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  • The Tarim Basin Bronze Age horizon: Isolated Paleo-Siberians or recent colonists from the West ?

    I’m an admirer of the works contributed to the scientific community by Cui, Jeong & the various other contributors of the paper The genomic origins of the Bronze Age Tarim Basin mummies. (https://www.nature.com/articles/s41586-021-04052-7/figures/3). The Tarim mummies are of course well known in popular culture.

    They concluded that ‘we find that the earliest Tarim Basin cultures appear to have arisen from a genetically isolated local population that adopted neighbouring pastoralist and agriculturalist practices ”. That begs the question – where are the pre-2200 BC sites in the Tarim basin ? Is it mere coincidence that the horizon became established ca 2200 BC, during the so-called 4.2 kiloyear phenomenon, when much of Eurasia was experiencing a complex and inter-connected series of demographic and socio-cultural shifts ?

    As such, I thought I’d take a look into these individuals. This glimpse into the Tarim basin is a preliminary section into what I hope some day might be a more formalised synthesis and re-assessment of ‘steppe cultural dynamics’ which hopes to collate the growing body of data and assess it via a common pipeline, so to speak.

    In looking at the Tarim#1 cluster, the successful model offered by the study entailed a 2-way admixture between Kolyma_mesolithic (~ 30%) and Afonotova-Gora (~ 70%). If true, then this would indeed support the hypothesis of ‘relictual Siberian population’. Their p-value was 0.219. Their finding of high ROH does lend support to the existence of a bottle-necked population,

    (What I also have issues with is the modelling of clusters such as Kumsay & Botai- which date to ca 3000 BC- on the basis of Tarim 2200 BC. Whilst we sometimes have to accept ‘dyschronological’ models for the sake of hypothesis building, this approach is contingent on some unwarranted assumptions (such as the primordialism of the said Tarim basin population)).

    However, there is also this possibility.

    p-value 0.412936

    left pops:
    Tarim_EMBA1
    BZK002 (Bazhaka)
    Kazakhstan_Kumsay_EBA

    best coefficients: 0.394 0.606 (SEs 0.09)

    tail prob 0.39

    right pops:

    Cameroon_SMA.DG
    Pinarbasi
    MA1
    Israel_PPNB
    Brazil_LapaDoSanto_9600BP
    Kostenki14a
    Tianyuan
    Iran_GanjDareh_N
    Mongolia_North_N
    Russia_HG_Karelia
    Satsurblia_HG
    Villabruna_HG
    Hungary_EN_Starcevo_1

    Also interesting is the uniparental data. The Tarim_BA males feature R1b-Ph155. R1b is so-far missing in pre-Copper/Bronze Age remains from central, ‘inner’ and northern Asia, as well as the parts of Siberia from where the Kolyma individual was found. Instead, its links to other ‘basal’ R1b lineages such as R1b-V88 and V3616 in Eastern Europe, having branched out ca 18,000 BP according to YFull. This is the start of climactic amelioration following the LGM.

    For me, the evidence suggests that the Tarim _EBA horizon was neither completely isolated nor ‘local’ to the Tarim. Instead, they probably arrived from regions to the north/ northwest (? central/west Siberia, the Mountain corridor, Kazakh steppe). Of course, this is consistent with archaeological observations of early forms of pastoralism developing in Central Eurasia (e.g Frachetti), and we are beginning to understand that they engaged in complex forms of interaction across the steppe from ca 3000 BC, if not earlier.

    Since then, a new study (care of Prof. Fu’s team) has come out covering the Iron Age. During this period, the basin becomes a lot more heterogeneous, with groups bearing Northeast Asian and Bactrian-related ancestry also appearing. What is also intriguing is the prevalence of Andronovo-related R1a-Z93 in the the Dzhungar basin but also a sample from the (southern) Tarim; not suprising given the expansion of Andronovo communities into the Dhzungar region (e.g. Jie et al )

    Whilst I’m not going to get into historical linguistic details for now, these data provide conclusive evidence of western steppe herder presence in the vicinity of attested Tocharian speakers. Exactly with which group ‘pre-proto-Tocharian’ arrived is more difficult to answer. However, it might not be a simplistic case of Afansievo=Tocharian, Sintashta/Andronovo= proto-Indo-Iranian (requiring the introduction of concepts from the fields of contact & socio-linguistics). More data from the Tarim basin is required to synthesise a holistic framework.

