Middle Pleistocene fire use: The first signal of widespread cultural diffusion in human evolution

Evolved Open-Endedness in Cultural Evolution: A New Dimension in Open-Ended Evolution Research

The goal of Artificial Life research, as articulated by Chris Langton, is "to contribute to theoretical biology by locating life-as-we-know-it within the larger picture of life-as-it-could-be." The study and pursuit of open-ended evolution in artificial evolutionary systems exemplify this goal. However, open-ended evolution research is hampered by two fundamental issues: the struggle to replicate open-endedness in an artificial evolutionary system and our assumption that we only have one system (genetic evolution) from which to draw inspiration. We argue not only that cultural evolution should be seen as another real-world example of an open-ended evolutionary system but that the unique qualities seen in cultural evolution provide us with a new perspective from which we can assess the fundamental properties of, and ask new questions about, open-ended evolutionary systems, especially with regard to evolved open-endedness and transitions from bounded to unbounded evolution. Here we provide an overview of culture as an evolutionary system, highlight the interesting case of human cultural evolution as an open-ended evolutionary system, and contextualize cultural evolution by developing a new framework of (evolved) open-ended evolution. We go on to provide a set of new questions that can be asked once we consider cultural evolution within the framework of open-ended evolution and introduce new insights that we may be able to gain about evolved open-endedness as a result of asking these questions.

Capacities for peace, and war, are old and related to Homo construction of worlds and communities

The capacities required for both peace and war predate 100,000 years ago in the genus Homo are deeply entangled in the modes by which humans physically and perceptually construct their worlds and communities, and may not be sufficiently captured by economic models.

Spread of the cycles: a feedback perspective on the Anthropocene

What propelled the human 'revolutions' that started the Anthropocene? and what could speed humanity out of trouble? Here, we focus on the role of reinforcing feedback cycles, often comprised of diverse, unrelated elements (e.g. fire, grass, humans), in propelling abrupt and/or irreversible, revolutionary changes. We suggest that differential 'spread of the cycles' has been critical to the past human revolutions of fire use, agriculture, rise of complex states and industrialization. For each revolution, we review and map out proposed reinforcing feedback cycles, and describe how new systems built on previous ones, propelling us into the Anthropocene. We argue that to escape a bleak Anthropocene will require abruptly shifting from existing unsustainable 'vicious cycles', to alternative sustainable 'virtuous cycles' that can outspread and outpersist them. This will need to be complemented by a revolutionary cultural shift from maximizing growth to maximizing persistence (sustainability). To achieve that we suggest that non-human elements need to be brought back into the feedback cycles underlying human cultures and associated measures of progress. This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'.

Measuring ancient technological complexity and its cognitive implications using Petri nets

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.

Scaling Palaeolithic tar production processes exponentially increases behavioural complexity

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.

Production method of the Königsaue birch tar documents cumulative culture in Neanderthals

Birch tar is the oldest synthetic substance made by early humans. The earliest such artefacts are associated with Neanderthals. According to traditional interpretations, their study allows understanding Neanderthal tool behaviours, skills and cultural evolution. However, recent work has found that birch tar can also be produced with simple processes, or even result from fortuitous accidents. Even though these findings suggest that birch tar per se is not a proxy for cognition, they do not shed light on the process by which Neanderthals produced it, and, therefore, cannot evaluate the implications of that behaviour. Here, we address the question of how tar was made by Neanderthals. Through a comparative chemical analysis of the two exceptional birch tar pieces from Königsaue (Germany) and a large reference birch tar collection made with Stone Age techniques, we found that Neanderthals did not use the simplest method to make tar. Rather, they distilled tar in an intentionally created underground environment that restricted oxygen flow and remained invisible during the process. This degree of complexity is unlikely to have been invented spontaneously. Our results suggest that Neanderthals invented or developed this process based on previous simpler methods and constitute one of the clearest indicators of cumulative cultural evolution in the European Middle Palaeolithic.

Supplementary information

The online version contains supplementary material available at 10.1007/s12520-023-01789-2.

