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Early hominin group size: A perspective from Bestwood 1, Northern Cape Province, South Africa
Abstract
The study of primate social behavior in the wild has emerged as a tool with great potential for increasing our understanding early hominins. However, the application of models generated from observation of living primates to the archaeological record is challenging. Bestwood 1, a component of the Kathu Complex of site in the Northern Cape Province, South Africa provides an opportunity to consider the spatial organization of hominin activity across a landscape at ca. 360 kyr in an archaeological context attributed to the Fauresmith. This article provides the first data for the spatial distribution of artifacts at Bestwood 1 and argues in favor of a baboon model of social organization for the hominin groups that generated the spatial patterning found at this locality.
... Helgren and Brooks 1983). However, the enormous Acheulean stone tool accumulations present in the southern Kalahari at sites such as Kathu Townlands and Bestwood, with millions of stone tools on and below the surface (Walker et al. 2014;Chazan 2022), as well as sites with remains of wetland species (Brink 2016) and multi-proxy palaeoenvironmental studies (Matmon et al. 2015;Ecker et al. 2018;van der Meden 2022) argue for substantial wet phases in the Pleistocene. A link to a substantial drainage system, the (now non-existent) Nossob-Molopo drainage system, has been proposed based on geochemical analysis of Kalahari sediments (Vainer et al. 2018). ...
... Often, the highest density sites are located on ridges overlooking pans, whereas so far no sites have been identified in pans that are not connected to raw material sources. Overall, the emerging picture is similar to that seen in landscapes around Kathu Townlands or Bestwood in South Africa (Walker et al. 2014;Chazan 2022) in lithic abundance, although differing in raw material and containing a much smaller percentage of heavy-duty tools. There are, at first glance, few commonalities with the younger MSA sites in the Makgadikgadi Basin and Tsodilo Hills of northern Botswana Coulson et al. 2022;Staurset et al. 2022aStaurset et al. , 2022b. ...
... Hunter-gatherers tend to selforganize into hierarchical macro-structures [11][12][13], which are more in line with a baboon-like troop organization than a bonobo or chimpanzee one. This is despite the fact that the human microorganization is very different from baboons, the latter being a clan, dominated by a single male, while humans form predominantly pair-bonded multi-male-multi-female societies [14]. ...
... Did structural solutions for macro-network management, like fission-fusion pattern, evolve or emerge to facilitate large groups or rather to facilitate temporal variation in the environment's carrying capacity [96][97][98][99][100]? In particular, is the presence of a baboon-like fission-fusion dynamic a clue towards the evolution of the ability to form large complex groups in humans, or is this a case of parallel evolution [14,101]? Is a central figure's one-way communication, as in the case of priesthood [102] or in social technologies facilitated by mass media [103,104], another social technology that allows larger groups? ...
Human groups tend to be much larger than those of non-human primates. This is a puzzle. When ecological factors do not limit primate group size, the problem of coordination creates an upper threshold even when cooperation is guaranteed. This paper offers a model of group coordination towards behavioural synchrony to spell out the mechanics of group size limits, and thus show why it is odd that humans live in large societies. The findings suggest that many of our species' evolved social behaviours and culturally maintained social technologies emerged as solutions to this problem.
... Hunter-gatherers all across the world self-organise into hierarchical group macro-structure [11][12][13], which is more in line with a baboon-like troop organisation than a bonobo or chimpanzee one. This is despite the fact that our micro-organisation is very different from baboons, the latter being a clan dominated by a single male, while we form multi-male-multi-female societies in which the smallest unit is predominantly pair-bonded, the human equivalents of the baboon 'clan' [14]. ...
... Did language evolve as a third-party information tool to facilitate larger groups [58][59][60]? Did the structural solutions for macro-network management, like fission-fusion pattern, evolve to facilitate large groups or to facilitate temporal variation in the environment's carrying capacity [61][62][63][64][65]? In particular, is baboon-like fission-fusion dynamic a clue towards the evolution of the ability to form large complex groups in humans, or is this a case for parallel evolution [14,66]? Is a central figure's one-way communication, as in the case of priesthood [67], or in social technologies facilitated by mass media [68,69], another social technology that allows larger groups? ...
Human groups tend to be much larger than those of non-human primates. This is a puzzle. When ecological factors do not limit primate group size, the problem of coordination creates an upper threshold even when cooperation is guaranteed. This paper offers a simple model of group coordination towards behavioural synchrony to spell out the mechanics of group size limits, and thus show why it is odd that humans live in large societies. The findings suggest that many of our species` evolved social behaviours and culturally-maintained social technologies emerged as a solution to this problem.
... Nonhuman primates, specifically within the genus Pan, are often used as analogues for early human dispersal models (Copeland et al., 2011;Lockwood et al., 2007). Yet given the remaining unknowns about dispersal in chimpanzees, additional sources of information about their origins and distance traveled would enrich the comparative model for apes (Koenig & Borries, 2012) and be useful in contextualizing emerging evidence for early African hominin mobility (Chazan, 2022; Heydari-Guran & Ghasidian, 2020). ...
Objectives
Chimpanzees ( Pan troglodytes ) are patrilocal, with males remaining in their natal community and females dispersing when they reach sexual maturity. However, the details of female chimpanzee dispersal, such as their possible origin, are difficult to assess, even in habituated communities. This study investigates the utility of ⁸⁷ Sr/ ⁸⁶ Sr analysis for (1) assessing Sr baseline differences between chimpanzee territories and (2) identifying the status (immigrant or natal) of females of unknown origin within the territories of five neighboring communities in Taï National Park (Côte d'Ivoire).
Materials and Methods
To create a local Sr isoscape for the Taï Chimpanzee Project (TCP) study area, we sampled environmental samples from TCP‐established territories ( n = 35). To assess dispersal patterns, 34 tooth enamel samples (one per individual) were selected from the Taï chimpanzee skeletal collection. ⁸⁷ Sr/ ⁸⁶ Sr analysis was performed on all 69 samples at the W.M. Keck Lab. The theoretical density and overlap of chimpanzee communities as well as generalized linear mixed models (GLMMs) were used to test each question.
Results
⁸⁷ Sr/ ⁸⁶ Sr ratios for natal male chimpanzees ranged from 0.71662 to 0.72187, which is well within the corresponding environmental baseline range of 0.70774–0.73460. The local Sr isoscapes fit was estimated with the root‐mean‐square error value, which was 0.0048 (22% of the whole ⁸⁷ Sr/ ⁸⁶ Sr data range). GLMMs identified significant differences in ⁸⁷ Sr/ ⁸⁶ Sr ratios between natal and unknown North community origin groups, suggesting that after 1980, females of unknown origin could be immigrants to North community ( n = 7, z ‐ratio = −4.08, p = 0.0001, power = 0.94).
Discussion
This study indicates that ⁸⁷ Sr/ ⁸⁶ This study indicates that ⁸⁷ Sr/ ⁸⁶ Sr analysis can successfully identify immigrant females in skeletal collections obtained from wild chimpanzee communities, enabling the tracking of female dispersal patterns historically. There are, however, significant limitations within the scope of this study, such as (1) the absence of reliable maps for the TCP study area, (2) limited capacity for environmental sampling, (3) small sample sizes, and (4) tooth formation in wild chimpanzees.