  • On the eastern affinities of Bacho Kiro IUP.

    The recent re-excavations at Bacho Kiro cave (Bulgaria) by archaeologists from Bulgaria and Germany discovered remains of Homo sapiens dated to ~ 45/ 43,000 calBP (Hublin 2020). Three individuals from the Initial Upper Paleolithic layer and another one (a lovely lady) dating to ~ 37,000 calBP (~ Aurignacian era in Europe) were sequenced (Hajdinjak 2021).

    Analysis showed affinity between the IUP horizon Bacho-Kirians (BK-IUP) and quasi-contemporaneous East Asian groups, e.g. the man from Tianyuan cave, China. And this was not the first time ‘eastern affinities’ were noted in Upper Paleolithic Europeans – such a signal had been previously noted in a ~ 35,000 year old sample from Goyet, Belgium (‘Goyet -Q116’) (Yang 2017). The shared affinities between Goyet and Tianyuan did not extend to later (partial) descendants of Goyet (such as El Miron) nor did the affinities involve more recent ancient or modern East Asians.

    Were there populations movements from Eastern Asia into Europe, as some in the webosphere have suggested ? To be sure, a model of early (even pre-Toba) ‘southern coastal dispersals’ to the East have figured prominently in anthropological literature, and patterns inferred from modern DNA were suggested to support such a scenario.

    However, with direct evidence from ancient DNA, the picture evolved. The paper by Hajdinjak et al found that IUP Bacho Kiro Cave individuals were related to populations that contributed ancestry to the Tianyuan individual in China as well as, to a lesser extent, to the GoyetQ116-1 and Ust’Ishim individuals (all |Z| < 3; Fig. 2d, Supplementary Information 6). This resolves the previously unclear relationship between the GoyetQ116-1 and Tianyuan individuals without the need for gene flow between these two geographically distant individuals. The cumulative evidence has also established that Upper Paleloithic populations in Europe and Siberia carried ‘East Asian’ lineages like Y-hg NO, C, F and mtDNA M, but these became increasingly attenuated by the Holocene.

    From Hajdinjak – populations related to the IUP Bacho Kiro Cave individuals disappeared in western Eurasia without leaving a detectable genetic contribution to later populations, as indicated by the fact that later individuals, including BK1653 at Bacho Kiro Cave, were closer to present-day European populations than to present-day Asian populations.

    Evidently, IUP diversity in Europe and western Siberia diminished and was supplanted by so-called West Eurasians (with some IUP-related ancestry preserved in the western Europe and Siberia in the East). Campanian ignimbrite ?

    Marti 2016.

    The below qpGraph provisionally explores affinities of early ancient Eurasian populations. Our understanding will continue to evolve with more data, however the basic structure of Out-of-African populations is becoming understood.

    1. Zlaty Kun +/- related groups
    2. A ‘West Eurasian’ cluster consisting of post-42 kyBP individuals from Europe and likely Western Asia, linked at least in part to the dispersal of Aurignacian, Ahmarian & related industries.
    3. The ‘IUP’ dispersal, which includes Ust-Ishim, BK-IUP, proto-ENA and a ”pre-Papuan” branch. To speculate, given the distribution of these populations, one wonders if it indeed is a relatively more eastern branch dispersing from ~ Central Asia.
    Zwyns 2021

    ADD: Brief sketch of putative dispersal paths ~ 45-40,000 bp, plus ANE 30-20,000 BP

    References

    Initial Upper Palaeolithic Homo sapiens from Bacho Kiro Cave, Bulgaria. Hublin et al 2020.

    Initial Upper Palaeolithic humans in Europe had recent Neanderthal ancestry. Hajdinjak et al 2021.

    40,000-Year-Old Individual from Asia Provides Insight into Early Population Structure in Eurasia; Yang et al 2017

    Genetics and material culture support repeated expansions into
    Paleolithic Eurasia from a population hub out of Africa. Vallini et al; 2021

    The Initial Upper Paleolithic in Central and East Asia: Blade Technology, Cultural Transmission, and Implications for Human Dispersals. N Zwyns 2021

    Microliths in the South Asian rainforest ~45-40 ka: New insights from Fa-Hien Lena Cave, Sri Lanka. O Wedage et al 2021

    Population increase and environmental deterioration correspond with microlithic innovations in South Asia ca. 35,000 years ago. Petraglia et al 2009.

