New insight into prehistoric craft specialisation. Tooth-tool use in the Chalcolithic burial site of Camino del Molino, Murcia, SE Spain

Producción CientíficaThe study of non-alimentary tooth wear is an excellent tool to identify the development of specific activities and thus, to delve deeper into the social organisation and complexity of past populations. This paper analyses extra-masticatory wear in the dentition of a sample of 102 articulated skeletons from Camino del Molino, a unique collective tomb that housed 1,348 individuals throughout two contiguous phases spanning much of the 3rd millennium BC. After preliminary macroscopic observation of the dental sample, 8 individuals with cultural dental wear were identified and 5 of them were analysed with SEM. In all cases, the maxillary anterior dentition displays evidence that can be defined as occlusal and interproximal grooves consisting of fine, parallel striations, as well as labial notches and chipping of the enamel. The results suggest that 8 individuals, mostly women, used their dentition in craft tasks, such as in the processing of fibres for textile production, hence representing the earliest evidence of craft specialisation in the Iberian Peninsula and potential proof of a possible sex-based division of labour in a Chalcolithic community

Emphasising the community: demographic composition of an exceptional tomb—the Chalcolithic burial site of Camino del Molino, Caravaca de la Cruz, Murcia

Producción CientíficaReconstructing the biological profile of a skeletal sample is essential for defining a particular demographic group or classifying isolated remains. These results allow us to complete the population pyramid of a settlement, analyse mortality trends and relate individuals of a particular sex or age-at-death category to possible funerary rituals, lifestyles and/or states of health and disease. In this work, we carry out a paleodemographic analysis of a singular tomb: the chalcolithic burial site of Camino del Molino, Murcia, SE Spain. The tomb hosted 1348 individuals (30.7% non-adults and 69.3% adults) over two contiguous funerary phases, spanning a large part of the third millennium BC, which makes it a reference site for knowledge of the Recent Prehistoric populations. For this purpose, we estimated different paleodemographic parameters (life tables, mortality rates and sex ratios) and compared them to model life tables of preindustrial populations and data from other contemporary peninsular series to evaluate possible demographic anomalies. The results suggest that Camino del Molino was home to individuals of all ages and sex. However, there is a clear under-representation of newborns and nursing/breastfeeding infants and an over-representation of 5–15-year-old individuals. These findings could indicate potential issues related to diet/weaning, disease and early inclusion in the economic activities of the group.Junta de Castilla y León y el Fondo Social Europeo (ORDEN EDU/574/2018)Universidad de Valladolid - Proyecto de Investigación “METOO” (PROYEMER-2021-45)Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Understanding the microbial biogeography of ancient human dentitions to guide study design and interpretation

The oral cavity is a heterogeneous environment, varying in factors such as pH, oxygen levels, and salivary flow. These factors affect the microbial community composition and distribution of species in dental plaque, but it is not known how well these patterns are reflected in archaeological dental calculus. Inmost archaeological studies, a single sample of dental calculus is studied per individual and is assumed to represent the entire oral cavity. However, it is not known if this sampling strategy introduces biases into studies of the ancient oral microbiome. Here, we present the results of a shotgun metagenomic study of a dense sampling of dental calculus from four Chalcolithic individuals from the southeast Iberian peninsula (ca. 4500-5000 BP). Interindividual differences in microbial composition are found to be much larger than intraindividual differences, indicating that a single sample can indeed represent an individual in most cases. However, there are minor spatial patterns in species distribution within the oral cavity that should be taken into account when designing a study or interpreting results. Finally, we show that plant DNA identified in the samples is likely of postmortem origin, demonstrating the importance of including environmental controls or additional lines of biomolecular evidence in dietary interpretations

Assesing use and suitability of scanning electron microscopy in the analysis of micro remains in dental calculus

Dental calculus is increasingly recognized as a major reservoir of dietary information. Palaeodietary studies using plant and animal micro remains (e.g. phytoliths, pollen, sponge spicules, and starch grains) trapped in calculus have the potential to revise our knowledge of the dietary role of plants in past populations. The conventional methods used to isolate and identify these micro remains rely on removing them from their microenvironment in the calculus, thus the microenvironment that traps and preserves micro remains is not understood. By using scanning electron microscopy and energy dispersive X-ray spectroscopy (SEMeEDX) on modern chimpanzee calculus from the Taï Forest, Côte d¿Ivoire, and human calculus from the Chalcolithic site of Camino del Molino, Spain, we present the first reported observations on characteristics of the matrix setting that are conducive to the survival of starch in dental calculus. We also assess the potential for SEMeEDX to detect starch and differentiate it from structurally and molecularly similar substrates. We demonstrate that SEMeEDX may offer a nondestructive technique for studying micro remains in certain contexts. Finally, we compare traditional optical analytical techniques (OM) with less invasive electron microscopy. The results indicate that SEM-EDX and OM are both effective for observing micro remains in calculus, but differ in their analytical resolution to identify different micro remains, and we therefore recommend a sequential use of both techniques

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

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.Introduction Results - Genetic substructure in the Iberian CA - Genetic turnover in the southern Iberian BA and the rise of El Argar - Mediterranean and central European ancestries shaped the genetic profile of southeastern BA groups in Iberia - A late Argar genetic outlier makes links to North Africa and the central Mediterranean - Insights into phenotypic variation, demography, and social correlates of CA and EBA El Argar societies Discussion Material and method

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

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

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

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.This work was supported by the Max Planck Society (V.V.-M. and W.H.); European Research Council (ERC) grant 771234—PALEoRIDER (W.H.); Spanish Ministry of Economy, Industry and Competitiveness project HAR2017-85962-P (C.O., C.R.-H., M.I.F., E.C.B., C.V.-F., V.L., R.M., and R.R.); AGAUR 2017SGR1044 (C.O., C.R.-H., M.I.F., E.C.B., C.V.-F., V.L., R.M., and R.R.); ICREA Academia program (R.R.); John Templeton Foundation grant 61220 (D.R.); and Paul Allen Family Foundation (D.R.). D.R. is an Investigator of the Howard Hughes Medical Institute

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

[EN]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 similar to 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.This work was supported by the Max Planck Society (V.V.-M. and W.H.); European Research Council (ERC) grant 771234-PALEoRIDER (W. H.); Spanish Ministry of Economy, Industry and Competitiveness project HAR2017-85962-P (C.O., C.R.-H., M.I.F., E.C.B., C.V.-F., V.L., R.M., and R.R.); AGAUR 2017SGR1044 (C.O., C.R.-H., M.I.F., E. C.B., C.V.-F., V. L., R.M., and R.R.); ICREA Academia program (R.R.); John Templeton Foundation grant 61220 (D.R.); and Paul Allen Family Foundation (D.R.). D.R. is an Investigator of the Howard Hughes Medical Institute

The Beaker phenomenon and the genomic transformation of northwest Europe

From around 2750 to 2500 bc, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 bc. The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain’s gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries