Pastoral subsistence and mounted fighting in the Eastern Tianshan Mountain region: New insights from the Shirenzigou worked bone assemblage.

Situated at a geographic crossroads, the eastern Tianshan Mountain region in northwest China is crucial to understanding various economic, social, and cultural developments on the Eurasian Steppes. One promising way to gain a better knowledge of ancient subsistence economy, craft production, and social change in the eastern Tianshan Mountain region is to study the artifact assemblages from archaeological contexts. Here, we present an analysis of 488 worked animal bones from the large site of Shirenzigou (ca. 1300-1 BCE), to date the largest assemblage of this kind uncovered in the eastern Tianshan Mountain region. We classified these worked bones into six categories, including "ritual objects", "ornaments", "tools", "worked astragali", "warfare and mobility", and "indeterminate". The identification of animal species and skeletal elements indicates that worked bones from Shirenzigou are characterized by a predominance of caprine products, particularly worked astragali, which is consistent with the large proportion of caprine fragments found in animal remains associated with food consumption. This demonstrates the contribution of caprine pastoralism to bone working activities at Shirenzigou. The making of most worked bones does not appear to have required advanced or specialized skills. Considering the absence of dedicated bone working space, alongside the variability in raw material selection and in dimensions of certain types of artifacts, we infer that worked bone production at Shirenzigou was not standardized. In terms of raw material selection and mode of production, Shirenzigou differed from their settled, farming counterparts in the Yellow River valley of northern China. In addition, along with the evidence for violence and horseback riding, the increasing use of bone artifacts associated with warfare and mobility during the late occupation phase of Shirenzigou reflects growing social instability and implies the likely emergence of single mounted horsemen, equipped with light armors, in the region during the late first millennium BCE. Our results provide new insights into animal resource exploitation and changing lifeways of early pastoral societies in the eastern Tianshan Mountain region, expanding our knowledge of the economic, social, and political milieu of late Bronze Age and early Iron Age eastern Eurasia.

Early Pleistocene faunivorous hominins were not kleptoparasitic, and this impacted the evolution of human anatomy and socio-ecology.

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

Integrative analysis of DNA, macroscopic remains and stable isotopes of dog coprolites to reconstruct community diet.

Paleofeces or coprolites are often used to reconstruct diet at archaeological sites, usually using macroscopic analyses or targeted DNA amplification and sequencing. Here we present an integrative analysis of dog coprolites, combining macroscopic analyses, stable isotope measurements, and DNA shotgun sequencing to examine diet and health status. Dog coprolites used in this study were recovered from the Janey B. Goode and East Saint Louis archaeological sites, both of which are located in the American Bottom, an extensive Mississippi River floodplain in Southwestern Illinois. Based on the context of recovery, coprolites are assigned to the Late Woodland and Terminal Late Woodland periods (ca. 600-1050 AD). Given the scarcity of human remains from this time period, these dog coprolites can be useful as a proxy for understanding human diet during the Late Woodland period. We find that the Late Woodland dogs consumed a variety of fish as well as bird and plant taxa, possibly including maize, and also harbored intestinal parasites and pathogenic bacteria. By sequencing the fecal microbiome of the coprolites, we find some similarities to modern dog microbiomes, as well as specific taxa that can be used to discriminate between modern and ancient microbiomes, excluding soil contaminants. As dogs are often used as a surrogate to assess human diet, humans living with these dogs likely had a similar diet and were affected by similar parasites. These analyses, when integrated, show a more comprehensive view of ancient dog and human diet and health in the region during the initial expansion of maize agriculture than any individual method could alone.

Shaped stone balls were used for bone marrow extraction at Lower Paleolithic Qesem Cave, Israel.