Combustion, Chemistry, and Carbon Neutrality

Combustion is a reactive oxidation process that releases energy bound in chemical compounds used as fuels─energy that is needed for power generation, transportation, heating, and industrial purposes. Because of greenhouse gas and local pollutant emissions associated with fossil fuels, combustion science and applications are challenged to abandon conventional pathways and to adapt toward the demand of future carbon neutrality. For the design of efficient, low-emission processes, understanding the details of the relevant chemical transformations is essential. Comprehensive knowledge gained from decades of fossil-fuel combustion research includes general principles for establishing and validating reaction mechanisms and process models, relying on both theory and experiments with a suite of analytic monitoring and sensing techniques. Such knowledge can be advantageously applied and extended to configure, analyze, and control new systems using different, nonfossil, potentially zero-carbon fuels. Understanding the impact of combustion and its links with chemistry needs some background. The introduction therefore combines information on exemplary cultural and technological achievements using combustion and on nature and effects of combustion emissions. Subsequently, the methodology of combustion chemistry research is described. A major part is devoted to fuels, followed by a discussion of selected combustion applications, illustrating the chemical information needed for the future.

Homo medicus: The transition to meat eating increased pathogen pressure and the use of pharmacological plants in Homo

The human lineage transitioned to a more carnivorous niche 2.6 mya and evolved a large body size and slower life history, which likely increased zoonotic pathogen pressure. Evidence for this increase includes increased zoonotic infections in modern hunter-gatherers and bushmeat hunters, exceptionally low stomach pH compared to other primates, and divergence in immune-related genes. These all point to change, and probably intensification, in the infectious disease environment of Homo compared to earlier hominins and other apes. At the same time, the brain, an organ in which immune responses are constrained, began to triple in size. We propose that the combination of increased zoonotic pathogen pressure and the challenges of defending a large brain and body from pathogens in a long-lived mammal, selected for intensification of the plant-based self-medication strategies already in place in apes and other primates. In support, there is evidence of medicinal plant use by hominins in the middle Paleolithic, and all cultures today have sophisticated, plant-based medical systems, add spices to food, and regularly consume psychoactive plant substances that are harmful to helminths and other pathogens. We propose that the computational challenges of discovering effective plant-based treatments, the consequent ability to consume more energy-rich animal foods, and the reduced reliance on energetically-costly immune responses helped select for increased cognitive abilities and unique exchange relationships in Homo. In the story of human evolution, which has long emphasized hunting skills, medical skills had an equal role to play.

The house as a mind

Palaeoanthropologists and evolutionary psychologists have successfully used the increasing size of the brain during human evolution to infer cognitive and social outcomes. Archaeologists have applied similar reasoning to the development of technology in deep history. This paper goes beyond these approaches by considering the house as a metaphor for the structure of hominin minds. It is argued that the study of the mind in deep history requires, (1) a recognition that mind is distributed between bodies, brains, and the world. The implications are examined through a magnetic resonance imaging (MRI) study (that unwraps the cerebellum and which suggests that folding rather than cortex size may be more important for understanding cognition.; (2) unmasking the ingrained container- habitus that has been used to describe and investigate minds either in the present or deep past. This bias is explored by entering the eccentric house-mind of Sir John Soane (1753-1837) with its many compartments, paintings, and antiquities; and (3) an exploration of alternative embodied metaphors to enable archaeologists to study distributed mind in deep history. The metaphor ARCHITECTURE WITHOUT WALLS is discussed and briefly compared to the evidence for 'houses' in the Middle and Upper Pleistocene. The evidence indicates that hominins have always had complex, distributed minds but only recently in our deep history did we come to think predominantly through and with artificial containers such as houses. Late in human history these constructions became a common-sense habitus that expressed and fashioned our cognitive experience of the world.

Evidence for the cooking of fish 780,000 years ago at Gesher Benot Ya'aqov, Israel

Although cooking is regarded as a key element in the evolutionary success of the genus Homo, impacting various biological and social aspects, when intentional cooking first began remains unknown. The early Middle Pleistocene site of Gesher Benot Ya'aqov, Israel (marine isotope stages 18-20; ~0.78 million years ago), has preserved evidence of hearth-related hominin activities and large numbers of freshwater fish remains (>40,000). A taphonomic study and isotopic analyses revealed significant differences between the characteristics of the fish bone assemblages recovered in eight sequential archaeological horizons of Area B (Layer II-6 levels 1-7) and natural fish bone assemblages (identified in Area A). Gesher Benot Ya'aqov archaeological horizons II-6 L1-7 exhibited low fish species richness, with a clear preference for two species of large Cyprinidae (Luciobarbus longiceps and Carasobarbus canis) and the almost total absence of fish bones in contrast to the richness of pharyngeal teeth (>95%). Most of the pharyngeal teeth recovered in archaeological horizons II-6 L1-7 were spatially associated with 'phantom' hearths (clusters of burnt flint microartifacts). Size-strain analysis using X-ray powder diffraction provided evidence that these teeth had been exposed to low temperature (<500 °C), suggesting, together with the archaeological and taphonomic data, that the fish from the archaeological horizons of Area B had been cooked and consumed on site. This is the earliest evidence of cooking by hominins.

