or Great Alföld, in the central Carpathian Basin, a grassland plain mainly located north and east of the Danube, mainly east of the Tisza River. It covers 50,000 km2 in Hungary, but reaches also neighbouring modern countries, e.g. Croatia, Serbia and Romania with the regions of Banat and Transylvania forming part of it. The core area of these lowlands is the Hungarian Puszta (‘plain’), and Yamna tumuli and burials (Figure 29) are spread all over it, with the largest concentration located in the steppe areas neighbouring the Tisza River. There were originally around 40,000 kurgans in Hungary, but a more recent estimate suggests that there are today less than 2,000 left (Suppl. Fig. 10.A).
Figure 29. A kurgan stands out on a flat ‘sea of grass’ from the Great Alföld. Hegyes Mound, in the flood-free bank of the Kösely Stream (Nádudvar). Photo by Csaba Tóth, modified from (Tóth, Joó, and Barczi 2015).
Based on the distribution map of kurgans, burials are densest where there were no Boleráz or Baden occupations, although they partially overlapped. Boleráz–Baden groups represented settled, agriculturalist, indigenous groups, while Yamna formed small animal-keeping mobile groups. Where they appear at the same time, the kurgan is always situated on top of a settlement, indicating that they followed Baden and represented a somewhat higher social power and belief system. Apart from burials, no Yamna settlements are known in Hungary, so it is unknown whether they were situated close to the kurgans or somewhere else entirely (Horváth 2016).
Most kurgans are located on the plains, and a smaller portion appear in neighbouring hills and mountains, while in unfavourable areas of sand dunes (Nyírség Region, Danube–Tisza interfluve) kurgans are virtually absent. The highest density of mounds appear in alluvial and loess plains rich in active and abandoned river channels, usually on natural levees, sometimes concentrated along streams forming small or large clusters. Their distribution usually follows a curved line, and vertically mounds usually appear above a certain elevation corresponding to flood-free levees and small aeolian dunes (Tóth, Joó, and Barczi 2015).
In contrast to their compatriots around the Lower Danube and Moldavia, settlers from the Carpathian Basin applied reed mats, textiles, leather, and even furs (possibly even felt and carpets) for the pit walls and floors, and these have been documented outside the grave pit. These colourful decorations – despite the poorly furnished graves and generalized lack of accompanying grave gifts – must have played a distinct role in the Yamna society, as well as the importance of colour combinations and pattern as emplematic and symbolic signs based on associations. Burial chambers prepared in this way were covered with wooden beams, planks, or logs, reminiscent of the few cases in Bulgaria and Romania which show big stone slabs covering the grave pit. All of this is compatible with the importance of the domus-idea, as are additional wooden posts, stone frames, and fireplaces or hearths attached (Heyd 2011).
Sizeable concentrations of tumuli are found in steppe areas around the Middle and Upper Danube and its tributaries—such as the 8,000 km2 wide Little Hungarian Plain (or Little Alföld)—as well as in neighbouring forest-steppe regions close to the Danube, representing a gradual adaptation of Yamna settlers to the forest-steppe region (Horváth et al. 2013; Horváth 2016). Some distant settlements to the west show strong hints of the Yamna culture, such as concentration of tumuli, elements of Yamna burial customs, anthropomorphic statue-stelae, and artefacts with eastern links or origins. These groups include, for example, the north/north-central Middle Elbe–Saale area of east Germany with steppe vegetations, in the shadow of the Harz mountains, or a stripe in the foreland along the east Carpathians and southeast Poland, the border between Romania, the Ukraine, and Poland (Heyd 2011).
Figure 30. Distribution of artefacts and customs related to the Yamna culture (approximate border delineated up to the Tisza River), after Bátora (2006), fig. 15: 1 – Königshofen, 2 – Nohra, 3 – Kbely u Prahy, 4 – Cerhenice, 5 – Suchohrdly, 6 – Jelsovce, 7 – Nitra-Cermân, 8 – Nitra-Dolné Krskany, 9 – Sala, 10 – Kétegyháza, 11 – Kost’any, 12 – Lesné, 13 – Kietrz, 14 – Miemowo, 15 – Samborzec, 16 – Żuków, 17 – Püspökladány.
Many neighbouring regions with similar environment and landscape are thought to have been likely targets of that westward Yamna migration, although they have not yet yielded archaeological records, such as Black Sea shores of Bulgaria, East Thrace, modern Turkey, and northeast Greece south of the Rhodopes mountains. Interesting are the isolated findings of Yamna material culture in Corded Ware territory to the north (Bátora 2006), probably representing trade contacts or vanguard settlements (Figure 30) before the evolution into (and explosive expansion of) Bell Beakers.
