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The Raw and the Stolen: Cooking and the Ecology of Human Origins

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Cooking is a human universal that must have had widespread effects on the nutrition, ecology, and social relationships of the species that invented it. The location and timing of its origins are unknown, but it should have left strong signals in the fossil record. We suggest that such signals are detectable at ca. 1.9 million years ago in the reduced digestive effort (e.g., smaller teeth) and increased supply of food energy (e.g., larger female body mass) of early Homo erectus. The adoption of cooking required delay of the consumption of food while it was accumulated and/or brought to a processing area, and accumulations of food were valuable and stealable. Dominant (e.g., larger) individuals (typically male) were therefore able to scrounge from subordinate (e.g., smaller) individuals (typically female) instead of relying on their own foraging efforts. Because female fitness is limited by access to resources (particularly energetic resources), this dynamic would have favored females able to minimize losses to theft. To do so, we suggest, females formed protective relationships with male co-defenders. Males would have varied in their ability or willingness to engage effectively in this relationship, so females would have competed for the best food guards, partly by extending their period of sexual attractiveness. This would have increased the numbers of matings per pregnancy, reducing the intensity of male intrasexual competition. Consequently, there was reduced selection for males to be relatively large. This scenario is supported by the fossil record, which indicates that the relative body size of males fell only once in hominid evolution, around the time when H. erectus evolved. Therefore we suggest that cooking was responsible for the evolution of the unusual human social system in which pair bonds are embedded within multifemale, multimale communities and supported by strong mutual and frequently conflicting sexual interest.

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... Much attention has thus focused on the evolution of food sharing by males (4,8,9). But extracting, preparing, and sharing plant foods-which among contemporary foragers are performed mainly by women-also constitute key economic strategies that differ strikingly from those observed in other primates (10)(11)(12)(13)(14). Forager diets at high latitudes consist largely of meat and fish obtained by men [ (15), but in warmer climates, where early hominins evolved, women contribute substantially to the diet median 30.5% of calories provided by adults; range: 15.9 to 57.0%, n = 9 populations; (16)]. ...
... Efforts to explain the origin of hominin plant food sharing focus on surplus production by grandmothers (14,30) and cooking, particularly by females (13). Grandmothers can increase their fitness by provisioning descendants (31). ...
... Cooking likely impacted human evolution profoundly (13,33), but hominins probably relied on extracted plant foods long before controlling fire (22). We thus consider the possibility that sharing of extracted plant foods originated in hominins before meat and cooking predominated hominin diets. ...
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How did humans evolve from individualistic to collective foraging with sex differences in production and widespread sharing of plant and animal foods? While current evolutionary scenarios focus on meat, cooking, or grandparental subsidies, considerations of the economics of foraging for extracted plant foods (e.g., roots, tubers), inferred to be important for early hominins (∼6 to 2.5 mya), suggest that early hominins shared such foods with offspring and others. Here, we present a conceptual and mathematical model of early hominin food production and sharing, prior to the emergence of frequent hunting, cooking, and increased lifespan. We hypothesize that extracted plant foods were vulnerable to theft, and that male mate guarding protected females from food theft. We identify conditions favoring extractive foraging and food sharing across mating systems (i.e., monogamy, polygyny, promiscuity), and we assess which system maximizes female fitness with changes in the profitability of extractive foraging. Females extract foods and share them with males only when: i) extracting rather than collecting plant foods pays off energetically; and ii) males guard females. Males extract foods when they are sufficiently high in value, but share with females only under promiscuous mating and/or no mate guarding. These results suggest that if early hominins had mating systems with pair-bonds (monogamous or polygynous), then food sharing by adult females with unrelated adult males occurred before hunting, cooking, and extensive grandparenting. Such cooperation may have enabled early hominins to expand into more open, seasonal habitats, and provided a foundation for the subsequent evolution of human life histories.
... Another transformational event in human evolution was that humans are the only species to cook food [20]. Although the exact time at which cooking became widespread is not known, it is thought to have been long enough for biological adaptations to occur, such as a reduction in tooth size and a reduced ability to digest raw and fibrous foods due to a reduction in gut size [21]. ...
... In this regard, it is believed that the cooking of starchy plant foods co-evolved with an increase in salivary amylase activity. Without cooking, the consumption of starchy plant foods is unlikely to have met the high glucose demands observed in modern humans [20]. Similarly, the increased accessibility of starch to amylases through cooking would, in turn, have led to a greater advantage for high levels of salivary amylase expression, particularly in infants [21]. ...
... Starch constitutes up to 80% of the dry weight of some edible roots and tubers and, if left intact in the soil, they remain stable and can be harvested for months when needed. Thus, the ability to utilize starch-rich roots and tubers in early hominin diets is seen as a potentially crucial step in differentiating early australopithecines from other hominins and in enabling expansion into new habitats [20]. In this regard, and despite the fact that evidence of plant foods rarely survives, making it difficult to reconstruct their diet, it is likely that the gradual replacement of fibrous plants with more energy-efficient plant foods, including starchy tubers, led to a reduction in gut size [22]. ...
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Foods high in carbohydrates are an important part of a healthy diet, since they provide the body with glucose to support bodily functions and physical activity. However, the abusive consumption of refined, simple, and low-quality carbohydrates has a direct implication on the physical and mental pathophysiology. Then, carbohydrate consumption is postulated as a crucial factor in the development of the main Western diseases of the 21st century. We conducted this narrative critical review using MedLine (Pubmed), Cochrane (Wiley), Embase, and CinAhl databases with the MeSH-compliant keywords: carbohydrates and evolution, development, phylogenetic, GUT, microbiota, stress, metabolic health, consumption behaviors, metabolic disease, cardiovascular disease, mental disease, anxiety, depression, cancer, chronic kidney failure, allergies, and asthma in order to analyze the impact of carbohydrates on health. Evidence suggests that carbohydrates, especially fiber, are beneficial for the well-being and growth of gut microorganisms and consequently for the host in this symbiotic relationship, producing microbial alterations a negative effect on mental health and different organic systems. In addition, evidence suggests a negative impact of simple carbohydrates and refined carbohydrates on mood categories, including alertness and tiredness, reinforcing a vicious circle. Regarding physical health, sugar intake can affect the development and prognosis of metabolic disease, as an uncontrolled intake of refined carbohydrates puts individuals at risk of developing metabolic syndrome and subsequently developing metabolic disease.
... Another possibility is that the modifications to food through cooking provided the necessary additional calories and nutrients to support a reduction of gut and increase in encephalization 32 . The hypothesis has been extended to encompass others. ...
... The hypothesis has been extended to encompass others. For example, cooked tubers have been proposed as an important component of the "cooked foods" diet 27,28,32 and it has been suggested that scavenged carcasses were cooked to mitigate microbiological contamination 33 . The trend of reduction of molar size in hominin evolution, perhaps an adaptation from moving from tougher to softer foods 34 , fits well with this hypothesis 35 . ...
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Brain tissue is metabolically expensive. Consequently, the evolution of humans’ large brains must have occurred via concomitant shifts in energy expenditure and intake. Proposed mechanisms include dietary shifts such as cooking. Importantly, though, any new food source must have been exploitable by hominids with brains a third the size of modern humans’. Here, we propose the initial metabolic trigger of hominid brain expansion was the consumption of externally fermented foods. We define “external fermentation” as occurring outside the body, as opposed to the internal fermentation in the gut. External fermentation could increase the bioavailability of macro- and micronutrients while reducing digestive energy expenditure and is supported by the relative reduction of the human colon. We discuss the explanatory power of our hypothesis and survey external fermentation practices across human cultures to demonstrate its viability across a range of environments and food sources. We close with suggestions for empirical tests.
... It is widely accepted that the ability to harness combustion played a significant role in hominin evolution and dispersal and is fundamental to humanity (e.g. Clark and Harris 1985;James et al. 1989;Wrangham et al. 1999;Wrangham 2009;Beaumont 2011, Gowlett 2016Parker et al. 2016;Sandgathe and Berna 2017;Dunbar 2020). However, it is disputed when and how this remarkable ability to harness fire began, with several hypotheses proposing hominin control of fire arising at different points between two million and 100,000 years ago (e.g., Wrangham et al. 1999;Roebroeks and Villa 2011;Sandgathe et al. 2011;Gowlett 2016;Parker et al. 2016;Chazan 2017;Sandgathe 2017;Mac-Donald et al. 2021;Scott and Hosfield 2021). ...
... Clark and Harris 1985;James et al. 1989;Wrangham et al. 1999;Wrangham 2009;Beaumont 2011, Gowlett 2016Parker et al. 2016;Sandgathe and Berna 2017;Dunbar 2020). However, it is disputed when and how this remarkable ability to harness fire began, with several hypotheses proposing hominin control of fire arising at different points between two million and 100,000 years ago (e.g., Wrangham et al. 1999;Roebroeks and Villa 2011;Sandgathe et al. 2011;Gowlett 2016;Parker et al. 2016;Chazan 2017;Sandgathe 2017;Mac-Donald et al. 2021;Scott and Hosfield 2021). Particularly lacking is the ability to differentiate unambiguous evidence of anthropogenic fire activities in archaeological sites from natural fire events (see James et al. 1989;Bellomo 1993;Gowlett 2016;Parker et al. 2016;Sandgathe 2017;Deldicque et al. 2021;Scott and Hosfield 2021;Sobkowiak-Tabaka and Diachenko 2021), as well as control versus opportunistic use of fire (see Oakley 1961;Gowlett 2016;Chazan 2017;Sandgathe 2017;Parker et al. 2016, Dunbar 2020, McCauley et al. 2020Scott and Hosfield 2021). ...