    Reconstructing the plinian and co-ignimbrite sources of large volcanic eruptions: A novel approach for the Campanian Ignimbrite. Marti et al 2016

  • Cultural & Demographic Flux in Southeast Iberia – the Case of El Argar

    The emerging Bronze Age (BA) of southeastern Iberia saw marked social changes. Late Copper Age (CA) settlements were abandoned in favor of hilltop sites, and collective graves were largely replaced by single or double burials with often distinctive grave goods indirectly reflecting a hierarchical social organization, as exemplified by the BA El Argar group. We explored this transition from a genomic viewpoint by tripling the amount of data available for this period. Concomitant with the rise of El Argar starting ~2200 cal BCE, we observe a complete turnover of Y-chromosome lineages along with the arrival of steppe-related ancestry. This pattern is consistent with a founder effect in male lineages, supported by our finding that males shared more relatives at sites than females. However, simple two-source models do not find support in some El Argar groups, suggesting additional genetic contributions from the Mediterranean that could predate the BA.

    https://www.science.org/doi/10.1126/sciadv.abi7038

    VANESSA VILLALBA-MOUCO et al

    Genomic transformation and social organization during the Copper Age–Bronze Age transition in southern Iberia

    As the introductory post to this new blog, I thought we might cover the fascinating & complex transitions evident in Iberia. One of the topics covered by the paper (excellently executed by the multi-team authorship – holistically incorporating ancient DNA data with archaeology, paleoclimatology, sociology, so forth) is the transitions evident in southern Iberia ~ 2200 BC.

    Students of paleogenomics and European history alike are by now aware of widespread changes taking place in Europe during the third millennium BC. This was already evident before the advent of ancient DNA – a shift from Neolithic to Bronze Age world systems. Since 2015, paleogenomic studies demonstrated large scale impacts by colonists from the Ponto-Caspian steppe and adjacent parts of forest-steppe and southeastern Europe. This generated much discussion and even controversy in the academic world for several reasons. On the one hand, to be frank, this came as a shock to the prevailing zeitgeist in Anglophone archaeological and anthropological literature, where the ideas of migration, ethnic groups and their material culture correlates had come to be seen as skeletons of fallible past generations of scholars. On the other hand, some of the criticisms were justified – early papers could have done more to control sampling and observer error and offer more nuanced contextual understanding of the presented data. A lot of readers – from interested archaeologists, to linguists and community enthusiasts were left with a simplified picture of what was undoubtedly a complex and multifarous process which can only be understood via contextual and regionally-specific analysis. If I manage to persevere with this Blog amidst a highly busy lifestyle (don’t we all), and with future published contributions, we hope to begin to understand how genes, material culture, identity and language can intersect and how they can be combined to understand how past groups, populations, “tribes’ formed and interacted across social boundaries.

    Southern Iberia during the pre-Beaker Copper Age

    The ‘Late Neolithic – Copper Age’ in Iberia begins ~ 3300 BC, as is often seen as a culmination of the preceding Neolithic period. Whilst broadly correct, this gives the image of a gradualist, almost monolithic Neolithic. Indeed, the genesis of Neolithic Cardial groups in western Europe deserves further attention, as genetics papers have so far focussed on emphasizing the ‘Aegean-Anatolian’ origins of these groups. Whilst such a conclusion is true for their Impressa predecessors, it is wrong to extend the same conclusion to Cardial groups. I will address this issue in the future, however, for now I will simply state that the genesis (admixture processes, identity formation, etc) of Cardial Neolithic groups occurred locally in southwestern Europe. The Middle Neolithic period in turn seems somewhat murky. Something changed in society, as the anthropological record in much of Iberia is meagre. Nevertheless, broadly during the MN & Late Neolithic – Copper Age, there is a rise in the levels of hunter-gatherer admixture.

    Specifically for southeast Iberia, The new CA individuals from southern Iberia fall onto a position that partially overlaps with previous Middle Neolithic (MN), Middle/Late Neolithic (MLN), and CA (non-steppe) groups from Iberia but are slightly positively shifted in their coordinates for PC1 toward previously published Early Neolithic (EN) groups from Iberia and later groups such as Sardinia Chalcolithic, suggesting an equally small hunter-gatherer (HG) ancestry contribution in the CA individuals of southern Iberia [V-M et al].