The presence of shaped stone balls at early Paleolithic sites has attracted scholarly attention since the pioneering work of the Leakeys in Olduvai, Tanzania. Despite the persistent presence of these items in the archaeological record over a period of two million years, their function is still debated. We present new results from Middle Pleistocene Qesem Cave on the use of these implements as percussion tools. Use-wear and abundant bone and fat residues found on ten shaped stone balls indicate crushing of fresh bones by thrusting percussion and provide direct evidence for the use of these items to access bone marrow of animal prey at this site. Two experiments conducted to investigate and verify functional aspects proved Qesem Cave shaped stone balls are efficient for bone processing and provide a comfortable grip and useful active areas for repeated use. Notably, the patina observed on the analyzed items precedes their use at the cave, indicating that they were collected by Qesem inhabitants, most probably from older Lower Paleolithic Acheulian sites. Thus, our results refer only to the final phases of the life of the items, and we cannot attest to their original function. As bone marrow played a central role in human nutrition in the Lower Paleolithic, and our experimental results show that the morphology and characteristics of shaped stone ball replicas are well-suited for the extraction of bone marrow, we suggest that these features might have been the reason for their collection and use at Qesem Cave. These results shed light on the function of shaped stone balls and are consistent with the significance of animal fat in the caloric intake of Middle Pleistocene humans as shown by the archeozoological evidence at Qesem Cave and possibly beyond.

Child development, physiological stress and survival expectancy in prehistoric fisher-hunter-gatherers from the Jabuticabeira II shell mound, South Coast of Brazil.

In this study, we shed light on the interdependency of child growth, morbidity and life expectancy in the fisher-hunter-gatherers of the Jabuticabeira II shell mound (1214-830 cal B.C.E. - 118-413 cal C.E.) located at the South Coast of Brazil. We test the underlying causes of heterogeneity in frailty and selective mortality in a population that inhabits a plentiful environment in sedentary settlements. We reconstruct osteobiographies of 41 individuals (23 adults and 18 subadults) using 8 variables, including age-at-death, stature, non-specific stress markers (cribra orbitalia, porotic hyperostosis, periosteal reactions, periapical lesions and linear enamel hypoplasia), as well as weaning patterns based on stable isotope data to examine how stress factors module growth and survival. Our results show that shorter adult statures were linked to higher morbidity around weaning age and higher chances of dying earlier (before 35 years) than taller adult statures. In addition, short juvenile stature was related to physiological stressors and mortality. The adult "survivors" experienced recurrent periods of morbidity during childhood and adulthood, possibly associated with the high parasite load of the ecosystem and dense settlement rather than to malnourishment. An association between early-stress exposure and premature death was not demonstrated in our sample. To explain our data, we propose a new model called "intermittent stress of low lethality". According to this model, individuals are exposed to recurrent stress during the juvenile and adult stages of life, and, nevertheless survive until reproductive age or later with relative success.

Mugharat an-Nachcharini: A specialized sheep-hunting camp reveals high-altitude habitats in the earliest Neolithic of the Central Levant.

The earliest Neolithic of southwest Asia is generally perceived and portrayed as a period of emerging economic practices that anticipated full-fledged food-producing economies. This first Neolithic, however, can also be seen as the last gasp of an earlier way of life that remained fundamentally Epipaleolithic in character. While people at this time had begun to cultivate some of the plant foods gathered in preceding periods, and to live for lengthy periods in sites with substantial architecture, they also relied on hunting for a significant portion of their diet and logistical movement across landscapes to exploit diverse environments. The objective of our research on Nachcharini Cave, the only excavated early Neolithic site in the high mountains of northeastern Lebanon, is to evaluate its role in a form of logistical organization not well attested at other sites in the Levant during this period. On the basis of material that Bruce Schroeder excavated in the 1970s, we present here for the first time analyses of faunal and lithic evidence from Nachcharini Cave, along with new radiocarbon dates that place the major occupation layer of the site firmly in the earliest Neolithic. We conclude that Nachcharini was a short-term hunting camp that was periodically used over some two centuries.

Cooked starchy rhizomes in Africa 170 thousand years ago.

Plant carbohydrates were undoubtedly consumed in antiquity, yet starchy geophytes were seldom preserved archaeologically. We report evidence for geophyte exploitation by early humans from at least 170,000 years ago. Charred rhizomes from Border Cave, South Africa, were identified to the genus Hypoxis L. by comparing the morphology and anatomy of ancient and modern rhizomes. Hypoxis angustifolia Lam., the likely taxon, proliferates in relatively well-watered areas of sub-Saharan Africa and in Yemen, Arabia. In those areas and possibly farther north during moist periods, Hypoxis rhizomes would have provided reliable and familiar carbohydrate sources for mobile groups.

Analysis of whole Y-chromosome sequences reveals the Japanese population history in the Jomon period.