Article
FTIR spectroscopy has played an important role in attempts to understand the use of fire in prehistory, particularly through the identification of heated bone. The presence of the OH libration band at ca. 630 cm⁻¹ in the FTIR spectrum of archaeological bone has been assumed to be indicative of bone that has been altered by fire. However, no definitive research has explored what the effects of heating variables may be on the appearance of this band. This paper studied the nature of heated bone, with the understanding that the FTIR 630 cm⁻¹ band is the result of the formation of pure hydroxyapatite through the loss of carbonates from the bone mineral, carbonated hydroxyapatite. A set of experiments was designed to determine the impact of temperature, duration, and bone size on the appearance of the 630 cm⁻¹ band: using samples of cortical bone from micro- and macrofauna, heating experiments were carried out to explore the appearance and change in the OH libration band. Results showed that this band appeared in bone samples heated to temperatures above 537 °C, and demonstrated that microfauna were more sensitive to thermal alteration. Bones heated in reducing conditions and bones which are fluoridated do not express the 630 cm⁻¹ OH libration band, therefore FTIR is underrepresenting burning in the archaeological record. A quantitative method “HATI” was created to objectively assess whether a bone sample has been heated above 537 °C.
... Segundo alguns autores, muitas dessas novidades só foram possíveis pela entrada de um novo elemento na história hominínia: o fogo. De acordo com Richard Wrangham e sua famosa hipótese do cozimento, o aumento no tamanho do cérebro só foi possível através do cozimento dos alimentos (Wrangham et al., 1999). Segundo o pesquisador, o ato de cozinhar o alimento, em especial a carne, torna mais simples sua digestão e aumenta a quantidade de energia que se pode retirar da comida. ...
... It is hypothesized that they learned to transport natural fire to expand burned area and resource availability in this interval [49], thus increasing food capture, energy input, population and fire use (R1). Resulting improvement in diet, including naturally cooked food, has been argued responsible for reductions in tooth size, increased mobility, and thus early dispersal of Homo erectus approximately 1.9 Ma [49,50]. ...
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What propelled the human ‘revolutions' that started the Anthropocene? and what could speed humanity out of trouble? Here, we focus on the role of reinforcing feedback cycles, often comprised of diverse, unrelated elements (e.g. fire, grass, humans), in propelling abrupt and/or irreversible, revolutionary changes. We suggest that differential ‘spread of the cycles' has been critical to the past human revolutions of fire use, agriculture, rise of complex states and industrialization. For each revolution, we review and map out proposed reinforcing feedback cycles, and describe how new systems built on previous ones, propelling us into the Anthropocene. We argue that to escape a bleak Anthropocene will require abruptly shifting from existing unsustainable ‘vicious cycles’, to alternative sustainable ‘virtuous cycles' that can outspread and outpersist them. This will need to be complemented by a revolutionary cultural shift from maximizing growth to maximizing persistence (sustainability). To achieve that we suggest that non-human elements need to be brought back into the feedback cycles underlying human cultures and associated measures of progress. This article is part of the theme issue ‘Evolution and sustainability: gathering the strands for an Anthropocene synthesis’.
... Wildfires presented a great danger to our early ancestors but also held a great evolutionary potential (Herzog et al. 2022;Pruetz and LaDuke 2010). Exploitation of natural fires and fire use would have provided our ancestors with a range of critical benefits: increased food range and competitiveness, new technology and improvement of materials, increased independence from natural sources of light and warmth, and the manipulation of environments (see, e.g., Ahler 1983;Bellomo 1994;Brain 1981;Goldberg et al. 2009;Goudsblom 1986;Oakley 1956;Wrangham et al. 1999). Researchers have therefore invested much effort into identifying the development of fire use behaviors and their significance for human evolution. ...
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Heat-altered bones are a common occurrence in the archaeological record, and their analysis can provide detailed insights into past fire use behaviors and subsistence strategies. Heat-altered bones, however, may also result from natural fire events such as wildfires that are unrelated to human activity. We currently lack robust reference materials from natural fire events, analyzed using the same methodological approaches as we apply them to archaeological assemblages, that can be used to differentiate between natural and anthropogenic origins of heated materials. Here, we studied an assemblage of 50 tortoises that perished in a brushfire in Cape Point, South Africa. We used a combination of (1) zooarchaeological assessments of heating pattern and (2) infrared spectroscopy including a heating experiment to reconstruct heating temperatures with the aim to document the fire impact on the tortoise remains. For both approaches, we used statistical models to develop and test predictions that can also be applied to archaeological material. Our analyses suggest a quickly moving and low temperature brushfire in the study region with a generally low and superficial heating impact on the tortoise remains. However, we also observed several high-temperature alterations with calcination and speculate that naturally occurring fuel sources controlled the severity of the fire impact. The evidence of heating on the tortoise was unpatterned. We conclude that temperature alone presents a low confidence deciding factor between wildfires and campfires while skeletal heating pattern, in concert with other contextual analysis, may be able to facilitate this distinction with more localized heating signatures for campfires.
... Early stone technologies, notably, Mode 1 tools (Oldowan industry) allowed Homo habilis to manipulate their surroundings in new ways and thereby extract unprecedented amounts of energy from their environments. This is why as stone technologies were consolidated in the hominid cultural repertoire, we see a considerable expansion of the human brain (Aiello and Wheeler 1995;Antón et al. 2014;Rightmire 2004;Wrangham et al. 1999). In other words, the exponential increase in energy capture that tools enabled, provided a nonhuman species with the new and rich energy regime that was needed to evolve into a new species with larger brains-Homo habilis. ...
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This chapter explores universal evolution as it is applied to cultural evolution, focusing on major transitions in religious culture from the early Paleolithic to the rise of world (axial) religions. The perspective I take is an evolutionary-systems approach, which integrates insights from biological and cultural evolutionary theory, systems theory, information theory, the cognitive science of religion, religious studies, and cultural anthropology. The chapter argues for the necessity of a holistic evolutionary theory that integrates physical, biological, and cultural evolution.
... The extinction of ancestral gut bacterial lineages from Homo sapiens regardless of lifestyle may have resulted from immune, physiological or behavioural changes that occurred along the human lineage. For instance, changes in diet that occurred after humans diverged from Pan, such as the transition away from eating raw leaves and fruit towards cooking food and higher consumption of animal fat and proteins 40 , may have altered the selective environment within the gut in a manner that selects against the assembly of microbiota as diverse as those found in other apes. In contrast, co-diversifying symbionts absent specifically from industrialized human populations were probably driven to local extinction by recent lifestyle changes that differentiate these populations from non-industrialized populations. ...
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Humans and other primates harbour complex gut bacterial communities that influence health and disease, but the evolutionary histories of these symbioses remain unclear. This is partly due to limited information about the microbiota of ancestral primates. Here, using phylogenetic analyses of metagenome-assembled genomes (MAGs), we show that hundreds of gut bacterial clades diversified in parallel (that is, co-diversified) with primate species over millions of years, but that humans have experienced widespread losses of these ancestral symbionts. Analyses of 9,460 human and non-human primate MAGs, including newly generated MAGs from chimpanzees and bonobos, revealed significant co-diversification within ten gut bacterial phyla, including Firmicutes, Actinobacteriota and Bacteroidota. Strikingly, ~44% of the co-diversifying clades detected in African apes were absent from available metagenomic data from humans and ~54% were absent from industrialized human populations. In contrast, only ~3% of non-co-diversifying clades detected in African apes were absent from humans. Co-diversifying clades present in both humans and chimpanzees displayed consistent genomic signatures of natural selection between the two host species but differed in functional content from co-diversifying clades lost from humans, consistent with selection against certain functions. This study discovers host-species-specific bacterial symbionts that predate hominid diversification, many of which have undergone accelerated extinctions from human populations.
... We have argued previously that this might reflect underlying foraging efficiency [83]. Many argue that the invention of cooking can be traced back to a decrease in gut size and an increase in brain size [84]. Cooking eliminates pathogens and increases the energy that can be extracted from food [85]. ...
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The social and cultural significance of food is woven into every aspect of our dietary behaviour, and it contributes to our complex interaction with food. To find order within this complexity scientists often look for dietary 'universals' - phenomena or basic principles that guide our food choice and meal size, irrespective of wider context. One such idea is that taste characteristics provide a signal for dietary composition (e.g., sweet taste signals carbohydrate). Others have suggested that behaviour is guided by learning and is based on associations that form between the flavour of a food and its post-ingestive effects. Despite a large body of research, evidence supporting both processes is equivocal, leading some to conclude that humans are largely indifferent to food composition. Here, we argue that human abilities to gauge the nutritional composition or value of food have been underestimated, and that they can be exposed by embracing alternative methods, including cross-cultural comparisons, large nutrition surveys, and the use of virtual portion-selection tools. Our group has focused on assessments of food choice and expected satiety, and how comparisons across everyday foods can reveal non-linear relationships with food energy density, and even the potential for sensitivity to micronutrient composition. We suggest that these abilities might reflect a complex form of social learning, in which flavour-nutrient associations are not only formed but communicated and amplified across individuals in the form of a cuisine. Thus, rather than disregarding sociocultural influences as extraneous, we might reimagine their role as central to a process that creates and imbues a 'collective dietary wisdom.' In turn, this raises questions about whether rapid dietary, technological, and cultural change disrupts a fundamental process, such that it no longer guarantees a 'nutritional intelligence' that confers benefits for health.
