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Outstanding questions about human evolution include systematic connections between critical landscape resources—such as water and food—and how these shaped the competitive and biodiverse environment(s) that our ancestors inhabited. Here, we report fossil n-alkyl lipid biomarkers and their associated δ13C values across a newly discovered Olduvai Gorge site (AGS) dated to 1.84 million years ago, enabling a multiproxy analysis of the distributions of critical local landscape resources across an explicit locus of hominin activity. Our results reveal that AGS was a seasonally waterlogged, largely unvegetated lakeside site situated near an ephemeral freshwater river surrounded by arid-adapted C4 grasses. The sparse vegetation at AGS contrasts with reconstructed (micro)habitats at the other anthropogenic sites at Olduvai Gorge, suggesting that central-provisioning places depended more heavily on water access than vegetation viz. woody plants as is often observed for modern hunter-gatherers. As hominins at AGS performed similar butchering activities as at other Bed I sites, our results suggest they did not need the shelter of trees and thus occupied a competitive position within the predatory guild. [ABSTRACT FROM AUTHOR]

Human carnivory is atypical among primates. Unlike chimpanzees and bonobos, who are known to hunt smaller monkeys and eat them immediately, human foragers often cooperate to kill large animals and transport them to a safe location to be shared. While it is known that meat became an important part of the hominin diet around 2.6-2 Mya, whether intense cooperation and food sharing developed in conjunction with the regular intake of meat remains unresolved. A widespread assumption is that early hominins acquired animal protein through klepto-parasitism at felid kills. This should be testable by detecting felid-specific bone modifications and tooth marks on carcasses consumed by hominins. Here, deep learning (DL) computer vision was used to identify agency through the analysis of tooth pits and scores on bones recovered from the Early Pleistocene site of DS (Bed I, Olduvai Gorge). We present the first objective evidence of primary access to meat by hominins 1.8 Mya by showing that the most common securely detectable bone-modifying fissipeds at the site were hyenas. The absence of felid modifications in most of the carcasses analyzed indicates that hominins were the primary consumers of most animals accumulated at the site, with hyenas intervening at the post-depositional stage. This underscores the role of hominins as a prominent part of the early Pleistocene African carnivore guild. It also stresses the major (and potentially regular) role that meat played in the diet that configured the emergence of early Homo. [ABSTRACT FROM AUTHOR]

Meat eating is one of the hallmarks of human evolution. It has been linked to the beginning of stone tool use, to physiological changes leading to crucial anatomical transformations defining our genus, and to new socioreproductive and cognitive behaviors. Uncontroversial evidence of meat eating goes back to 2.6 million years ago; however, little is known about the frequency and timing with which early hominins acquired animal resources. Here, we show that the combination of hunting and scavenging documented in some modern human foragers may have a long evolutionary trajectory. Using a new set of artificial intelligence methods for objective identification, we present direct evidence of an episode of hominins scavenging from large felids—probably lions—discovered at Olduvai Gorge (DS site, Bed I). This casts a new perspective on the diversity of hominin carcass acquisition behaviors and survival strategies, and places some early Pleistocene hominins in ecological proximity to African large carnivore guilds. [ABSTRACT FROM AUTHOR]

Humans are unique in their diet, physiology and socio-reproductive behavior compared to other primates. They are also unique in the ubiquitous adaptation to all biomes and habitats. From an evolutionary perspective, these trends seem to have started about two million years ago, coinciding with the emergence of encephalization, the reduction of the dental apparatus, the adoption of a fully terrestrial lifestyle, resulting in the emergence of the modern anatomical bauplan, the focalization of certain activities in the landscape, the use of stone tools, and the exit from Africa. It is in this period that clear taphonomic evidence of a switch in diet with respect to Pliocene hominins occurred, with the adoption of carnivory. Until now, the degree of carnivorism in early humans remained controversial. A persistent hypothesis is that hominins acquired meat irregularly (potentially as fallback food) and opportunistically through klepto-foraging. Here, we test this hypothesis and show, in contrast, that the butchery practices of early Pleistocene hominins (unveiled through systematic study of the patterning and intensity of cut marks on their prey) could not have resulted from having frequent secondary access to carcasses. We provide evidence of hominin primary access to animal resources and emphasize the role that meat played in their diets, their ecology and their anatomical evolution, ultimately resulting in the ecologically unrestricted terrestrial adaptation of our species. This has major implications to the evolution of human physiology and potentially for the evolution of the human brain. [ABSTRACT FROM AUTHOR]

The Acheulean materials documented in FLK West dated c. 1.7 Ma. are the focus of the present work. An original techno-functional approach is applied here to analyze the origin of Acheulean tools. According to the results, these tools were employed in different functional contexts in which tasks of different durations that transformed resources with different resistances were carried out. The exploitation of large and resistant resources suggests that the economic mechanism governing the manufacture of these tools was an increase in the demand of the work load. The decision processes underlying the production of these tools have thus an evident functional motivation. However, the presence of a refined handaxe in the studied sample indicates that the design form and production principles of handaxe manufacture were the result of an abrupt emergence rather than a long gradual development. The integration of mechanical and ergonomic investigation in our research has been crucial to explain how a core-and-flake industry gave way to a technology based on the production of large and heavy shaped tools. [ABSTRACT FROM AUTHOR]