The Jomon and the Yayoi are considered to be the two major ancestral populations of the modern mainland Japanese. The Jomon people, who inhabited mainland Japan, admixed with Yayoi immigrants from the Asian continent. To investigate the population history in the Jomon period (14,500-2,300 years before present [YBP]), we analyzed whole Y-chromosome sequences of 345 Japanese males living in mainland Japan. A phylogenetic analysis of East Asian Y chromosomes identified a major clade (35.4% of mainland Japanese) consisting of only Japanese Y chromosomes, which seem to have originated from indigenous Jomon people. A Monte Carlo simulation indicated that ~70% of Jomon males had Y chromosomes in this clade. The Bayesian skyline plots of 122 Japanese Y chromosomes in the clade detected a marked decrease followed by a subsequent increase in the male population size from around the end of the Jomon period to the beginning of the Yayoi period (2,300 YBP). The colder climate in the Late to Final Jomon period may have resulted in critical shortages of food for the Jomon people, who were hunter-gatherers, and the rice farming introduced by Yayoi immigrants may have helped the population size of the Jomon people to recover.

Quantifying spatial variability in shell midden formation in the Farasan Islands, Saudi Arabia.

During the past decade, over 3000 shell middens or shell matrix deposits have been discovered on the Farasan Islands in the southern Red Sea, dating to the period c. 7,360 to 4,700 years ago. Many of the sites are distributed along a palaeoshoreline which is now 2-3 m above present sea level. Others form clusters with some sites on the shoreline and others located inland over distances of c. 30 m to 1 km. We refer to these inland sites as 'post-shore' sites. Following Meehan, who observed a similar spatial separation in shell deposition in her ethnographic study of Anbarra shellgathering in the Northern Territory of Australia, we hypothesise that the shoreline sites are specialised sites for the processing or immediate consumption of shell food, and the post-shore sites are habitation sites used for a variety of activities. We test this proposition through a systematic analysis of 55 radiocarbon dates and measurement of shell quantities from the excavation of 15 shell matrix sites in a variety of locations including shoreline and post-shore sites. Our results demonstrate large differences in rates of shell accumulation between these two types of sites and selective removal of shoreline sites by changes in sea level. We also discuss the wider implications for understanding the differential preservation and visibility of shell-matrix deposits in coastal settings in other parts of the world extending back into the later Pleistocene in association with periods of lowersea level. Our results highlight the importance of taphonomic factors of post-depositional degradation and destruction, rates of shell accumulation, the influence on site location of factors other than shell food supply, and the relative distance of deposits from their nearest palaeoshorelines as key variables in the interpretation of shell quantities. Failure to take these variables into account when investigating shells and shell-matrix deposits in late Pleistocene and early Holocene contexts is likely to compromise interpretations of the role and significance of shell food in human evolutionary and socio-cultural development.

Spreading Waves in a Farmers and Hunter-Gatherers Model of the Neolithic Transition in Europe.

The Neolithic transition began the spread of early agriculture throughout Europe through interactions between farmers and hunter-gatherers about 10,000 years ago. Archeological evidence produced by radiocarbon dating indicates that the expanding velocity of farming is roughly constant all over Europe. Theoretical understanding of such evidence has been performed from mathematical modeling viewpoint. However, the expanding velocity determined by existing modeling approaches is faster than the observed velocity. For understanding this difference, we propose a three-component reaction-diffusion system which consists of two different types of farmers (sedentary and migratory) and hunter-gatherers from the viewpoint of the influence of farming technology. Our purpose is to study the relation between the expanding velocity of farmers and the farming technology parameter (say, [Formula: see text]). In this paper, we mainly focus on the one-dimensional traveling wave solution with minimal velocity and show that the minimal velocity decreases, as [Formula: see text] increases. This can be compatible with the observed velocity when farming technology is developed. Our results suggest that the reason for the slowdown of the Neolithic transition might be related to the increase in the development of farming technology.

Contrasting patterns of prehistoric human diet and subsistence in northernmost Europe.