... For reasons that are not clear, Pleistocene artifacts are not found in areas covered by sheets of calcrete. The archaeological locality of Bestwood 1 is found at the interface of a deep gravel deposit (>30 m) and overlying Kalahari sands that fill a large valley between two hills (Chazan, 2022;Chazan et al., 2012;Papadimitrios et al., 2019) (Fig. 4). Artifacts are limited to a thin horizon and are in fresh conditions, indicating rapid burial and a lack of significant transport. ...
The Kalahari has a powerful hold on the collective imagination as an environment of extreme aridity where survival is a challenge. However, the current aridity of the Kalahari (which is classified as a savannah biome) is a relatively recent phenomenon that emerged in the Holocene. Particularly for the Early Pleistocene, there are compelling indicators, especially from studies of the Mamatwan mine, of greater availability of water from both precipitation and an active drainage system that ran southward through the Kalahari from the Angolan highlands (Matmon et al., 2015; Vainer et al., 2018). There are currently few documented Pleistocene archaeological localities within the Kalahari. It is within this context that the sites of the Kathu Complex and Wonderwerk Cave, located on the Ghaap Plateau on the southern edge of the Kalahari (Northern Cape Province of South Africa), take on particular significance for the study of human evolution in southern Africa.
... How is paleoanthropology different today, nearly a quarter way along the 21st century? The baboons have turned out to be durable models for human evolution, particularly with regard to dietary strategies and social organization (Codron et al., 2008;Macho, 2014;Badenhorst, 2018;Swedell and Plummer, 2019;Chazan, 2022). This reflects a great deal of field research that has been undertaken over the last several decades that has reinforced the view that Papio is a remarkably flexible genus and represents a suitable behavioral analog for hominins before the advent of material technology, regardless (and in spite of) its phylogenetic distance. ...
Despite substantial additions to the paleontological record and unanticipated improvements in analytical techniques since the Journal of Human Evolution was first published, consensus on the diet of early hominin species remains elusive. For instance, the notable advances in the analyses of hominin dental microwear and stable isotopes have provided a plethora of data that have in some instances clouded what was once ostensibly a clear picture of dietary differentiation between and within hominin taxa. In the present study, we explore the reasons why the retrodiction of diet in human evolution has proven vexing over the last half century from the perspective of both ecological and functional-mechanical models. Such models continue to be indispensable for paleobiological reconstructions, but they often contain rigid or unstated assumptions about how primary paleontological data, such as fossils and their geological and taphonomic contexts, allow unambiguous insight into the evolutionary processes that produced them. In theoretical discussions of paleobiology, it has long been recognized that a mapping function of morphology to adaptation is not one-to-one, in the sense that a particular trait cannot necessarily be attributed to a specific selective pressure and/or behavior. This article explores how the intrinsic variability within biological systems has often been underappreciated in paleoanthropological research. For instance, to claim that derived anatomical traits represent adaptations related to stereotypical behaviors largely ignores the importance of biological roles (i.e., how anatomical traits function in the environment), a concept that depends on behavioral flexibility for its potency. Similarly, in the paleoecological context, the underrepresentation of variability within the ‘edible landscapes’ our hominin ancestors occupied has inhibited an adequate appreciation of early hominin dietary flexibility. Incorporating the reality of variation at organismal and ecological scales makes the practice of paleobiological reconstruction more challenging, but in return, allows for a better appreciation of the evolutionary possibilities that were open to early hominins.
... Seasonal aggregations of larger group sizes, typical of multilevel modular primate societies in open-air and arid environments (e.g. Grüter and Zinner 2004;Grueter, Chapais, and Zinner 2012;Swedell and Plummer 2012), would have constituted an important anti-predator defence mechanism among hominins lacking specialised climbing abilities, particularly when they approached contested spaces, such as permanent freshwater sources (Isbell et al. 2018;Chazan 2021). Larger and well-coordinated group sizes would have also facilitated the procurement of very large animals through the targeting of less predatorwary individuals by approaching within close striking distance (e.g. ...
The Early Pleistocene (2.58-0.78 Ma) was a period of major evolutionary changes in the hominin lineage. The progressive consolidation of bipedal locomotion, alongside increases in cranial capacity and behavioural flexibility, allowed early Homo to exploit an increasing diversity of resources and environmental settings within the changing landscapes of East Africa and beyond. These complex processes were not necessarily linear or spatially uniform, given the technological diversity documented, particularly during the Oldowan-Acheulean transition. In this paper, we argue that human populations experienced a considerable demographic expansion from c.1.7-1.5 Ma onwards, expressed in the number, size, density, and distribution of archaeological sites. These patterns resulted from the interplay of high-yielding animal resource exploitation strategies, technological investment, prosocial behaviours as well as increasingly structured land use patterns. A more consolidated hominin demographic structure led to the extinction of large sympatric carnivore species, while larger group sizes would have led to more successful Out-of-Africa dispersals.
The temporal coupling of the structural evolution of the Kalahari Basin and the accumulation of the Kalahari Group sediments has been an accepted paradigm leading to the assumption that the Kalahari group sediments have been accumulating gradually since the mid-Cretaceous. Here we review the first actual ages for the Kalahari Group based on cosmogenic ages from six geological localities. These results demonstrate that Kalahari Basin infill was a more dynamic process than previously thought and that the Kalahari Group sediments are mostly Plio-Pleistocene in age (∼4 Ma to 1–2 Ma). The hiatus between the initial structural subsidence of the basin, during the Cretaceous, and the general young age of the investigated sediments, implies a dynamic landscape in which significant phases of erosion occurred during the Mesozoic and Cenozoic. The magnitude of erosion is manifested by the fact that in many locations Kalahari Neogene to Quaternary sediments overlie Precambrian basement.
The age of the present infill of the Kalahari thus falls within the temporal range of the genus Homo. In light of this new understanding, we provide a review of the archaeological evidence from the Kalahari Basin and along its southern fringe. Initial hominin presence is found at Wonderwerk Cave during the Olduvai Event and there is subsequent high-density occupation along the southern fringe of the Kalahari Basin during the Acheulean and the Fauresmith. Middle Stone Age occupation is limited to localities of limited size and small artifact counts and it appears that the focus of human occupation, particularly in the later stages of the Middle Stone Age, shifts southward, including along the coastal regions.
Wonderwerk Cave, located in the Northern Cape Province of South Africa, is a rare cave site with a sequence of Acheulean occupation that is derived from activity within the cave rather than via avens. Building on previous publication of the sedimentary context for the Acheulean sequence based on the North Profile of Excavation 1 at Wonderwerk Cave, we present here new observations based on micromorphological analysis of the Southern Profile of Excavation 1 and the Acheulean component of Excavation 2, along with preliminary observations on the context of artifact deposition based on renewed high-precision excavation. The results largely support earlier observations including the low density of artifacts, the aeolian contribution to the sediments, and the absence of water transport within the cave. New observations are primarily the presence of a significant component of rhizoliths in the South Profile that appear to be the result of the penetration of roots into the cave from the surface of the hill. This study adds significantly to our understanding of site formation processes and hominin activity during the Acheulean at the front of the cave. However, these remain limited windows into a much larger system that will require continued investigation.