Sound reasons for unsound sleep: Comparative support for the sentinel hypothesis in industrial and nonindustrial groups

Background and objectives

Sleep is a vulnerable state in which individuals are more susceptible to threat, which may have led to evolved mechanisms for increasing safety. The sentinel hypothesis proposes that brief awakenings during sleep may be a strategy for detecting and responding to environmental threats. Observations of sleep segmentation and group sentinelization in hunter-gatherer and small-scale communities support this hypothesis, but to date it has not been tested in comparisons with industrial populations characterized by more secure sleep environments.

Methodology

Here, we compare wake after sleep onset (WASO), a quantitative measure of nighttime awakenings, between two nonindustrial and two industrial populations: Hadza hunter-gatherers (n = 33), Malagasy small-scale agriculturalists (n = 38), and Hispanic (n = 1,531) and non-Hispanic White (NHW) (n = 347) Americans. We compared nighttime awakenings between these groups using actigraphically-measured sleep data. We fit linear models to assess whether WASO varies across groups, controlling for sex and age.

Results

We found that WASO varies significantly by group membership and is highest in Hadza (2.44 h) and Malagasy (1.93 h) and lowest in non-Hispanic Whites (0.69 h). Hispanics demonstrate intermediate WASO (0.86 h), which is significantly more than NHW participants. After performing supplementary analysis within the Hispanic sample, we found that WASO is significantly and positively associated with increased perception of neighborhood violence.

Conclusions and implications

Consistent with principles central to evolutionary medicine, we propose that evolved mechanisms to increase vigilance during sleep may now be mismatched with relatively safer environments, and in part responsible for driving poor sleep health.

Laboratory-based experimental research into the effect of diagenesis on heated bone: implications and improved tools for the characterisation of ancient fire

The use of fire is considered to be one of the most important cultural innovations in human evolution. Understanding the taphonomy of fire remains is an important prerequisite for valid interpretations of hominin fire-related behaviour. Presented here are the results of a series of laboratory-based experiments testing the effect of different pH conditions (acidic, neutral, alkaline) on the physical and chemical properties of heated bone (charred and combusted). By taking a fundamental-research approach the study gives insight into the specific effect of pH exposure and its underlying chemical processes, and provides data that can be applied to heated bone from any context and time period. Results show that diagenesis has a significant impact on the preservation potential of heated bones, as well as on the reliability of the analytical techniques used to reconstruct past heating conditions. The study provides reference data and a toolkit for the analysis of heated bone, that explicitly takes diagenesis into account, and in doing so offers a significant improvement to the accuracy with which we can reconstruct heating conditions and fire-related human behaviour in the past.

Inferring cultural reproduction from lithic data: A critical review

The cultural reproduction of lithic technology, long an implicit assumption of archaeological theories, has garnered increasing attention over the past decades. Major debates ranging from the origins of the human culture capacity to the interpretation of spatiotemporal patterning now make explicit reference to social learning mechanisms and cultural evolutionary dynamics. This burgeoning literature has produced important insights and methodological innovations. However, this rapid growth has sometimes led to confusion and controversy due to an under-examination of underlying theoretical and methodological assumptions. The time is thus ripe for a critical assessment of progress in the study of the cultural reproduction of lithic technology. Here we review recent work addressing the evolutionary origins of human culture and the meaning of artifact variation at both intrasite and intersite levels. We propose that further progress will require a more extended and context-specific evolutionary approach to address the complexity of real-world cultural reproduction.