Current archaeological evidence indicates the transition from hunting-fishing-gathering to agriculture in Northern Europe was a gradual process. This transition was especially complex in the prehistoric North Fennoscandian landscape where the high latitude posed a challenge to both domestic animal breeding and cereal cultivation. The conditions varied, the coastal dwellers had access to rich marine resources and enjoyed a milder climate due to the Gulf Stream, while those living in the inland Boreal forest zone faced longer and colder winters and less diversity in animal and plant resources. Thus, the coastal area provided more favourable conditions for early agriculture compared to those found inland. Interestingly, a cultural differentiation between these areas is archaeologically visible from the late 2nd millennium BC onwards. This is most clearly seen in regionally distinct pottery styles, offering unique opportunities to probe diet and subsistence through the organic residues preserved in ceramic vessels. Herein, we integrate the lipid biomarker, compound-specific stable carbon isotopes (δ13C), and zooarchaeological evidence to reveal culturally distinct human diets and subsistence patterns. In northern Norway, some of the coastal people adopted dairying as part of their subsistence strategy, while the inhabitants of the interior, in common with northern Finland, continued their hunter-gatherer-fisher lifestyles.

Breastfeeding, weaning, and dietary practices during the Western Zhou Dynasty (1122-771 BC) at Boyangcheng, Anhui Province, China.

OBJECTIVES: Here we investigate breastfeeding and weaning practices and adult dietary habits at the Western Zhou Dynasty (1122-771 BC) site of Boyangcheng () located in Anhui Province, China. In addition, we utilize the differences in bone collagen turnover rates between rib and long bones from the same individual to examine past life histories, such as changes in diet or residence. MATERIALS AND METHODS: Bone collagen from both the rib and long bones (either femora or humeri) of 42 individuals was measured for stable isotope ratios of carbon (δ13 C) and nitrogen (δ15 N). In addition, δ13 C and δ15 N values are reported for 35 animals (dogs, cows, horses, pigs, and deer). RESULTS: The human δ13 C values range from -20.7‰ to -12.0‰ with a mean value of -18.8 ± 1.6‰. The human δ15 N values range from 9.1‰ to 13.4‰ with a mean value of 10.9 ± 1.0‰. The animals display a wide range of δ13 C (-21.5‰ to -8.2‰; -15.8 ± 4.5‰) and δ15 N values (4.0‰ to 9.5‰; 6.5 ± 1.8‰). CONCLUSIONS: The adult δ13 C and δ15 N results indicate that mixed C3 (rice) and C4 (millet) terrestrial diets with varying levels of animal protein (mostly pigs and deer) were consumed. The elevated subadult δ15 N results return to adult levels by approximately 3-4 years of age, indicating that the weaning process was completed during this period. Individuals between 2 and 10 years old, with lower δ13 C and δ15 N results than the adult mean, possibly consumed more plant-based diets, and this is consistent with Chinese medical teachings ∼1500 years later during the Tang Dynasty (AD 618-907). The isotopic offsets between the ribs and long bones revealed that five adults experienced dramatic dietary shifts in their later lives, switching from predominately C3 /C4 to C3 diets. This research provides the first isotopic information about ancient Chinese breastfeeding and weaning practices and establishes a foundation for future studies to examine diachronic trends.

Holocene fluctuations in human population demonstrate repeated links to food production and climate.

We consider the long-term relationship between human demography, food production, and Holocene climate via an archaeological radiocarbon date series of unprecedented sampling density and detail. There is striking consistency in the inferred human population dynamics across different regions of Britain and Ireland during the middle and later Holocene. Major cross-regional population downturns in population coincide with episodes of more abrupt change in North Atlantic climate and witness societal responses in food procurement as visible in directly dated plants and animals, often with moves toward hardier cereals, increased pastoralism, and/or gathered resources. For the Neolithic, this evidence questions existing models of wholly endogenous demographic boom-bust. For the wider Holocene, it demonstrates that climate-related disruptions have been quasi-periodic drivers of societal and subsistence change.

Human paleodiet and animal utilization strategies during the Bronze Age in northwest Yunnan Province, southwest China.

Reconstructing ancient diets and the use of animals and plants augment our understanding of how humans adapted to different environments. Yunnan Province in southwest China is ecologically and environmentally diverse. During the Neolithic and Bronze Age periods, this region was occupied by a variety of local culture groups with diverse subsistence systems and material culture. In this paper, we obtained carbon (δ13C) and nitrogen (δ15N) isotopic ratios from human and faunal remains in order to reconstruct human paleodiets and strategies for animal exploitation at the Bronze Age site of Shilinggang (ca. 2500 Cal BP) in northwest Yunnan Province. The δ13C results for human samples from Shilinggang demonstrate that people's diets were mainly dominated by C3-based foodstuffs, probably due to both direct consumption of C3 food and as a result of C3 foddering of consumed animals. Auxiliary C4 food signals can also be detected. High δ15N values indicate that meat was an important component of the diet. Analysis of faunal samples indicates that people primarily fed pigs and dogs with human food waste, while sheep/goats and cattle were foddered with other food sources. We compare stable isotope and archaeobotanical data from Shilinggang with data from other Bronze Age sites in Yunnan to explore potential regional variation in subsistence strategies. Our work suggests that people adopted different animal utilization and subsistence strategies in different parts of Yunnan during the Bronze Age period, probably as local adaptations to the highly diversified and isolated environments in the region.

