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Post by Admin on Mar 22, 2024 21:27:42 GMT
 Figure 2. Ancient individuals are highlighted on the western Eurasian PCA and in geographical space for the main four steppe-related clusters. On the PCA, samples older than 2800 BP are indicated with a ‘.’, on the map, only samples older than 2800 BP are shown. To understand the variation between these clusters in finer detail, we undertook IBD Mixture Modelling (Supplementary Note 6.5). In Extended Data Figure 1 and Figure S6.5.2.1, we plot the admixture proportions inferred by the IBD mixture modelling (Supplementary Note S6.2, Supplementary Fig) on top of the standard western Eurasian PCA to explore the geographic apportionment of each genomic ancestry. We see the relative proportions of Steppe and Farmer-related ancestry along the Yamnaya-Neolithic Farmer cline in Extended Data Figure 1A and B, the relative proportions of Farming- and WHG-related ancestry along respective cline in Extended Data Figure 1B and C, and WHG and EHG along the respective cline in Extended Data Figure 1C and D. Furthermore, this representation of our results revealed a series of novel genetic clines and provide additional resolution to previously found clines within the densely overlapping Bronze Age PCA space. |
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Post by Admin on Mar 23, 2024 20:54:55 GMT
 Extended Data Figure 1. A subset of Mixture modelling results from Auxiliary set 1 displayed on the western Eurasian PCA, (Supplementary Note S6.5.2), showing the clines representing the diversity of western Eurasian Hunter-gatherers, the arrival of Neolithic Farmers in Europe admixing with the local Hunter-gatherers, and the arrival of Yamnaya-related ancestry admixing with European Farmers. Source individuals are circled, and admixture proportions follow a cline from coloured to grey. We first modelled all individuals in the dataset using representatives of the Yamnaya-, Corded Ware (East)- and Bell Beaker-related clusters as sources to explore the relationship between the early individuals from each cluster and later populations in time. To explore interactions with the farming populations present in Europe during this time, we also included representatives of three clusters - the Globular Amphora Culture (GAC) of North East Europe, European Farmers, and Levant / Bronze Age Anatolians. Despite all being modelled primarily with Neolithic Farming ancestry, they are modelled with small proportions of North East European Hunter Gatherer (Latvian/Lithuanian), Western Hunter Gatherer (Italy) and Caucasus Hunter Gatherer ancestry respectively. We find that the estimated Yamnaya admixture proportions previously shown to decrease along the cline connecting Yamnaya individuals and the dense clustering of BA diversity in Set X (Extended Data Figure 1) to now be modelled by Corded Ware source (Figure 3B). The decrease corresponds with increasing farming-related ancestry, which is here modelled as GAC (Figure 3D, Figure S6.5.1.6.). We interpret this cline to correspond to the admixture with GAC previously documented to occur prior to the arrival of steppe ancestry in Europe 60. This cline corresponds to one of the four previously mentioned clusters, the ‘Corded Ware (East)’ cluster (Figure 2). |
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Post by Admin on Mar 25, 2024 20:22:14 GMT
 Figure 3. A subset of Mixture modelling results from Set 5 displayed on the western Eurasian PCA, (Supplementary Note S6.5). A subset of IBD Mixture Modelling results from Set 5. Mixture Modelling Proportions for Steppe Ancestry related clusters A) Yamnaya-reltaed, B) Corded Ware-related and C) Bell Beaker-related, and Farming ancestry related clusters: D) Globular Amphora Culture-related, E) European Farmer-related and F) Levant / Bronze Age Anatolia-related. Source individuals are circled, and admixture proportions follow a cline from coloured to grey. Results shown here are a subset of Figure S6.5.1.3. Overlapping with the admixed European tip of this Corded Ware (East) cline we find a series of additional clines, representing additional admixture between early European steppe people already carrying GAC ancestry, and additional farming-related groups in Europe. The first cline within this diversity extends from this point to the European Farmer cline. The Steppe ancestry in this cline is modelled by the Bell Beaker-related source (Figure 3C), and the additional Farming ancestry by the European Farmers (Figure 3E). We interpret this cline to represent additional admixture with Farming sources within Europe who themselves carry some Western Hunter Gatherer ancestry. This cline