Conflict, violence, and warfare amongst early farmers in north western Europe

Bioarchaeological evidence of interpersonal violence and early warfare presents important insights into conflict in past societies. This evidence is critical for understanding the motivations for violence and its effects on opposing and competing individuals and groups across time and space. Selecting the Neolithic of northwestern Europe as an area for study, the present paper examines the variation and societal context for the violence recorded in the human skeletal remains from this region as one of the most important elements of human welfare. Compiling data from various sources, it becomes apparent that violence was endemic in Neolithic Europe, sometimes reaching levels of intergroup hostilities that ended in the utter destruction of entire communities. While the precise comparative quantification of healed and unhealed trauma remains a fundamental problem, patterns emerge that see conflict likely fostered by increasing competition between settled and growing communities, e.g., for access to arable land for food production. The further development of contextual information is paramount in order to address hypotheses on the motivations, origins, and evolution of violence as based on the study of human remains, the most direct indicator for actual small- and large-scale violence

Unraveling Neolithic sharp-blunt cranial trauma:Experimental approach through synthetic analogues

Interpersonal violence in the past is studied from different perspectives, one of which is experimentation. Using analogues to the human skeleton it is possible to replicate fractures found in the archaeological record and understand how they were produced. The main objective of this paper is to describe and differentiate sharp-blunt force cranial trauma caused by stone axes and adzes, to test previous interpretations of an archaeological case. This will create a comparative frame of reference for future studies. In the present experiment, seven Synbone polyurethane spheres were used as analogues to the human skull. These were covered with rubber skin, filled with ballistic gelatin, and fixed in a way that allowed some mobility when struck. This system creates a skinskull-brain-neck model. A replica of a stone axe and adze were used as weapon-tools, simulating a face-toface attack. The results of the experiment showed that there are a series of characteristics that differentiate the fracture pattern associated with each one, confirming previous bioarchaeological interpretations. The differentiation between both weapon-tools through the resulting cranial trauma allows conclusions about the direction of the blow and the position of the attacker with respect to the victim. This provides a better reconstruction of the most likely scenario surrounding the confrontation and the possible cause of death of the individuals, which is especially important during the Neolithic period, when this type of cranial trauma is very common.This work has been supported by the Spanish Ministry of Universities of Spain (FPU18-02291 grant, and EST22/00015 international short stay grant); Spanish Ministry of Science and Innovation through the “María de Maeztu” program for Units of Excellence (CEX2019-000945-M); Spanish Ministry of Economy and Competitiveness (MINECO) through Sierra de Atapuerca project (PID2021-122355NB-C32); Agencia de Gestio d’Ajuts Universitaris i de Recerca (SGR 2017–1040); and Universitat Rovira i Virgili (2022PFRURV- 64).With funding from the Spanish government through the "Severo Ochoa Center of Excellence" accreditation CEX2019-000945-M.Peer reviewe

Ancient genomes from Bronze Age remains reveal deep diversity and recent adaptive episodes for human oral pathobionts

Ancient microbial genomes can illuminate pathobiont evolution across millenia, with teeth providing a rich substrate. However, the characterization of prehistoric oral pathobiont diversity is limited. In Europe, only preagricultural genomes have been subject to phylogenetic analysis, with none compared to more recent archaeological periods. Here, we report well-preserved microbiomes from two 4,000-year-old teeth from an Irish limestone cave. These contained bacteria implicated in periodontitis, as well as Streptococcus mutans, the major cause of caries and rare in the ancient genomic record. Despite deriving from the same individual, these teeth produced divergent Tannerella forsythia genomes, indicating higher levels of strain diversity in prehistoric populations. We find evidence of microbiome dysbiosis, with a disproportionate quantity of S. mutans sequences relative to other oral streptococci. This high abundance allowed for metagenomic assembly, resulting in its first reported ancient genome. Phylogenetic analysis indicates major postmedieval population expansions for both species, highlighting the inordinate impact of recent dietary changes. In T. forsythia, this expansion is associated with the replacement of older lineages, possibly reflecting a genome-wide selective sweep. Accordingly, we see dramatic changes in T. forsythia's virulence repertoire across this period. S. mutans shows a contrasting pattern, with deeply divergent lineages persisting in modern populations. This may be due to its highly recombining nature, allowing for maintenance of diversity through selective episodes. Nonetheless, an explosion in recent coalescences and significantly shorter branch lengths separating bacteriocin-carrying strains indicate major changes in S. mutans demography and function coinciding with sugar popularization during the industrial period