... New evidence supports that the computational demands of living in complex societiesin particular the demands of pair-bondingwere the critical factor (Dunbar & Shultz, 2007). A growing brain drove a need for high-caloric foodi.e., meatwhich contributed to a division of labori.e., hunting and cookingthat turned pair-bonding into even more of a win-win proposition (Wrangham et al., 1999). These virtuous circles made Homo sapiens emerge with a brain three times bigger than that of a comparably sized primate (Chapais, 2011). ...
Chapter
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... The significance of its use for cooking was long under-estimated. However, more recently the "cooking hypothesis" promoted by Wrangham et al. (1999) has highlighted how cooking plays a key role in making foods more digestible and their energy and nutritional contents more bioaccessible, and thereby feeding large brains. Thus, cooking and the "domestication" of fire represent a convergence of scientific hypotheses and many traditional mythological framings of what makes humans human (Schrempp, 2011). ...
... The 641 most important innovation in diet at this stage was cooking and control of fire. 642 Cooking increased the digestibility of plants and meat and conserved energy and 643 time for brain growth and social interactions (Wrangham et al. 1999;Wrangham 644 and Conklin-Brittain 2003;Boback et al. 2007). It also facilitated bonding between 645 individual females and males to facilitate a family formation within the larger 646 community structure (Foley and Gamble 2009). ...
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... En effet, dans les régions subarctiques, la viande est souvent consommée crue ou à peine cuite, ce qui permet de préserver la vitamine C -si rare dans les régimes alimentaires des chasseurs-cueilleurs subarctiques durant la mauvaise saison -mais aussi de limiter les besoins en combustible dans ces environnements à faible couvert forestier (voir Speth 2017 pour une discussion). Plus difficile à digérer que la viande cuite, la viande crue est aussi beaucoup moins énergétique (Aiello, Wheeler 1995 ;Wrangham et al. 1999 ;Wrangham, Conklin-Brittain 2003). La consommation de viande fermentée et donc en partie prédigérée par les enzymes des bactéries apparaît ainsi comme un bon compromis, permettant d'augmenter la part énergétique tout en préservant la vitamine C (Speth 2017). ...
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Over the past decade, biological anthropologists have increasingly begun to rely on energetic models for understanding patterns and trends in hominin evolution (e.g., Leonard and Robertson, 1994, 1997a; Aiello and Wheeler, 1995; Leonard, 2002). The study of energetics is important to evolutionary research for several reasons. First, food energy represents a critical interface between organisms and their environment. The search for food energy, its consumption, and ultimately its allocation for biological processes are all critical aspects of an organism’s ecology (McNab, 2002). In addition, the energy dynamic between organisms and their environments—energy expenditure in relation to energy consumed—has important adaptive consequences for both survival and reproduction. Energy thus provides a useful currency for measuring fitness. Indeed, the two components of Darwinian fitness—survival and reproduction—are reflected in the way that total energy budgets for animals are typically divided (see fig. 18.1). “Maintenance” energy expenditure represents the costs of keeping an animal alive on a day-to-day basis.
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Chapter
Although the baobab can be described as a multipurpose tree wherever it grows, it is also true that different groups throughout its range emphasize some uses over others in keeping with their way of life. In the wetter parts of Africa to which the baobab has been introduced, other plants provide preferred alternatives to some of its many products, and the baobab retains its natural form consisting of one or more massive smooth trunks, with a dome-like canopy. The tree also retains its natural form where appreciated for its shade, its symbolic and religious value, and its much-loved fruit. However, in the dryness of the savanna where alternative resources are scarce, the baobab bears the conspicuous marks of its diverse uses. For foragers like the Hadza who climb the baobab to gather honey, water, fiber, birds, and other resources, the tree is dotted with holes and small sticks used as climbing pegs. For many who value baobab leaves for food and fodder, the baobab is a pollarded tree with a swollen trunk and stubby branches, a sight especially common in West Africa. For those interested in the baobab’s strong versatile bark fiber, which is often obtained from the lower part of the trunk, the telltale scars of ring-barking are clearly evident. Many marvel at the baobab’s remarkable ability to survive ring-barking, which highlights its status as a manifest tree of life. The value of plant fibers, especially for binding, stringing, bundling, fastening, hoisting, hanging, lashing, packaging, wrapping, sowing, weaving, anchoring, and mooring, is often overlooked or poorly treated in theoretical discussions of early hominin material culture (Lancaster 1968; Ambrose 2001). But as Plotkin (1988) notes, “Fibre plants are second only to food plants in terms of their usefulness to humans and their influence on the advancement of civilization” (Cited in Cotton 1996: 190).
Chapter
As a fiber tree, the baobab enters into Hadza aesthetics by its contribution to the making of wellness objects, personal ornaments, decorations, and musical instruments. The Hadza are fond of jewelry, as earlier noted, especially necklaces and headbands made with beads and other natural and acquired materials. Beadwork is also used to decorate containers and other objects. According to Matthiessen (1972:234): “Sometimes the seeds are left inside the hull to make a baby’s rattle.” Woodburn (1970) had earlier mentioned this toy rattle and provided photographic illustrations. One wonders if this baobab rattle is ever used in the Epeme Dance, if only as a last resort when cultivated Lagenaria gourds are not available. Of course, baobab and wild Lagenaria rattles would also have been available prior to the development of agriculture some twelve thousand years ago.
Chapter
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Reflecting the general understanding at the time, Christian Kull and Paul Laris (2009:187) wrote, “Humans evolved in Africa in the presence of fire,” noting that “Little is known, however, about the interconnections between human evolution and the flammable savanna biome (Keeley and Rundel 2005; Ségalen et al. 2007; Bowman et al. 2008).” Consider the baobab, for example. It has received increasing attention in recent years for its dietary, nutritional, medicinal, and commercial value; the same cannot be said for the intriguing ways in which it enters into the fire-related activities of Africans of the savanna. But the value of the baobab as one of the mediating factors in the Hadza interaction with fire is an important aspect of its multipurpose use, and this points to the possible significance of the baobab/fire association in the foraging adaptation of early hominins. As earlier noted, hominin evolution is theorized to have involved a transition from an arboriterrestrial ancestor to a committed terrestrial adaptation to the mosaic savanna. The natural fire regime of the African savanna would have been, without doubt, a key factor in the foraging way of life that was the foundation of hominin evolution, and the baobab was likely a part of this history.
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The Middle Pleistocene is associated with a new level of technology, Mode 2, commonly called the Acheulean Culture. This appears in Africa and Western Asia, but only later in Europe and not at all in Asia. It appears to be an indicator of communication, if not actual migration, among these areas. Climate swings, particularly in Europe, suggest that some forms of shelter and clothing had been invented, but more direct evidence is scarce. Controlled fire appears about a million years ago, but what traces are found suggest it was not widely used. Hunting of larger animals is well documented in the Middle Pleistocene employing weaponry such as lances and throwing spears. Meat consumption appears to have increased in importance, especially in temperate Europe. Strangely, Asian populations did not follow the same behavioral trends.
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Both morphometric and proteomic studies have revealed the close relationship of Homo antecessor with Neanderthals and H. sapiens. Considering this relationship, we aim to characterize the Early Pleistocene Atapuerca‐Gran Dolina (TD6) maxillary premolars to test if their pattern of enamel thickness is shared with Neanderthals or H. sapiens. We employed microcomputed tomography to estimate 2D and 3D tissue proportions in seven H. antecessor maxillary premolars, belonging to two individuals: H1 and H3, and compared them to a sample of extinct and extant Homo populations of African, Asian and European origin (n = 52). Our results reveal a different pattern of enamel thickness between the Atapuerca‐Gran Dolina two individuals. While TD6‐H1 possesses thin‐enameled crowns, with a clear affinity with Neanderthals, TD6‐H3 exhibits the thick pattern, a trait shared with the majority of fossil hominins and H. sapiens. This work provides new data on upper premolar enamel thickness in H. antecessor. By documenting both a thin and a thick pattern of enamel thickness in the TD6 sample, we warn about the taxonomic utility of this feature in the characterization of isolated remains. We suggest that the thin enamel condition would have emerged during the Early Pleistocene and it became the most frequent and typical condition in Neanderthals. Possible causes for the pattern observed in TD6 include sexual dimorphism or presence of two populations in the sample; however, population variability is the most plausible explanation with a character expression intermediate between those of Neanderthals and other members of the genus Homo. This interpretation is compatible with the phylogenetic position of H. antecessor close to the ancestor of Neanderthals and H. sapiens.