corresponds to another of the four previously mentioned clusters, the ‘Bell Beaker’ cluster (Figure 2). Very few individuals within Europe are modelled as ‘Yamnaya’ when the Corded Ware and Bell Beaker source clusters are included (Figure 3A). From within the Corded Ware (East) and Bell-Beaker diversity we find an additional two clines extending to the Levant / Bronze Age Anatolians cluster (Figure 3F). The steppe ancestry of first is modelled as Bell Beaker-related, and corresponds to a sub-cluster (Figure S6.1.12) within the main Bell Beaker cluster and contains many Hallstatt and La Tene individuals (Table X), which we interpret as admixture within the range of these cultures, from France to the Black Sea. However, no suitable Bronze Age source cluster could be identified, suggesting a higher degree of continuity and complexity within the Bell Beaker related populations of this region, consistent with previous studies 63. The steppe ancestry of the second cline is modelled as Corded Ware (East) ancestry (Figure 3B), and corresponds to the Corded Ware (North) cline (Figure 2), which we interpret as admixture between Northeast and Southeast Europe. For both clines, the additional farmer ancestry is modelled as Levant / Bronze Age Anatolian. The second cline represents admixture with North East Europeans, who form the ‘Corded Ware (North)’ cline (Figure 2) and are modelled as Corded Ware (Figure 3B) and GAC ancestry (Figure 3D). Individuals with varying proportions of Corded Ware, Bell Beaker and Eastern Mediterranean Bronze Age ancestry are present as a cloud between the two clines. Entering this cloud at various angles we find three Corded Ware (North) sub-clusters (Eastern Scandinavian, Southern Scandinavian, Baltic) and one Bell Beaker subcluster (Eastern North Sea), which we interpret as admixture into different regions of Europe with varying proportions of the farming-related sources (Extended Data Figure 2). |
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Post by Admin on Mar 26, 2024 22:17:10 GMT
 Figure 4. Geographical distributions of major Archaeological Cultures and Language Families and contemporaneous Steppe Ancestry Source. Individuals with less than 10% Steppe Ancestry, or less than 66% from one of the source groups are indicated with an ‘x’. Archaeological boundaries modified from 64. The border between these Corded Ware and Bell Beaker Steppe ancestries remains relatively stable throughout the Iron Age, until the fall of the Roman Empire (Figure 4). Beginning in the Migration Period, we see a southward shift of these borders. In Britain, the beginning of the Anglo-Saxon period has previously been linked to a demographic movement from continental Europe 47,65; this transition is reflected here in the shift among individuals from the Bell Beaker to Corded Ware clusters. In addition, we see a similar but slightly earlier result for the Netherlands and Germany (Figure S6.3.1.1). The presence of Bell Beaker-related ancestry in the Norwegian Viking Period represents previously documented migrations from Celtic regions within Britain and Ireland, however here we detect these migrations as early as the Iron Age (1242 BP, Figure S6.4.2.1). Population dynamics in Scandinavia from the LNBA to Iron Age In order to identify whether migrations had occurred within Northern Europe, understanding the substructure within the Bronze Age populations of this region was necessary. We therefore reclustered all ancient samples older than 2800 BP, to remove the impact of later admixture between structured populations present in the Bronze Age (Supplementary Note 6.4.2, Supplementary Table x). Within Scandinavia, three clusters are apparent (Extended Data Figure 4): 1) an early Scandinavian cluster, including the oldest Swedish (Battle Axe Culture) and Danish samples and almost all Norwegians, 2) a later ‘Southern Scandinavian’ cluster restricted to Denmark and the southern tip of Sweden, and 3) a second later ‘Eastern Scandinavian’ cluster, spread across Sweden and overlapping with that of the Southern Scandinavia cluster. In all three instances, there is a very close correspondence between Y-haplogroups and the IBD clusters (Extended Data Figure 4A), largely driven by different frequencies of haplogroups I1a-DF29, R1a1a1b1a3a (R1a-Z284) and R1b1a1b1a1a1 (R1b-U106), which are all strongly associated with Scandinavian ancestry (Supplementary Note 6.4.2). |
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Post by Admin on Mar 31, 2024 19:59:41 GMT