In Hidden Depths, Professor Penny Spikins explores how our emotional connections have shaped human ancestry. Focusing on three key transitions in human origins, Professor Spikins explains how the emotional capacities of our early ancestors evolved in response to ecological changes, much like similar changes in other social mammals. For each transition, dedicated chapters examine evolutionary pressures, responses in changes in human emotional capacities and the archaeological evidence for human social behaviours. Starting from our earliest origins, in Part One, Professor Spikins explores how after two million years ago, movement of human ancestors into a new ecological niche drove new types of collaboration, including care for vulnerable members of the group. Emotional adaptations lead to cognitive changes, as new connections based on compassion, generosity, trust and inclusion also changed our relationship to material things. Part Two explores a later key transition in human emotional capacities occurring after 300,000 years ago. At this time changes in social tolerance allowed ancestors of our own species to further reach out beyond their local group and care about distant allies, making human communities resilient to environmental changes. An increasingly close relationship to animals, and even to cherished possessions, appeared at this time, and can be explained through new human vulnerabilities and ways of seeking comfort and belonging. Lastly, Part Three focuses on the contrasts in emotional dispositions arising between ourselves and our close cousins, the Neanderthals. Neanderthals are revealed as equally caring yet emotionally different humans, who might, if things had been different, have been in our place today. This new narrative breaks away from traditional views of human evolution as exceptional or as a linear progression towards a more perfect form. Instead, our evolutionary history is situated within similar processes occurring in other mammals, and explained as one in which emotions, rather than ‘intellect’, were key to our evolutionary journey. Moreover, changes in emotional capacities and dispositions are seen as part of differing pathways each bringing strengths, weaknesses and compromises. These hidden depths provide an explanation for many of the emotional sensitivities and vulnerabilities which continue to influence our world today.
In Hidden Depths, Professor Penny Spikins explores how our emotional connections have shaped human ancestry. Focusing on three key transitions in human origins, Professor Spikins explains how the emotional capacities of our early ancestors evolved in response to ecological changes, much like similar changes in other social mammals. For each transition, dedicated chapters examine evolutionary pressures, responses in changes in human emotional capacities and the archaeological evidence for human social behaviours. Starting from our earliest origins, in Part One, Professor Spikins explores how after two million years ago, movement of human ancestors into a new ecological niche drove new types of collaboration, including care for vulnerable members of the group. Emotional adaptations lead to cognitive changes, as new connections based on compassion, generosity, trust and inclusion also changed our relationship to material things. Part Two explores a later key transition in human emotional capacities occurring after 300,000 years ago. At this time changes in social tolerance allowed ancestors of our own species to further reach out beyond their local group and care about distant allies, making human communities resilient to environmental changes. An increasingly close relationship to animals, and even to cherished possessions, appeared at this time, and can be explained through new human vulnerabilities and ways of seeking comfort and belonging. Lastly, Part Three focuses on the contrasts in emotional dispositions arising between ourselves and our close cousins, the Neanderthals. Neanderthals are revealed as equally caring yet emotionally different humans, who might, if things had been different, have been in our place today. This new narrative breaks away from traditional views of human evolution as exceptional or as a linear progression towards a more perfect form. Instead, our evolutionary history is situated within similar processes occurring in other mammals, and explained as one in which emotions, rather than ‘intellect’, were key to our evolutionary journey. Moreover, changes in emotional capacities and dispositions are seen as part of differing pathways each bringing strengths, weaknesses and compromises. These hidden depths provide an explanation for many of the emotional sensitivities and vulnerabilities which continue to influence our world today.
Kathu Pan 6 (Northern Cape Province) is an open-air site exposed by sinkhole activity that includes a Middle Stone Age Howiesons Poort (HP) component in a stratigraphic sequence that also includes Later Stone Age, early Middle Stone Age, and Earlier Stone Age (Fauresmith) assemblages. Here, we present the dating of the Kathu Pan 6 sequence using multiple luminescence signals: optically stimulated luminescence (blue OSL) and thermally transferred OSL (TT-OSL) on quartz; and the infrared stimulated luminescence (IRSL) post IR-IR290 signal on potassium feldspar. The results obtained from analyses of different minerals and signals for the archaeological deposits do not always conform but the quartz OSL provides the most accurate set of ages for the HP at KP6 (between 100 ± 6 and 74 ± 5 ka). This age range places the KP6 HP earlier than any of the scenarios considered plausible by Jacobs and Roberts (Journal of Human Evolution, 107, 1–13 2017) but fits well with the extended duration for the HP at Diepkloof proposed by Tribolo et al. (Journal of Archaeological Science, 36(3) 730–39 2009) and promoted by Feathers (Journal of Archaeological Science, 63, 164–174 2017). Two OSL ages bracket the Later Stone Age Wilton industry at KP6, placing it between 5.7 ± 0.3 ka and 2.3 ± 0.1 ka. These fit with known ages for the Wilton and place the KP6 occupation contemporary with Strata 4c–3b at Wonderwerk Cave.
Social networks in modern societies are highly structured, usually involving frequent contact with a small number of unrelated ‘friends’ 1 . However, contact network structures in traditional small-scale societies, especially hunter-gatherers, are poorly characterized. We developed a portable wireless sensing technology (motes) to study within-camp proximity networks among Agta and BaYaka hunter-gatherers in fine detail. We show that hunter-gatherer social networks exhibit signs of increased efficiency 2 for potential information exchange. Increased network efficiency is achieved through investment in a few strong links among non-kin ‘friends’ connecting unrelated families. We show that interactions with non-kin appear in childhood, creating opportunities for collaboration and cultural exchange beyond family at early ages. We also show that strong friendships are more important than family ties in predicting levels of shared knowledge among individuals. We hypothesize that efficient transmission of cumulative culture 3, 4, 5, 6 may have shaped human social networks and contributed to our tendency to extend networks beyond kin and form strong non-kin ties.
The spatial structure of archeological sites can help reconstruct the settlement dynamics of hunter-gatherers by providing information on the number and length of occupations. This study seeks to access this information through a comparison of seven sites. These sites are open-air and were all excavated over large spatial areas, up to 2,000 m2, and are therefore ideal for spatial analysis, which was done using two complementary methods, lithic refitting and density zones. Both methods were assessed statistically using confidence intervals. The statistically significant results from each site were then compiled to evaluate trends that occur across the seven sites. These results were used to assess the “spatial consistency” of each assemblage and, through that, the number and duration of occupations. This study demonstrates that spatial analysis can be a powerful tool in research on occupation dynamics and can help disentangle the many occupations that often make up an archeological assemblage.
