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With a rich sequence of floral and faunal remains spanning the past >65,000 years, Boomplaas Cave is among the more important paleoenvironmental archives from South Africa's southern Cape. However, over the last several decades, its paleoenvironmental records have been the subject of conflicting interpretations, fueling uncertainty over fundamental aspects of Quaternary climate change in the region. Most significantly, researchers have variably interpreted the fossil plant and animal assemblages dating to the Last Glacial Maximum (LGM) as indicating harsh and arid or humid and productive conditions. This review critically examines the paleoenvironmental evidence from Boomplaas Cave, focusing on its LGM deposits and how they relate to the contentious problem of moisture availability through time. We show that interpretations of aridity during the LGM either (i) lack robust ecological links between the evidence and the paleoenvironmental interpretation, or (ii) are based on spurious patterns arising from sampling effects. In contrast, interpretations of relatively humid conditions during the LGM are grounded in present-day ecological observations and are consistent with both local and regional paleoenvironmental datasets. Overall, the evidence strongly supports the characterization of the LGM as a time of relatively humid conditions, with the transition to the Holocene characterized by increasing aridity. Several lines of evidence from Boomplaas Cave further suggest that this phase of increased humidity was associated with a dominance of winter rainfall, in contrast to the aseasonal rainfall regime that characterizes the southern Cape today. 

The use of stone hammers to produce sharp stone flakes—knapping—is thought to represent a significant stage in hominin technological evolution because it facilitated the exploitation of novel resources, including meat obtained from medium‐to‐large‐sized vertebrates. The invention of knapping may have occurred via an additive (i.e., cumulative) process that combined several innovative stages. Here, we propose that one of these stages was the hominin use of ‘naturaliths,’ which we define as naturally produced sharp stone fragments that could be used as cutting tools. Based on a review of the literature and our own research, we first suggest that the ‘typical’ view, namely that sharp‐edged stones are seldom produced by nonprimate processes, is likely incorrect. Instead, naturaliths can be, and are being, endlessly produced in a wide range of settings and thus may occur on the landscape in far greater numbers than archaeologists currently understand or acknowledge. We then explore the potential role this ‘naturalith prevalence’ may have played in the origin of hominin stone knapping. Our hypothesis suggests that the origin of knapping was not a ‘Eureka!’ moment whereby hominins first made a sharp flake by intention or by accident and then sought something to cut, but instead was an emulative process by hominins aiming to reproduce the sharp tools furnished by mother nature and already in demand. We conclude with a discussion of several corollaries our proposal prompts, and several avenues of future research that can support or question our proposal. 

Abstract Backing is a procedure for retouching a stone tool edge to an angle of or near 90°. Archaeologists have recorded backed lithic specimens in the Pleistocene and Holocene around the world. One prominent hypothesis for the occurrence of backing is that it increases a stone tool's adhesion relative to what it would have otherwise been with unmodified, sharp edges. We conducted a highly controlled semi‐static tensile test in which we assessed lithic specimens that possessed both a backed and a non‐backed edge, opposing each other. We hafted each specimen's backed and non‐backed edges to wood, and the bi‐hafted stone implement was then pulled apart using an Universal Instron Materials Tester, allowing for a direct ‘head‐to‐head’ comparison of the two edge types’ adhesive properties. Our tensile test results suggested no significant difference between backed and non‐backed edges in terms of adhesion, which does not support the hypothesis that backing increases a lithic specimen's adhesion. 

Abstract Waterfall Bluff is a rock shelter in eastern Pondoland, South Africa, adjacent to a narrow continental shelf that limited coastline movements across glacial/interglacial cycles. The archaeological deposits are characterized by well-preserved stratigraphy, faunal, and botanical remains alongside abundant stone artifacts and other materials. A comprehensive dating protocol consisting of 5 optically stimulated luminescence ages and 51 accelerator mass spectrometry 14 C ages shows that the record of hunter-gatherer occupations at Waterfall Bluff persisted from the late Pleistocene to the Holocene, spanning the last glacial maximum and the transition from the Pleistocene to the Holocene. Here, we provide detailed descriptions about the sedimentary sequence, chronology, and characteristics of the archaeological deposits at Waterfall Bluff. Remains of marine mollusks and marine fish also show, for the first time, that coastal foraging was a component of some hunter-gatherer groups’ subsistence practices during glacial phases in the late Pleistocene. The presence of marine fish and shellfish further demonstrates that hunter-gatherers selectively targeted coastal resources from intertidal and estuarine habitats. Our results therefore underscore the idea that Pondoland's coastline remained a stable and predictable point on the landscape over the last glacial/interglacial transition being well positioned for hunter-gatherers to access resources from the nearby coastline, narrow continental shelf, and inland areas.