An interesting finding is the discovery of a Yamna-like kurgan in Valencina de la Concepción, in southern Iberia (ca. 2875 BC), below which was the body of a man buried with a dagger and Yamna-like sandals, and decorated with red pigment just as Yamna dead were. This suggests that the ideology, lifestyle and death rituals of the Yamna could run far ahead of migrants. The distribution of Yamna findings along the Danube, in central Germany, and up to Chalcolithic Iberia (Suppl. Fig. 10.B) before the emergence of East Bell Beakers—whose emergence happened roughly around the same areas (see below §VII.7.2. East Bell Beaker group)—suggests a complex framework of vanguard settlements and intense exchange contacts in central Europe.
Different from all these attested or supposed Yamna territories are some early samples of tumuli of mixed culture (e.g. those including cremation, or foreign material culture, or avoiding certain typical Yamna rites), which may point to Yamna influence on adjacent territories or local ‘kurgan’ cultures extant from the evolution of the previous Suvorovo–Novodanilovka expansion (see §IV.2. Khvalynsk–Novodanilovka).
Remains including a Coţofeni vessel from a Yamna grave in the Dniester (dating to the beginning of the Yamna migrations), and a typical Makó handled pot from Sofievka on the left side of the Dnieper (dating to the mid–3rd millennium) point to Yamna settlements closely connected to the core Yamna territory, thus considered an extension of their normal roaming area, and keeping a close contact among different groups (Heyd 2011).
Close contacts with adjacent cultures can also be seen in the Hungarian group, where for example herders from the Lizevile group in Transylvania seem to have used and economic model of transhumance, with livestock passing the winter and spring in the milder regions of the Great Hungarian Plain, as revealed by certain foreign tumuli in Yamna territory. Such regular visits increased the likelihood of these transhumant herders becoming integrated locally, and during the second quarter of the third millennium the internal coherence of the Yamna ideology had already diminished, which allowed other Lizevile and other herders to step in and take over locally, initially on a seasonal basis, and then permanently (Gerling et al. 2012).
The so-called “Yamna package” (Figure 31) includes eleven components common to the initial western migrants (Harrison and Heyd 2007):
A) The social sphere:
1. The most important and visible is the round barrow as a personalised monument. Emblematic symbolic signs based on associations, using patterns and colourful decorations, often combining two or more different colours, apart from reed mats, textiles, leather, and even furs for the pit walls and floors, even outside the grave pit, and possibly felt and carpets. Burial chambers are then covered with wooden beams, planks, or logs. These are often combined in Bulgarian and Romanian groups with an anthropomorphic stela covering the grave pit (none are known from Serbia or Hungary). All this reinforces the importance of the domus-idea of the tumuli.
2. The single burial with a typical supine position on its back with flexed legs, usually upright (possibly to the side or in frog-position after a process of decay), often covered in red ochre, in a deep rectangular pit. The most common orientation of pits and skeletons is east–west, with heads in the west, but other directions are also attested.
3. Social position and gender are systematically marked. Most burials are of adult males, and their percentage is higher in primary graves (so probably very much a masculine society). The wooden wagon marks an elevated social position in the north Pontic area; however, typical of west Yamna migrants are the poorly furnished graves and the general lack of accompanying grave gifts (with complete absence of weaponry and tools). The social expression in west Yamna is thus not manifested in grave goods, but firstly in the labour and communal exertion to erect a tumulus, and secondarily in the efforts to create a burial chamber, the new house of the dead.
4. The creation of a special status for craftsmen (especially metalworkers), especially widespread in the north Pontic region and western migrants. For the first time, metallurgists had a specific social status. The development of the so-called Circum-Pontic Metallurgical Province is also associated with the spread of Yamna—taking over the previous north Pontic industry (see §IV.3.1. Metalworking)—including the wide distribution of new methods of copper and arsenical bronze metallurgy, and a set of bronze objects.
5. Hoarding metal objects begins again in steppe cultures, with hoards of shaft–hole axes. Furthermore, the deposition of lumps of ochre in the graves and the fewer secondary burials cut into existing tumuli are typical of the Carpathian basin. This is useful when distinguishing Yamna burials of the Carpathian group from those on the lower Danube and the Prut.
B) The technological sphere:
6. Re-establishment of metallurgy of gold and copper, following a long decline after 3500 BC, but with a different technology of smelting, working and casting in two-piece stone moulds, or ‘Caucasian metallurgy’ (Sherratt 2004).
7. New weapon designs in copper: the single-edged shaft–hole axe, and the tanged metal dagger.
Figure 31. Examples of the western ‘Yamna Package’ material culture. Image modified from (Harrison and Heyd 2007).