Lithic technological responses to Late Pleistocene glacial cycling at Pinnacle Point Site 5-6, South Africa.

There are multiple hypotheses for human responses to glacial cycling in the Late Pleistocene, including changes in population size, interconnectedness, and mobility. Lithic technological analysis informs us of human responses to environmental change because lithic assemblage characteristics are a reflection of raw material transport, reduction, and discard behaviors that depend on hunter-gatherer social and economic decisions. Pinnacle Point Site 5-6 (PP5-6), Western Cape, South Africa is an ideal locality for examining the influence of glacial cycling on early modern human behaviors because it preserves a long sequence spanning marine isotope stages (MIS) 5, 4, and 3 and is associated with robust records of paleoenvironmental change. The analysis presented here addresses the question, what, if any, lithic assemblage traits at PP5-6 represent changing behavioral responses to the MIS 5-4-3 interglacial-glacial cycle? It statistically evaluates changes in 93 traits with no a priori assumptions about which traits may significantly associate with MIS. In contrast to other studies that claim that there is little relationship between broad-scale patterns of climate change and lithic technology, we identified the following characteristics that are associated with MIS 4: increased use of quartz, increased evidence for outcrop sources of quartzite and silcrete, increased evidence for earlier stages of reduction in silcrete, evidence for increased flaking efficiency in all raw material types, and changes in tool types and function for silcrete. Based on these results, we suggest that foragers responded to MIS 4 glacial environmental conditions at PP5-6 with increased population or group sizes, 'place provisioning', longer and/or more intense site occupations, and decreased residential mobility. Several other traits, including silcrete frequency, do not exhibit an association with MIS. Backed pieces, once they appear in the PP5-6 record during MIS 4, persist through MIS 3. Changing paleoenvironments explain some, but not all temporal technological variability at PP5-6.

Dental wear quantity and direction in Chalcolithic and Medieval populations from southwest France.

The aim of this study was to verify if dental wear changed due to the dietary shift between the Chalcolithic and Middle Ages from relatively hard and fibrous foods to soft cooked cereals. This was accomplished by comparing dental wear quantity and direction between people from two archaeological sites, Les Treilles during the Chalcolithic (mixed subsistence farmers) and Marsan from the Middle Ages (agriculturalists) in southwest France. The materials studied include 65 mandibles, 32 from Les Treilles and 33 from Marsan; 549 teeth were studied. The results show statistically significant difference in wear quantity and direction, the Chalcolithic population (Les Treilles) had the greatest levels of wear in a mainly oblique direction, with the anterior teeth heavily affected by wear. Comparatively, the Medieval sample (Marsan) had lesser levels of wear in a mainly horizontal direction, and the most heavily worn teeth were the molars and incisors. The quantity of wear seems to correlate well with changes in diet, the high level of wear on the anterior teeth in the Chalcolithic sample corresponds with the consumption of a mixed diet of fibrous and tough foods. At Marsan, the lower wear quantity was likely due to a diet of soft boiled cereals, requiring less mastication. However, wear direction appears dependent on several factors and may correlate with more mixed subsistence practices. This study demonstrates the need for additional research into the complex actions of mastication and its effect on dental wear, as well as standardised methodology for the examination of dental wear in archaeological samples.

First insight into the Neolithic subsistence economy in the north-east Iberian Peninsula: paleodietary reconstruction through stable isotopes.