Oxytocin and vasotocin receptor variation and the evolution of human prosociality

Modern human lifestyle strongly depends on complex social traits like empathy, tolerance and cooperation. These diverse facets of social cognition have been associated with variation in the oxytocin receptor (OTR) and its sister genes, the vasotocin/vasopressin receptors (VTR1A/AVPR1A and AVPR1B/VTR1B). Here, we compared the available genomic sequences of these receptors between modern humans, archaic humans, and 12 non-human primate species, and identified sites that show heterozygous variation in modern humans and archaic humans distinct from variation in other primates, and for which we could find association studies with clinical implications. On these sites, we performed a range of analyses (variant clustering, pathogenicity prediction, regulation, linkage disequilibrium frequency), and reviewed the literature on selection data in different modern-human populations. We found five sites with modern human specific variation, where the modern human allele is the major allele in the global population (OTR: rs1042778, rs237885, rs6770632; VTR1A: rs10877969; VTR1B: rs33985287). Among them, variation in the OTR-rs6770632 site was predicted to be the most functional. Two alleles (OTR: rs59190448 and rs237888) present only in modern humans and archaic humans were putatively under positive selection in modern humans, with rs237888 predicted to be a highly functional site. Three sites showed convergent evolution between modern humans and bonobos (OTR: rs2228485 and rs237897; VTR1A: rs1042615), with OTR-rs2228485 ranking highly in terms of functionality and reported to be under balancing selection in modern humans (Schaschl, 2015) [1]. Our findings have implications for understanding hominid prosociality, as well as the similarities between modern human and bonobo social behavior.

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We compared the oxytocin/vasotocin receptors in modern humans, archaic humans, and non-human primates.

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We found 5 sites with modern human specific variation.

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In these sites, the modern human allele is the major allele in the global population.

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Several sites were predicted to be functional and with selection signatures in modern humans.

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We also identified 3 sites of convergent evolution in modern humans and bonobos.

Reimagine fire science for the anthropocene

Fire is an integral component of ecosystems globally and a tool that humans have harnessed for millennia. Altered fire regimes are a fundamental cause and consequence of global change, impacting people and the biophysical systems on which they depend. As part of the newly emerging Anthropocene, marked by human-caused climate change and radical changes to ecosystems, fire danger is increasing, and fires are having increasingly devastating impacts on human health, infrastructure, and ecosystem services. Increasing fire danger is a vexing problem that requires deep transdisciplinary, trans-sector, and inclusive partnerships to address. Here, we outline barriers and opportunities in the next generation of fire science and provide guidance for investment in future research. We synthesize insights needed to better address the long-standing challenges of innovation across disciplines to (i) promote coordinated research efforts; (ii) embrace different ways of knowing and knowledge generation; (iii) promote exploration of fundamental science; (iv) capitalize on the "firehose" of data for societal benefit; and (v) integrate human and natural systems into models across multiple scales. Fire science is thus at a critical transitional moment. We need to shift from observation and modeled representations of varying components of climate, people, vegetation, and fire to more integrative and predictive approaches that support pathways toward mitigating and adapting to our increasingly flammable world, including the utilization of fire for human safety and benefit. Only through overcoming institutional silos and accessing knowledge across diverse communities can we effectively undertake research that improves outcomes in our more fiery future.

Hidden signatures of early fire at Evron Quarry (1.0 to 0.8 Mya)

Pyrotechnology is a key element of hominin evolution. The identification of fire in early hominin sites relies primarily on an initial visual assessment of artifacts' physical alterations, resulting in potential underestimation of the prevalence of fire in the archaeological record. Here, we used a suite of spectroscopic techniques to counter the absence of visual signatures for fire and demonstrate the presence of burnt fauna and lithics at the Lower Paleolithic (LP) open-air site of Evron Quarry (Israel), dated between 1.0 and 0.8 Mya and roughly contemporaneous to Gesher Benot Ya'aqov where early pyrotechnology has been documented. We propose reexamining finds from other LP sites lacking visual clues of pyrotechnology to yield a renewed perspective on the origin, evolution, and spatiotemporal dispersal of the relationship between early hominin behavior and fire use.