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Increased brain size in humans and other primates is hypothesized to confer cognitive benefits but brings costs associated with growing and maintaining energetically expensive neural tissue. Previous studies have argued that changes in either diet or levels of sociality led to shifts in brain size, but results were equivocal. Here we test these hypotheses using phylogenetic comparative methods designed to jointly account for and estimate the effects of adaptation and phylogeny. Using the largest current sample of primate brain and body sizes with observation error, complemented by newly compiled diet and sociality data, we show that both diet and sociality have influenced the evolution of brain size. Shifting from simple to more complex levels of sociality resulted in relatively larger brains, while shifting to a more folivorous diet led to relatively smaller brains. While our results support the role of sociality, they modify a range of ecological hypotheses centered on the importance of frugivory, and instead indicate that digestive costs associated with increased folivory may have resulted in relatively smaller brains.
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In the space of one generation major changes have begun to take place in the field of human reproduction. A rapid increase in the control of fertility and the understanding and treatment of sexual health issues have been accompanied by an emerging threat to reproductive function linked to increasing environmental pollution and dramatic changes in lifestyle. Organised around four key themes, this book provides a valuable review of some of the most important recent findings in human reproductive ecology. Major topics include the impact of the environment on reproduction, the role of physical activity and energetics in regulating reproduction, sexual maturation and ovulation assessment and demographic, health and family planning issues. Both theoretical and practical issues are covered, including the evolution and importance of the menopause and the various statistical methods by which researchers can analyse characteristics of the menstrual cycle in field studies.
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The interface of sexual behavior and evolutionary psychology is a rapidly growing domain, rich in psychological theories and data as well as controversies and applications. With nearly eighty chapters by leading researchers from around the world, and combining theoretical and empirical perspectives, The Cambridge Handbook of Evolutionary Perspectives on Sexual Psychology is the most comprehensive and up-to-date reference work in the field. Providing a broad yet in-depth overview of the various evolutionary principles that influence all types of sexual behaviors, the handbook takes an inclusive approach that draws on a number of disciplines and covers nonhuman and human psychology. It is an essential resource for both established researchers and students in psychology, biology, anthropology, medicine, and criminology, among other fields. Volume 4: Controversies, Applications, and Nonhuman Primate Extensions addresses controversies and unresolved issues; applications to health, law, and pornography; and non-human primate evolved sexual psychology.
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Wide-ranging and inclusive, this text provides an invaluable review of an expansive selection of topics in human evolution, variation and adaptability for professionals and students in biological anthropology, evolutionary biology, medical sciences and psychology. The chapters are organized around four broad themes, with sections devoted to phenotypic and genetic variation within and between human populations, reproductive physiology and behavior, growth and development, and human health from evolutionary and ecological perspectives. An introductory section provides readers with the historical, theoretical and methodological foundations needed to understand the more complex ideas presented later. Two hundred discussion questions provide starting points for class debate and assignments to test student understanding.
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Wide-ranging and inclusive, this text provides an invaluable review of an expansive selection of topics in human evolution, variation and adaptability for professionals and students in biological anthropology, evolutionary biology, medical sciences and psychology. The chapters are organized around four broad themes, with sections devoted to phenotypic and genetic variation within and between human populations, reproductive physiology and behavior, growth and development, and human health from evolutionary and ecological perspectives. An introductory section provides readers with the historical, theoretical and methodological foundations needed to understand the more complex ideas presented later. Two hundred discussion questions provide starting points for class debate and assignments to test student understanding.
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Wide-ranging and inclusive, this text provides an invaluable review of an expansive selection of topics in human evolution, variation and adaptability for professionals and students in biological anthropology, evolutionary biology, medical sciences and psychology. The chapters are organized around four broad themes, with sections devoted to phenotypic and genetic variation within and between human populations, reproductive physiology and behavior, growth and development, and human health from evolutionary and ecological perspectives. An introductory section provides readers with the historical, theoretical and methodological foundations needed to understand the more complex ideas presented later. Two hundred discussion questions provide starting points for class debate and assignments to test student understanding.
Chapter
Wide-ranging and inclusive, this text provides an invaluable review of an expansive selection of topics in human evolution, variation and adaptability for professionals and students in biological anthropology, evolutionary biology, medical sciences and psychology. The chapters are organized around four broad themes, with sections devoted to phenotypic and genetic variation within and between human populations, reproductive physiology and behavior, growth and development, and human health from evolutionary and ecological perspectives. An introductory section provides readers with the historical, theoretical and methodological foundations needed to understand the more complex ideas presented later. Two hundred discussion questions provide starting points for class debate and assignments to test student understanding.
Chapter
In the space of one generation major changes have begun to take place in the field of human reproduction. A rapid increase in the control of fertility and the understanding and treatment of sexual health issues have been accompanied by an emerging threat to reproductive function linked to increasing environmental pollution and dramatic changes in lifestyle. Organised around four key themes, this book provides a valuable review of some of the most important recent findings in human reproductive ecology. Major topics include the impact of the environment on reproduction, the role of physical activity and energetics in regulating reproduction, sexual maturation and ovulation assessment and demographic, health and family planning issues. Both theoretical and practical issues are covered, including the evolution and importance of the menopause and the various statistical methods by which researchers can analyse characteristics of the menstrual cycle in field studies.
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In the space of one generation major changes have begun to take place in the field of human reproduction. A rapid increase in the control of fertility and the understanding and treatment of sexual health issues have been accompanied by an emerging threat to reproductive function linked to increasing environmental pollution and dramatic changes in lifestyle. Organised around four key themes, this book provides a valuable review of some of the most important recent findings in human reproductive ecology. Major topics include the impact of the environment on reproduction, the role of physical activity and energetics in regulating reproduction, sexual maturation and ovulation assessment and demographic, health and family planning issues. Both theoretical and practical issues are covered, including the evolution and importance of the menopause and the various statistical methods by which researchers can analyse characteristics of the menstrual cycle in field studies.
Chapter
In the space of one generation major changes have begun to take place in the field of human reproduction. A rapid increase in the control of fertility and the understanding and treatment of sexual health issues have been accompanied by an emerging threat to reproductive function linked to increasing environmental pollution and dramatic changes in lifestyle. Organised around four key themes, this book provides a valuable review of some of the most important recent findings in human reproductive ecology. Major topics include the impact of the environment on reproduction, the role of physical activity and energetics in regulating reproduction, sexual maturation and ovulation assessment and demographic, health and family planning issues. Both theoretical and practical issues are covered, including the evolution and importance of the menopause and the various statistical methods by which researchers can analyse characteristics of the menstrual cycle in field studies.
Chapter
In the space of one generation major changes have begun to take place in the field of human reproduction. A rapid increase in the control of fertility and the understanding and treatment of sexual health issues have been accompanied by an emerging threat to reproductive function linked to increasing environmental pollution and dramatic changes in lifestyle. Organised around four key themes, this book provides a valuable review of some of the most important recent findings in human reproductive ecology. Major topics include the impact of the environment on reproduction, the role of physical activity and energetics in regulating reproduction, sexual maturation and ovulation assessment and demographic, health and family planning issues. Both theoretical and practical issues are covered, including the evolution and importance of the menopause and the various statistical methods by which researchers can analyse characteristics of the menstrual cycle in field studies.
Chapter
In the space of one generation major changes have begun to take place in the field of human reproduction. A rapid increase in the control of fertility and the understanding and treatment of sexual health issues have been accompanied by an emerging threat to reproductive function linked to increasing environmental pollution and dramatic changes in lifestyle. Organised around four key themes, this book provides a valuable review of some of the most important recent findings in human reproductive ecology. Major topics include the impact of the environment on reproduction, the role of physical activity and energetics in regulating reproduction, sexual maturation and ovulation assessment and demographic, health and family planning issues. Both theoretical and practical issues are covered, including the evolution and importance of the menopause and the various statistical methods by which researchers can analyse characteristics of the menstrual cycle in field studies.
Chapter
In the space of one generation major changes have begun to take place in the field of human reproduction. A rapid increase in the control of fertility and the understanding and treatment of sexual health issues have been accompanied by an emerging threat to reproductive function linked to increasing environmental pollution and dramatic changes in lifestyle. Organised around four key themes, this book provides a valuable review of some of the most important recent findings in human reproductive ecology. Major topics include the impact of the environment on reproduction, the role of physical activity and energetics in regulating reproduction, sexual maturation and ovulation assessment and demographic, health and family planning issues. Both theoretical and practical issues are covered, including the evolution and importance of the menopause and the various statistical methods by which researchers can analyse characteristics of the menstrual cycle in field studies.
Chapter
In the space of one generation major changes have begun to take place in the field of human reproduction. A rapid increase in the control of fertility and the understanding and treatment of sexual health issues have been accompanied by an emerging threat to reproductive function linked to increasing environmental pollution and dramatic changes in lifestyle. Organised around four key themes, this book provides a valuable review of some of the most important recent findings in human reproductive ecology. Major topics include the impact of the environment on reproduction, the role of physical activity and energetics in regulating reproduction, sexual maturation and ovulation assessment and demographic, health and family planning issues. Both theoretical and practical issues are covered, including the evolution and importance of the menopause and the various statistical methods by which researchers can analyse characteristics of the menstrual cycle in field studies.
