Search

Detailed, well-dated palaeoclimate and archaeological records are critical for understanding the impact of environmental change on human evolution. Ga-Mohana Hill, in the southern Kalahari, South Africa, preserves a Pleistocene archaeological sequence. Relict tufas at the site are evidence of past flowing streams, waterfalls, and shallow pools. Here, we use laser ablation screening to target material suitable for uranium-thorium dating. We obtained 33 ages covering the last 110 thousand years (ka) and identify five tufa formation episodes at 114–100 ka, 73–48 ka, 44–32 ka, 15–6 ka, and ~3 ka. Three tufa episodes are coincident with the archaeological units at Ga-Mohana Hill dating to ~105 ka, ~31 ka, and ~15 ka. Based on our data and the coincidence of dated layers from other local records, we argue that in the southern Kalahari, from ~240 ka to ~71 ka wet phases and human occupation are coupled, but by ~20 ka during the Last Glacial Maximum (LGM), they are decoupled. [ABSTRACT FROM AUTHOR]

There is consensus that the modern human lineage appeared in Africa before 100,000 years ago (1,2). But there is debate as to when cultural and cognitive characteristics typical of modern [...]

Ostrich eggshell (OES) beads from southern African archaeological contexts shed light on past traditions of personal ornamentation, and they are also argued to provide a proxy for understanding past social networks. However, OES beads are often understudied and not reported on in detail. In particular, there has been little research on OES bead variation during Marine Isotope Stage 2 (29,000–12,000 years ago) which includes the Last Glacial Maximum when changing climatic conditions are hypothesized to have significant impact on forager social networks. Here, we present the first technological analysis of terminal Pleistocene OES beads and fragments in the Kalahari from the ~15 ka levels at Ga-Mohana Hill North Rockshelter. We contextualise these findings through comparison with coeval OES bead assemblages across southern Africa during MIS 2. Results indicate that OES beads were manufactured at Ga-Mohana Hill North during the terminal Pleistocene occupation, based on the presence of most stages of bead manufacture. The review shows that OES beads were present across southern Africa through MIS 2, suggesting that culturing of the body was an embodied and persistent practice during that time. While the importance of OES beads as decorative objects was shared by populations across southern Africa, variation in bead diameters indicate that there was stylistic variation. [ABSTRACT FROM AUTHOR]

Composite tool manufacture is a complex technological behaviour that arose in the Middle Stone Age. The hafting of stone tools to handles or shafts seems to depend on the use of glue or adhesive. Chemical and microscopic analysis of glue or adhesive residues on lithic artefacts show the origins of these residues to be from various plant and animal sources, although attributing these residues to specific species has been problematic for various reasons. Experimental evaluation of the efficacy of glue for composite tool manufacture is a valuable method to identify possible sources of residues found on lithic artefacts. Various plant sources of glue have been identified in historical accounts, but some are yet to be identified in the archaeological record or need to be tested for their efficacy. The botanical remains of the genus Watsonia are particularly well represented in the archaeological record, where it is thought to have been foraged as a food source by Stone Age hunter-gatherers. During field observations, Watsonia underground storage organs (USOs) have been found to produce exudate. We test the efficacy of this exudate as a hafting glue for stone tools. Our results indicate that Watsonia exudate is nearly as effective as resin from Vachellia karroo (previously Acacia karroo) trees. These results lay the groundwork for identifying glue as part of composite tool technological components in the archaeological record that may not yet have been identified by other analytical methods, and highlight the role USOs might have played in human technology. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The Middle Stone Age (MSA) is associated with early evidence for symbolic material culture and complex technological innovations. However, one of the most visible aspects of MSA technologies are unretouched triangular stone points that appear in the archaeological record as early as 500,000 years ago in Africa and persist throughout the MSA. How these tools were being used and discarded across a changing Pleistocene landscape can provide insight into how MSA populations prioritized technological and foraging decisions. Creating inferential links between experimental and archaeological tool use helps to establish prehistoric tool function, but is complicated by the overlaying of post-depositional damage onto behaviorally worn tools. Taphonomic damage patterning can provide insight into site formation history, but may preclude behavioral interpretations of tool function. Here, multiple experimental processes that form edge damage on unretouched lithic points from taphonomic and behavioral processes are presented. These provide experimental distributions of wear on tool edges from known processes that are then quantitatively compared to the archaeological patterning of stone point edge damage from three MSA lithic assemblages—Kathu Pan 1, Pinnacle Point Cave 13B, and Die Kelders Cave 1. By using a model-fitting approach, the results presented here provide evidence for variable MSA behavioral strategies of stone point utilization on the landscape consistent with armature tips at KP1, and cutting tools at PP13B and DK1, as well as damage contributions from post-depositional sources across assemblages. This study provides a method with which landscape-scale questions of early modern human tool-use and site-use can be addressed. [ABSTRACT FROM AUTHOR]