Variations by degrees: Western European paleoenvironmental fluctuations across MIS 13-11

Marine Isotope Stages (MIS) 13-11 saw a major transformation in the hominin occupation of Europe, with an expansion in the scale and geographical distribution of sites and artifact assemblages. That expansion is explored here in the context of paleoenvironmental variability, focusing on geographical and chronological trends in climatic and habitat conditions at and between key Lower Paleolithic sites in Western Europe. Climatic conditions at British sites are compared across MIS 13-11, and used to test predicted values from the Oscillayers data set. Conditions at hominin and nonhominin sites are compared to explore possible limitations in hominin tolerances during MIS 13-11. Trends in conditions are explored with reference to long-term global patterns, short-term substage events, and seasonal variations. The apparent increase in the scale of hominin activity in north-western Europe during MIS 13 is surprising in light of the relatively harsh conditions of late MIS 13, and is likely to reflect significant physiological and/or behavioral adaptations, a mild south-north temperature gradient in western Europe during MIS 13, and the relatively mild, sustained conditions spanning MIS 15-13. The expanded occupation of north-western Europe during MIS 11 probably reflects the extended mild conditions of MIS 11c, since marked seasonal temperature differences and substantial behavioral changes between hominin sites in MIS 13 and 11 are not clearly evident. Site-specific conditions in south-western Europe during MIS 11 suggest milder winters, warmer summers, and reduced seasonal variability compared to north-western Europe. Some or all of these conditions may have supported larger, core populations, as may the relatively mild conditions associated with south-western European sites during MIS 12. Finally, comparisons between north-western and north-central European sites indicate relatively small differences in seasonal temperatures, suggesting that climate may only be a partial factor behind the smaller-scale occupations of north-central Europe during MIS 13-11.

Field Model-Based Cultural Diffusion Patterns and GIS Spatial Analysis Study on the Spatial Diffusion Patterns of Qijia Culture in China

Cultural diffusion is one of the core issues among researchers in the field of cultural geography. This study aimed to examine the spatial diffusion patterns of the Qijia culture (QJC) to clarify the origin and formation process of Chinese field model-based cultural diffusion patterns (FM-CDP) and geographic information system (GIS) spatial analysis methods. It used the point data of Qijia cultural sites without time information and combined them with the relevant records of Qijia cultural and historical documents, as well as archaeological excavation materials. Starting with the spatial location information of cultural distribution, it comprehensively analysed the cultural hearth, regions, diffusion patterns, and diffusion paths. The results indicated the following. (1) The QJC’s heart is in the southeast of Gansu Province, where the Shizhaocun and Xishanping sites are distributed. (2) Five different levels of cultural regions were formed, which demonstrated different diffusion patterns at different regional scales. On a large regional scale, many cultural regions belong to relocation diffusion patterns. Meanwhile, at the small regional scale (in the Gansu–Qinghai region), there are two patterns of diffusion: expansion diffusion and relocation diffusion; however, the expansion diffusion pattern is the main one. (3) Based on the relationship between the QJC, altitude, and the water system, the culture also has the characteristics of diffusion to low altitude areas and a pattern of diffusion along water systems. (4) There is a circular structure of the core, periphery, and fringe regions of the QJC. Finally, (5) the dry and cold climate around 4000a B.P., the cultural exchange between Europe and the Asian continent (the introduction of barley, wheat, livestock and sheep, and copper smelting technology), and the war in the late Neolithic period were important factors affecting the diffusion of the QJC.

What Are the “Costs and Benefits” of Meat-Eating in Human Evolution? The Challenging Contribution of Behavioral Ecology to Archeology

Despite the omnivorous diet of most human populations, meat foraging gradually increased during the Paleolithic, in parallel with the development of hunting capacities. There is evidence of regular meat consumption by extinct hominins from 2 Ma onward, with the first occurrence prior to 3 Ma in Eastern Africa. The number of sites with cut-marked animal remains and stone tools increased after 2 Ma. In addition, toolkits became increasingly complex, and various, facilitating carcass defleshing and marrow recovery, the removal of quarters of meat to avoid carnivore competition, and allowing the emergence of cooperative (i.e., social) hunting of large herbivores. How can we assess the energy costs and benefits of meat and fat acquisition and consumption for hunter-gatherers in the past, and is it possible to accurately evaluate them? Answering this question would provide a better understanding of extinct hominin land use, food resource management, foraging strategies, and cognitive abilities related to meat and fat acquisition, processing, and consumption. According to the Optimal Foraging Theory (OFT), resources may be chosen primarily on the basis of their efficiency rank in term of calories. But, could other factors, and not only calorific return, prevail in the choice of prey, such as the acquisition of non-food products, like pelts, bone tools or ornaments, or symbolic or traditional uses? Our main goal here is to question the direct application of behavioral ecology data to archeology. For this purpose, we focus on the issue of animal meat and fat consumption in human evolution. We propose a short review of available data from energetics and ethnographic records, and provide examples of several various-sized extant animals, such as elephants, reindeer, or lagomorphs, which were some of the most common preys of Paleolithic hominins.