Chapter
In the space of one generation major changes have begun to take place in the field of human reproduction. A rapid increase in the control of fertility and the understanding and treatment of sexual health issues have been accompanied by an emerging threat to reproductive function linked to increasing environmental pollution and dramatic changes in lifestyle. Organised around four key themes, this book provides a valuable review of some of the most important recent findings in human reproductive ecology. Major topics include the impact of the environment on reproduction, the role of physical activity and energetics in regulating reproduction, sexual maturation and ovulation assessment and demographic, health and family planning issues. Both theoretical and practical issues are covered, including the evolution and importance of the menopause and the various statistical methods by which researchers can analyse characteristics of the menstrual cycle in field studies.
Chapter
In the space of one generation major changes have begun to take place in the field of human reproduction. A rapid increase in the control of fertility and the understanding and treatment of sexual health issues have been accompanied by an emerging threat to reproductive function linked to increasing environmental pollution and dramatic changes in lifestyle. Organised around four key themes, this book provides a valuable review of some of the most important recent findings in human reproductive ecology. Major topics include the impact of the environment on reproduction, the role of physical activity and energetics in regulating reproduction, sexual maturation and ovulation assessment and demographic, health and family planning issues. Both theoretical and practical issues are covered, including the evolution and importance of the menopause and the various statistical methods by which researchers can analyse characteristics of the menstrual cycle in field studies.
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The book of Esther was a conscious reaction to much of the conventional wisdom of its day, challenging beliefs regarding the Jerusalem Temple, the land of Israel, Jewish law, and even God. Aaron Koller identifies Esther as primarily a political work, and shows that early reactions ranged from ignoring the book to 'rewriting' Esther in order to correct its perceived flaws. But few biblical books have been read in such different ways, and the vast quantity of Esther-interpretation in rabbinic literature indicates a conscious effort by the Rabbis to present Esther as a story of faith and traditionalism, and bring it into the fold of the grand biblical narrative. Koller situates Esther, and its many interpretations, within the intellectual and political contexts of Ancient Judaism, and discusses its controversial themes. His innovative line of enquiry will be of great interest to students and scholars of Bible and Jewish studies.
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The book of Esther was a conscious reaction to much of the conventional wisdom of its day, challenging beliefs regarding the Jerusalem Temple, the land of Israel, Jewish law, and even God. Aaron Koller identifies Esther as primarily a political work, and shows that early reactions ranged from ignoring the book to 'rewriting' Esther in order to correct its perceived flaws. But few biblical books have been read in such different ways, and the vast quantity of Esther-interpretation in rabbinic literature indicates a conscious effort by the Rabbis to present Esther as a story of faith and traditionalism, and bring it into the fold of the grand biblical narrative. Koller situates Esther, and its many interpretations, within the intellectual and political contexts of Ancient Judaism, and discusses its controversial themes. His innovative line of enquiry will be of great interest to students and scholars of Bible and Jewish studies.
Chapter
The book of Esther was a conscious reaction to much of the conventional wisdom of its day, challenging beliefs regarding the Jerusalem Temple, the land of Israel, Jewish law, and even God. Aaron Koller identifies Esther as primarily a political work, and shows that early reactions ranged from ignoring the book to 'rewriting' Esther in order to correct its perceived flaws. But few biblical books have been read in such different ways, and the vast quantity of Esther-interpretation in rabbinic literature indicates a conscious effort by the Rabbis to present Esther as a story of faith and traditionalism, and bring it into the fold of the grand biblical narrative. Koller situates Esther, and its many interpretations, within the intellectual and political contexts of Ancient Judaism, and discusses its controversial themes. His innovative line of enquiry will be of great interest to students and scholars of Bible and Jewish studies.
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Cellular agriculture, an emerging method for producing meat in the laboratory, is proposed as part of the solution to anthropogenic climate change and justified with narratives about the deep prehistoric interconnection of human carnivory and technology. Evidence from the archaeological record and contemporary human entanglements with meat are discussed across evolutionary, geologic, geographic, and biosocial scales to examine cellular agriculture as the evolution of human diet in the Anthropocene. Without critical attention to uncertainties inherent to interpreting the fossil record, moments in prehistory are woven into a timeline, creating a narrative of technological innovation in the diet that evolves toward the present. This primordial view of meat-eating and its intersection with technology struggles to avoid an essentialist view of the past and a teleological view of the present, but also impacts how we imagine our future, limiting critical examination of the future human diet.
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As observed in recent centuries, the contemporary variety of kinship systems reflects millennia of human migration, cultural inheritance, adaptation, and diversification. This review describes key developments in prehistoric kinship, from matricentric hominin evolution to the Neolithic transition to agriculture and the heterogeneous resilience of matriliny. Starting with our hominin ancestors, kinship evolved among a cooperative breeding species to multilevel group structure among human hunter-gatherers, to substantial kinship changes brought on by the origins of intensified farming, to permanent settlements and unequal resource access. This review takes the approach that new forms of subsistence facilitated new equations of reproductive success, which changed cultural norms of kinship systems and heritable wealth. Subsequently, the formation of complex societies diminished kinship as the primary organizing principle of society. The article describes new methodologies and theoretical developments, along with critiques of bioarchaeological interpretations of prehistoric kinship.
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Among the primates, one group stands out by a huge brain, short dental arcade without prominent canines, habitually upright body posture, absence of prehensile characteristics in the foot and instead an integrated big toe and bipedal locomotion: the hominidae. Together with the mentioned traits, most members of this group show less obvious characteristics: vertically orientated, chisel-shaped front teeth (including the canines), the development of a long thumb, strongly reinforced second and third finger (“entaxonic” hand in the terminology of Jouffroy and Lessertisseur (1993)), reduction of the lateral toes for the sake of the big first toe, length and slender shape of the trunk, in comparison to the hindlimbs “weakly” developed forelimbs, deep position of the shoulder and constriction of the caudal opening of the rib cage, particular shape of the pelvis.KeywordsPre-humansEarly humansHuman footLower legKnee jointLength of hindlimbPelvisLumbar lordosisTrunk shapeKinetics of bipedalityHuman handMorphometry of skullMechanics of human skull
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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.
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Modern East African savannas serve as the primary model for the paleoenvironments of early hominids. However, throughout the Neogene there have been cooling and drying trends through time and fluctuations in seasonality. As a result, many modern East African savannas are drier, with more severe dry seasons, than during some periods in the Plio/Pleistocene in which early hominids lived. Our understanding of these moister and less seasonal periods is crucial for reconstructing early hominid lifeways. This paper presents a study of the ecology and bone taphonomy of a savanna less dry and less seasonal than the East African ones, the Central African savanna in Parc National des Virunga, Zaire. The natural bone distributions across the landscape of Parc National des Virunga contain information about the spatial distribution of scavenging opportunities and the effects on bone deposition of ecological variables such as large-herbivore biomass, proximity to water, and tree density. This information is a significant for taphonomic interpretation of fossil distributions in paleosols and the paleoecology of hominid scavenging. My results indicate that the Central African savanna differs in bone distributions and scavenging opportunities from the savannas of East Africa. Bone deposition is higher in open grasslands than in wooded areas near rivers, and there is no dry-season glut of carcasses. There is also no evidence for increased bone deposition near permanent water or ephemeral water holes. These differences are ultimately the result of the less seasonal rainfall pattern. For early periods in human evolution, Central African savannas may be a useful analog, and the implications for site formation and the ecology of scavenging are profound.
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Male aggression against females in primates, including humans, often functions to control female sexuality to the male's reproductive advantage. A comparative, evolutionary perspective is used to generate several hypotheses to help to explain cross-cultural variation in the frequency of male aggression against women. Variables considered include protection of women by kin, male-male alliances and male strategies for guarding mates and obtaining adulterous matings, and male resource control. The relationships between male aggression against women and gender ideologies, male domination of women, and female sexuality are also considered.
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The observation that absolute brain size increased over the past 2 million years is one of the few uncontested facts of hominid evolution. There is, however, less agreement about how the size of the brain evolved relative to that of the body. Relative brain size has proven to be difficult to quantify because fossil hominid crania that offer the endocranial measurements, and postcrania that generally provide the body-mass estimates, can only rarely be attributed to the same individual. If it could be established that some aspect of the cranium is strongly correlated with body mass, then relative brain size could be calculated for each fossil hominid cranium that has a measured endocranial volume. This paper investigates one such cranial feature, the area of the orbital aperture, and its correlation with body mass in a large sample of extant primates. The results demonstrate that orbital area is correlated with body mass atr=0·987. Predictions of body mass on the basis of orbital area measured for fossil hominids suggest that body mass inHomoincreased through time, and that body mass sexual dimorphism was possibly somewhat greater for some fossil hominid species than it is in living humans. Combining these body mass estimates with measures of endocranial volume demonstrates increased relative brain size for bothAustralopithecusand archaicHomo, with the values forAustralopithecusexceeding those of the living hominoids, and archaicHomoexceeding those ofAustralopithecus. The step-like differences among these taxa stand in contrast to the observation that there appears to have been no or only a negligible increase in relative brain size through the subsequent nearly 2 million years of evolution in the genusHomo. The most dramatic changes occur with the appearance of modernHomo sapiensat about 100,000 years ago and include a decrease in body mass and an increase in relative brain size that appears to have been driven by selection for smaller body mass.
