Lithic technological responses to Late Pleistocene glacial cycling at Pinnacle Point Site 5-6, South Africa

There are multiple hypotheses for human responses to glacial cycling in the Late Pleistocene, including changes in population size, interconnectedness, and mobility. Lithic technological analysis informs us of human responses to environmental change because lithic assemblage characteristics are a reflection of raw material transport, reduction, and discard behaviors that depend on hunter-gatherer social and economic decisions. Pinnacle Point Site 5-6 (PP5-6), Western Cape, South Africa is an ideal locality for examining the influence of glacial cycling on early modern human behaviors because it preserves a long sequence spanning marine isotope stages (MIS) 5, 4, and 3 and is associated with robust records of paleoenvironmental change. The analysis presented here addresses the question, what, if any, lithic assemblage traits at PP5-6 represent changing behavioral responses to the MIS 5-4-3 interglacial-glacial cycle? It statistically evaluates changes in 93 traits with no a priori assumptions about which traits may significantly associate with MIS. In contrast to other studies that claim that there is little relationship between broad-scale patterns of climate change and lithic technology, we identified the following characteristics that are associated with MIS 4: increased use of quartz, increased evidence for outcrop sources of quartzite and silcrete, increased evidence for earlier stages of reduction in silcrete, evidence for increased flaking efficiency in all raw material types, and changes in tool types and function for silcrete. Based on these results, we suggest that foragers responded to MIS 4 glacial environmental conditions at PP5-6 with increased population or group sizes, 'place provisioning', longer and/or more intense site occupations, and decreased residential mobility. Several other traits, including silcrete frequency, do not exhibit an association with MIS. Backed pieces, once they appear in the PP5-6 record during MIS 4, persist through MIS 3. Changing paleoenvironments explain some, but not all temporal technological variability at PP5-6.Social Science and Humanities Research Council of Canada; NORAM; American-Scandinavian Foundation; Fundacao para a Ciencia e Tecnologia [SFRH/BPD/73598/2010]; IGERT [DGE 0801634]; Hyde Family Foundations; Institute of Human Origins; National Science Foundation [BCS-9912465, BCS-0130713, BCS-0524087, BCS-1138073]; John Templeton Foundation to the Institute of Human Origins at Arizona State Universit

Rethinking use-wear analysis and experimentation as applied to the study of past hominin tool use

In prehistoric human populations, technologies played a fundamental role in the acquisition of different resources and are represented in the main daily living activities, such as with bone, wooden, and stone-tipped spears for hunting, and chipped-stone tools for butchering. Considering that paleoanthropologists and archeologists are focused on the study of different processes involved in the evolution of human behavior, investigating how hominins acted in the past through the study of evidence on archeological artifacts is crucial. Thus, investigat ing tool use is of major importance for a comprehensive understanding of all processes that characterize human choices of raw materials, techniques, and tool types. Many functional assumptions of tool use have been based on tool design and morphology according to archeologists’ interpretations and ethnographic observations. Such assumptions are used as baselines when inferring human behavior and have driven an improvement in the methods and techniques employed in functional studies over the past few decades. Here, while arguing that use-wear analysis is a key discipline to assess past hominin tool use and to interpret the organization and variability of artifact types in the archeological record, we aim to review and discuss the current state-of-the-art methods, protocols, and their limitations. In doing so, our discussion focuses on three main topics: (1) the need for fundamental improvements by adopting established methods and techniques from similar research fields, (2) the need to implement and combine different levels of experimentation, and (3) the crucial need to establish standards and protocols in order to improve data quality, standard ization, repeatability, and reproducibility. By adopting this perspective, we believe that studies will increase the reliability and applicability of use-wear methods on tool function. The need for a holistic approach that combines not only use-wear traces but also tool technology, design, curation, durability, and efficiency is also debated and revised. Such a revision is a crucial step if archeologists want to build major inferences on human decision making behavior and biocultural evolution processes.info:eu-repo/semantics/publishedVersio

