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.