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Post by Admin on May 21, 2024 21:45:05 GMT
 Extended Data Figure 3: A 4-way model for the entire Dnipro-Don-Volga-Caucasus region. Error bars show ±1 standard error. From Serednii Stih to Yamnaya: the 4th millennium BCE We estimated the population growth trajectory of Core Yamnaya using HapNe-LD, a methodology that can infer effective population size fluctuations in low-coverage ancient DNA data.53 Figure 5 shows the results separately analyzed for Core Yamnaya dating to the first three hundred years of our sampling (n=25) who produce a 95% confidence interval of 3829-3374 BCE for the time before growth, and 3642-3145 BCE for Core Yamnaya groups from the later three hundred years (n=26). In both cases, these correspond to growth from an effective number of reproducing individuals of a few thousand people. These intervals overlap at 3642-3374 BCE, corresponding to the late Serednii Stih period. Taken together with the admixture dating, these findings point to a scenario where the Serednii Stih were largely formed by admixture before 4000 BCE likely somewhere within the geographic span of the Dnipro-Don Cline. Half a millennium later, a subgroup of them developed cultural innovations that allowed them to expand dramatically, manifesting in a way that can be detected in the archaeological record around 3300 BCE in both the Pontic and Caspian Steppes. Figure 5:  Figure 5: Trajectory of the Yamnaya expansion. We use HapNe-LD to estimate the changes in effective population size over time of Yamnaya ancestors, performing the computation separately for the individuals from the earlier three hundred years (a) of our sampling, and the later three hundred years (b); shading shows uncertainty intervals. We infer an extraordinary population expansion (c) after 3642-3374 BCE (intersection of 95% confidence intervals for the two analyses for the minimum), from a time when the effective size is a few thousand to an order of magnitude larger. We tested for segments of the genome Identical-By-Descent (IBD) between pairs of individuals54, and found that the Yamnaya expansion transformed the interconnectedness of steppe populations. Before the Yamnaya, IBD links of ≥20cM did exist between regional populations (Fig. 6a), but this network of connections expanded dramatically in the Yamnaya period (Fig. 6b). Prior to the Yamnaya period, the rate of IBD links for individuals separated by more than 500km was vanishingly low (Fig. 6c), but in Yamnaya times, it was measurably non-zero (at a few percent) for distance separations between 500-5000km (Fig. 6d). We also studied close genetic relatives, defined as sharing at least three ≥20cM segments or a total sum of IBD ≥100cM. Both before and during the Yamnaya period, close relatives are only detected living within 500km, with a greatly elevated rate in the same cemetery (Fig. 6e, f). We examined Yamnaya-Afanasievo individuals in kurgans or kurgan cemeteries represented by at least two individuals (Fig. 6g), and found that around 14.4% of individual pairs were close relatives within kurgans and 7.4% of individual pairs were close relatives across kurgans of the same cemetery. These patterns are general across Yamnaya kurgan cemeteries (they are not dominated by one or a few sites with large numbers of samples). The observed rate of close relatives is much less than the 29.0% rate among pairs of individuals in Hazleton North chambered tomb in Neolithic Britain ∼3700BCE55 (p=0.00075; Fisher’s exact test), where 27 of 35 sequenced individuals were all found to be part of the same genetically tightly connected pedigree. These findings disprove theories that kurgans were “family tombs”56 of biological relatives. Instead, kurgan cemeteries largely included individuals that were biological kin only in the sense of sharing common descent for a population that lived many centuries in the past; if there were kinship links within the same kurgan, they were largely non-biological ones. Figure 6: |
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Post by Admin on May 26, 2024 22:32:17 GMT
 IBD analysis of the Yamnaya and their predecessors. Pairs of individuals linked by at least one IBD segment ≥20cM in length reveal a sparse and highly connected network in the Pre-Yamnaya (a) and Yamnaya (b) groups. No detectible IBD is found in the Pre-Yamnaya period beyond the scale of 1000km (c); Yamnaya share more IBD with each other at short distance scales but IBD sharing extends all the way to the ∼6000km scale of their geographical distribution. However, closely related individuals only occur at short distance scales in both Pre-Yamnaya (e) and Yamnaya (f) groups, indicating that the IBD sharing in the Yamnaya was a legacy of their common origin. (g) In a set of 9 Yamnaya cemeteries, and a total of 25 kurgans closely or distantly related individuals are virtually absent in inter-cemetery comparisons, more are found in inter-kurgan/within-cemetery comparisons, and more still in intra-kurgan comparisons; nonetheless, most Yamnaya individuals in all comparisons were unrelated. Kurgan burial of close kin was less common than in the case of a local patrilineal dynasty as at a Neolithic long cairn at Neolithic