We find a large degree of overlap between the Early, Southern and Eastern Scandinavian clusters of the pre-2800 BP individuals and three subclusters detected in the original northern Corded Ware cluster: Western, Southern and Eastern Scandinavian respectively (Supplementary Extended Data Figure 4B, Supplementary Note S6.4.2). A clear difference between the two clustering runs is the reduction from 175 to 123 individuals in the Eastern Corded Ware cluster in the pre-2800 BP clustering. Many of these individuals are instead found in clusters from Northern Europe in the pre-2800 BP clustering. The pre-2800 BP Early Scandinavian cluster contains 24 individuals rather than 13 in the corresponding Western Scandinavian cluster in the full clustering. Similarly, the pre-2800 BP Southern Scandinavian cluster sees 37 individuals rather than 25. From mixture modelling results (Figure S6.4.2.4), we see that the samples that moved from the Eastern Corded Ware cluster in the original modelling are modelled with the smallest amounts of the Eastern, Western and Southern Scandinavian that is widespread from the late Bronze Age onwards. In contrast, from 4000 BP almost all Scandinavians are well modelled as combinations of Eastern, Western and Southern Bronze Age ancestries. Combined, the results suggest a structured population in Scandinavia present from ∼4600 - 4000 BP. From the more basel set of sources (Set 1) for themixture modelling, we find Yamnaya related ancestry to be modelled as Eastern Hunter-gatherer and Caucasus Hunter-gatherer (Figure S6.5.1.10, S6.5.1.1, S6.5.1.2, S6.5.1.3), as expected 66. However, the pre-2800 BP Eastern Scandinavians are distinct in the relatively high proportion of Eastern Hunter-gatherer ancestry, compared to Northern and Western Scandinavians (Figure S6.5.1.6, S6.5.1.4). To identify the specific source of this Hunter-gatherer ancestry, we included additional Hunter-gatherer sources from the region (Norway, Sweden, Latvia and Lithuania, Denmark) together with Yamanya and find the Eastern Scandinavians hunter-gatherer ancestry modelled entirely by the Latvian HG source from across the Baltic, rather than the local Scandinavian hunter gatherers (Extended Data Figure 5, Figure S6.5.1.4, Supplementary Note S6.5.1). In contrast, the Southern and Western Scandinavians are modelled with additional Western Hunter-gatherer ancestry (Italian source clusters). These admixture results are consistent with the subtle differences in the distribution of the Scandinavian clusters in the western Eurasian PCA (Supplementary Note 6.1).  Extended Data Figure 5. Mixture Modelling sets showing the Hunter Gatherer admixture in Europe. Row 1 (set X) has no admixed source populations, showing Western Hunter Gatherer ancestry in European Farmers, North Western Hunter Gathers (Latvia, Lituania) admixture in GAC, and Eastern Hunter Gatherer along the ‘Baltic’ cline. The second row (set Y) includes the admixed Farmer populations, showing the required additional North Western Hunter Gatherer ancestry in Eastern Scandinavians and Eastern Hunter Gatherer ancestry in the Baltic cline. The clustering of the Eastern, Northern and Western Scandinavian sub-clusters within the Corded Ware (North Cluster) and the steppe ancestry being modelled as Corded Ware (East) points to a shared history as part of the Corded Ware expansions. However, first detection of Eastern Scandinavians 800 years after the earliest Corded Ware people in Scandinavia, and the presence of a Hunter-gatherer ancestry not local to Scandinavia points to an additional, late arrival into Scandinavia by the ancestors of the Eastern Scandinavians. While the steppe ancestry in the northern European clusters are modelled primarily by the Corded Ware source and the western European clusters by the Bell Beaker source, a Bronze Age Eastern North Sea (ENS) cluster from the coastal region in the overlap between the two cultures is modelled with equal proportions (Figure S6.5.1.7, Suppl Note S6.9.2). This result is also reflected in the position of these Bronze Age samples in the western Eurasian PCA, between the oldest Bell Beaker and Northern Corded Ware samples (Supplementary Note 6.1, Figure S6.1.13). When using an early Bronze Age cluster representing this population, we see genetic continuity between 3700 BP and 1700 BP with little evidence of admixture. With representatives of each of the additional northern European Bronze Age source clusters, we resolve in more detail the extent of a previously documented expansion of Eastern Scandinavian ancestry 59,60. By the Iron Age in Scandinavia, almost all individuals are modelled with >50% Eastern Scandinavian ancestry. The impact of this expansion is most apparent on the Danish Islands, followed by Norway (Supplementary Note S6.9.4) and finally the Danish peninsula of Jutland (Figure 5). |
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