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Group size covaries with relative neocortical volume in nonhuman primates. This regression equation predicts a group size for modern humans very similar to that for hunter-gatherer and traditional horticulturalist societies. Similar group sizes are found in other contemporary and historical societies. Nonhuman primates maintain group cohesion through social grooming; among the Old World monkeys and apes, social grooming time is linearly related to group size. Maintaining stability of human-sized groups by grooming alone would make intolerable time demands. It is therefore suggested (1) that the evolution of large groups in the human lineage depended on developing a more efficient method for time-sharing the processes of social bonding and (2) that language uniquely fulfills this requirement. Data on the size of conversational and other small interacting groups of humans accord with the predicted relative efficiency of conversation compared to grooming as a bonding process. In human conversations about 60% of time is spent gossiping about relationships and personal experiences. Language may accordingly have evolved to allow individuals to learn about the behavioural characteristics of other group members more rapidly than was feasible by direct observation alone.
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The interrelationships among development time, growth rate, and adult size are investigated using simple optimization models of a seasonal life history in which larger adults have greater reproductive output. Unlike most previous studies, our models assume that growth rate is an adaptively flexible character that can be increased at the expense of a greater juvenile mortality rate. Three components of fitness are considered: the cost of developing at a suboptimal time of the year, the reproductive advantage of larger adult size, and the increased mortality from rapid juvenile growth. The study focuses on the optimal responses of size, development time, and growth rate to changes in the amount of time available for completion of the life cycle. The models show that the optimal growth rate and size at maturity may respond in several different ways. Perhaps the most likely effect is that growth becomes faster and size smaller with less time available. It is also possible, however, for either growth rate or size (but not both) to stay constant; in other cases, less time available leads to slower growth or larger size. The effects of increased mortality on the juvenile stage are also explored; here, the optimal size is likely to decrease, but growth rate and development time may increase or decrease.
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A model is presented to account for the natural selection of what is termed reciprocally altruistic behavior. The model shows how selection can operate against the cheater (non-reciprocator) in the system. Three instances of altruistic behavior are discussed, the evolution of which the model can explain: (1) behavior involved in cleaning symbioses; (2) warning cries in birds; and (3) human reciprocal altruism. Regarding human reciprocal altruism, it is shown that the details of the psychological system that regulates this altruism can be explained by the model. Specifically, friendship, dislike, moralistic aggression, gratitude, sympathy, trust, suspicion, trustworthiness, aspects of guilt, and some forms of dishonesty and hypocrisy can be explained as important adaptations to regulate the altruistic system. Each individual human is seen as possessing altruistic and cheating tendencies, the expression of which is sensitive to developmental variables that were selected to set the tendencies at a balance ap...
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THERE IS CURRENTLY STRONG INTEREST IN DEVELOPING A BETTER understanding of the probable food habits and dietary niche of early humans (Isaac 1978; Peters and O'Brian 1981; Stahl 1984). Without such information, we are handicapped in our ability to interpret the significance of many features of human morphology and to construct viable models of early human ecology (Isaac 1978; Sussman 1978). Further, it is increasingly obvious that many of the major health problems faced today by more modern technological societies stem from factors related to diet. This strongly suggests that the average diet in such societies is not entirely suitable for human nutritional needs (Burkitt, Walker, and Painter, 1972; Trowell 1978; Truswell 1977). In this paper, I review information about dietary choice in primates, paying particular attention to members of the Hominoidea. I then examine features of the human gut, comparing it with the guts of other mammals, both primates and non-primates, to distinguish any features that appear to set humans apart. I conclude by speculating on the probable diet of early humans, using the behavior of extant pongids as a partial foundation for my speculations.
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Starting with the onset of the last glaciation approximately 100,000 years ago and continuing to the end of the Late Pleistocene approximately 10,000 years ago, human tooth size began to reduce at a rate of 1% every 2,000 years. Both the mesial-distal and the buccal-lingual dimensions of mandibular and maxillary teeth were undergoing the same rate of reduction. From the beginning of the Post-Pleistocene until the present, the overall rate of dental reduction doubled, becoming approximately 1% per thousand years. Buccal-lingual dimensions are now reducing twice as fast as mesial-distal dimensions, and maxillary teeth are reducing at an even more rapid rate than mandibular teeth. Late Pleistocene rates are comparable in Europe and the Middle East. The Post-Pleistocene rates are also the same for Europe, the Middle East, China, Japan, and Southeast Asia. It is suggested that the cookery at the beginning of the Late Pleistocene allowed the earlier changes to occur. The use of pottery within the last 10,000 years further reduced the amount of selection that had previously maintained usable tooth substance. Reduction then occurred as a consequence of the Probable Mutation Effect (Brace, 1963; McKee, 1984).
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Flying across Africa to attend the Pan-African Congress on Prehistory in Livingstone in July of last year I was frequently reminded of how characteristic of man is his continual use of fire, not only in cities but in the primitive open spaces. There were few moments in the course of the whole journey when signs of fire or artificial light were not somewhere visible. As we passed over the sparsely inhabited bush and savannah country of south-central Africa one could sometimes count up to a dozen columns of smoke rising from the landscape spread out below. Some of these were deliberate bush-fires which the native farmers start early in the dry season as a safeguard against the disastrous spread of uncontrolled fire at the end of that season when the vegetation is like tinder. At the Livingstone Congress there were several communications bearing directly or indirectly on the question of how long has man, particularly in Africa, had fire at his disposal.
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Abstracts “Modern” human form results from reduction in both craniofacial and postcranial Middle Pleistocene levels of robustness. In a classic manifestation of mosaic evolution, these reductions began at different times and proceeded at different rates in different places. They were produced by mutations acting alone when particular cultural developments eased the forces of selection. The separate regional appearances of obligatory cooking and projectile use late in the Middle Pleistocene produced separate and predictable manifestations of morphological reduction. There is no common “modern” configuration, and no single geographic locale was responsible for the various aspects of reduction that contribute to “modern” morphology.
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Females make large investments in their children and compete among themselves to establish and maintain privileged relationships with male allies who demonstrate both an ability and a willingness to provide fitness-enhancing advantages. Various "strategies" and their more numerous, associated "tactics" are utilized in the competition. Alleged strategies include using sexuality, producing offspring, assisting the male in his own intrasexual contests, and harassing female competitors. The strategies in question are documented in multiple primate species, including humans living in various times and places. Some variables are discussed that influence the degree to which human females rely upon them.
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The evolution of nonconceptive sexuality in bonobos and chimpanzees is discussed from a functional perspective. Bonobos and chimpanzees have three functions of sexual activity in common (paternity confusion, practice sex, and exchange for favors), but only bonobos use sex purely for communication about social relationships. Bonobo hypersexuality appears closely linked to the evolution of female-female alliances. I suggest that these alliances were made possible by relaxed feeding competition, that they were favored through their effect on reducing sexual coercion, and that they are ultimately responsible for the relaxed social conditions that allowed the evolution of "communication sex."
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Recent investigations of Lower Pleistocene sites at Chesowanja have yielded in situ Oldowan and Oldowan-like stone artefacts, evidence of fire and a fragmentary `robust' australopithecine cranium. Burnt clay found at one artefact locality dated to >1.42+/-0.07 Myr is the earliest known evidence of fire associated with a hominid occupation site.
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As our closest living relatives, chimpanzees and bonobos have been widely used as models of the behavior of early hominids. In recent years, as information on the social behavior and ecology of bonobos has come to light, many interspecific comparisons have been made. Chimpanzees have been characterized in terms of their intercommunity warfare, meat eating, infanticide, cannibalism, male status-striving, and dominance over females. Bonobos, meanwhile, have been portrayed as the "Make love, not war" ape, characterized by female power-sharing, a lack of aggression between either individuals or groups, richly elaborated sexual behavior that occurs without the constraint of a narrow window of fertility, and the use of sex for communicative purposes. This paper evaluates the evidence for this dichotomy and considers the reasons that contrasting portrayals of the two great apes have developed. While there are marked differences in social behavior between these two species, I argue that they are more similar behaviorally than most accounts have suggested. I discuss several reasons that current Views of bonobo and chimpanzee societies may not accord well with field data. Among these are a bias toward captive data on bonobos, the tendency to see bonobos as derived because their behavior has been described more recently than that of chimpanzees, and the possibility that interpretations of bonobo-chimpanzee differences are reflections of human male-female differences.
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Emergency behaviors of nonliterate groups are taken as a useful starting point for demonstrating that decisions can be integrated more directly into cultural analysis and that the explanatory payoffs can be far-reaching. The methodological feasibility of studying group decisions directly is explored through three exceptional tribal ethnographies with a focus on emergency adaptive problem solving and its implications for both cultural- and gene-selection theory. Urgently discussed decision alternatives become apprehensible to fieldworkers through open group debate, while the reproductive effects of decisions are readily assessed whenever groups act in unison. Implications for the development of a more effective theory of cultural microselection and a truly processual definition of culture in its guided phase are suggested. With respect to long-term genetic evolution, the implications of emergency decision making are extended to foragers, exploring special possibilities that enable genetic group selection to become robust when groups are egalitarian and engage in consensual problem solving. Prehistorically, the verdict is that group-selection effects were amplified at the same time that individual effects were suppressed. On this basis it is hypothesized that the genetic evolution of human cooperative and altruistic tendencies can be explained in part by selection at the level of groups rather than inclusive fitness.