Significance
Humans evolved in response to the availability of plant and water resources over space and through time. Their influence on our species’ evolution is debated, though, because archives of their spatial distribution are scarce at early human (hominin) localities. Meter-scale vegetation patterns are revealed from sedimentary plant biomarkers across an archaeological horizon at Olduvai Gorge (FLK Zinj ). Biomarkers evince a varied local landscape with a woodland patch near a small freshwater wetland, surrounded by an open grassland landscape. Biomarkers from the wetland indicate diverse edible plants near potable water. The coexistence of butchered large animal bones and hominin remains, including juveniles, within an isolated biomarker-delineated wooded microhabitat at FLK Zinj provide support for early provisioning behaviors by our ancestors.
This paper examines the home base/food sharing model developed by Glynn Isaac
in light of recent research on the Late Lower Paleolithic of Israel. The focus is on
a comparison of the cave site of Qesem and the open air site of Holon, both of
which have been the subject of comprehensive research. This comparison leads to a
consideration of an alternative model for early hominin mobility that draws on the
Lèvy walk foraging pattern in which a cluster of many short-distance excursions
are interspersed with occasional longer distance excursions comprising the full
range of landscapes exploited. Base camps may have emerged as one type of hub
for such excursions.
The assemblage of stone tools from P. Beaumont’s Excavation 1 at Wonderwerk Cave, Northern Cape Province, South Africa, provides a unique stratified sequence covering a large part of the Earlier Stone Age. A combination of cosmogenic burial age and paleomagnetic age dating provides limited chronometric constraint on this sequence. The Wonderwerk sequence provides evidence for the development of Earlier Stone Age technology in southern Africa that parallels the sequence known from East Africa. This paper presents a technological discussion of biface technology at Wonderwerk Cave as well as an overview of the associated lithic assemblage.
Large social aggregations are among the most highly organized events associated with mobile hunter-gatherers. The Bull Brook Paleoindian site in Ipswich, Massachusetts provides the strongest case for large-scale Paleoindian aggregation in North America, with 36 discrete concentrations of artifacts arranged in a large circle. Avocational archaeologists who salvaged the site in the 1950s interpreted it as a single occupation. Professionals first rejected and then revived this hypothesis, but the site remained insufficiently analyzed to evaluate. New research supports the single occupation hypothesis with a fully reconstructed site plan and the first complete analysis of artifact distributions. Clear spatial structure of activities within the ring-shaped site plan provides a window on social contexts that are also visible in smaller Paleoindian settlements.
At Maastricht-Belvédère an attempt was made to document the low-density scatter of flint artefacts against which the 'rich' sites are present within the 250,000 years old interglacial deposits there. A short presentation and interpretation of the low-density scatter (Site N) is followed by a brief discussion of the implications this work might have for our understanding of the archaeological record.
The Earlier Stone Age (ESA) sequence of Excavation 1 at Wonderwerk Cave is the longest stratified sedimentary sequence associated with hominin occupation in Southern Africa. This sequence has been constrained chronologically on the basis of cosmogenic burial age and paleomagnetic dating. Geoarchaeological analysis of two exposed profiles covering strata 12–9 that combine micromorphology and FTIR on the ESA deposits shows shifts in depositional sources, transport, and diagenesis. This analysis provides insight into the paleoenvironmental context of hominin occupation and suggests that during part of the stratigraphic sequence, there was an ephemeral body of water in proximity to the cave. These results provide the basis for ongoing geoarchaeological research on the landscape outside the cave and other components of the cave deposits.
Kalahari Group sediments accumulated in the Kalahari basin, which started forming during the breakup of Gondwana in the early Cretaceous. These sediments cover an extensive part of southern Africa and form a low-relief landscape. Current models assume that the Kalahari Group accumulated throughout the entire Cenozoic. However, chronology has been restricted to early–middle Cenozoic biostratigraphic correlations and to OSL dating of only the past ~300 ka. We present a new chronological framework that reveals a dynamic nature of sedimentation in the southern Kalahari. Cosmogenic burial ages obtained from a 55 m section of Kalahari Group sediments from the Mamatwan Mine, southern Kalahari, indicate that the majority of deposition at this location occurred rapidly at 1–1.2 Ma. This Pleistocene sequence overlies the Archaean basement, forming a significant hiatus that permits the possibility of many Phanerozoic cycles of deposition and erosion no longer preserved in the sedimentary record. Our data also establish the existence of a shallow early–middle Pleistocene water body that persisted for N450 ka prior to this rapid period of deposition. Evidence from neighboring archeological excavations in southern Africa suggests an association of high-density hominin occupation with this water body.
Kathu Townlands is a high density Earlier Stone Age locality in the Northern Cape Province, South Africa. Here we present the first detailed information on this locality based on analysis of a sample of lithic material from excavations by P. Beaumont and field observations made in the course of fieldwork in 2013. The results confirm the remarkably high artefact density at Kathu Townlands and do not provide evidence consistent with high energy transport as a mechanism of site formation, suggesting that Kathu Townlands was the site of intensive exploitation of highly siliceous outcroppings of banded iron formation. The results presented here provide a first step towards understanding this complex locality and point to the need for further research and the importance of preserving this locality in the face of intensive and rapid development.
Multi-level societies are unique in their ability to facilitate the maintenance of strong and consistent social bonds among some individuals while allowing separation among others, which may be especially important when social and sexual bonds carry significant and reliable benefits to individuals within social groups. Here we examine the importance of social and sexual bonds in the multilevel society of hamadryas baboons, Papio hamadryas, and apply these principles to social evolution in Plio-Pleistocene hominins. The behavior, adaptations and socioecology of baboons (Papio spp.) have long been recognized as providing an important comparative sample to elucidate the processes of human evolution, and the multi-level society of hamadryas baboons in particular shares even more similarities with humans than other baboons. Here we draw parallels between processes during the evolution of hamadryas social organization and those characterizing late Pliocene or early Pleistocene hominins, most likely Homo erectus. The higher costs of reproduction faced by Homo erectus females, exacerbated by an increased reliance on difficult to acquire, nutrient-dense foods, are commonly thought to have been alleviated by a strengthening of male-female bonds (via male provisioning and the evolution of monogamy) or by the assistance of older, post-reproductive females (via grandmothering). We suggest that both of these social arrangements could have been present in Plio-Pleistocene hominins if we assume the development of a multi-level society such as that in hamadryas baboons. The evolution of a multi-level society thus underlies the adaptive potential for the complexity that we see in modern human social organization.
Chimpanzee referential models for early hominid behavior have become the most common of all current approaches. In addition to chimpanzees' close evolutionary relationship to humans, the justification for this approach is that their behaviors are complex and human-like compared with those of other animals. An examination of four aspects of chimpanzee society that are prominent in discussions of human evolution - bipedal posture, tool use, cooperative hunting, and culture indicates that other animals, even nonprimates, engage in analogous behaviors. Some referential models describe early hominid niches ( e. g., locomotion, meat procurement) as presumably similar to those of extant great apes, but observed fossil anatomy suggests otherwise. Others attempt to explain hominid innovations with chimpanzee-like behaviors ( e. g., bipedal posture, simple tool use, social hunting) when basic evolutionary theory dictates that only differences between closely related forms explain their divergence. Although data on the great apes are crucial for origins modeling, they are too often misapplied in reference to human behavioral evolution.