Organic residues in archaeology - the highs and lows of recent research

YesThe analysis of organic residues from archaeological materials has become increasingly important to our understanding of ancient diet, trade and technology. Residues from diverse contexts have been retrieved and analysed from the remains of food, medicine and cosmetics to hafting material on stone arrowheads, pitch and tar from shipwrecks, and ancient manure from soils. Research has brought many advances in our understanding of archaeological, organic residues over the past two decades. Some have enabled very specific and detailed interpretations of materials preserved in the archaeological record. However there are still areas where we know very little, like the mechanisms at work during the formation and preservation of residues, and areas where each advance produces more questions rather than answers, as in the identification of degraded fats. This chapter will discuss some of the significant achievements in the field over the past decade and the ongoing challenges for research in this area.Full text was made available in the Repository on 15th Oct 2015, at the end of the publisher's embargo period

Arnhemsebovenweg, Driebergen (gemeente Utrechtse-Heuvelrug) : archeologisch bureauonderzoek

Met lit. op

Experimental methods for the Palaeolithic dry distillation of birch bark: implications for the origin and development of Neandertal adhesive technology

Abstract The destructive distillation of birch bark to produce tar has recently featured in debates about the technological and cognitive abilities of Neandertals and modern humans. The abilities to precisely control fire temperatures and to manipulate adhesive properties are believed to require advanced mental traits. However, the significance given to adhesive technology in these debates has quickly outgrown our understanding of birch bark tar and its manufacture using aceramic techniques. In this paper, we detail three experimental methods of Palaeolithic tar production ranging from simple to complex. We recorded the fuel, time, materials, temperatures, and tar yield for each method and compared them with the tar known from the Palaeolithic. Our results indicate that it is possible to obtain useful amounts of tar by combining materials and technology already in use by Neandertals. A ceramic container is not required, and temperature control need not be as precise as previously thought. However, Neandertals must have been able to recognize certain material properties, such as adhesive tack and viscosity. In this way, they could develop the technology from producing small traces of tar on partially burned bark to techniques capable of manufacturing quantities of tar equal to those found in the Middle Palaeolithic archaeological record

Salicylate effect on platelets and vascular thrombosis in rheumatoid arthritis

Platelet surface activation was surveyed by electron microscopy (EM) in 40 patients with classical rheumatoid arthritis (RA) without clinical evidence of recent intravascular coagulation. Increased platelet surface activity (PSA) was noted in 8 of 25 females and 8 of 15 males (16 of 40 or 40%). Abnormal PSA failed to correlate with either the presence of rheumatoid nodules or the titer of rheumatoid factor. Hyperactive platelet populations, however, did tend to correlate with a serum urate level above 5 mg% (7 of 12 vs 9 of 28). Neither low nor anti-inflammatory levels of serum salicylate appear to afford protection from abnormal PSA. The authors consecutively reviewed 100 patients with classical RA diagnosed and followed at Henry Ford Hospital (72 females and 28 males) to determine their incidence of thrombotic episodes. The mean age of the group was 59 years and the mean duration of follow-up was 14 years. They found 43 clotting episodes in 30 patients (21 females). There were 14 myocardial infarctions (5 in females); 19 episodes of thrombophlebitis (12 in females); 4 pulmonary embolisms (females); 5 cerebral vascular accidents (4 in females); and one female with peripheral arterial occlusive disease. No significant correlation with rheumatoid nodules, stage of disease progression or functional class of disease was noted when those patients with thromboembolic complications were compared to the others who manifested no clinical thrombosis. This study suggests that in vivo salicylate fails to inhibit PSA as determined by EM and by retrospective review of 100 patients who used prolonged daily dosage of salicylate. The thrombotic episodes were as frequent as in general population surveys, except for data from a cerebral vascular (stroke) survey

Relative stiffness of beeswax and beeswax-ochre containing adhesives.

<p>Boxplot displaying how the stiffness (N/m) of three different rosin-beeswax adhesives is affected by the addition of 100 mg ochre. Adhesive recipes are expressed by the mass of each ingredient (mg).</p

Idealised example of stress/strain curves.

<p>Curves for two different materials displaying brittle and ductile failures. The elastic region is the linear part of the curve, and any displacement along this section is temporary. The plastic region occurs after, and displacement here is permanent.</p

Overview of lap shear results.

<p>Overview of lap shear results.</p

Sample in lap shear test apparatus.

<p>Clamps of a Zwick-Roell 1455 tensile bench containing standard adhesive lap shear test specimen with arrows indicating the applied direction of force.</p