Hazleton North,55 but more common than in Neolithic monuments of Neolithic Ireland.57 The origin and spread of the first speakers of Indo-Anatolian languages Different terminologies exist to designate the linguistic relationship of Anatolian and Indo-European languages. The traditional view includes both within an “Indo-European” (IE) group in which Anatolian languages usually represent the first split58,59. An alternative terminology, which we use here, names the entire linguistic group “Indo-Anatolian” (IA) and uses IE to refer to the set of related non-Anatolian languages such as Tocharian, Greek, Celtic, and Sanskrit.6,49 Dates between 4300-3500 BCE have been proposed for the time of IA split49,59–61 predating both the first attestation of the Hittite language in Central Anatolia (post-2000 BCE49) and the expansion of the Yamnaya archaeological culture (post-3300 BCE). We identify the Yamnaya population as Proto-IE for several reasons. First, the Yamnaya were formed by admixture ∼4000 BCE and began their expansion during the middle of the 4th millennium BCE, corresponding to this linguistic split date between IE and Anatolian. Second, the Yamnaya were the source of the Afanasievo migration to the east62 a leading candidate for the split of the ancestral form of Tocharian, widely recognized as the second split after that of Anatolian.63 Third, the Yamnaya can be linked to the languages of Armenia45 via both autosomal and Y-chromosome ancestry after ∼2500 BCE, and to the languages of the Balkans13 such as Greek.45,47 Fourth, the Yamnaya can be linked indirectly to other IE speakers via the demographically and culturally transformative Corded Ware and Beaker archaeological cultures of the 3rd millennium BCE that postdate it by centuries. Most people of the Corded Ware culture of central-northern Europe had about three quarters of Yamnaya ancestry,2 a close connection within a few generations that can be traced to the late 4th millennium BCE. The Beaker archaeological culture of central-western Europe also shared a substantial amount of autosomal ancestry with the Yamnaya and were also linked to them by their possession of R-M269 Y-chromosomes.3 The impact of these derivative cultures in Europe leaves no doubt that they were linguistically Indo-European as most later Europeans were; the Corded Ware culture itself can also be tentatively linked via both autosomal ancestry and R-M417 Y-chromosomes with Indo-Iranian speakers via a long migratory route that included Fatyanovo20 and Sintashta4,22 intermediaries. A recent study proposed a much deeper origin of IA/IE languages64 to ∼6000 BCE or about two millennia older than our reconstruction and the consensus of other linguistic studies. The technical reasons for these older dates will doubtlessly be debated by linguists. From the point of view of archaeogenetics, we point out that the post-3000 BCE genetic transformation of Europe by Corded Ware and Beaker cultures on the heels of the Yamnaya expansion is hard to reconcile with linguistic split times of European languages consistently >4000 BCE as no major pan-European archaeological or migratory phenomena that are tied to the postulated South Caucasus IA homeland ∼6000 BCE can be discerned. The Yamnaya culture stands as the unifying factor of all attested Indo-European languages. Yet, the homogeneity of the Yamnaya patrilineal community was formed out of the admixture of diverse ancestors, via proximal ancestors from the Dnipro and CLV clines (Fig. 2e). Yamnaya and Anatolians share ancestry from the CLV Cline (Fig. 2e,f), and thus, if the earliest IA language speakers shared any genetic ancestry at all—the possibility of an early transfer of language without admixture must not be discounted—then the CLV Cline is where this ancestry must have come from. On the Anatolian side, we see that ancestry from the southern Caucasus Neolithic end of the CLV Cline was impactful during the Chalcolithic and Bronze Ages45 and Bronze Age Central Anatolians over the time span of Hittite presence there also had traces of Lower Volga-related ancestry which implies an origin north of the Caucasus (Fig. 2f; Extended Data Fig. 1). On the steppe side, we see that mixed Lower Volga/Caucasus Neolithic ancestry was present in the Dnipro Cline and maximized in the Yamnaya population along that cline (Fig. 2e). IBD analysis identifies long (≥30cM) segments shared by Eneolithic individuals from Berezhnovka-2 in the Lower Volga with Khvalynsk, Igren-8 Serednii Stih, and Areni-1 Armenian Chalcolithic populations, providing strong direct evidence for the impact of Lower Volga ancestry on the Middle Volga, Dnipro, and South Caucasus regions, and active gene flow among these regions around the time the sampled individuals lived (Extended Data Table 5). The individual from Vonyucka-1 in the North Caucasus, in fact, has an IBD link (15.2cM) with an early Bronze Age Anatolian from Ovaören. Indo-Anatolian languages must have been spread widely by people carrying CLV cline ancestry (Fig. 2) >4000BCE. However, only two descendant groups transmitted their languages to later groups: the Yamnaya in the Dnipro-Don area, aided by the mobility of their horse-wagon technology, and the Proto-Anatolians in the south, surviving