Wonderwerk Cave (Northern Cape Province, South Africa) is an example of a natural locality that, in the past as in the present, was imbued with meaning and symbolism. Today, local communities associate the cave with a snake spirit, while rock art adorning the cave walls attests to the special status of the cave during the Later Stone Age. In the terminal Acheulean (over 180,000 years ago), hominins introduced manuports with special sensory properties into the back of the cave, a locality with singular acoustic and visual qualities. Thus, the archaeological record of Wonderwerk Cave serves as a unique and extensive diachronic record of milestones in the development of symbolic behaviour. It provides evidence to support the position that elements of symbolic behaviour emerged long before the dispersal of modern humans out of Africa.
This paper presents a first summary of results of an ongoing study, started some two years ago, of high-grade iron ore deposits in South Africa, India and Brazil, including a comparison with the rather well-studied deposits of the Hamersley Province in Australia. Large, high-grade hematite iron ore bodies hosted by Precambrian banded iron formations are the world's most important source of iron ore. Despite their great economic importance, the origin of these deposits has remained rather enigmatic. Results of preliminary investigations into the geological setting, petrography and geochemistry of BIF-hosted high-grade hematite iron ore deposits in South Africa, India, Western Australia and Brazil reveal distinct similarities, suggest ing a very similar mode of hydrothermal and supergene-modified hydrothermal origin for most BIF-hosted highgrade hematite ore deposits. Differences between the deposits of this type are largely the result of varying intensities of supergene modification in Late Cretaceous to Tertiary times. Notable exceptions are the deposits in the Griqualand West region of South Africa, including the giant Sishen deposit, that are regarded to be of ancient supergene origin.
Multilevel (or modular) societies are a distinct type of primate social system whose key features are single-male-multifemale, core units nested within larger social bands. They are not equivalent to fission-fusion societies, with the latter referring to routine variability in associations, either on an individual or subunit level. The purpose of this review is to characterize and operationalize multilevel societies and to outline their putative evolutionary origins. Multilevel societies are prevalent in three primate clades: papionins, Asian colobines, and hominins. For each clade, we portray the most parsimonious phylogenetic pathway leading to a modular system and then review and discuss likely socioecological conditions promoting the establishment and maintenance of these societies. The multilevel system in colobines (most notably Rhinopithecus and Nasalis) has likely evolved as single-male harem systems coalesced, whereas the multilevel system of papionins (Papio hamadryas, Theropithecus gelada) and hominins most likely arose as multimale-multifemale groups split into smaller units. We hypothesize that, although ecological conditions acted as preconditions for the origin of multilevel systems in all three clades, a potentially important catalyst was intraspecific social threat, predominantly bachelor threat in colobines and female coercion/infanticide in papionins and humans. We emphasize that female transfers within bands or genetic relationships among leader males help to maintain modular societies by facilitating interunit tolerance. We still lack a good or even basic understanding of many facets of multilevel sociality. Key remaining questions are how the genetic structure of a multilevel society matches the observed social effort of its members, to what degree cooperation of males of different units is manifest and contributes to band cohesion, and how group coordination, communication, and decision making are achieved. Affiliative and cooperative interunit relations are a hallmark of human societies, and studying the precursors of intergroup pacification in other multilevel primates may provide insights into the evolution of human uniqueness.
We studied territory characteristics among three neighboring chimpanzee communities in the Ta National Park, Cte d''Ivoire, and compared them with other chimpanzee populations. We characterized territories and ranging patterns by analyzing six variables:, (1) territory size, (2) overlap zone, (3) territory utilization, (4) core area, (5) territory shift, and (6) travel distance. Data collection covered a period of 10 mo, during which we simultaneously sampled the local positions of mostly large parties, including males in each community, in 30-min intervals. In Ta, chimpanzees used territories in a clumped way, with small central core areas being used preferentially over large peripheral areas. Although overlap zones between study communities mainly represented infrequently visited peripheral areas, overlap zones with all neighboring communities also included intensively used central areas. Territory utilization was not strongly seasonal, with no major shift of activity center or shift of areas used over consecutive months. However, we observed shorter daily travel distances in times of low food availability. Territory sizes of Ta chimpanzees tended to be larger than territories in other chimpanzee communities, presumably because high food availability allows for economical defense of territorial borders and time investment in territorial activities. Therefore we suggest, that use of territory in Ta chimpanzees is strongly influenced by intercommunity relations. To understand differences in territory characteristics between various populations, it is of major importance to consider not only the intracommunity but also the intercommunity context.
The multilevel society of hamadryas baboons, consisting of troops, bands, clans, and one-male units (OMUs), is commonly perceived to be an effective means of adapting to variable food availability while allowing spatial cohesion in response to predator pressure. The relationship between these variables, however, has never been tested quantitatively. The Filoha site in Awash National Park, Ethiopia is ideally suited to such an investigation as it contains nutrient-dense palm forests in addition to the Acacia scrublands typical of hamadryas distribution elsewhere, allowing comparisons of spatial cohesion across habitat types. Here, we use observations over a 1-year period to examine the relationship between resource availability, perceived predator pressure, and spatial cohesion in a band of wild hamadryas baboons at Filoha. Our results demonstrate that the band was more likely to break into OMUs when foraging in habitats with lower food availability, and that the band fissioned into independent clans more often when preferred resources were not available. Furthermore, the baboons remained in larger aggregations for longer periods of time (i.e., prior to embarking on their daily foraging route) on mornings after predators were heard in the vicinity, and increased cohesion in response to encounters with people who may have been perceived as predators. These results support the notion that hamadryas baboons change their social groupings in response to both food availability and predation risk and that the ability of hamadryas bands to cleave and coalesce in response to changes in these factors underlies the evolution of the hamadryas modular social structure.
In nature, many different types of complex system form hierarchical, self-similar or fractal-like structures that have evolved to maximize internal efficiency. In this paper, we ask whether hunter-gatherer societies show similar structural properties. We use fractal network theory to analyse the statistical structure of 1189 social groups in 339 hunter-gatherer societies from a published compilation of ethnographies. We show that population structure is indeed self-similar or fractal-like with the number of individuals or groups belonging to each successively higher level of organization exhibiting a constant ratio close to 4. Further, despite the wide ecological, cultural and historical diversity of hunter-gatherer societies, this remarkable self-similarity holds both within and across cultures and continents. We show that the branching ratio is related to density-dependent reproduction in complex environments and hypothesize that the general pattern of hierarchical organization reflects the self-simi
In the 1970s, researchers provided the first detailed descriptions of intergroup conflict in chimpanzees. These observations stimulated numerous comparisons between chimpanzee violence and human warfare. Such comparisons have attracted three main objections: (a) The data supporting such comparisons are too few, (b) intergroup aggression is the result of artificial feeding by observers, and (c) chimpanzee data are irrelevant to understanding human warfare. Recent studies provide strong evidence against these criticisms. Data from the five long-term sites with neighboring groups show that intergroup aggression is a pervasive feature of chimpanzee societies, including sites where artificial feeding never took place. Recent studies have clarified questions about the fundamental goals and proximate mechanisms underlying intergroup aggression. Male chimpanzees compete with males in other groups over territory, food, and females, base their decisions to attack strangers on assessments of numerical strength, and strive for dominance over neighboring groups. Human males likewise compete over territory, food, and females and show a preference for low-risk attacks and intergroup dominance. Chimpanzee studies illustrate the promise of the behavioral biology approach for understanding and addressing the roots of violence in our own species.
