Violence in fishing, hunting, and gathering societies of the Atacama Desert coast: A long-term perspective (10,000 BP-AD 1450).

In this study, we examine the long-term trajectory of violence in societies that inhabited the coast of the Atacama Desert in northern Chile using three lines of evidence: bioarchaeology, geoarchaeology and socio-cultural contexts (rock art, weapons, and settlement patterns). These millennia-old populations adopted a way of life, which they maintained for 10,000 years, based on fishing, hunting, and maritime gathering, complementing this with terrestrial resources. We analyzed 288 adult individuals to search for traumas resulting from interpersonal violence and used strontium isotopes 87Sr/86Sr as a proxy to evaluate whether individuals that showed traces of violence were members of local or non-local groups. Moreover, we evaluated settlement patterns, rock art, and weapons. The results show that the violence was invariant during the 10,000 years in which these groups lived without contact with the western world. During the Formative Period (1000 BC-AD 500), however, the type of violence changed, with a substantial increase in lethality. Finally, during the Late Intermediate Period (AD 1000-1450), violence and lethality remained similar to that of the Formative Period. The chemical signal of Sr shows a low frequency of individuals who were coastal outsiders, suggesting that violence occurred between local groups. Moreover, the presence of weapons and rock art depicting scenes of combat supports the notion that these groups engaged in violence. By contrast, the settlement pattern shows no defensive features. We consider that the absence of centralized political systems could have been a causal factor in explaining violence, together with the fact that these populations were organized in small-scale grouping. Another factor may have been competition for the same resources in the extreme environments of the Atacama Desert. Finally, from the Formative Period onward, we cannot rule out a certain level of conflict between fishers and their close neighbors, the horticulturalists.

The role of dietary calcium in the etiology of childhood rickets in the past and the present.

For more than two centuries, lack of sunlight has been understood to cause vitamin D deficiency and documented as a primary cause of rickets. As such, evidence of rickets in the archeological record has been used as a proxy for vitamin D status in past individuals and populations. In the last decade, a clinical global consensus has emerged wherein it is recognized that dietary calcium deficiency also plays a role in the manifestation of rickets and classic skeletal deformities may not form if dietary calcium is normal even if vitamin D is deficient. This disease is now clinically called "nutritional rickets" to reflect the fact that rickets can take calcium deficiency-predominant or vitamin D deficiency-predominant forms. However, there are currently no paleopathological studies wherein dietary calcium deficiency is critically considered a primary etiology of the disease. We review here the interplay of calcium, vitamin D, and phosphorous in bone homeostasis, examine the role of dietary calcium in human health, and critically explore the clinical literature on calcium deficiency-predominant rickets. Finally, we report a case of rickets from the late Formative Period (~2500-1500 years ago) of the Atacama Desert and argue the disease in this infant is likely an example of calcium deficiency-predominant rickets. We conclude that most archeological cases of rickets are the result of multiple micronutrient deficiencies that compound to manifest in macroscopic skeletal lesions. For clinicians, these factors are important for implementing best treatment practice, and for paleopathologists they are necessary for appropriate interpretation of health in past communities.

Five thousand years of bellyaches: Exploring boron concentration in ancient populations of the Atacama Desert.

OBJECTIVES: This study explores whether ancient Atacama Desert populations in northern Chile were exposed to endemic boron contamination. MATERIALS AND METHODS: Using Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS), we studied 144 strands of ancient mummy hair, ranging from 3000 B.C. to 1500 A.D., excavated from the Lluta, Azapa, and Camarones valleys in northern Chile. We tested whether these ancient populations showed signs of significant boron concentration in hair tissue. RESULTS: On average, all individuals from these valleys showed high boron concentrations, ranging from 1.5 to 4 times above the average boron concentration in contemporary hair (baseline <0.85 µg/g). The boron concentration in mummy hair varied according to the main geographic areas mentioned above. CONCLUSIONS: The rivers of northern Chile have high geogenic boron concentrations. They contain 38 times above the recommended limit for human consumption. Geogenic boron contamination likely played a role in population morbidity and the types of crops that were cultivated in antiquity. The ancient populations were chronically affected by boron overexposure, suggesting that ancient geogenic water contamination should be considered when discussing the biocultural trajectories of ancient populations.

Violence in hunters, fishermen, and gatherers of the Chinchorro culture: Archaic societies of the Atacama Desert (10,000-4,000 cal yr BP).