Cost-Benefit Trade-Offs of Aquatic Resource Exploitation in the Context of Hominin Evolution

While the exploitation of aquatic fauna and flora has been documented in several primate species to date, the evolutionary contexts and mechanisms behind the emergence of this behavior in both human and non-human primates remain largely overlooked. Yet, this issue is particularly important for our understanding of human evolution, as hominins represent not only the primate group with the highest degree of adaptedness to aquatic environments, but also the only group in which true coastal and maritime adaptations have evolved. As such, in the present study we review the available literature on primate foraging strategies related to the exploitation of aquatic resources and their putative associated cognitive operations. We propose that aquatic resource consumption in extant primates can be interpreted as a highly site-specific behavioral expression of a generic adaptive foraging decision-making process, emerging in sites at which the local cost-benefit trade-offs contextually favor aquatic over terrestrial foods. Within this framework, we discuss the potential impacts that the unique intensification of this behavior in hominins may have had on the evolution of the human brain and spatial ecology.

Acheulean variability in Western Europe: The case of Menez-Dregan I (Plouhinec, Finistère, France)

The establishment of the Acheulean in Europe occurred after MIS 17, but it was after the harsh glaciation of MIS 12 and during the long interglacial of MIS 11 that human occupation of Western Europe became more sustained, with an increased number of sites. Menez-Dregan I (Brittany, France) is one of the key sites in Western Europe that dates from this threshold, with an alternating sequence of 16 occupation levels and four marine deposits, from MIS 12 to 8. The large lithic assemblages of more than 154,000 artifacts from knapping (cores, flakes) and shaping (macrotools and shaping flakes) show the varying use of raw materials and activities at the site through the sequence. This work focuses on the study of the handaxes and cleavers using technological and metrical methods with multivariate analysis, in combination with geometric morphometrics, and places these analyses within the context of other technological changes at the site. Collectively, results show the persistent use through the sequence of the same lithic raw materials and technologies, including fire use and the import of glossy sandstone from 20 km away, but with variation in activities at the site. These findings suggest that Menez-Dregan I shows the development of a specific material culture that reflects the local resources and environment. Results further indicate that the site shows the sustained hominin occupation of the area, despite varying climate and environment, with strong traditions of social learning that were maintained through flexibility of site use, deep understanding of the local territory, and the innovation of new technologies, such as the use of fire. Evidence from the site is placed within the wider context of Europe, and contrasted with areas to the north, such as Britain, where hominin occupation was more sporadic and driven by cyclical climate change.

Night Capture of Roosting Cave Birds by Neanderthals: An Actualistic Approach

Evidence is accumulating on the regular and systematic Neanderthal exploitation of birds. However, the motivations, mechanisms, and circumstances underlying this behavior remains little explored despite their potential implications on Neanderthal ecology and capabilities. Fossil remains of choughs (Pyrrhocorax, Corvidae) are among the most abundant in cave sites with Mousterian technology. We reviewed the evidence showing that Neanderthals processed choughs for food, and confirmed that it occurred frequently over a widespread spatial and temporal scale. This lead us to propose the hypothesis that the cave-like refuge is the keystone resource connecting Neanderthals and choughs captured at night in rocky shelters eventually used by both species. By adopting an actualistic approach, we documented the patterns of refuge use and population dynamics of communally roosting choughs, the strategies and technology currently used to capture them, and their behavioral response against experimental human predators at night. Actualistic experiments showed that large numbers of choughs can be captured without highly sophisticated tools at night regularly and periodically, due to their occupation year-round during long-term periods of the same nocturnal shelters, the constant turnover of individuals, and their high site tenacity at these roost-sites even after recurrent disturbance and predation. Captures even with bare hands are further facilitated because choughs tend to flee confused into the cavity in darkness when dazzled and cornered by human (experimental) predators. Given the extreme difficulty of daylight chough capturing in open country, nocturnal hunting with the help of fire in the roosting caves and consumption in situ are proposed as the most plausible explanations for the strong association of choughs and Neanderthals in fossil assemblages. Night hunting of birds has implications for the social, anatomical, technological, and cognitive capacities of Neanderthals.