2,491 research outputs found

    Animal residues found on tiny Lower Paleolithic tools reveal their use in butchery

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    Stone tools provide a unique window into the mode of adaptation and cognitive abilities of Lower Paleolithic early humans. The persistently produced large cutting tools (bifaces/handaxes) have long been an appealing focus of research in the reconstruction of Lower Paleolithic survival strategies, at the expenses of the small flake tools considered by-products of the stone production process rather than desired end products. Here, we use use-wear, residues and technological analyses to show direct and very early evidence of the deliberate production and use of small flakes for targeted stages of the prey butchery process at the late Lower Paleolithic Acheulian site of Revadim, Israel. We highlight the significant role of small flakes in Lower Paleolithic adaptation alongside the canonical large handaxes. Our results demonstrate the technological and cognitive flexibility of early human groups in the Levant and beyond at the threshold of the departure from Lower Paleolithic lifeways

    The evolutionary neuroscience of tool making

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    The appearance of the first intentionally modified stone tools over 2.5 million years ago marked a watershed in human evolutionary history, expanding the human adaptive niche and initiating a trend of technological elaboration that continues to the present day. However, the cognitive foundations of this behavioral revolution remain controversial, as do its implications for the nature and evolution of modern human technological abilities. Here we shed new light on the neural and evolutionary foundations of human tool making skill by presenting functional brain imaging data from six inexperienced subjects learning to make stone tools of the kind found in the earliest archaeological record. Functional imaging of this complex, naturalistic task was accomplished through positron emission tomography with the slowly decaying radiological tracer (18)flouro-2-deoxyglucose. Results show that simple stone tool making is supported by a mosaic of primitive and derived parietofrontal perceptual-motor systems, including recently identified human specializations for representation of the central visual field and perception of three-dimensional form from motion. In the naive tool makers reported here, no activation was observed in prefrontal executive cortices associated with strategic action planning or in inferior parietal cortex thought to play a role in the representation of everyday tool use skills. We conclude that uniquely human capacities for sensorimotor adaptation and affordance perception, rather than abstract conceptualization and planning, were central factors in the initial stages of human technological evolution. The appearance of the first intentionally modified stone tools over 2.5 million years ago marked a watershed in human evolutionary history, expanding the human adaptive niche and initiating a trend of technological elaboration that continues to the present day. However, the cognitive foundations of this behavioral revolution remain controversial, as do its implications for the nature and evolution of modern human technological abilities. Here we shed new light on the neural and evolutionary foundations of human tool making skill by presenting functional brain imaging data from six inexperienced subjects learning to make stone tools of the kind found in the earliest archaeological record. Functional imaging of this complex, naturalistic task was accomplished through positron emission tomography with the slowly decaying radiological tracer (18)flouro-2-deoxyglucose. Results show that simple stone tool making is supported by a mosaic of primitive and derived parietofrontal perceptual-motor systems, including recently identified human specializations for representation of the central visual field and perception of three-dimensional form from motion. In the naive tool makers reported here, no activation was observed in prefrontal executive cortices associated with strategic action planning or in inferior parietal cortex thought to play a role in the representation of everyday tool use skills. We conclude that uniquely human capacities for sensorimotor adaptation and affordance perception, rather than abstract conceptualization and planning, were central factors in the initial stages of human technological evolution

    Making tools and making sense: complex, intentional behaviour in human evolution

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    Stone tool-making is an ancient and prototypically human skill characterized by multiple levels of intentional organization. In a formal sense, it displays surprising similarities to the multi-level organization of human language. Recent functional brain imaging studies of stone tool-making similarly demonstrate overlap with neural circuits involved in language processing. These observations consistent with the hypothesis that language and tool-making share key requirements for the construction of hierarchically structured action sequences and evolved together in a mutually reinforcing way

    41BX68: A Preshitoric Quarry-Workshop In Northern Bexar County, Texas

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    During late February and early March of 1978, personnel from the Center for Archaeological Research, The University of Texas at San Antonio, conducted intensive mapping and limited subsurface testing of the prehistoric quarry-workshop site of 41 BX 68. Investigations of the site, located near the intersection of FM 1604 and Elm Creek in northern Bexar County (see Fig. 1), were conducted under the terms of a contract (Purchase Order No. 40-7442-8-426) with the Soil Conservation Service. Located near proposed Floodwater Retarding Structure 11, portions of the extensive site will soon be altered or critically damaged by modification. Preliminary observations of the site indicated large areas were relatively undisturbed since the original aboriginal activity had taken place (Brown et al. 1977). Intact, relatively undisturbed concentrations of lithic debris were noted (see Fig. 2). The frequency, distribution and association of these materials were considered to be of unusual value in identifying intra-site activity areas. The intent of the current investigation was to formulate a preliminary description of the site and identify various aspects of lithic technological processes and their intra-site relationships in a prehistoric south central Texas quarry-workshop area