C) The economic sphere:
8. The domesticated horse features importantly in a dedicated pastoral economy which raises herds of cattle, and perhaps flocks of sheep for wool. Domesticated horse is documented since the EBA on both sides of the Carpathians from bone cheek-pieces, both as transport and as traction animals (Boroffka 2013).
9. Wooden wagons placed in graves as social markers; the westernmost example is the ox-pulled wagon grave of Placidol in northern Bulgaria.
10. The custom of using simple golden, electrum or silver hair rings, a distinctive bone toggle, and decorated bone discs, whose distribution covers all regions of western Yamna. Common adornments are also necklaces and chains of beads or perforated teeth.
11. Widespread use of cord decoration on pottery; the common cross-footed bowls copy models on the eastern Pontic steppes.
The use of pottery in western Yamna points to the import from neighbouring archaeological cultures, such as Coţofeni III vessels in Tarnava; Cernavodă II vessels in the lower Danube; Vučedol-like vessels in Romania and Bulgaria; and Makó and Lizevile-like vessels in Hungary. Most ‘original’ Yamna vessels include cord-impression techniques, and especially interesting is the classical beaker-like vessel widely distributed in the western regions, as well as the recurring decoration motif of triangles, fringes, or long triangles intermingled with each other, a specific decoration known from the north Pontic area (Heyd 2011).
Animals bones found next to the burial chamber, or part of the meals consumed during the ceremonies found around or on top of the graves, include dogs, sheep–goats, cattle, and horses (which hint at their relevance in the Yamna subsistence economy), and also hunted animals such as deer and birds (Heyd 2011). An important part of the industry related to pastoralism was the production of leather and wool. Examples are found, apart from western settlers, in Kalmykia, where wool and leather are widely used for the production of underlay, pillows, and clothes, with weaving skills showing up in good quality mats; or in Mikhailovka II-III, which shows a high level of leather production, as well as ceramic spindle whorls and weights. Based on scarce findings from Eneolithic steppe cultures, and on the analysis of Khvalynsk posttery ornamented with imprints of textile goods, Yamna findings likely show ultimately a great degree of continuity of an ancestral tradition (Morgunova and Turetskij 2016).
The interaction with previous cultures from south-east Europe may have been resolved in different ways, either violent confrontation, peaceful interaction, or neutral ignorance of each other. Since Yamna settlers occupied the steppe habitat, most economically important territories from neighbouring cultures would have been spared, at least initially, triggering mostly cultural interaction. However, communities derived from the small Suvorovo–Novodanilovka groups that settled the region may have entered into direct contact, which would have been resolved either violently or, perhaps, with rapid assimilation due to the similar economic/social background with comparable lifestyles (Heyd 2011).
Violence and raids must have been present with neighbouring cultures, though, and perhaps the building of a defence-like chain of hill forts along the south shore of the Danube by the Vučedol culture points to such contacts, although this is not the only interpretation possible. On a wider scale, the expansion of the Yamna culture begins a true horizon of transformation and cultural change in many European regions (Harrison and Heyd 2007).
Unlike western Yamna, where cattle dominates the diet and funerary rites, eastern Yamna in the Volga–Ural and in the northern Caucasian–northern Caspian steppes show a subsistence economy continuing the previous period, based on mainly sheep–goat and (less prominently) cattle, based on remains found in grave sacrifices (Shishlina 2008). The early Volga–Ural Yamna culture is represented by some settlements, small kurgans (ca. 20–25 m in diameter), and Repin-type pottery. The classical or developed phase is represented by the “unification of the funeral ritual, round bottomed pottery, the disappearance of settlements, and the prevalence of wheeled transport” (Morgunova 2002).
Differences between Yamna culture of the Volga–Ural interfluve and west Yamna groups are observed at both the social and economic levels. The traditional development of hereditary social strata in the Volga–Ural region was increasingly based on specific regional developments, such as the common interest in supply of metal objects and wooden products of cattle farming groups, which contributed to greater mobility of the nomadic pastoral population (Morgunova and Fayzullin 2018).
Such specialised production made it possible to raise the prestige of a given activity and individuals producing the necessary vehicles, tools, and weapons. The role of priests and producers (carpenters, blacksmiths) stands out by their unconventional burial rite: isolated skull burials and dismembered sacrifices the former, weapons and tools the latter, as in middle-aged men’s burials accompanied by sets of tools for woodworking (axe, adze, big knife, gouge, pin, chisel) in some barrows of the Orenburg oblast. The lack of specific warrior burials points to the likely participation of the whole adult society in battles (Morgunova and Fayzullin 2018).