    Already present in the early Neolithic, Hunter-Gatherer [HG] ancestry rises to ~ 30% in some regions of Iberia. Several papers (Valdiosera 2018, Rivollat 2020, Villalba-Muoco 2020/21) have looked for source populations (‘local’ vs allogenic HGs) based on differential Villabruna and Goyet-Q2 -related affinities, however the presence of both components in, both, French & Iberian HGs complicates the analysis. In my opinion, the most straightforward way to look at sources for hunter-gatherer rise in Iberia is (a) to understand the demographic background of hunter-gatherers in the late Mesolithic (who lived where & when) and (b) tracking Y-haplogroup uniparental markers. These point to France as the major – but not exclusive- source of HG introgression, moving into Iberia during the late/ post-Cardial but especially after ~ 4500 BC with the introduction of Megalithic burial ideas.

    Southern Iberia reached an apogee during the pre-BB Copper Age. Demographic growth and the utilization of elements of Secondary Products allowed the formation of more complex societies with wide-ranging but episodic & idiosyncratic trans-Mediterranean contacts.

    A Crisis ~ 24/2200 BC ?

    Both north- and south-western Europe experienced major cultural and demographic shifts during this period. Several explanations, including plague and climactic events, have been invoked to explain. Naturally, from Ireland to southern Iberia we encounter vastly different landscapes, ecotones and pre-Beaker societies. Therefore, the elephant in the room, so to speak, is the emergence of the Bell Beaker phenomenon itself. The emerging archeogenetic paradigms constructed by geneticists or genetically-inclined archaeologists to date leave some perplexing contradictions around the bell Beaker Phenomenon. Whilst I will not delve into this question at present, the progression in Iberia can be summarised :

    1. Abandonement of characteristic Copper Age ‘ditched & enclosed settlements’ ~ 2600-2500 BCE in the middle basins of the Douro and Tagus which had emerged in late fourth millennium BCE.
      They are considered emblematic of the solid communal ties of Chalcolithic societies, expressed also by the collective
      burial rite in a variety of funerary structures.
    2. In those same areas of central-northern Iberia the end of this type of settlement is roughly contemporary with the
      introduction of the funeral ritual in individual tombs. I will add that these burials mirror those in beaker communities north of the Pyrenees (the same set of assemblages, same body positioning evident, when remains analysed adequately) .
    3. A ‘resistence’ in southeastern Iberia; however, societies in the Southeast also experienced significant changes from approximately 2500 BCE onwards, which were perhaps not unrelated to the dynamics in the northern neighbouring regions and possibly to pressure exercised
      from there. The proliferation of small scale hill-top settlements with good defensive conditions, probably
      indicating an increase in violent conflicts and social fragmentation. At this time, some of the tholoi tombs from Valencina Concepcion were erected (Matarrubilla and La Pastora), some with evidence of scalping and Beaker ceramics; whilst earlier ones clearly represented local chiefs who based their power on redistribution of exotic and finely produced goods (e.g. Matarrubilla 27/26th century BC).
    4. Southern Chalcolithic communities disappeared completely by 2200 BCE. In the southwest, sporadic Beaker-using individuals appear, whilst remaining populations concentrated in the El Argar region (between c. 2200 and 2000 BCE in the coastal and pre-littoral areas of Almería and Murcia). The first individual and double burials in the vicinity of inhabited areas can be dated shortly before 2200, setting the regional precedent of the characteristic Argaric ritual.

    Hybridization and Transformation:

    When compared to the preceding CA groups, individuals associated with El Argar BA and SE_Iberia_BA form a dense cloud in PC space that is shifted toward populations with steppe-related ancestry from central Europe and positioned between individuals from the Iberian CA and those of the north Iberian BA..

    The genetic contribution of steppe-related ancestry to Iberia was a long-term process starting around 2400 cal BCE in the northern and central regions (7), from where it spread southward over ~300 years. At a local scale, this change might have occurred faster. A similar situation might have existed in central Portugal, where we still find individuals with no steppe-related ancestry in collective CA burials (Galería da Cisterna and Cova da Moura) around 2300 to 2200 cal BCE. However, after 2100 cal BCE, all individuals from all sites carry steppe-related ancestry, in line with R1b-P312 becoming the predominant Y-chromosomal lineage present not only in El Argar but also in the rest of BA Iberia.