    Big Hole (41TV2161): Two Stratigraphically Isolated Middle Holocene Components in Travis County, Texas Volume I

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    During April and May 2006, an archeological team from the Cultural Resources Section of the Planning, Permitting and Licensing Practice of TRC Environmental Corporation’s (TRC) Austin office conducted geoarcheological documentation and data recovery excavations at prehistoric site 41TV2161 (CSJ: 0440-06-006). Investigations were restricted to a 70 centimeter (cm) thick target zone between ca. 220 and 290 cm below surface (bs) on the western side of site 41TV2161 – the Big Hole site in eastern Travis County, Texas. This cultural investigation was necessary under the requirements of Section 106 of the National Historic Preservation Act (NHPA), the implementing regulations of 36CRF Part 800 and the Antiquities Code of Texas (Texas Natural Resource Code, Title 9, Chapter 191 as amended) to recover a sample of the significant cultural materials prior to destruction by planned construction of State Highway 130 (SH 130). The latter by a private construction firm – Lone Star Infrastructure. This necessary data recovery was for Texas Department of Transportation (TxDOT), Environmental (ENV) Affairs Division under a Scientific Services Contract No. 577XXSA003 (Work Authorization No. 57701SA003). Over the years since the original award, multiple work authorizations between TxDOT and TRC were implemented and completed towards specific aspects of the analyses and reporting. The final analyses and report were conducted under contract 57-3XXSA004 (Work Authorization 57-311SA004). All work was under Texas Antiquities Committee Permit No. 4064 issued by the Texas Historical Commission (THC) to J. Michael Quigg. Initially, an archeological crew from Hicks & Company encountered site 41TV2161 during an intensive cultural resource inventory conducted south of Pearce Lane along the planned construction zone of SH 130 in the fall of 2005. Following the initial site discovery, archeologists expanded their investigations to the west across the SH 130 right-of-way, and completed excavation of 10 backhoe trenches, 13 shovel tests, and 11 test units at site 41TV2161. The investigations encountered at least seven buried cultural features and 1,034 artifacts, some in relatively good context. The survey and testing report to TxDOT presented their findings and recommendations (Campbell et al. 2006). The ENV Affairs Division of TxDOT and the THC reviewed the initial findings and recommendations, and determined site 41TV2161 was eligible for listing on the National Register of Historic Places and as State Antiquities Landmark as the proposed roadway development was to directly impact this important site and further excavations were required. Subsequently, TRC archeologists led by Paul Matchen (Project Archeologist) and J. Michael Quigg (Principal Investigator) initiated data recovery excavations through the mechanical-removal of between 220 and 250 cm of sediment from a 30-by-40 meter (m) block area (roughly 3,000 m3). This was conducted to allow hand-excavations to start just above the deeply buried, roughly 70 cm thick targeted zone of cultural material. Mechanical stripping by Lone Star Infrastructure staff created a large hole with an irregular bottom that varied between 220 and 260 cmbs. To locate specific areas to initiate hand-excavations within the mechanically stripped area, a geophysical survey that employed ground penetrating radar (GPR) was conducted by Tiffany Osburn then with Geo-Marine in Plano, Texas. Over a dozen electronic anomalies were detected through the GPR investigation. Following processing, data filtering, and assessment, Osburn identified and ranked the anomalies for investigation. The highest ranked anomalies (1 through 8) were thought to have the greatest potential to represent cultural features. Anomalies 1 through 6 were selected and targeted through hand-excavations of 1-by-1 m units that formed continuous excavation blocks of various sizes. Blocks were designated A, B, C, D, E, and F. The type, nature, quantity, and context of encountered cultural materials in each block led the direction and expansion of each excavation block as needed. In total, TRC archeologists hand-excavated 38.5 m3 (150 m2) from a vertically narrow target zone within this deep, multicomponent and stratified prehistoric site. Hand-excavation in the two largest Blocks, B and D (51 m2 and 62 m2 respectively), revealed two vertically separate cultural components between roughly 220 and 290 cmbs. The younger component was restricted to Block B and yielded a Bell/Andice point and point base, plus a complete Big Sandy point. These points were associated with at least eight small burned rock features, one cluster of ground stone tools, limited quantities of lithic debitage, few formal chipped and ground stone tools, and a rare vertebrate faunal assemblage. Roughly 20 to 25 cm below the Bell/Andice component in Block B and across Block D was a component identified by a single corner-notched Martindale dart point. This point was associated with a scattered burned rocks, three charcoal stained hearth features, scattered animal, bird, and fish bones, mussel shells, and less than a dozen formal chipped and ground stone tools. Both identified components contained cultural materials in good stratigraphic context with high spatial integrity. Significant, both were radiocarbon dated by multiple charcoal samples to a narrow 200-year period between 5250 and 5450 B.P. during the middle Holocene. With exception of the well-preserved faunal assemblages, perishable materials were poorly preserved in the moist silty clay loam. Charcoal lacked structure and was reduced to dark stains. Microfossils (e.g., phytoliths and starch gains) were present, although in very limited numbers and deteriorated conditions. The four much smaller Blocks (A, C, E, and F) yielded various quantities of cultural material and features, but these blocks also lacked sufficient charcoal dates and diagnostic artifacts Those artifacts and samples were left unassigned and analyzed separately from the Bell/Andice and Martindale components. The two well-defined components in Blocks B and D are the focus of this technical report. The components provide very significant data towards understanding rare and poorly understood hunter-gatherer populations during late stages of the Altithermal climate period. This final report builds upon the interim report submitted to TxDOT (Quigg et al. 2007) that briefly described the methods, excavations, preliminary findings, initial results from six feasibility studies, and proposed an initial research design for data analyses. Context and integrity of the cultural materials in the two identified components was excellent. This rare circumstance combined with detailed artifact analyses, solid documentation of their ages through multiple radiocarbon dates, and multidisciplinary approach to analyses, allowed significant insights and contributions concerning the two populations involved. Results provide a greater understanding of human behaviors during a rarely identified time in Texas Prehistory. The cultural materials and various collected samples were temporarily curated at TRC’s Austin laboratory. Following completion of analyses and acceptance of this final report, the artifacts, paper records, photographs, and electronic database were permanently curated at the Center for Archaeological Studies (CAS) at Texas State University in San Marcos