The construction of monumental kurgans with rich assemblages—such as those of Utevka I, Bodyrevo IV or Krasnosamarskoe IV, or the individual kurgans of Shumaevo II, Kalmytskaya Shishka, Dedurovskiy Mar—support the existence of ruling leaders among the elite, an aristocracy capable of: controlling competition (or supporting alliances) regarding territory, water resources, or raw materials; guiding the tribes; unifying their ritual and promoting the erection of sacred places; and enabling the expansion of homogeneous cultural elements through a huge territory. These elites probably concentrated economic–administrative, military, and religious functions under their charismatic leadership, which would become hereditary, evidenced by the presence of children burials among a majority of adult male elite burials (Morgunova and Fayzullin 2018).
The material culture of the Volga–Ural region (Figure 32) shows a clear connection with that of further eastern groups, including Afanasevo in the Altai region. This connection is evidenced by pieces of copper-containing sandstone from the southern Urals. A Yamna miner was buried in a mining pit ca. 3000 BC in the Kargaly copper ore field, located beyond the headwaters of the Samara River, in south-eastern Kazakhstan. Substantial deforestation near the ore field suggest large-scale copper-ore mining in the Kargaly area, with important mining and smelting operations during the early Yamna period (Parzinger 2013), incrementing in later periods (see §VII.2.1. Poltavkaand §VIII.18.1. Sintashta–Potapovka–Filatovka).
Figure 32. Material culture of Yamna on the Cis-Ural region (after Larin 2005). From Morgunova (2014). Compare with Afanasevo-type materials (see above).
Yamna samples had been described as being mainly composed of EHG:CHG ancestry (Jones et al. 2015; Lazaridis et al. 2016). Nevertheless, based on the ancestry of Afanasevo samples without EEF, and on later Yamna samples with EEF contributions, the late Repin expansion to the north Pontic area must have caused a mean EEF increase of ca. 15% to their typical Steppe ancestry inherited from the Khvalynsk–Novodanilovka expansion, varying from a minimum in the east (ca. 13%) to a maximum in the west in Hungary (ca. 17%), with intergroup differences not statistically significant (Suppl. Graph. 7). Further external contributions are found from a source related to Eneolithic Caucasus individuals in Yamna samples from the northern Caucasus (ca. 2900–2400 BC), and especially in a Yamna outlier from Ozera in the north Pontic area (ca. 40%), apart from later Catacomb samples from the same area (Wang et al. 2019), which support admixture with locals through exogamy.
The EEF ancestry found in Yamna points to a mix of NWAN (ca. 80%) and WHG (ca. 20%), and groups as distant from each other as Globular Amphora and Iberian Chalcolithic work as proximate surrogate populations for this kind of contribution (Wang et al. 2019). A similar ancestry may probably be found in Middle and Late Neolithic farmer groups from east-central Europe, such as Funnel Beaker and other post-LBK groups near the Balkans, and perhaps certain late Trypillian groups of the north Pontic forests, based on their close interaction with TRB—although samples from the Verteba cave have shown more EHG contribution (see §v.6. Late Uralians). EEF ancestry is also found elevated in Corded Ware samples, possibly up to 50% in certain groups (Wang et al. 2019), with a great part probably due to north Pontic-related Eneolithic interactions.
Compared to the Eneolithic Volga–Ural population, which had probably little or no EEF ancestry, the appearance of this ancestry in Yamna suggests thus an admixture of expanding late Repin groups from the Middle Don with Eneolithic populations of the north Pontic steppe and forest-steppe areas, which are also the likely source (or one of the main sources) of this ancestry found later in Corded Ware migrants. This admixture was probably driven by exogamy during the expansion of the late Repin strict patrilineal society, dominated by male elites, evidenced by the expansion of an overwhelming majority of R1b1a1b1-L23 lineages with Yamna. This is supported by the finding of late Sredni Stog samples as one of the best proxy populations (together with GAC and Iberia Chalcolithic samples) for the extra EEF ancestry found among Yamna peoples. On the other hand, the homogenisation of this new EEF ancestry among all Yamna peoples—with no statistically significant differences between groups with the current number of samples—supports additional intense contacts and “internal exogamy” between Yamna clans of both western and eastern groups, and potentially also the expansion of ‘admixed’ late Repin settlers to the east.