Zooarchaeologists frequently use the relative abundance of skeletal elements in faunal assemblages in conjunction with foraging theory models to infer subsistence decisions made by prehistoric hunter-gatherers. However, foraging models applied to ethnoarchaeological cases have had variable success linking skeletal transport decisions with foraging predictions. Here, we approach this issue with the well-known Hadza data to statistically model the skeletal element transport decisions in response to distance from the residential hub and the number of carriers available for carcass transport. We compare our modeling approach to the traditional skeletal element utility curves from Binford's work with the Nunamiut, and to the more recently proposed Shannon evenness measure. Our approach, based on standard yet powerful statistical modeling techniques, can help researchers gain increased insight into the prey part transport responses of hunter-gatherers. Our analyses treat individual prey skeletal elements by body size as the response variable. The results of this analysis suggest that utility curves, and the Shannon evenness approach as a proxy for utility curves, are problematic for making statements about prehistoric foraging from zooarchaeological data. Transport distance does not explain a significant portion of small prey (size class 2) skeletal element transport variation. However, distance explains a great deal of transport variation in large prey (size classes 4 and 5). Inferences from skeletal element profiles should be made relative to prey body size and the discard probability of individual elements. Understanding the influence of these variables allows construction of a framework for testing archaeological element profiles against ethnographically derived transport models. [ABSTRACT FROM AUTHOR]

Stone-tipped weapons were a significant innovation for Middle Pleistocene hominins. Hafted hunting technology represents the development of new cognitive and social learning mechanisms within the genus Homo, and may have provided a foraging advantage over simpler forms of hunting technology, such as a sharpened wooden spear. However, the nature of this foraging advantage has not been confirmed. Experimental studies and ethnographic reports provide conflicting results regarding the relative importance of the functional, economic, and social roles of hafted hunting technology. The controlled experiment reported here was designed to test the functional hypothesis for stone-tipped weapons using spears and ballistics gelatin. It differs from previous investigations of this type because it includes a quantitative analysis of wound track profiles and focuses specifically on hand-delivered spear technology. Our results do not support the hypothesis that tipped spears penetrate deeper than untipped spears. However, tipped spears create a significantly larger inner wound cavity that widens distally. This inner wound cavity is analogous to the permanent wound cavity in ballistics research, which is considered the key variable affecting the relative ‘stopping power’ or ‘killing power’ of a penetrating weapon. Tipped spears conferred a functional advantage to Middle Pleistocene hominins, potentially affecting the frequency and regularity of hunting success with important implications for human adaptation and life history. [ABSTRACT FROM AUTHOR]

Hafting stone points to spears was an important advance in weaponry for early humans. Multiple lines of evidence indicate that ~500,000-year-old stone points from the archaeological site of Kathu Pan 1 (KP1), South Africa, functioned as spear tips. KP1 points exhibit fracture types diagnostic of impact. Modification near the base of some points is consistent with hafting. Experimental and metric data indicate that the points could function well as spear tips. Shape analysis demonstrates that the smaller retouched points are as symmetrical as larger retouched points, which fits expectations for spear tips. The distribution of edge damage is similar to that in an experimental sample of spear tips and is inconsistent with expectations for cutting or scraping tools. Thus, early humans were manufacturing hafted multicomponent tools ~200,000 years earlier than previously thought. [ABSTRACT FROM AUTHOR]

Abstract: Unretouched convergent flakes are frequently a well represented tool type in many Middle Stone Age (MSA) assemblages. Damage to the lateral margins of these points is frequent; however, analytical methods for dealing with the frequency and distribution of edge damage on points have not been developed and applied to a complete MSA lithic assemblage. A method for using GIS to quantify edge damage and statistically analyze the relative location and frequency of edge damage is presented here and applied to the complete assemblage of MSA points from Pinnacle Point Cave 13B (PP13B), South Africa. The results indicate a frequency of edge damage consistent with heavier utilization of the dorsal surface over the ventral surface, and the left side over the right, with the dorsal left lateral margin being most heavily damaged. Additionally, the distribution of edge damage and low frequency of impact damage to the points suggest that PP13B represents a location where points were used for cutting activities and discarded. Applying the recording procedures advocated here to controlled edge damage replication experiments will help provide the interpretive linkages to site assemblage edge damage distributions. [ABSTRACT FROM AUTHOR]

An abstract of the article "Landscape variability in tool-use and edge damage formation in South African Middle Stone Age lithic assemblages" is presented.

The invention of projectile technology had important ramifications for hominin evolution. However, the number of stone points that could have been used as projectiles fluctuates in archaeological assemblages, making it difficult to define when projectile technology was first widely adopted and how its usage changed over time. Here we use an agent-based model to simulate a hunter-gatherer foraging system where armatures are dropped according to their usage. We explore the impact of interactions between human behaviors and the environmental constraints of a data-informed landscape on the distribution and number of lithic armatures found in archaeological assemblages. We ran 2400 simulations modeling different population sizes, rates of hunting with projectiles, and tool curation levels. For each simulation, we recorded the location of dropped armatures and calculated the number and percentage of used armatures that were discarded at habitation camps vs. lost during hunting. We used linear regression to identify the demographic, behavioral, and environmental factor(s) that best explained changes in these numbers and percentages. The model results show that in a well-controlled environment, most armatures used as projectile weapons are lost or discarded at hunting sites; only ∼4.5% of used armatures (or ∼2 armatures per year of simulation) are discarded in habitation camps where they would likely be excavated. These findings suggest that even rare hafted armatures found in the Early and Middle Stone Age could indicate a well-established use of such tools. Our model shows that interactions between reoccupation of archaeological sites, population size, rate of hunting with projectile weapons, and tool curation levels strongly influence the count of lithic armatures found in archaeological assemblages. Therefore, we argue that fluctuations in the counts of armatures documented at archaeological sites should be evaluated within their demographic and environmental contexts to better understand if they reflect spatiotemporal changes in hunting behavior. [ABSTRACT FROM AUTHOR]