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On-site observations on the faunal collections remaining in Beijing from the prewar excavations of Zhoukoudian are reported. Assessments are made regarding the degree to which these collections represent both the faunal remains removed from the site. Comparative studies of the observed materials are then presented with the aim of assessing the relative roles of hominids and other denning animals. It is concluded that, given our current knowledge of diagnostic criteria, nonhominid denning animals were the dominant agents responsible for the Zhoukoudian faunal remains and that, while hominids were certainly also involved, they are likely to have been scavenging animal products rather than hunting. Provocative evidence of the "roasting" of horse heads seems indicated for the recent (<250,000 years ago) levels at Zhoukoudian.
Article
Human origins research by archaeologists has expanded the evidence of the diet and subsistence activities of ancient hominids. We examine an important component of that evidence, the 1.75-million-year-old faunal assemblage from the FLK Zinjanthropus site at Olduvai Gorge, Tanzania. Skeletal-part frequencies are used to evaluate hominid access to and differential transport of carcass portions of differing nutritional value. Cut-mark frequencies and locations are used to evaluate butchery patterns including skinning, disarticulation, and defleshing of carcasses. In contrast to other recently published assessments of the FLK Zinjanthropus data, we conclude that (1) ancient hominids had full access to meaty carcasses of many small and large animals prior to any substantial loss of meat or marrow bones through other predator or scavenger feeding; (2) ancient hominids were butchering animal carcasses by an efficient and systematic technique that involved skinning, disarticulation, and defleshing; and (3) the FLK Zinjanthropus site represents a place where the secondary butchering of selected carcass portions and the consumption of substantial quantities of meat and marrow occurred.
Article
Zhoukoudian is often cited as yielding some of the earliest evidence for the use of fire and as documenting "man the hunter" living in caves during the Middle Pleistocene. In addition, it is commonly believed that this important Chinese site documents cannibalism on the part of Middle Pleistocene hominids. We examine the data from Zhoukoudian with several questions in mind: (1) What are the agents responsible for the bone accumulations inside the cave? (2) What materials within the cave reflect early hominid behavior? (3) What was the nature of that behavior? Our conclusions are at variance with traditional interpretations.
Article
Many plants contain secondary compounds that are potentially antagonistic to hominids, and their presence must be considered as a factor influencing dietary selection by hominids who did not possess a means of externally detoxifying foodstuffs (eg cooking). Behavioral strategies which might have been employed as a means of reducing intake of secondary compounds include ingestion of a mix of plants in order to minimize intake of a particular allelochemical, avoidance of species or plant parts with a high proportion of secondary compounds, and/or a focus on foods with high nutrient quality, thereby providing a return despite the metabolic costs of dealing with the allelochemical. A ranking of potential foodstuffs which considers the role of secondary compounds, indigestible constituents, and soluble carbohydrate and protein content has been proposed. When combined with an assessment of the ecological characteristics of particular plant species in specific geographical settings, such a ranking should be helpful in generating models of hominid dietary selection prior to the application of fire to food preparation. Comments by K.Homewood and 9 others and a reply by the author are included.-from Author
Article
Male mating competition is generally regarded to account for sexual dimorphism in body size, but levels of sexual dimorphism do not appear to be associated with the intensity of intrasexual selection in polygynous mammals. In contrast, observations of accentuated dimorphism in certain taxa and in large species are consistent with nonadaptive explanations for the evolution of sexual size dimorphism based on phylogenetic inertia and allometry. Here we employ a weight-corrected measure of sexual dimorphism and a biologically realistic assay of mating competition, the operational sex ratio, to reexamine the factors favoring the evolution of sexual size dimorphism in primates. Independent contrasts that control for the effects of allometry and phylogeny produce results consistent with the sexual selection hypothesis; a strong relationship exists between sexual dimorphism in size and the intensity of male mating competition among polygynously mating primates. Increased sexual dimorphism in large primates may not be an inevitable consequence of allometry but instead may result from a reduction in the temporal availability of fertile females due to long birth intervals.
Article
Perspectives have shifted recently from the traditional view that early hominids were hunters to one which now sees them as opportunistic scavengers. However, both views share the common underlying nutritional assumption that meat inevitably provides a “high quality” food that will be incorporated into human diet more or less to the extent that animals are avaible and accessible. This paper argues that meat may actually have been a relatively marginal source of sustenance for early hominids, because physiological limits to total protein intake (plant and animal), scarcity of fat in most African ungulates, comparatively high levels of protein in many plant foods, and the inability of early hominids to extract lipids from the cancellous tissue of bones, acted together to maintain their total meat intakes at modest levels, particularly during seasonal or inter-annual periods of resource stress.
Article
The earliest undoubted evidence for the controlled use of fire by humans comes from sites no more than a million years old. Recently, however, very tentative evidence for the presence of fire has come from several Lower Pleistocene sites in Africa. A systematic approach to the problem of detecting and characterizing possible ancient fireplaces is clearly needed. The use of archaeometric techniques, particularly magnetic surveying and palaeomagnetism, may be crucial. Results from experimental and Holocene fireplaces in Australia are used here in an attempt to begin formulating an approach, and palaeomagnetic results from Lower Pleistocene sites in Africa are reviewed.
Article
Chemical analyses and a digestibility trial were carried out to determine the effect of cooking full-fat soya beans on their proximate analysis, level of antinutritional factors and apparent nutrient digestibility by weanling pigs. Samples of soya bean meal and of raw soya beans subjected to four different periods of cooking were assayed for nutrient analysis and level of antinutritional factors. The digestibility trial was conducted with five pairs of two littermate (Large White × Hampshire) castrates of an average initial weight of 9.28 kg to evaluate the effect of cooking soya beans at 100°C for 15, 20, 25 or 30 min on apparent nutrient digestibility.The results showed that duration of cooking had no effect on the proximate analysis of soya beans. However, trypsin inhibitor activity level and percentage tannin decreased linearly (P < 0.01), while percentage phytic acid decreased non-significantly (P < 0.05) with increase in duration of cooking. Apparent digestibility and retention of dietary dry matter, nitrogen and ether extract increased linearly with increase in duration of cooking (P < 0.05).
Article
Discovery of the uses and later the invention of fire-making are fundamental to humanity. Following reports over the last decade of traces of fire found on Lower Pleistocene archaeological sites in eastern Africa, the dating of the control of fire by hominids has become a controversial issue. In this paper we critically review the contexts and, in the light of a battery of archaeometric techniques, the nature of reported instances of fire from Koobi Fora and Chesowanja in Kenya, and from Gadeb and the Middle Awash in Ethiopia. We conclude with a discussion of the roles fire may have played in the lifeways of early Pleistocene savanna-living hominids.
Article
The effects oi nonselective predation on the optimal age and size of maturity of their prey tire investigated using mathematical models of a simple life history with juvenile and adult stages. Fitness is measured by the product of survival ro the adult stage and expected adult reproduction, which is usually an increasing function of size at maturity. Size is determined by both age at maturity and the value of costly traits that increase mean growth rate (growth effort), The analysis includes cases with fixed size but flexible time to maturity, fixed time but flexible size, and adaptively flexible values of both variables. In these analyses, growth effort is flexible. For comparison with previous theory, models with a fixed growth effort are analyzed, In each case, there may he indirect effects of predation on the prey's food supply. The effect of increased predation depends on (I) which variables are flexible; (2) whether increased growth effort requires increased exposure to predators; and (3) how increased predator density affects the abundance of Pc,od for juvenile prey; Ii there is no indirect effect of predators on prey food supply, size at maturity will generally decrease in response to increased predation. However, the indirect effect from increased food has the opposite effect, and the net result of predation is often increased size. Age at maturity may either increase or decrease, depending on functional forms and parameter values; this is true regardless of the presence of indirect effects. The results are compared with those of previous theoretical analyses. Observed shifts in life history in response to predation am reviewed, and the role of lie-selective predation is reassessed.
Article
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Article
Examen critique des donnees de 30 sites du Pleistocene inferieur et moyen d'Afrique, Asie et Europe, concernant l'utilisation du feu chez les premiers hominides. Les donnees anterieures aux neandertaliens sont equivoques. Discussion du role des processus naturels dans la production du feu. Presentation d'une methode d'evaluation des donnees
Article
Brain tissue is metabolically expensive, but there is no significant correlation between relative basal metabolic rate and relative brain size in humans and other encephalized mammals. The expensive-tissue suggests that the metabolic requirements of relatively large brains are offset by a corresponding reduction of the gut. The splanchnic organs (liver and gastro-intestinal tract) are as metabolically expensive organs in the human body that is markedly small in relation to body size. Gut size is highly correlated with diet, and relatively small guts are compatible only with high-quality, easy-to-digest food. The often -cited relationship between diet and relative brain size is more properly viewed as a relationship between relative brain size and relative gut size, the latter being determined by dietary quality. No matter what is selecting for relatively large brains in humans and other primates, they cannot be achieved without a shift to a high-quality diet unless there is a rise in the metabolic rate. Therefore the incorporation of increasingly greater amounts of animal products into the diet was essential in the evolution of the large human brain.