in the diverse linguistic landscape of ancient Western Asia long enough for their languages to be recorded in writing after 2000BCE. Whatever their deeper origins in time out of the diverse constituents of CLV cline populations, the Indo-Anatolians must have been part of that cline. Genetics has little to say whether within this cline the IA languages were first spoken in the Caucasus end of the cline and spread into the steppe along with the spread of Caucasus ancestry, or vice versa, or even if a linguistic unity uncoupled with ancestry existed within the CLV continuum. DNA has traced back the ancestors of both Anatolian and IE speakers to the part of the CLV Cline that was north of the Caucasus mountains, bringing them into proximity with each other and uncovering their common CLV ancestry. However, it cannot adjudicate, on its own, who among the proximate and diverse distal ancestors of the CLV people were Pre-IA speaking. Future studies of the dynamics and temporality of intra-CLV contacts (to which genetics may add its information) and of the cultures of CLV people (as reconstructed by archaeology and linguistics) may decide who among them were most likely to have been the “original” Indo-Anatolians. |
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Post by Admin on May 28, 2024 19:48:36 GMT
 Linguistic evidence has been advanced in favor of different solutions of the Proto-IE origins problem for more than two centuries and we review some recent proposals relevant to our reconstruction of early IA/IE history. First, the presence of some cereal terminology in IA languages and even more in IE was suggested to reflect a subsistence strategy that relied in part on agriculture; this was interpreted as providing evidence against a geographic origin of the populations that spread Indo-European languages east of the Dnipro valley, the easternmost point in which agriculture was used (along with foraging and herding) during the Eneolithic.65 Our genetic findings are consistent with this constraint. If a Caucasus Neolithic population like that at Aknashen spread IA languages to the north (via the CLV cline to the Dnipro-Don area) it would almost certainly have had a cereal vocabulary, and then this vocabulary would have been retained during the Serednii Stih culture of the Eneolithic down to the time of the Yamnaya as agriculture continued to be used there.65 Second, the fact that Anatolian languages are attested largely in western Anatolia has been interpreted as evidence for entry into Anatolia from the west (via the Balkans),49 and thus we need compelling genetic evidence to provide a strong synthetic case for an eastern route. In fact, however, our genetic data does provide such a strong case, greatly increasing the plausibility of scenarios of an eastern entry of Proto-Anatolian speaking ancestors into Anatolia.66 This is because we find that Central Anatolian Early Bronze Age people who were plausibly speakers of Anatolian languages based on their archaeological contexts, were striking genetic outliers from their neighbors due to having a minority component of their ancestry from the CLV (plausibly from the people who brought the ancestral form of Anatolian languages to Anatolia), the majority of their ancestry from Mesopotamian Neolithic farmers, and little or no ancestry from the Neolithic and Chalcolithic Anatolians who were overwhelming the source populations of other Early Bronze Age Anatolians. Mesopotamian Neolithic ancestry almost certainly had an eastern geographic distribution, while the Central Anatolian Bronze Age people had no evidence of the European farmer or European hunter-gatherer ancestry that CLV have encountered if they had migrated to Anatolia from the west, so the genetic data favor an eastern route. How then could it be that there is no linguistic evidence of Anatolian speakers in eastern Anatolia? We propose that the archaeologically momentous expansion of the Kura-Araxes archaeological culture in the Caucasus and eastern Anatolia after around 3000BCE may have driven a wedge between steppe and West Asian speakers of IA languages, isolating them from each other and perhaps explaining their survival in western Anatolia into recorded history. That the expansion of the Kura-Araxes archaeological culture could have had a profound enough demographic impact to have pushed out Anatolian-speakers, is attested by genetic evidence showing that in Armenia, the spread of the Kura-Araxes culture was accompanied by the complete disappearance of CLV ancestry that had appeared there in the Chalcolithic (Fig. 2f).9,45,67 The Kura-Araxes culture may not be the only reason for the IA split. The ancestors of the Yamnaya did not only become separated from their Anatolian linguistic relatives but from other steppe populations as well. The homogenization of the Yamnaya ancestral population during the 4th millennium BCE, both in terms of its autosomal ancestry, and in terms of its Y-chromosome lineage, attest to a period of relative isolation and the cessation of admixture. Such isolation would foster linguistic divergence of the languages spoken in the pre-Yamnaya community with those of their linguistic relatives on the steppe. This isolation must have