A new approach to measure reduction intensity on cores and tools on cobbles: the Volumetric Reconstruction Method

Knowing to what extent lithic cores have been reduced through knapping is an important step toward understanding the technological variability of lithic assemblages and disentangling the formation processes of archaeological assemblages. In addition, it is a good complement to more developed studies of reduction intensity in retouched tools, and can provide information on raw material management or site occupation dynamics. This paper presents a new methodology for estimating the intensity of reduction in cores and tools on cobbles, the Volumetric Reconstruction Method (VRM). This method is based on a correction of the dimensions (length, width, and thickness) of each core from an assemblage. The mean values of thickness and platform thickness of the assemblage’s flakes are used as corrections for the cores’ original dimensions, after its diacritic analysis. Then, based on these new dimensions, the volume or mass of the original blank are reconstructed using the ellipsoid volume formula. The accuracy of this method was experimentally tested, reproducing a variety of possible archaeological scenarios. The experimental results demonstrate a high inferential potential of the VRM, both in estimating the original volume or mass of the original blanks, and in inferring the individual percentage of reduction for each core. The results of random resampling demonstrate the applicability of VRM to non size-biased archaeological contexts.Introduction Methods - The Volumetric Reconstruction Method - Experimental design - Statistical procedures - Resamples Results - Geometric formulas - Reduction strategy and size - Resampling (randomly biased record) - Resampling (size bias) - Measuring the effect of number of generations Discussion and conclusion

Oldowan Technology Amid Shifting Environments ∼2.03–1.83 Million Years Ago

The Oldowan represents the earliest recurrent evidence of human material culture and one of the longest-lasting forms of technology. Its appearance across the African continent amid the Plio-Pleistocene profound ecological transformations, and posterior dispersal throughout the Old World is at the foundation of hominin technological dependence. However, uncertainties exist concerning the degree to which the Oldowan constitutes an environment-driven behavioral adaptation. Moreover, it is necessary to understand how Oldowan technology varied through time in response to hominin ecological demands. In this study, we present the stone tool assemblage from Ewass Oldupa, a recently discovered archeological site that signals the earliest hominin occupation of Oldupai Gorge (formerly Olduvai) ∼2.03 Ma. At Ewass Oldupa, hominins underwent marked environmental shifts over the course of a ∼200 kyr period. In this article, we deployed an analysis that combines technological and typological descriptions with an innovative quantitative approach, the Volumetric Reconstruction Method. Our results indicate that hominins overcame major ecological challenges while relying on technological strategies that remained essentially unchanged. This highlights the Oldowan efficiency, as its basic set of technological traits was able to sustain hominins throughout multiple environments.Introduction Ewass Oldupa Materials and methods - Stone Tool Techno-Typological Analysis - The Volumetric Reconstruction Method Results - Assemblage Overview - Techno-Typological Variation Over Time and Across Environments - The Volumetric Reconstruction Method Discussio

Unravelling technological behaviours through core reduction intensity. The case of the early Protoaurignacian assemblage from Fumane Cave.

This paper investigates core reduction intensity in the early Protoaurignacian lithic assemblage from Fumane Cave in northeastern Italy. Reduction intensity serves as a key tool to characterize blank selection strategies, raw material management, and the variability of knapping strategies throughout the reduction sequence by reconstructing the operatory field of core assemblages. Finally, it also aids in addressing the relationship between blades and bladelets, providing valuable insights into the behavioral and chrono-cultural significance of laminar productions within the Aurignacian technocomplex. To achieve these research goals, experimental work employing 3D scanning technology was conducted. This facilitated the comparison of different methods and variables for measuring reduction intensity, including the percentage of non-cortical surface, the Scar Density Index (SDI), and a novel adaptation of the Volumetric Reconstruction Method (VRM). Results demonstrate the effectiveness and potential of adapting the VRM for the study of reduction intensity in Upper Paleolithic laminar cores, and the provided R scripts and datasets will enable this method to be applied to other contexts with minimal need for modification to the workflow. Analysis of reduction intensity measures applied to the Protoaurignacian assemblage from Fumane Cave reveals slight variations based on factors such as the abundance and proximity of selected raw materials for blank production. Notably, the most prevalent raw material variety, the Maiolica, yields a higher number of less reduced cores, while reduction levels across all cores discarded at the site remain relatively high. The observed variability in the operatory field and the interrelation between blade and bladelet productions underscore the complexity and flexibility of Protoaurignacian behavior. This inherent complexity challenges any definitive separation between the operatory fields of blade and bladelet productions. These findings are particularly important to emphasize the importance of considering reduction intensity when examining technological variability and human behavior in Aurignacian studies. The proposed adaptation of the VRM and the effective combination with other measures of reduction, promises to allow future research to incorporate reduction intensity as a vital temporal component within studies on stone tool production. This integration offers a pathway to enhancing our understanding of the adaptive behaviors exhibited by Homo sapiens across diverse ecological settings and provides a clearer framework for better framing the development of the Upper Paleolithic

History, development and current advances concerning the evolutionary roots of human right‐handedness and language: Brain lateralisation and manual laterality in non‐human primates

International audienceThis review highlights the scientific advances concerning the origins of human right‐handedness and language (speech and gestures). The comparative approach we adopted provides evidence that research on human and non‐human animals’ behavioural asymmetries helps understand the processes that lead to the strong human left‐hemisphere specialisation. We review four major non‐mutually exclusive environmental factors that are likely to have shaped the evolution of human and non‐human primates’ manual asymmetry: socioecological lifestyle, postural characteristics, task‐level complexity and tool use. We hypothesise the following scenario for the evolutionary origins of human right‐handedness: the right‐direction of modern humans’ manual laterality would have emerged from our ecological (terrestrial) and social (multilevel system) lifestyle; then, it would have been strengthened by the gradual adoption of the bipedal stance associated with bipedal locomotion, and the increasing level of complexity of our daily tasks including bimanual coordinated actions and tool use. Although hemispheric functional lateralisation has been shaped through evolution, reports indicate that many factors and their mutual intertwinement can modulate human and non‐human primates’ manual laterality throughout their life cycle: genetic and environmental factors, mainly individual sociodemographic characteristics (e.g., age, sex and rank), behavioural characteristics (e.g., gesture per se and gestural sensory modality) and context‐related characteristics (e.g., emotional context and position of target). These environmental (evolutionary and life cycle) factors could also have influenced primates’ manual asymmetry indirectly through epigenetic modifications. All these findings led us to propose the hypothesis of a multicausal origin of human right‐handedness