OBJECTIVES: The study of subsistence strategies among Neolithic communities in north-east Iberia, late-fifth to early-fourth millennia cal BC, enables a more in-depth study of the activities and behavior of the inhabitants of this region, where paleodiets have been little studied. The objectives of this study are, therefore, to determine the diet and subsistence patterns of those communities and to consider whether any relation existed between their subsistence strategies and environmental, geographic, and/or social factors. MATERIALS AND METHODS: Bone samples from 25 middle Neolithic human individuals at seven archeological sites and comparative faunal samples were analyzed, and compared with contemporary series in Mediterranean Europe. Carbon and nitrogen isotope ratios (δ13 C and δ15 N) of bone collagen were studied to determine the dietary patterns. RESULTS: Dietary habits proved to be similar between communities, apart from some interpopulational variations in subsistence strategies. Their diet was based on C3 terrestrial resources with a major vegetal protein component. DISCUSSION: The reported variations in interpopulational subsistence strategies among the compared Mediterranean societies do not seem to be directly related to the settlement region. Together with archeological data, this indicates the influence of socioeconomic factors in the Neolithic human diet. A general tendency toward a lesser use of aquatic resources is seen in this period in Iberia and the rest of the Mediterranean, as also documented for contemporary communities in the west and north of Europe. The data obtained will be important for further studies of socioeconomic patterns in European Neolithic societies.

Ancient tortoise hunting in the southwest Pacific.

We report the unprecedented Lapita exploitation and subsequent extinction of large megafauna tortoises (?Meiolania damelipi) on tropical islands during the late Holocene over a 281,000 km2 region of the southwest Pacific spanning from the Vanuatu archipelago to Viti Levu in Fiji. Zooarchaeological analyses have identified seven early archaeological sites with the remains of this distinctive hornless tortoise, unlike the Gondwanan horned meiolaniid radiation to the southwest. These large tortoise radiations in the Pacific may have contributed to the rapid dispersal of early mobile Neolithic hunters throughout southwest Melanesia and on to western Polynesia. Subsequent rapid extinctions of these terrestrial herbivorous megafauna are likely to have led to significant changes in ecosystems that help explain changes in current archaeological patterns from Post-Lapita contexts in the region.

How to make stone soup: Is the "Paleo diet" a missed opportunity for anthropologists?

For the past few years, people everywhere have been "going Paleo." Websites and social media touting the benefits of eating a "Paleo diet" and following a "Paleolithic life style" serve as calls to arms for health-conscious individuals seeking information about the latest health and fitness trends. Many of these people participate in programs such as Crossfit, which involve major social and life-style modification components and therefore facilitate the dissemination of dietary fads.1 The PALEOf(x)TM conference, which bills itself as "the world's premier holistic wellness event," has attracted sellout crowds of thousands of attendees for the last four years.2 Consumers can wear Paleo clothing, download Paleo shopping and exercise apps to their smartphones, order prepackaged Paleo food, prepare it using Paleo cooking implements, or expediently buy Paleo convenience foods from Paleodiet™ vending machines3 and "Cultured Caveman" food trucks.4 The Paleo diet is touted by movie stars, reality TV personalities, and professional athletes, including LeBron James and the entire Miami Dolphins NFL team.5,6 Books with titles such as The Primal Blueprint,7 Cavewomen Don't Get Fat,8 and Paleo Perfected9 (the latter by the stodgy America's Test Kitchen) are legion, and many are bestsellers.

Resource scarcity drives lethal aggression among prehistoric hunter-gatherers in central California.

The origin of human violence and warfare is controversial, and some scholars contend that intergroup conflict was rare until the emergence of sedentary foraging and complex sociopolitical organization, whereas others assert that violence was common and of considerable antiquity among small-scale societies. Here we consider two alternative explanations for the evolution of human violence: (i) individuals resort to violence when benefits outweigh potential costs, which is likely in resource poor environments, or (ii) participation in violence increases when there is coercion from leaders in complex societies leading to group level benefits. To test these hypotheses, we evaluate the relative importance of resource scarcity vs. sociopolitical complexity by evaluating spatial variation in three macro datasets from central California: (i) an extensive bioarchaeological record dating from 1,530 to 230 cal BP recording rates of blunt and sharp force skeletal trauma on thousands of burials, (ii) quantitative scores of sociopolitical complexity recorded ethnographically, and (iii) mean net primary productivity (NPP) from a remotely sensed global dataset. Results reveal that sharp force trauma, the most common form of violence in the record, is better predicted by resource scarcity than relative sociopolitical complexity. Blunt force cranial trauma shows no correlation with NPP or political complexity and may reflect a different form of close contact violence. This study provides no support for the position that violence originated with the development of more complex hunter-gatherer adaptations in the fairly recent past. Instead, findings show that individuals are prone to violence in times and places of resource scarcity.