    Foraging environment determines the genetic architecture and evolutionary potential of trophic morphology in cichlid fishes

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    Phenotypic plasticity allows organisms to change their phenotype in response to shifts in the environment. While a central topic in current discussions of evolutionary potential, a comprehensive understanding of the genetic underpinnings of plasticity is lacking in systems undergoing adaptive diversification. Here, we investigate the genetic basis of phenotypic plasticity in a textbook adaptive radiation, Lake Malawi cichlid fishes. Specifically, we crossed two divergent species to generate an F3 hybrid mapping population. At early juvenile stages, hybrid families were split and reared in alternate foraging environments that mimicked benthic/scraping or limnetic/sucking modes of feeding. These alternate treatments produced a variation in morphology that was broadly similar to the major axis of divergence among Malawi cichlids, providing support for the flexible stem theory of adaptive radiation. Next, we found that the genetic architecture of several morphological traits was highly sensitive to the environment. In particular, of 22 significant quantitative trait loci (QTL), only one was shared between the environments. In addition, we identified QTL acting across environments with alternate alleles being differentially sensitive to the environment. Thus, our data suggest that while plasticity is largely determined by loci specific to a given environment, it may also be influenced by loci operating across environments. Finally, our mapping data provide evidence for the evolution of plasticity via genetic assimilation at an important regulatory locus, ptch1. In all, our data address long-standing discussions about the genetic basis and evolution of plasticity. They also underscore the importance of the environment in affecting developmental outcomes, genetic architectures, morphological diversity and evolutionary potential

    Experimental production of lithic artefacts: Developing understanding; developing engagement

