Three-dimensional surface morphometry differentiates behaviour on primate percussive stone tools

The Early Stone Age record preserves a rich behavioural signature of hominin stone tool making and use. The role of percussive technology in the daily subsistence strategies of our earliest ancestors has seen renewed focus recently. Studies of modern primate tool use highlight the diverse range of behaviours potentially associated with percussive technology. This has prompted significant methodological developments to characterize the associated damage marks (use-wear) on hammerstones and anvils. Little focus has, however, been paid to identifying whether these techniques can successfully differentiate between the damage patterns produced by specific and differing percussive behaviours. Here, we present a novel workflow drawing on the strengths of visual identification and three-dimensional (3D) surface quantification of use-wear. We apply this methodology firstly to characterize macaque percussive use-wear and test the efficacy of 3D surface quantification techniques in differentiating between percussive damage and natural surface topography. Secondly, we use this method to differentiate between use-wear associated with various wild macaque percussive behaviours. By combining analyst-directed, 3D surface analysis and use-wear dimensional analysis, we show that macaque percussive behaviours create specific diagnostic signatures and highlight a means of quantifiably recording such behavioural signatures in both primate and hominin contexts.

First high resolution chronostratigraphy for the early North African Acheulean at Casablanca (Morocco)

The onset of the Acheulean, marked by the emergence of large cutting tools (LCTs), is considered a major technological advance in the Early Stone Age and a key turning point in human evolution. The Acheulean originated in East Africa at ~ 1.8–1.6 Ma and is reported in South Africa between ~ 1.6 and > 1.0 Ma. The timing of its appearance and development in North Africa have been poorly known due to the near-absence of well-dated sites in reliable contexts. The ~ 1 Ma stone artefacts of Tighennif (Algeria) and Thomas Quarry I-Unit L (ThI-L) at Casablanca (Morocco) are thus far regarded as documenting the oldest Acheulean in North Africa but whatever the precision of their stratigraphical position, both deserve a better chronology. Here we provide a chronology for ThI-L, based on new magnetostratigraphic and geochemical data. Added to the existing lithostratigraphy of the Casablanca sequence, these results provide the first robust chronostratigraphic framework for the early North African Acheulean and firmly establish its emergence in this part of the continent back at least to ~ 1.3 Ma.

Genomic inference of a human super bottleneck in the Early Stone Age

The demographic history has been a foundation of human evolutionary studies for more than a century. In this study, we developed a novel method referred to as the fast infinitesimal time coalescent (FitCoal) process. This method allows the accurate calculation of the composite likelihood of a site frequency spectrum and provides the precise inference of recent and ancient demographic history. Genomic sequences of the 1000 Genomes Project and the Human Genome Diversity Project-Centre d'Etude du Polymorphisme Humain panel were analyzed. Results showed that all ten African populations had a population super bottleneck, a small effective size of approximately 1,280 breeding individuals between 813 and 930 thousand years ago, and a 20-fold rapid growth at the end of the bottleneck. The super bottleneck caused a loss of 65.85% in current human genetic diversity, but it may have separated our ancestors from other hominins. Further analysis confirmed the existence of the super bottleneck in all 40 non-African populations. Our results provide new insights into human evolution in the Early Stone Age.

Archaeology in the Public Space in Nigeria

Nigeria, with over 200 million people, covers an area of 923,768 km2 and it occupies the eastern section of the West African region (Figure 1). The regions of Nigeria have prehistoric sites spanning from the Early Stone Age through the Middle Stone Age, the Late Stone Age/Neolithic to the Iron Age and the beginning of urbanization. Several historic empires, states and polities developed within the geographical area now occupied by Nigeria and had left archaeological relics.