Contemporary humans exhibit spectacular biological success derived from cumulative culture and cooperation. The origins of these traits may be related to our ancestral group structure. Because humans lived as foragers for 95% of our species' history, we analyzed co-residence patterns among 32 present-day foraging societies (total n = 5067 individuals, mean experienced band size = 28.2 adults). We found that hunter-gatherers display a unique social structure where (i) either sex may disperse or remain in their natal group, (ii) adult brothers and sisters often co-reside, and (iii) most individuals in residential groups are genetically unrelated. These patterns produce large interaction networks of unrelated adults and suggest that inclusive fitness cannot explain extensive cooperation in hunter-gatherer bands. However, large social networks may help to explain why humans evolved capacities for social learning that resulted in cumulative culture.
Culture has traditionally been attributed only to human beings. Despite growing evidence of behavioral diversity in wild chimpanzee populations, most anthropologists and psychologists still deny culture to this animal species. We argue here that culture is not monolithic but a set of processes. These processes show much diversity both in the social norms and models that determine which individuals will be exposed to particular cultural variants and what cultural variants will be present in the population and in the social learning mechanisms that determine the fidelity of transmission of the variants over time. Recognition of the diversity of these processes is important because it affects cultural dissemination, cultural evolution, and the complexity of cultural artifacts. A comparison of chimpanzee and human cultures shows many deep similarities, thus suggesting that they share evolutionary roots. Two possible differences between the two species are discussed. First, thanks to indirect means of transmission such as language, cultural dissemination is possible over greater stretches of time and space in humans than in chimpanzees. Second, human cultures rely more intensively than chimpanzee cultures on cumulative cultural evolution through the ratchet effect, which allows the accumulation of modifications over time and produces more elaborate cultural artifacts.
The great apes (chimpanzees, bonobos, gorillas and orangutans) are our closest living relatives, sharing a common ancestor only five million years ago. We also share key features such as high intelligence, omnivorous diets, prolonged child-rearing and rich social lives. The great apes show a surprising diversity of adaptations, particularly in social life, ranging from the solitary life of orangutans, through patriarchy in gorillas to complex but different social organisations in bonobos and chimpanzees. As great apes are so close to humans, comparisons yield essential knowledge for modelling human evolutionary origins. Great Ape Societies provides comprehensive up-to-date syntheses of work on all four species, drawing on decades of international field work, zoo and laboratory studies. It will be essential reading for students and researchers in primatology, anthropology, psychology and human evolution.
The transition from the Earlier Stone Age (ESA) to the Middle Stone Age (MSA) in the interior of southern Africa is associated with the Fauresmith Industry. Major cultural developments found in the Fauresmith include regular use of ochre and other coloured minerals, prepared core technology including blade and point production, and the use of hafted spears. Chronological control for the Fauresmith is weak so that critical questions regarding the relationship of this industry to the evolution of modern humans remain unresolved. Here we present ages for the Bestwood 1 site, an open-air locality in the Northern Cape Province (South Africa) where an extensive Fauresmith occupation is found underlying sand deposits.Optically stimulated luminescence (OSL) was first applied to samples from the sands overlying the Bestwood 1 occupation horizon, and from the occupation horizon itself, in order to establish the chronology of the site. However, sediment mixing resulting from bioturbation processes has been observed, causing post-depositional bleaching of the majority of the grains, thus limiting the use of OSL. In addition, given the identification of the lithic assemblage to the Fauresmith, it seems likely that the sands were beyond the dating range of conventional OSL. Due to its hard-to-bleach properties, the thermally transferred-optically stimulated luminescence (TT-OSL) signal was deemed suitable for detecting the least-bleached grains.Single grain TT-OSL analyses combined with the finite mixture model (FMM) were conducted in order to isolate the oldest grains that could be contemporaneous with the time of deposition of the sediment associated with the ESA assemblage. High scattering of the equivalent doses is consistent with bioturbation processes that mixed sediment; the distribution of the equivalent dose values suggests that younger grains were incorporated into the ESA layers, thus supporting the use of the oldest component determined using the FMM to calculate the TT-OSL ages. This approach allowed us to establish the time for the Fauresmith occupation at 366 ± 32 ka, and the age of the overlying sand deposits, spanning from 350 ± 22 ka to 226 ± 13 ka.
Mobile hunter-gatherers are often characterized as living in small communities where mobility and group size are products of the environmentally determined distribution of resources, and where social organization is multi-scalar: groups of co-residents are nested within small communities that are, in turn, nested within small-scale societies. Such organization is often assumed to be reflective of the human past, emerging as human cognition and communication evolved through earlier fission-fusion social processes, typical of many primate social systems. We review the history of this assumption in light of recent empirical data of co-residence and social networks among contemporary hunter-gatherers. We suggest that while residential and foraging groups are often small, there is little evidence that these groups are drawn from small communities nested within small-scale societies. Most mobile hunter-gatherers live in groups dominated by links between non-relatives, where residential group membership is fluid and supports large-scale social networks of interaction. We investigate these dynamics with fine-grained observational data on Martu foraging groups and social organization in Australia's Western Desert. The composition of Martu foraging groups is distinct from that of residential groups, although both are dominated by ties between individuals who have no close biological relationships. The number of individuals in a foraging group varies with habitat quality, but in a dynamic way, as group size is shaped by ecological legacies of land use. The flexible size and composition of foraging groups link individuals across their "estates": spatially explicit storehouses of ritual and relational wealth, inherited across generations through maintaining expansive networks of social interaction in a large and complex society. We propose that human cognition is tied to development of such expansive social relationships and co-evolved with dynamic socio-ecological interactions expressed in large-scale networks of relational wealth.
Archaeological recovery of chimpanzee Panda oleosa nut cracking tools at the Panda 100 (P100) and Noulo sites in the Taï Forest, Côte d'Ivoire, showed that this behavior is over 4000 years old, making it the oldest known evidence of non-human tool use. In 2002, the first report on the lithic material from P100 was directly compared to early hominin stone tools, highlighting their similarities and proposing the name 'Pandan' for the chimpanzee material. Here we present an expanded and comprehensive technological, microscopic, and refit analysis of the late twentieth century lithic assemblage from P100. Our re-analysis provides new data and perspectives on the applicability of chimpanzee nut cracking tools to our understanding of the percussive behaviors of early hominins. We identify several new refit sets, including the longest (>17 m) hammerstone transport seen in the chimpanzee archaeological record. We provide detailed evidence of the fragmentation sequences of Panda nut hammerstones, and characterize the percussive damage on fragmented material from P100. Finally, we emphasize that the chimpanzee lithic archaeological record is dynamic, with the preservation of actual hammerstones being rare, and the preservation of small broken pieces more common. P100 - the first archaeological chimpanzee nut cracking lithic assemblage - provides a valuable comparative sample by which to identify past chimpanzee behavior elsewhere, as well as similar hominin percussive behavior in the Early Stone Age.