Traditionally, insights into hominin technology, behaviours and activities are mostly inferred from the analysis of stone artifacts. Cognition, oncethought to be determined by brain size and complexity alone, can now also be measured by examining the relationships between core reduction strategies, tool types and lithic raw material utilizations and procurement strategies. The objectives of this study are to define the lithic industry and determine hominin behaviours, activities and cognition as reflected by the stone artifacts collected from the Middle Pleistocene upper Ngaloba Beds at Laetoli, Tanzania. The upper Ngaloba Beds, dated to about 200 kya have also yielded a cranium of Early Homo sapiens (EHs: referred to as Laetoli Hominin 18, LH18) or Homo heidelbergensis, in direct association with stone artifacts. The study reveals that the upper Ngaloba Beds' stone tools represent a predominantly (93.840 %) light-duty toolkit (scrapers, becs, burins and points) mixed with a lower percentage (6.16 %) of heavy-duty toolkit (core/large scrapers, bifaces/picks and core axes). This combination of light-duty and heavy-duty toolkits is best described as Early Middle Stone Age (EMSA) Ngaloban industry. Analysis of lithic raw materials shows that EHs at Laetoli utilized both local and non-local materials indicating wide-ranging patterns. Therefore, during 200 kya, EHs at Laetoli had a thorough knowledge of the landscape, using it to find and transport lithic raw materials. Moreover, analyses of stone artifact size, tool types and core utilizations versus lithic raw materials show that EHs knew how to manipulate lithic materials to the best of their abilities. The occurrences of retouched and Levallois points in general and some with thinned bulbs signals that EHs at Laetoli had knowledge of projectile weaponry and hafting systems. Moreover, the presence of red ochre indicates procurement and use of pigments and therefore, evidence for symbolic behaviour by EHs during EMSA at Laetoli, 200 kya. [ABSTRACT FROM AUTHOR]

Meat-eating was an important factor affecting early hominin brain expansion, social organization and geographic movement. Stone tool butchery marks on ungulate fossils in several African archaeological assemblages demonstrate a significant level of carnivory by Pleistocene hominins, but the discovery at Olduvai Gorge of a child's pathological cranial fragments indicates that some hominins probably experienced scarcity of animal foods during various stages of their life histories. The child's parietal fragments, excavated from 1.5-million-year-old sediments, show porotic hyperostosis, a pathology associated with anemia. Nutritional deficiencies, including anemia, are most common at weaning, when children lose passive immunity received through their mothers' milk. Our results suggest, alternatively, that (1) the developmentally disruptive potential of weaning reached far beyond sedentary Holocene food-producing societies and into the early Pleistocene, or that (2) a hominin mother's meat-deficient diet negatively altered the nutritional content of her breast milk to the extent that her nursing child ultimately died from malnourishment. Either way, this discovery highlights that by at least 1.5 million years ago early human physiology was already adapted to a diet that included the regular consumption of meat. [ABSTRACT FROM AUTHOR]

The association of stone tools and modified bones at archaeological African Plio-Pleistocene sites is essential to understanding the socio-economics of early hominin behavior. Previous research at BK suggests the site was repeatedly visited by hominins for short time periods. During these occupations, the hominins had a primary role in the exploitation of small, medium, and large size carcasses. The present study analyzes the faunal material recovered from level 3b at BK (BK3b). The results indicate that BK3b operated as a place consciously selected by hominins to carry out specific activities, which resulted in a large accumulation of lithic materials and bone remains. The high frequency of cut-marked specimens, even more than is documented at FLK Zinj, supports the idea that hominins at BK3b butchered and demarrowed the bones from animals of all sizes. [ABSTRACT FROM AUTHOR]

Olduvai Gorge (Tanzania) is a key site for the study and comprehension of human evolution in East Africa. However, the origin of Homo sapiens and the Middle Stone Age have been poorly understood in the Gorge thus far. In this study, we present the dating, taphonomic, technological and typological analyses of the lithic industry and faunal remains excavated at the Victoria Cabrera Site (VCS) during the 2017 fieldwork season. The stratigraphic sequence of the site contains several levels of fluvial origin, some of them with lithic and faunal remains. Most remains (lithics and bones) are affected by rounding processes. Infrared stimulated luminescence (IRSL) dating has provided ages between 90 and 70 ka BP for these layers that can be related to the Marine Isotope Stage 5a. Lithics are scarce and the dominant raw materials are Naibor Soit quarzite and basalt, followed by phonolite, chert and quartz as the most common raw materials. The lithic technology is based on the production of flakes obtained from prepared cores, with the discoid method and, to a lesser extent the Levallois method being the most frequently used. The retouched blanks are described as "substratum" or "domestic" tools (sidescrapers, notches or denticulates). There is just one heavy duty piece and points are absent. The faunal assemblage includes Alcelaphinae , Antilopinae and Equidae. The major parts of the unidentified faunal remains are size 3 ungulates, followed by carcasses of size 2 and size 4 species. We cannot relate lithic and bones because no cut marks or percussion marks have been identified and carnivore action is scarce. In sum, VCS represents the first accurately dated Middle Stone Age site, with lithic and faunal remains in Olduvai Gorge. [ABSTRACT FROM AUTHOR]