The Effect of Raw Material on the Identification of Knapping Skill: a Case Study from Olduvai Gorge, Tanzania

The identification of Oldowan hominin knapping skill levels has been a focus of numerous studies, with apparent variation in technical abilities identified between a number of Early Stone Age archaeological sites. Raw material variability, however, can play a significant role in the outcomes of knapping events as well as in the accuracy of analysis. Implications of such variability are yet to be fully understood. Here we present an experimental study to assess the effects that varying raw materials have on the identification of technological attributes typically associated with varying skill levels and whether it is possible to identify knapper skill levels across multiple raw materials. Variation was tested between raw materials from Olduvai Gorge across and between skill levels. The results suggest that knapping skill levels manifest differently in the material record across raw materials. In addition, we suggest that raw material has a significant effect on identifying knapper skill variation. This has implications for future research concerned with identifying knapper skill within and between early assemblages of differing raw materials.

Raw material optimization and stone tool engineering in the Early Stone Age of Olduvai Gorge (Tanzania)

For more than 1.8 million years hominins at Olduvai Gorge were faced with a choice: whether to use lavas, quartzite or chert to produce stone tools. All are available locally and all are suitable for stone tool production. Using controlled cutting tests and fracture mechanics theory we examine raw material selection decisions throughout Olduvai's Early Stone Age. We quantify the force, work and material deformation required by each stone type when cutting, before using these data to compare edge sharpness and durability. Significant differences are identified, confirming performance to depend on raw material choice. When combined with artefact data, we demonstrate that Early Stone Age hominins optimized raw material choices based on functional performance characteristics. Doing so flexibly: choosing raw materials dependent on their sharpness and durability, alongside a tool's loading potential and anticipated use-life. In this way, we demonstrate that early lithic artefacts at Olduvai Gorge were engineered to be functionally optimized cutting tools.

HUNT THE SYMBOL. SOME THOUGHTS ON IMAGE MAKING, IMAGES AND SIGNS IN THE PALAEOLITHIC

The expression symbolic behaviour has become a familiar term in the archaeological literature of the last twenty-five years. It is generally used to refer to surviving evidence for the use of colour, ornaments, image making and signs to distinguish them from the material remains of subsistence activities. Understanding what such items represented symbolically to the makers is unknown but it is a reasonable assumption that symbolizing or making thoughts visible as objects, images or signs was generally intended to influence relationships between people, to sustain relationships with the environment and establish relationships with spiritual powers. In this respect, symbolic labour, the effort of producing symbolic items, is a worthwhile activity that is a vital part of the social and economic viability of human groups. Consequently, images and signs need to be considered in context and in relation to the diverse activities indicated by other artefacts and remains. This paper uses objects from different times and cultures to review these aspects of image making, images and signs. It poses more questions than it offers answers. A 1.4 million-year-old handaxe from Olduvai Gorge, Tanzania is used to consider the significance of the materialization of thoughts into objects and the shaping of objects beyond utilitarian requirements and with unnecessary symmetry. Is this symbolic behaviour in the Early Stone Age Did natural selection favour tool using hominins who were able to combine the functions of the brains amygdala to memorize, interpret and process all kinds of sensory signs in seconds and instantly make behavioural reactions with new responses connected to planning, creativity and other executive functions driven by the pre-frontal cortex Did a developing function of symbolising thought improve social bonding and contribute to the survival of early hominin groups who were the hunted rather than the hunters Is it correct to regard symbolic behaviour as an evolutionary threshold rather than part of the long continuum of human evolution The talk will refer briefly to other objects from the Upper Palaeolithic of Europe and include discussion of the image of a creature that does not exist in nature, the Lion Man from Stadel Cave, Germany, and the significance of deliberate breakage as a sign or symbol, animal images associated with signs, as well as marked tools and weapons from the French Magdalenian.

Aesthetic sense and social cognition: a story from the Early Stone Age

Human aesthetic practices show a sensitivity to the ways that the appearance of an artefact manifests skills and other qualities of the maker. We investigate a possible origin for this kind of sensibility, locating it in the need for co-ordination of skill-transmission in the Acheulean stone tool culture. We argue that our narrative supports the idea that Acheulean agents were aesthetic agents. In line with this we offer what may seem an absurd comparison: between the Acheulean and the Quattrocento. In making it we display some hidden complexity in human aesthetic responses to an artefact. We conclude with a brief review of rival explanations—biological and/or cultural—of how this skills-based sensibility became a regular feature of human aesthetic practices.