OBJECTIVES: This article addresses evidence of violence imbedded in both soft and hard tissues from early populations of hunters, fishermen, and gatherers, known as the Chinchorro culture, who lived between 10,000 and 4,000 cal yr BP, along the coast of the Atacama Desert, one of the driest environments on Earth. Our study is aimed to test two hypotheses (a) that interactions and violent behaviors increased through time as population density and social complexity augmented; and (b) that violence was more prevalent between local Chinchorro groups and groups from other inland locations. MATERIAL AND METHODS: Two lines of data were analyzed: (1) bioarchaeology, through the quantification of physical traces of interpersonal violence in skeletons and mummies from a sample of 136 adult individuals and, (2) isotopic chemical analysis (strontium) of individuals with traces of trauma in order to determine their local or foreign origin. RESULTS: Violence among Chinchorro populations was ubiquitous and remained invariant over time, with a remarkable skew to male (about 25% above female across the complete sample). Moreover, the chemical signature of individuals with traces of violence was not of foreign origin. DISCUSSION: The violence exerted by the Chinchorro groups was not related to increased population size, nor social complexity and was mostly restricted to individuals coming from the same coastal habitat. That is, our data suggest that violence was constant across the Archaic period among the Chinchorro, implying that violent behavior was part of the sociocultural repertory of these populations, likely associated to mechanisms to resolve conflicts and social tensions.

Macroscopic features of scurvy in human skeletal remains: A literature synthesis and diagnostic guide.

The past two decades have seen a proliferation in bioarchaeological literature on the identification of scurvy, a disease caused by chronic vitamin C deficiency, in ancient human remains. This condition is one of the few nutritional deficiencies that can result in diagnostic osseous lesions. Scurvy is associated with low dietary diversity and its identification in human skeletal remains can provide important contextual information on subsistence strategy, resource allocation, and human-environmental interactions in past populations. A large and robust methodological body of work on the paleopathology of scurvy exists. However, the diagnostic criteria for this disease employed by bioarchaeologists have not always been uniform. Here we draw from previous research on the skeletal manifestations of scurvy in adult and juvenile human skeletal remains and propose a weighted diagnostic system for its identification that takes into account the pathophysiology of the disease, soft tissue anatomy, and clinical research. Using a sample of individuals from the prehistoric Atacama Desert in Northern Chile, we also provide a practical example of how diagnostic value might be assigned to skeletal lesions of the disease that have not been previously described in the literature.

Prehistoric polydactylism: Biological evidence and rock art representation from the Atacama Desert in northern Chile.

A review of the bioarchaeological collections from the site Morro de Arica in northern Chile allowed the identification of two cases of human polydactyly. Both cases are from the Chinchorro culture, hunters, fishers, and gatherers with a maritime orientation who inhabited the coast of the Atacama Desert (9000-3400 BP). Additionally, the analyses of 75 rock art sites in the area, from the Formative to Late Intermediate Periods (3000-550 BP), allowed the identification of hands and feet with six digits. Given the bioarchaeological record of polydactyly, it is highly probable that the rock art images were based on real individuals with polydactyly. However, the Sr chemical signal in a juvenile with polydactyly is the same as the Sr chemical signal in the rest of the individuals buried in the same site, proving that all the individuals were born and lived on the coast. We discuss the idea that, although these anomalies could have been the result of genetic mutations, endogamy and exposition to ecotoxic environments could also be at play within the Chinchorro groups.

Let's talk about stress, baby! Infant-feeding practices and stress in the ancient Atacama desert, Northern Chile.

AIMS AND OBJECTIVES: The transition to an agricultural economy is often presumed to involve an increase in female fertility related to changes in weaning practice. In particular, the availability of staple crops as complementary foods is hypothesized to allow earlier weaning in agricultural populations. In this study, our primary aim is to explore whether this model fits the agricultural transition in the Atacama Desert using incremental isotopic analysis. A secondary aim of this study is to identify isotopic patterns relating to weaning, and assess how these may be differentiated from those relating to early life stress. MATERIALS AND METHODS: We use incremental isotopic analysis of dentine to examine changes in δ15 N and δ13 C values from infancy and childhood in sites of the Arica region (n = 30). We compare individuals from pre-agricultural and agricultural phases to establish isotopic patterns and relate these patterns to maternal diet, weaning trajectory and physiological stress. RESULTS: We find that there is no evidence for systematic temporal or geographic variation in incremental isotopic results. Instead, results from all time periods are highly variable, with weaning completed between 1.5 and 3.5 years. Characteristics of the incremental profiles indicate that both in utero and postnatal stress were a common part of the infant experience in the Atacama. DISCUSSION: In the Atacama Desert it appears that the arrival of agricultural crops did not result in uniform shifts in weaning behavior. Instead, infant and child diet seems to have been dictated by the broad-spectrum diets of the mothers, perhaps as a way of mitigating the stresses of the harsh desert environment.