The eastern Yamna or Volga–Ural–North Caucasian group includes the Volga–Ural variant between the Volga and Ural rivers (with Lower Volga, Middle Volga, and Ural regions), and the North Caucasus variant (right bank of the Volga River region, Kalmykia, and northern Caucasus steppes until the Terek River). Among the dialects spoken in this region was probably the ancestor of Indo-Iranian. Most reported Y-chromosome haplogroups of Yamna samples are from sites in Samara, Kalmykia, and northern Caucasus areas ca. 3100–2500 BC (Haak et al. 2015; Allentoft et al. 2015; Mathieson et al. 2015; Wang et al. 2019): sixteen out of eighteen are of haplogroup R1b1a1b1-L23, with further reported subclades mainly from the R1b1a1b1b-Z2103 trunk, except one sample from Lopatino II, in the R1b1a1b1a-L51 line (see §v.7. Common Indo-Europeans). A sample from Karagash in Kazakhstan, of subclade R1b1a1b1b3-Z2106 (de Barros Damgaard, Marchi, et al. 2018), further supports the connection of eastern Yamna groups of the southern Urals with Afanasevo.
The western Yamna or Southern Buh–Lower Don group included the Don River variant (Lower Don from the Ilovlya River to the mouth of the Don River and valley of the Western Manych River); the Siverskyi Donets variant (right bank of the Siverskyi Donets River between modern Kharkiv and Luhansk cities); the Azov variant (steppe of the Northern Azov Sea coast); the Crimea variant; the Lower Dnieper variant (from the Orel River and the Inhulets River to the Black Sea coast) with the Bilozirka, Nikopol, Kryvyi Rih, Dnieper “Stone stream”, Left Bank of the Dnieper, and Black Sea coast regions; the North-Western variant (steppe and forest-steppe borderland on the Middle Dnieper and to the west from it), and the South-Western Variant (between the Buh and Danube rivers).
Local groups of the north Pontic steppe include the Donetsk group, the Middle Dnieper group, the Lower Dnieper and the Azov–Crimea groups, and the Southern Buh group. The kurgans between the Dniester and the Prut Rivers received influences from the main neighbouring regions—such as EBA of central and south-east Europe, Globular Amphora, and Corded Ware, Foltești 2 and Coţofeni cultures—and two cultural-chronological variants are described: the Early Dniester variant, and the Late Budzhak variant (Rassamakin and Nikolova 2008).
Western Yamna and Danube groups probably spoke the ancestral language to both North-West Indo-European and Palaeo-Balkan languages. While there is scarce data on Y-chromosome haplogroups, based on later European samples it is very likely that these territories hosted R1b1a1b1a-L51 subclades—in particular R1b1a1b1a1a-L151 (TMRCA ca. 2800 BC)—whose lineages are found centuries later spreading with East Bell Beakers (see §vii.7. North-West Indo-Europeans), and were probably in the majority among Pre-North-West Indo-European-speakers. It is also likely that West Yamna hosted R1b1a1b1b-Z2103 lineages, probably associated mainly with Palaeo-Balkan-speaking clans.
Two samples show I2a1b1a2a2a-L699 lineages (formed ca. 6800 BC, TMRCA ca. 4500 BC, one in Kalmykia and one in Bulgaria (an outlier with contributions from NWAN-related ancestry), which supports the presence of this lineage among certain Yamna clans (Mathieson et al. 2018). Similarly, the presence of R1b1a1b-M269 subclade R1b1a1b2-PF7562 among modern populations in the Balkans, Central Europe, Anatolia, and the Caucasus (Myres et al. 2011; Herrera et al. 2012), speaks in favour of clans of this lineage also expanding with late Repin/early Yamna settlers, or potentially of remnant populations of the earlier Suvorovo–Novodanilovka migrations who were part of (or pushed by) expanding Yamna settlers. The finding of hg. R1b1a2-V1636 in Sharakhalsun (ca. 2780 BC) may also suggest that this lineage expanded with Yamna, or alternatively that it belonged to a remnant population of Maikop in the Northern Caucasus Piedmont eventually integrated in Repin or Yamna (see above §v.2. Early Caucasians).
The migration of Yamna settlers into Hungary appears to be homogeneous at first, with early samples clustering closely to other west Yamna samples. Two late samples from Hungary show already increased EEF ancestry (ca. 10% more than Yamna, with a close source for this ancestry found probably in neighbouring Baden-like Hungarian samples), at the same time as Catacomb individuals also received further EEF-related contributions (probably from the north Pontic area), whereas a late Yamna sampleshows no marked change, and Poltavka shows even less EEF ancestry than preceding eastern groups (Wang et al. 2018). This evolution ca. 3100–2500 BC suggests an initial homogeneous expansion, where Yamna clans either kept close contacts with other steppe clans or displayed little exogamy practices with the local groups they encountered; and a later gradual regional isolation, including interaction and admixture with different local groups.