The century long publication of this journal overlapped major changes in the sciences it covers. We have been eyewitnesses to vast changes during the final third of the last century and beginning of this one, momentous enough to fundamentally alter our work separately and collectively. One (NBJ) from animal ethology, another from western North American archaeology (JOC), and a third (KH) from cultural anthropology came to longtime collaboration as evolutionary ecologists with shared focus on studying modern hunter-gatherers to guide hypotheses about human evolution. Our findings have radically revised hypotheses each of us took for granted when we began. Our (provisional) conclusions are not the consensus among hunter-gatherer specialists; but grateful that personal reflections are invited, we aim to explain how and why we continue to bet on them.
Striding bipedalism is a key derived behaviour of hominids that possibly originated soon after the divergence of the chimpanzee and human lineages. Although bipedal gaits include walking and running, running is generally considered to have played no major role in human evolution because humans, like apes, are poor sprinters compared to most quadrupeds. Here we assess how well humans perform at sustained long-distance running, and review the physiological and anatomical bases of endurance running capabilities in humans and other mammals. Judged by several criteria, humans perform remarkably well at endurance running, thanks to a diverse array of features, many of which leave traces in the skeleton. The fossil evidence of these features suggests that endurance running is a derived capability of the genus Homo, originating about 2 million years ago, and may have been instrumental in the evolution of the human body form.
The ∼500 thousand year old stratum 4a lithic assemblage from Kathu Pan 1, Northern Cape, South Africa, is one of the earliest occurrences of blade technology and is the oldest dated assemblage attributed to the Fauresmith industry. A technological analysis of the Kathu Pan 1 stratum 4a assemblage reveals that blades were systematically removed using direct hard hammer percussion from organized blade cores that were extensively prepared via centripetal flaking. Some of these blades were retouched into points. Comparisons with published descriptions of the roughly contemporary blade assemblages from the Kapthurin Formation, Kenya and Qesem Cave, Israel demonstrate that diverse blade production strategies were employed during the earlier half of the Middle Pleistocene. The diversity best supports a scenario in which laminar technology was invented in multiple places and times.
The benefits of spatial memory for foraging animals can be assessed on two distinct spatial scales: small-scale space (travel within patches) and large-scale space (travel between patches). While the patches themselves may be distributed at low density, within patches resources are likely densely distributed. We propose, therefore, that spatial memory for recalling the particular locations of previously visited feeding sites will be more advantageous during between-patch movement, where it may reduce the distances traveled by animals that possess this ability compared to those that must rely on random search. We address this hypothesis by employing descriptive statistics and spectral analyses to characterize the daily foraging routes of a band of wild hamadryas baboons in Filoha, Ethiopia. The baboons slept on two main cliffs-the Filoha cliff and the Wasaro cliff-and daily travel began and ended on a cliff; thus four daily travel routes exist: Filoha-Filoha, Filoha-Wasaro, Wasaro-Wasaro, Wasaro-Filoha. We use newly developed partial sum methods and distribution-fitting analyses to distinguish periods of area-restricted search from more extensive movements. The results indicate a single peak in travel activity in the Filoha-Filoha and Wasaro-Filoha routes, three peaks of travel activity in the Filoha-Wasaro routes, and two peaks in the Wasaro-Wasaro routes; and are consistent with on-the-ground observations of foraging and ranging behavior of the baboons. In each of the four daily travel routes the "tipping points" identified by the partial sum analyses indicate transitions between travel in small- versus large-scale space. The correspondence between the quantitative analyses and the field observations suggest great utility for using these types of analyses to examine primate travel patterns and especially in distinguishing between movement in small versus large-scale space. Only the distribution-fitting analyses are inconsistent with the field observations, which may be due to the scale at which these analyses were conducted. Am. J. Primatol. 9999:1-15, 2013. © 2013 Wiley Periodicals, Inc.
The dense concentrations of faunal remains and stone tools at some Plio-Pleistocene sites at Olduvai Gorge (Tanzania) and Koobi Fora (Kenya) have traditionally been interpreted as favored locations to which hominids repeatedly transported carcass parts for processing (Leakey, 1971; Isaac, 1978, 1983, 1984; Bunn, 1982, 1991; Potts, 1982, 1988; Bunn and Kroll, 1986; Schick, 1987; Blumenschine, 1988, 1991, 1995; Bunn and Ezzo, 1993; Schick and Toth, 1993; Oliver, 1994; Rose and Marshall, 1996; O’Connell, 1997). These co-occurrences, which typically contain bones from several individuals within a vertically discrete horizon (referred to by Isaac [1978] as “Type C” sites), often preserve high densities of archaeological material in spatially restricted concentrations. For many researchers, these archaeological sites represent places where hominids may have stayed for extended periods, very likely performing activities beyond stone tool manufacture and carcass manipulation (Leakey, 1971; Isaac, 1978, 1984; Bunn, 1982; Stanley, 1992; Domínguez-Rodrigo, 1994a; Oliver, 1994). The seemingly frequent processing of nutrient-dense large mammal tissue by hominids between 2 and 1.5 Ma led many evolutionary anthropologists to suggest meat eating as the critical adaptation for understanding the emergence of stone tool use. These debates necessarily gravitated towards the evidence from Olduvai, and more specifically, from the single site of FLK Level 22 (the Zinjanthropus Floor). Despite its importance for reconstructing hominid behavior, an almost exclusive focus on the archaeological evidence from FLK Zinj has limited archaeologists’ views in two important ways. First, it forced researchers to neglect regional variability in hominid adaptive patterns (clearly stressed by Potts [1994]). Second, it hindered the development of explanatory frameworks that could deal with a diversity of site formation scenarios. Although the debates over these “Type C” sites have clearly generated fruitful discussions over the past two decades, it is also evident that other types of archaeological occurrences representing stone tool–using activities, not necessarily linked to carcass manipulation, have yet to be fully appreciated.
Since the late 19th century archaeologists have struggled to understand the behavioural significance of material remains surviving from the distant reaches of time. A study of the archaeological debris scattered through the lower Okote Member of the Koobi Fora Formation in northwestern Kenya reveals a serious mismatch between the interpretive models being applied to the earliest archaeological data and the empirical structure of those data. Both the low-density scatters and the high-density patches that make up this record are palimpsests of material remains that accumulated over tens of thousands of years. There is a remarkable similarity in the composition and characteristics of the archaeological assemblages recovered from the scatters and the patches. Both represent the material residues of many different and unrelated behavioural episodes, influenced by a different set of variables to those that produced the patterned distributions that archaeologists identify in these data. To decode the behavioural significance of these behavioural traces archaeologists need to investigate both the relationship between the material remains created by an infinitely variable set of behavioural episodes and the patterns and trends in these data created over long time spans and to develop a theory of human action over the middle to long term.