persisted even after the sudden appearance of the Yamnaya archaeological horizon. Mobility and geographical dispersal provided ample opportunities for the resumption of admixture, yet the genetic homogeneity of the “Core Yamnaya” across much of the steppe leaves little room for the absorption of any pre-existing steppe communities: they all seem to disappear in the face of the Yamnaya juggernaut. Did mixing occur between the segment of the Yamnaya population not buried in kurgans and locals they encountered while the kurgan-buried elite largely avoided it with some exceptions?15 The rise of the Yamnaya in the Steppe at the expense of their predecessors was followed by their demise after a thousand years (Fig. 3), displaced by descendants of people of the Corded Ware culture. Was this the demise of the kurgan elites of the Yamnaya or of the population as a whole? The steppe was dominated by many and diverse groups later still, such as the Scythians and Sarmatian nomads of the Iron Age. These groups are certainly very diverse genetically, but their kurgans scattered across the steppe attest to the persistence of at least some elements of culture that began in the Caucasus-Volga area seven thousand years ago before blooming, in the Dnipro-Don area, into the Yamnaya culture that first united the steppe and impacted most of Eurasia. To what symbolic purpose did the Yamnaya and their precursors erect these mounds we may not ever fully know. If they aimed to preserve the memory of those buried under them, they did achieve their goal, as the kurgans, dotting the landscape of the Eurasian steppe, drew generations of archaeologists and anthropologists to their study, and enabled the genetic reconstruction of their makers’ origins presented here. |
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Post by Admin on Oct 31, 2024 18:09:56 GMT
 With the time traveling ability of archaeogenetic studies, it has become possible to shed light onto the dynamic past of human populations world-wide. Integrated with archaeological and anthropological data, it has been shown that fundamental changes in lifestyle, culture, technical know-how and social systems were often linked to the movement and interaction of people. By studying 131 individuals from the wider Caucasus region, spanning a time transect of 6,000 years, a team of international researchers were able to reconstruct a series of key events when contact and innovation transfer facilitated the economic exploration of the West Eurasian steppe belt. The paper is published in the journal Nature. www.nature.com/articles/s41586-024-08113-5 |
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Post by Admin on Oct 31, 2024 18:10:32 GMT
The wider Caucasus region, between the Black and the Caspian Seas, connects Europe, the Near East and Asia. It displays a huge geographic, ecological, economic, cultural, and linguistic range today, from the steppe zone in the north, the Caucasus mountains in the center, to the highlands of today's Armenia, Georgia, Azerbaijan and Iran in the south.
This diversity was no different in the past, where the archaeological record attests to many different influences from many surrounding regions.
"It is precisely this interface of different eco-geographic features and archaeological cultures that makes the region so interesting to study," explains Dr. Wolfgang Haak, senior author and principal investigator of the study.
"By establishing a time series across many consecutive archaeological periods, we wanted to capture the time periods when, for example, the first farmers arrived in the region, or when the combination of new innovations in e.g., herd management, dairying, and mobility, enabled an autonomous nomadic lifestyle adapted to exploit the vast Eurasian steppe zone."
The team observed an alternating series of interaction and gene flow between inhabitants of the major eco-geographic zones of the mountainous upland regions and the steppes to the north of the Caucasus.
"Initially, we found two distinct genetic ancestries among the hunter-gatherer groups north and south of the Greater Caucasus," adds lead author Ayshin Ghalichi, Ph.D. candidate at the Max Planck Institute for Evolutionary Anthropology in Leipzig.
This picture changed with the arrival of early farmers from northern Mesopotamia in the 6th millennium BC, which led to two initial processes of mixture: one between these early farmers farmers and Caucasus/Iranian hunter-gatherers, which formed the predominant ancestry south of the Caucasus mountains, and a second one between the aforementioned hunter-gatherer groups, which resulted in the ancestry profile in the steppe zone north of the Caucasus.
During the following 5th and 4th millennium BC, Eneolithic cultures emerged in the river valleys of the North-Pontic steppe and became archaeologically visible as they built characteristic earthen burial mounds, known as "kurgans."
New Eneolithic groups arriving from the south led to a period of contact and exchange between both groups and resulted in the emergence of the Maykop culture phenomenon in the 4th millennium BC, which represents a horizon of technical and social innovations in archaeology.
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