Article
Archaeological evidence from the Lake Turkana basin, as well as from several other localities in eastern and central Africa, shows that stone tool manufacture and use occurred at least by the later part of the Pliocene, about 2·4 million years (Ma). However, little is known from the archaeological record about the technological characteristics of Pliocene material culture, and related aspects of hominid behavior, such as habitat use and preference and subsistence of the tool makers. Expanded excavations at the West Turkana site of Lokalalei, dated to about 2·35 Ma indicate that hominids making artifacts at this site had little success in striking off whole flakes from the parent core forms. The large number of scars left on these forms consists of step, hinge, and small flakes (>2 cm) which may not have been very successful in cutting or slicing, despite the fact that the raw material utilized was a medium-grained volcanic lava with observable conchoidal fracture mechanics. The fauna is characterized by mainly size 1 or 2 bovids, suggesting early access if scavenged or hunted. This lithic technology patterning, which is shared by other assemblages in the basin, suggests that the Oldowan is not the earliest stone tool technology industry. Rather, the Oldowan represents a point in a continuum from simpler Pliocene technology characterized by little understanding of stone fracture mechanics to greater technological complexity and appreciation of fracture mechanics in the Pleistocene.
Article
Presents a procedure for estimating the generic composition and size of the early hominid fundamental plant-food niche, specifying the types of plant foods that would have been exploited by the early hominids. The procedure consists of specifying the wild plant foods eaten today by humans, chimpanzees and baboons in eastern and southern Africa that could also have been eaten by the early hominids, and examining the paleobotanical evidence for the presence of these plant foods in environments where early hominids are found. There is an extended discussion and author's reply. -after Author
Article
The functions of the stone artefacts made and used by early hominids has been a matter for speculation. However, recent experimental work has demonstrated that microscopically distinct wear-polishes form on tools of cryptocrystalline silica when used on different materials, and that these microwear polishes survive on ancient implements1–3. We have now examined 54 artefacts from five early Pleistocene archaeological sites, dated to 1.5 Myr ago, in the Koobi Fora region of Kenya for microwear polishes and other traces of use. Wear traces were found on nine artefacts, variously resembling traces induced experimentally by cutting soft animal tissue and soft plant material and by scraping and sawing wood. These results greatly extend the time range for which microwear polish analysis is applicable and increase the evidence of early hominid adaptation.
Article
Hominids—both living and past—exhibit considerable variation in body size and shape. Both theoretical considerations and empirical observations indicate that some of this variation may be attributable to climatic adaptation. Application of the simple thermoregulatory principle of increasing and decreasing body surface area/body mass in hot and cold climates, respectively, may explain the major systematic differences in body form between living and fossil hominids inhabiting tropical and higher latitude regions of the world. Consideration of potential climatic influences on morphology has important ramifications for reconstructing body form and behavior of past hominids, interpreting geographic and temporal variability and migrational events, explaining the origins and perfection of hominid bipedalism, and better understanding changes in brain size and encephalization during hominid evolution. © 1994 Wiley-Liss, Inc.
Article
A methodological approach which can discriminate between archaeological evidence of fire resulting from natural processes and archaeological evidence of fire resulting from human activities has recently been used to identify evidence of hominid-controlled fire at FxJj 20 Main, an early Pleistocene archaeological site near Koobi Fora, Kenya. The evidence of fire at FxJj 20 Main consists of highly localized, fully oxidized sediment features found near the base of the archaeological horizon. Similar features are preserved at the nearby sites of FxJj 20 East and FxJj 20 AB, but evidence of hominid-controlled fire has not yet been confirmed at these sites. The use and control of fire is regarded as a major technological breakthrough which would have provided hominids with a number of adaptive advantages that have important evolutionary implications. The virtual lack of thermally-altered stone artifacts and bones, the localized configurations of the oxidized features, and the spatial patterning of the artifacts in relation to the oxidized features, indicate that the early hominids did not use fire for the purpose of hunting, cooking, preserving food, intentional plant selection, vegetation clearing, or improving the flaking characteristics of lithic materials. At present, it appears that the early hominids at FxJj 20 Main used controlled fire primarily as a source of protection against predators, as a source of light, and/or as a source of heat.
Article
Recent comparative studies point to the importance of mortality schedules as determinants in the evolution of life-history characteristics. In this paper, we compare patterns of mortality from natural populations of mammals with a variety of life histories. We find that, after removing the effects of body weight, mortality is the best predictor of variation in life-history traits. Mammals with high levels of natural mortality tend to mature early and give birth to small offspring in large litters after a short gestation, before and after body size effects are factored out. We examine the way in which life-history traits relate to juvenile mortality versus adult mortality and find that juvenile mortality is more highly correlated with life-history traits than is adult mortality. We discuss the necessity of distinguishing between extrinsic sources of mortality (e.g. predation) and mortality caused by intrinsic sources (e.g. costs of reproduction), and the role that ecology might play in the evolution of patterns of mortality and fecundity. We conclude that these results must be explained not simply in the light of the demographic necessity of balancing mortality and fecundity, but as a result of age-specific costs and benefits of reproduction and parental investment. Detailed comparative studies of mortality patterns in natural populations of mammals offer a promising avenue towards understanding the evolution of life-history strategies.
Article
We used morphometric techniques and isotope-labeled water to investigate the influence of abundant, accessible food and resultant low activity levels on body size and fatness in free-living adolescent and adult baboons as compared to animals in the same population that experienced more typical, wild-feeding conditions. Females that had access to abundant food from a nearby garbage dump averaged 16.7 kg body mass, 50% more than their wild-feeding counterparts in adjacent home ranges. Little of the difference was due to lean mass: the animals with an accessible abundance of food averaged 23.2% body fat in contrast to 1.9% for the wild-feeding animals. Significant differences between feeding conditions were found for all measured skinfolds and for upper arm circumference but not for linear measurements. Differences between feeding conditions were less for males than for females, perhaps reflecting persistent effects of nutritional conditions during the first eight years of life before dispersal from the group of birth. The difference in fatness between feeding conditions was similar to the difference between humans with frank obesity and those that are considered lean, but in both cases the percentages of body fat in the baboons were considerably less than those observed in humans. In levels of fatness, the relatively sedentary animals resembled their counterparts in group-housed captive conditions. © 1993 Wiley-Liss, Inc.
Article
Human dietary patterns and metabolic requirements are compared to those of nonhuman primate species in order to gain insights into the evolution of our nutritional needs. In general, primate diet quality (i.e., caloric and nutrient density) is inversely related to body size and total resting metabolic requirements (RMR). Humans, however, consume a diet of much higher quality than is expected for our size and metabolic needs. This energy-rich diet appears to reflect an adaptation to the high metabolic cost of our large brain. Among primates, the relative proportion of resting metabolic energy used for brain metabolism is positively correlated with relative diet quality. Humans represent the positive extreme, having both a very high quality diet and a large brain that accounts for 20–25% of resting metabolism. Evidence from the hominid fossil record implies that major changes in diet and relative brain metabolism occurred with the emergence of the genus Homo. © 1994 Wiley-Liss, Inc.
Article
Fully modern human form, more gracile than the antecedent archaic modern form was evident by 30,000 years ago. One hypothesis to explain this decrease in skeletal robustness is that change occurred in human diet and that this change was associated with a decrease in activity levels required in both individual and group behavior. It is possible to study dietary change directly using trace element analysis of strontium levels in bone. The amount of strontium in bone reflects the amount of strontium in diet. Since plants contain higher levels of strontium than do animal soft tissues, the level of bone strontium will differ between individuals according to the proportion of plant and animal products in their diets. In this study the ratio of strontium:calcium in human bone to strontium:calcium in faunal bone is compared for samples of archaic modern humans (from Mugharet et Tabũn, Mugharet es‐Skhũl, and Jebel Qafzeh) and fully modern humans (from Mugharet el‐Kebara and Mugharet el‐Wad) from Israel. The use of a ratio controls for potentially unequal strontium levels in soils at different sites and for different diagenetic histories between sites. The results of the analysis are internally reliable, reflecting bone strontium levels rather than technique error; therefore, they reflect diet. It appears that a change occurred in the amount of animal protein in the diet of humans but that this change occurred almost 20,000 years after the first appearance of skeletally modern humans. These results refute the hypothesis that the morphological transformation to modern human form occurred as a result of behavioral changes involved in obtaining previously unused foods. If any decrease in human activity level occurred between archaic modern and fully modern humans, this decrease probably was due to alterations in the means of procuring or processing the same kinds of foods that had been utilized earlier in time.
Article
The domestication of fire was a major breakthrough in the sociocultural development of humankind, puttingHomo at a tremendous advantage over other species. In this paper an attempt is. made to reconstruct the first stages of the domestication process, with special emphasis upon its socio-psychological aspects as a ‘civilizing process’. The problem is discussed, first, of what enabled hominid groups to acquire and maintain the learned capacity of handling fire, and, second, of how the control of fire became a species-monopoly shared by all human societies.