Ancient Weaponry
Hafting, which allowed projectile points to be attached to a staff, was an important technological advance that greatly increased the functionality of weapons of early humans. This technology was used by both Neandertals and early Homo sapiens and is readily seen after about 200,000 to 300,000 years ago, but whether it was used by a common ancestor or was separately acquired by each species is unclear. Supporting use by a common ancestor, Wilkins et al. (p. 942 ) report that stone points in a site in central South Africa were hafted to form spears around 500,000 years ago. The evidence includes damaged edges consistent with this use and marks at the base that are suggestive of hafting.
A central assumption of baboon socio-ecological models is that all populations have the same capacity to react to different environments. The burden of our argument is that this assumption needs to be reconsidered. Data suggest not only that hamadryas, but chacma as well, differ in interesting ways from the stock baboon model that has been derived, in the main, from earlier work on anubis and cynocephalus. Although environmental factors are behind these differences, much of their influence is a consequence of their effect on restricted ancestral populations, where selection for appropriate responses to the social challenges set by local conditions now constrains the nature of individual responses to contemporary environments. Available genetic evidence suggess a southern African origin for Papio at a time when climatic conditions were certainly no better than they are now and when temperatures, if nothing else, were probably lower. In light of this, a reconstruction of how climate has structured the sexual conflict between males and female charcma, which itself hinges on infanticide, can help explain not only the East African pattern, but also how the apparently anomalous hamadryas pattern has been derived.
During the last 25 years, there has been a shift towards the belief that early humans were scavengers instead of hunters. This revisionist interpretation has brought a reconciliation with the Darwinian paradigm of gradual progressive evolution that has traditionally guided (and very often, misled) an important part of anthropological thinking. However, empirical support for the scavenging hypothesis is still lacking. Recent data based on bone surface modifications from archaeological faunas suggest, in contrast, that hominids were primary agents of carcass exploitation. Meat seems to have been an important part of Plio-Pleistocene hominid diets. Passive scavenging scenarios show that this kind of opportunistic strategy cannot afford significant meat yields. Therefore, the hunting hypothesis has not yet been disproved. This makes the hunting-and-scavenging issue more controversial than before, and calls for a revision of the current interpretive frameworks and ideas about early human behavior.
Demographic and life history parameters were estimated for a band of free-ranging hamadryas baboons, observed for 5.5 years
in Ethiopia. Age-related changes in body weight and dentition were found to be delayed relative to laboratory-reared baboons.
On the average, females reached menarche at 4.3 years of age and had their first infant at the age of 6.1 years. The mean
interbirth interval was 24 months if the infant survived this period. The survival of infants and juveniles was higher compared
to Amboseli yellow baboons, but somewhat lower than in gelada baboons in the Simen Mountains. Males acquired their first juvenile
or adult female at the age of 8.5 to 11 years. Male-female pair-bonds lasted several years in most cases. The Cone Rock baboons
were organized in a four-level social structure. The troop could split into bands, bands were divided into clans, and clans
into one-male units with bachelor followers. The exchange of individuals between social units predominantly occurred within
the band. All males of known origin became adult members of their presumed natal clan. Most females transferred also within
clans, and juvenile females tended to remain in their natal clan. Females lost by one male to several rivals tended to reassemble
in the same new one-male units later on.
The Fauresmith lithic industry of South Africa has been described as transitional between the Earlier and Middle Stone Age. However, radiometric ages for this industry are inadequate. Here we present a minimum OSL age of 464 ± 47 kyr and a combined U-series–ESR age of 542−107+140 kyr for an in situ Fauresmith assemblage, and three OSL ages for overlying Middle and Later Stone Age strata, from the site of Kathu Pan 1 (Northern Cape Province, South Africa). These ages are discussed in relation to the available lithostratigraphy, faunal and lithic assemblages from this site. The results indicate that the Kathu Pan 1 Fauresmith assemblage predates transitional industries from other parts of Africa e.g. Sangoan, as well as the end of the Acheulean in southern Africa. The presence of blades, in the dated Fauresmith assemblages from Kathu Pan 1 generally considered a feature of modern human behaviour (McBrearty and Brooks, 2000, The revolution that wasn't: a new interpretation of the origin of modern human behavior, J. Human Evolution 39, 453–563),-provides evidence supporting the position that blade production in southern Africa predated the Middle Stone Age and the advent of modern Homo sapiens.
Territorial boundary patrols are a distinctive and unique aspect of wild chimpanzee, Pan troglodytes, behaviour. Although patrolling has been frequently observed in nature and several proposed functional explanations for it exist, scant information is available regarding the proximate factors that affect this activity. We found that there is considerable temporal variation in the frequency of patrolling by chimpanzees at Ngogo, Kibale National Park, Uganda. We examined several ecological and social factors that potentially influence this variation. Results of logistic regression analyses revealed that male party size was the single best predictor of the tendency to patrol. Lethal intergroup aggression occurs in chimpanzees, and patrols are likely to be dangerous and costly. Our findings are consistent with the hypothesis that chimpanzees at Ngogo reduce these costs by patrolling together in large parties.
Group size is expected to be an important factor to predict home-range (HR) size in social animals. In chimpanzees adult males play an important role in defending the HR against neighbors, and therefore it has been suggested that HR size depends on the number of adult males. In this long-term study on wild West African chimpanzees, we analyzed the relative importance of community size and composition on ranging patterns over a 10-year period, using multivariate statistics. Because community size decreased from 51 individuals with 6 adult males in 1992 to 22 individuals with only 1 adult male in 2001, we expected a decrease in HR size, which should be better predicted by the number of males than by community size. We further investigated the effect of fruit availability on monthly HRs over a 4-year period. As predicted, HR size decreased during the first 7 years of our study but increased during the last 3 years. Overall, the number of adult males was the best predictor of HR size, whereas fruit availability did not correlate with HR size. HR use remained stable over the entire study period, with a constant proportion of about 35% of the HR used as core area. High HR and core-area overlap values between different years indicated strong site-fidelity. Although the number of males within the community explained the decrease in HR size, the recent increase in size remains unexplained. This finding suggests that other factors such as relative fighting power of males affect HR size. Copyright 2003.
We address the interpretation of Plio/Pleistocene hominid 'home-base' sites in East Africa by integrating data from archaeology, primatology, and carnivore biology. Revisionist views of Plio/Pleistocene sites have emphasized the limited capacities of early hominids and the danger posed by large carnivores. We argue that flight and avoidance were not the most likely strategies for meat-eating hominids facing competition and increased risk of predation. Instead, we suggest, these pressures promoted increased sociality, cooperative protection from predators, and cooperative defense of resources. We present a resource-defense model of hominid land use in which, because meat represents a movable high-quality resource, hunted and scavenged carcasses were transported to focal sites that offered spatially fixed and defensible resources such as water, trees, and plant foods. Repeated use of such focal sites for a variety of diurnal and nocturnal activities would have resulted in a home-base or central-place pattern similar to that proposed by Glynn Isaac. However, we suggest that the use of home bases does not necessarily imply monogamy and a well defined sexual division of labor.