Palaeodemographic modelling supports a population bottleneck during the Pleistocene-Holocene transition in Iberia

Demographic change lies at the core of debates on genetic inheritance and resilience to climate change of prehistoric hunter-gatherers. Here we analyze the radiocarbon record of Iberia to reconstruct long-term changes in population levels and test different models of demographic growth during the Last Glacial-Interglacial transition. Our best fitting demographic model is composed of three phases. First, we document a regime of exponential population increase during the Late Glacial warming period (c.16.6-12.9 kya). Second, we identify a phase of sustained population contraction and stagnation, beginning with the cold episode of the Younger Dryas and continuing through the first half of the Early Holocene (12.9-10.2 kya). Finally, we report a third phase of density-dependent logistic growth (10.2-8 kya), with rapid population increase followed by stabilization. Our results support a population bottleneck hypothesis during the Last Glacial-Interglacial transition, providing a demographic context to interpret major shifts of prehistoric genetic groups in south-west Europe

Take Shelter! Short-Term Occupations of the Late Paleolithic and the Mesolithic in the French Far West

International audienceDespite the important development of radiocarbon dating and Bayesian analysis these past years or our ability to interpret the archaeological materials and their spatial organization, the definition of occupation span is still very uncertain in prehistory. The techno-economic approach of lithic materials, using the concept of chaine opératoire segmentation, allows, however, to broach this complex topic. Research on Northwestern Lateglacial and Mesolithic sites essentially invested large open-air sites these past years. If these results brought important data, it remains reductive in the perspective of a diachronic study of paleo-economic systems since small sites, complementary to these large occupations, are not included in the models. These small sites have a low archaeological visibility and are particularly difficult to identify in survey or during rescue archaeology. A new research program entitled “Take shelter!” aims to search for these sites focusing on small Armorican rock shelters. Because of particular geological contexts, these cavities are particularly small and atypical. For these reasons, archaeologists neglected them. The survey, testing, and excavation of some of these rock shelters allow illustrating occupations with very specific techno-economic signals that are interpreted to be good evidence for short-term occupations. From these results, we discuss various archaeological evidences we consider diagnostic of short-term occupation and propose a first diachronic model for the evolution of paleo-economic systems in Northwestern France between the Lateglacial and the end of the Mesolithic

Auf dem Weg zu einer gemeinschaftlichen Meta-Analyse des Endpaläolithikums/frühesten Mesolithikums in Europa. Bericht über den 2. CLIOARCH-Workshop, 26.-27. November 2020

We report on a virtual workshop aimed at advancing a new synthesis of techno-cultural patterns at the Pleistocene-Holocene boundary in Europe. We respond to the growing need of developing meta-analytical frameworks for comparing and eventually integrating disparate regional datasets and stress the opportunities of collaborative approaches. We propose that expert-sourced lithic data is a promising means of conducting systematic archaeological meta-analyses, and that the compilation and examination of similar continental-scale datasets may be an important research goal in the future.Wir berichten über den 2. Workshop im Rahmen des CLIOARCH-Projekts, der darauf abzielte, auf eine neue Synthese technokultureller Langzeitentwicklungen an der Pleistozän/Holozän-Grenze in Europa hinzuarbeiten. Wir reagieren damit auf den wachsenden Bedarf nach einem metaanalytischen Fundament für den Vergleich und die eventuelle Integration von heterogenen regionalen Datensätzen in der Archäologie des Spätpaläolithikums und frühesten Mesolithikums und betonen insbesondere die reichhaltigen Möglichkeiten, die kooperative Ansätze hierbei bieten. Wir schlagen vor, dass das Expert-Sourcing von vorgefilterten lithischen Informationen eine vielversprechende Grundlage zur Durchführung systematischer archäologischer MetaAnalysen ist und dass die Zusammenstellung, Untersuchung und Konservierung ähnlicher großräumiger Datensammlungen ein wichtiges Forschungsziel für die Zukunft sein könnte.CLIOARCH is an ERC Consolidator Grant project and has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 817564)

A quantitative analysis of Final Palaeolithic/earliest Mesolithic cultural taxonomy and evolution in Europe.

Archaeological systematics, together with spatial and chronological information, are commonly used to infer cultural evolutionary dynamics in the past. For the study of the Palaeolithic, and particularly the European Final Palaeolithic and earliest Mesolithic, proposed changes in material culture are often interpreted as reflecting historical processes, migration, or cultural adaptation to climate change and resource availability. Yet, cultural taxonomic practice is known to be variable across research history and academic traditions, and few large-scale replicable analyses across such traditions have been undertaken. Drawing on recent developments in computational archaeology, we here present a data-driven assessment of the existing Final Palaeolithic/earliest Mesolithic cultural taxonomy in Europe. Our dataset consists of a large expert-sourced compendium of key sites, lithic toolkit composition, blade and bladelet production technology, as well as lithic armatures. The dataset comprises 16 regions and 86 individually named archaeological taxa ('cultures'), covering the period between ca. 15,000 and 11,000 years ago (cal BP). Using these data, we use geometric morphometric and multivariate statistical techniques to explore to what extent the dynamics observed in different lithic data domains (toolkits, technologies, armature shapes) correspond to each other and to the culture-historical relations of taxonomic units implied by traditional naming practice. Our analyses support the widespread conception that some dimensions of material culture became more diverse towards the end of the Pleistocene and the very beginning of the Holocene. At the same time, cultural taxonomic unit coherence and efficacy appear variable, leading us to explore potential biases introduced by regional research traditions, inter-analyst variation, and the role of disjunct macroevolutionary processes. In discussing the implications of these findings for narratives of cultural change and diversification across the Pleistocene-Holocene transition, we emphasize the increasing need for cooperative research and systematic archaeological analyses that reach across research traditions

A pan-European dataset revealing variability in lithic technology, toolkits, and artefact shapes ~15-11 kya

Abstract Comparative macro-archaeological investigations of the human deep past rely on the availability of unified, quality-checked datasets integrating different layers of observation. Information on the durable and ubiquitous record of Paleolithic stone artefacts and technological choices are especially pertinent to this endeavour. We here present a large expert-sourced collaborative dataset for the study of stone tool technology and artefact shape evolution across Europe between ~15.000 and 11.000 years before present. The dataset contains a compendium of key sites from the study period, and data on lithic technology and toolkit composition at the level of the cultural taxa represented by those sites. The dataset further encompasses 2D shapes of selected lithic artefact groups (armatures, endscrapers, and borers/perforators) shared between cultural taxa. These data offer novel possibilities to explore between-regional patterns of material culture change to reveal scale-dependent processes of long-term technological evolution in mobile hunter-gatherer societies at the end of the Pleistocene. Our dataset facilitates state-of-the-art quantitative analyses and showcases the benefits of collaborative data collation and synthesis