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    This paper is reflective and discusses the results of a process experiment designed to develop understanding of a particular British Early Upper Palaeolithic stone tool technology. The technology in question is the Lincombian, and the discussion breaks down into three main parts. The first part argues that raw material availability and practitioner performance can be influential factors within the modern experimental reproduction process. When these issues were factored in for this experiment it became clear that early phase debitage materials reflected a process of interpretation, not replication. The second substantive part of this discussion focuses upon the final phase of the experimental process. Selection criterion for assessing finished artefacts was tightly constrained by archaeologically derived data. It is argued therefore that when finished artefacts fell within these assessment criteria the final phase of the process was akin to replication. Consequently, debitage associated with the final phase can provide useful analogue material to fill gaps in our understanding of this Lincombian technology. The final section is summative and returns to the issue of performance. It argues that practitioner performance facilitates audience engagement. Engagement is valuable for communicating understanding to both specialist and non-specialist audiences. The paper concludes by arguing that a rigorously evaluated experimental process can be used twice: firstly, as a tool for generating materials to develop our understanding; secondly, as an engaging performance to communicate understanding to specialist and non-specialist audiences

    Hand Adzes in the Palaeolithic Culture of India

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    New Radiocarbon Ages on Percussion-Fractured and Flaked Proboscidean Limb Bones from Yukon, Canada

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    Proboscidean limb bones discovered in Yukon during the 1960s and 1970s exhibit fracture patterns, notches, and bone flakes that are characteristic of percussion. Because of the unique properties of thick cortical proboscidean bone (probably woolly mammoth Mammuthus primigenius or less likely American mastodon Mammut americanum), some researchers hypothesized that these fracture patterns represent intentional hammerstone modification by humans for marrow extraction and bone tool production. As such, these fracture patterns represent evidence of early human dispersal into Eastern Beringia. Radiocarbon dating in the late 1980s indicated that the bone breakage occurred between about 25 000 and 40 000 radiocarbon years before present (14C yr BP). We report 11 new radiocarbon ages using ultra-filtration methods on a different sample of similarly fractured and flaked bones from Yukon. Only two of the radiocarbon ages fall within the expected range of 25 000 to 40 000 14C yr BP. Six other ages are non-finite, with five being more than 49 100 14C yr BP. Three finite ages range between 46 500 and 50 500 14C yr BP with large standard deviations, and these ages may also be non-finite. Two testable hypotheses to explain the observed breakage patterns were developed, the first being that humans broke the bones and the second that some presently unknown geological process broke the bones. Further research is needed to test these two hypotheses.Des ossements de membres de proboscidiens dĂ©couverts au Yukon dans les annĂ©es 1960 et 1970 prĂ©sentent des structures de fractures, des encoches et des traces d’enlĂšvements d’éclats caractĂ©ristiques de la percussion. En raison des propriĂ©tĂ©s uniques de l’os cortical proboscidien (provenant probablement d’un mammouth laineux Mammuthus primigenius ou, ce qui est moins probable, d’un mastodonte amĂ©ricain Mammut americanum), certains chercheurs ont avancĂ© une hypothĂšse selon laquelle ces structures reprĂ©sentent des modifications intentionnelles faites au marteau en pierre par des humains, Ă  des fins d’extraction de la moelle et de production d’outils en os. En tant que telles, ces structures de fractures tĂ©moignent de la prĂ©sence ancienne d’humains dans l’est de la BĂ©ringie. Vers la fin des annĂ©es 1980, la datation au radiocarbone a permis de dĂ©terminer que les fractures auraient Ă©tĂ© faites il y a environ 25 000 Ă  40 000 annĂ©es radiocarbones avant le prĂ©sent (14C ans BP). Nous faisons Ă©tat de 11 nouveaux Ăąges au radiocarbone Ă©tablis au moyen de mĂ©thodes d’ultrafiltration sur un Ă©chantillon diffĂ©rent d’os provenant Ă©galement du Yukon et prĂ©sentant de semblables fractures et traces d’enlĂšvements d’éclats. Seulement deux des Ăąges au radiocarbone font partie de la gamme attendue variant entre 25 000 et 40 000 14C ans BP. Six autres Ăąges sont non finis, dont cinq ayant plus de 49 100 14C ans BP. Trois Ăąges finis varient entre 46 500 et 50 500 14C ans BP et ont d’importants Ă©carts-types, et ces Ăąges pourraient Ă©galement ĂȘtre non finis. Deux hypothĂšses testables ont Ă©tĂ© Ă©mises afin d’expliquer les structures de fractures observĂ©es, la premiĂšre Ă©tant que les fractures ont Ă©tĂ© causĂ©es par des humains et la seconde Ă©tant que les fractures sont le rĂ©sultat d’un processus gĂ©ologique inconnu Ă  ce jour. Des recherches plus approfondies s’imposent afin de mettre ces deux hypothĂšses Ă  l’épreuve

    Non-flint pseudo-lithics: some considerations

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