    In sum, throughout all of western Europe, the heterogeneous medley of pre-Beaker societies were supplanted by a new social order by 2200 BC. The ‘descendants of Bell Beaker folk’ (I use this term intentionally but cautiously) would subsequently diverge toward their own trajectories (Food vessel horizon in Britain/Ireland, Rhenish Reisen-Beaker groups, Straubing and other Danubian groups in Bavaria).

    We are now in a position to understand how identity and biology may interact and transform. Beaker-using elites ? forced themselves to into a position of social and reproductive power, or were they simply better equipped to deal with the climatic challenges imposed by the 4.2 kiloyear event ? In any case, the fortifications at La Bastida and use of halberds makes a peaceful transition unlikely, despite the lack of widespread anthropological evidence of violence.

    Although the early El Argar material record shares some traits with the Bell Beaker complex (30), such as V-perforated buttons, Palmela-type points, or perforated stone plaques so-called “archers’ wristguards,” the characteristic Bell Beaker pottery is absent. Upon the discovery of the monumental fortification in the 5-ha hilltop settlement of La Bastida, dated to around 2200 BCE, a possible eastern Mediterranean contribution was reconsidered (32). The intramural burials in large storage vessels (pithoi), the circulation of silver rings and bracelets, and the characteristic footed Argar cup have also been interpreted as signs of Aegean or Near Eastern contacts (33), although all these features emerged during later phases of El Argar.

    Whatever symbolism Beaker vessels invoked, they were no longer required for the new social and ritual realities in the El Argar world. Instead, the new Beaker-derived elites found it expedient to construct a new symbolic set. Although clearly continuing from their own past traditions, they also referenced other societies, from the Aegean to Central Europe (Unetice). Although the study suggests a minor possible admixture from a yet to be resolved Mediterranean source and one African admixed (Y-hg E) outlier during late phases, these ‘exotic’ links must have been fostered by the Argarians themselves by way of sporadic but perhaps ritualised contacts.

    Ultimately, the El Argar society would itself collapse after 1600 BC. Perhaps the exploitative and extremely heirarchical society which had developed could no longer be sustained. However, its broad synchronization with the collapse of Unetice and ‘tell-socieites’ in the Carpathian basin, the Thera eruption, and rise of Mycenea hint at broader processes. A new chapter subsequently emerged in Iberia- with dominance shifting to the Cogotas complex.

    Sociolinguistic Implications

    At least at face value, the territorial distribution of El Argar might tentatively match the distribution of later Iberian languages. However, an emerging perspective views the BB phenomenon as the vector for western Indo-European languages.

    These observations can be reconciled in several possible ways which are not mutually exclusive:

    • incoming BB elites adopted the languages of the scattered post-Millaran populace, and a diglossic society emerged
    • language shift brought in via Mediterranean contacts: although the rather sporadic nature of contact isn’t substantive enough to account for a language shift
    • more relevant, however, is the post-El Argar period and when we enter the Iron Age
    • perhaps in the wake of the El Argar collapse, Iberian languages came to the fore during a period of social crisis.
    • or perhaps, BB groups – despite their common genetic origins, were from the outset linguistically heterogenous, with more westerly situated groups non-IE-speaking and eastern groups which became intertwined in the Unetice cultural zone spoke an ancestral language which would eventually lead to Italic, Celtic, Lusitanian…

    References:

    Genomic transformation and social organization during the Copper Age–Bronze Age transition in southern Iberia. Villalba-Muoco et al.

    Assembling the Dead, Gathering the Living:Radiocarbon Dating and Bayesian Modellingfor Copper Age Valencina de la Concepción (Seville, Spain). Leonardo Garcı́a Sanjuán et al

    The absolute chronology of Argaric halberds Vicente Lull et al

    Four millennia of Iberian biomolecular prehistory illustrate the impact of prehistoric migrations at the far end of Eurasia. C Valdiosera, et al

    Ancient genome-wide DNA from France highlights the complexity of interactions between Mesolithic hunter-gatherers and Neolithic farmers. M Rivollat, et al.