This study explores traditional adhesives using an ethnobiological approach within a multisocioecological context in Zambia. Through semi-structured interviews, videotaped demonstrations, and herbarium collections, we investigated the traditional adhesives people know and use, the flexibility of production processes, resource usage, and knowledge transmission in adhesive production. Our findings reveal flexibility in adhesive production systems. People use a wide range of organic and inorganic materials in their adhesive recipes. Recipes are flexible, demonstrating the ability to adapt to changes and substitute materials as needed to achieve the desired end product. Additionally, our study reveals a variety of redundant pathways for knowledge transmission typically confined within individual population groups. These include same-sex vertical transmission and distinct learning spaces and processes. Also, we identified material procurement zones showing that people are prepared to travel 70 km for ingredients. We use our findings to review the archaeology and we discuss the identification of archaeological adhesives, the functional roles of adhesive materials, adhesive storage, and the sustained human interaction with species from families such as Euphorbiaceae and Apiade. Our findings underscore the diversity and adaptability of traditional adhesive production and suggest that further research on adhesives would reveal similar diversity within the archaeological record.

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Technological processes, reconstructed from the archaeological record, are used to study the evolution of behaviour and cognition of Neanderthals and early modern humans. In comparisons, technologies that are more complex infer more complex behaviour and cognition. The manufacture of birch bark tar adhesives is regarded as particularly telling and often features in debates about Neanderthal cognition. One method of tar production, the ‘condensation technique’, demonstrates a pathway for Neanderthals to have discovered birch bark tar. However, to improve on the relatively low yield, and to turn tar into a perennial innovation, this method likely needed to be scaled up. Yet, it is currently unknown how scaling Palaeolithic technological processes influences their complexity. We used Petri net models and the Extended Cyclomatic Metric to measure system complexity of birch tar production with a single and three concurrent condensation assemblies. Our results show that changing the number of concurrent tar production assemblies substantially increases the measured complexity. This has potential implications on the behavioural and cognitive capacities required by Neanderthals, such as an increase in cooperation or inhibition control.

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We implement a method from computer sciences to address a challenge in Paleolithic archaeology: how to infer cognition differences from material culture. Archaeological material culture is linked to cognition, and more complex ancient technologies are assumed to have required complex cognition. We present an application of Petri net analysis to compare Neanderthal tar production technologies and tie the results to cognitive requirements. We applied three complexity metrics, each relying on their own unique definitions of complexity, to the modeled production processes. Based on the results, we propose that Neanderthal technical cognition may have been analogous to that of contemporary modern humans. This method also enables us to distinguish the high-order cognitive functions combining traits like planning, inhibitory control, and learning that were likely required by different ancient technological processes. The Petri net approach can contribute to our understanding of technology and cognitive evolution as it can be used on different materials and technologies, across time and species.

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Technologies and their production systems are used by archaeologists and anthropologists to study complexity of socio-technical systems. However, there are several issues that hamper agreement about what constitutes complexity and how we can systematically compare the complexity of production systems. In this work, we propose a novel approach to assess the behavioural and structural complexity of production systems using Petri nets. Petri nets are well-known formal models commonly used in, for example, biological and business process modelling, as well as software engineering. The use of Petri nets overcomes several obstacles of current approaches in archaeology and anthropology, such as the incompatibility of the intrinsic sequential logic of the available methods with inherently non-sequential processes, and the inability to explicitly model activities and resources separately. We test the proposed Petri net modelling approach on two traditional production systems of adhesives made by Ju/’hoan makers from Nyae, Namibia from Ammocharis coranica and Ozoroa schinzii plants. We run simulations in which we assess the complexity of these two adhesive production systems in detail and show how Petri net dynamics reveal the structural and behavioural complexity of different production scenarios. We show that concurrency may be prevalent in the production system of adhesive technologies and discuss how changes in location during the process may serve to control the behavioural complexity of a production system. The approach presented in this paper paves the way for future systematic visualization, analysis, and comparison of ancient production systems, accounting for the inherent complex, concurrent, and action/resource-oriented aspects of such processes.@en

An adhesive is any substance that bonds different materials together. This broad definition includes materials used in everything from hafted stone tools to monumental architecture. In addition, the combination of bonding, plasticity, and insolubility meant that some adhesives were exploited for waterproofing and sealing of materials, as self-adhering inlays and putties, and as paints, varnishes, and inks. Adhesives have a history of at least 200,000 years. Throughout (pre)history and around the world, people used materials, including bitumen/ asphalt, carbohydrate polymers such as starches and gums, natural rubbers, mortars, proteins (from casein, soy, blood, and animal connective tissue), insect and plant resins, and tars made from various barks and woods. Adhesives thus are very diverse and have widely varying properties: they can be tacky, pliable, elastic, brittle, water-resistant, fluid, viscous, clear, dark, and much more. They are a plastic avant la lettre. These properties can and were tweaked by mixing ingredients or by further processing. In the study of archaeological adhesives, their characterization is essential and this is best done with chemical and spectroscopic methods. When larger coherent samples as opposed to single finds are analyzed, adhesive studies can provide data on past technologies, socioeconomic organizations, and environments and raw material availability. Through sourcing and mapping of ingredients and adhesive end products, travel and transfer of materials and knowledge can be illuminated. Additionally, experimental reproductions provide data on technological aspects that otherwise are lost in the archaeological record. An archaeology of adhesives can reveal the transport networks, subsistence, mobility strategies, division of labor, and technological know-how that held societies together.@en

Studies of colonization processes in past human societies often use a standard population model in which population is represented as a single quantity. Real populations in these processes, however, are structured with internal classes or stages, and classes are sometimes created based on social differentiation. In this present work, information about the colonization of Old Providence Island was used to create an agent-based model of the colonization process in a heterogeneous environment for a population with social differentiation. Agents were socially divided into two classes and modeled with dissimilar spatial clustering preferences. The model and simulations assessed the importance of gregarious behavior for colonization processes conducted in heterogeneous environments by socially-differentiated populations. Results suggest that in these conditions, the colonization process starts with an agent cluster in the largest and most suitable area. The spatial distribu-tion of agents maintained a tendency toward randomness as simulation time increased, even when gregariousness values increased. The most conspicuous effects in agent clustering were produced by the initial conditions and behavioral adaptations that increased the agent capacity to access more resources and the likelihood of gregariousness. The approach presented here could be used to analyze past human colonization events or support long-term conceptual design of future human colonization processes with small social formations into unfamiliar and uninhabited environments.@en