Investigating cranial morphological variation of early human skeletal remains from Chile: A 3D geometric morphometric approach.

OBJECTIVES: Archaeological and genetic research has demonstrated that the Pacific Coast was a key route in the early colonization of South America. Research examining South American skeletons >8000 cal BP has revealed differences in cranial morphology between early and late Holocene populations, which may reflect distinct migration events and/or populations. However, genetic, cultural, and some skeletal data contradict this model. Given these discrepancies, this study examines ∼9000 years of prehistory to test the hypothesis that Early skeletons have a distinct cranial morphology from later skeletons. MATERIALS AND METHODS: Using 3D digital models, craniofacial landmarks, and geometric morphometric analyses, we compared Early Holocene crania (n = 4) to later Chilean samples (n = 90) frequently absent in continental assessments of craniofacial variation. PCA, Mahalanobis distances, posterior and typicality probabilities were used to examine variation. RESULTS: Two of the earliest skeletons from northern Chile show clear affinities to individuals from later sites in the same region. However, the hypothesis cannot be rejected as one Early individual from northern Chile and one individual from inland Patagonia did not always show clear affinities to coastal populations. DISCUSSION: Biological affinities among northern populations and other regions of Chile align with genetic and archaeological data, supporting cultural and biological continuity along the Pacific Coast. In Patagonia, archaeological data are in accordance with skeletal differences between the Early inland steppe individual and coastal populations. This study incorporates 3D methods and skeletal datasets not widely used in assessments of biological affinity, thus contributing to a critical body of research examining the ancient population history of western South America.

Scurvy at the agricultural transition in the Atacama desert (ca 3600-3200 BP): nutritional stress at the maternal-foetal interface?

Studies of contemporary populations have demonstrated an association between decreased dietary diversity due to resource scarcity or underutilization and an increase in diseases related to poor micronutrient intake. With a reduction of dietary diversity, it is often the women and children in a population who are the first to suffer the effects of poor micronutrient status. Scurvy, a disease of prolonged vitamin C deficiency, is a micronutrient malnutrition disorder associated with resource scarcity, low dietary diversity, and/or dependence on high carbohydrate staple-foods. The aim of this paper is to assess the potential impact of nutritional transition on the prevalence of diseases of nutritional insufficiency in an archaeological sample. Here, we report palaeopathological findings from an Early Formative Period transitional site located in coastal Northern Chile (Quiani-7). The subadult cohort from this site is composed of four perinates who exhibit a number of non-specific skeletal changes suggestive of a systemic pathological condition. One of these is associated with an adult female exhibiting diagnostic skeletal lesions of scurvy. We argue that the lesions exhibited by these perinates may represent maternal transmission of vitamin C deficiency but acknowledge that there are difficulties in applying current diagnostic criteria for scurvy to individuals this young.

Ancient mitochondrial DNA provides high-resolution time scale of the peopling of the Americas.

The exact timing, route, and process of the initial peopling of the Americas remains uncertain despite much research. Archaeological evidence indicates the presence of humans as far as southern Chile by 14.6 thousand years ago (ka), shortly after the Pleistocene ice sheets blocking access from eastern Beringia began to retreat. Genetic estimates of the timing and route of entry have been constrained by the lack of suitable calibration points and low genetic diversity of Native Americans. We sequenced 92 whole mitochondrial genomes from pre-Columbian South American skeletons dating from 8.6 to 0.5 ka, allowing a detailed, temporally calibrated reconstruction of the peopling of the Americas in a Bayesian coalescent analysis. The data suggest that a small population entered the Americas via a coastal route around 16.0 ka, following previous isolation in eastern Beringia for ~2.4 to 9 thousand years after separation from eastern Siberian populations. Following a rapid movement throughout the Americas, limited gene flow in South America resulted in a marked phylogeographic structure of populations, which persisted through time. All of the ancient mitochondrial lineages detected in this study were absent from modern data sets, suggesting a high extinction rate. To investigate this further, we applied a novel principal components multiple logistic regression test to Bayesian serial coalescent simulations. The analysis supported a scenario in which European colonization caused a substantial loss of pre-Columbian lineages.

Emergence of social complexity among coastal hunter-gatherers in the Atacama Desert of northern Chile.

The emergence of complex cultural practices in simple hunter-gatherer groups poses interesting questions on what drives social complexity and what causes the emergence and disappearance of cultural innovations. Here we analyze the conditions that underlie the emergence of artificial mummification in the Chinchorro culture in the coastal Atacama Desert in northern Chile and southern Peru. We provide empirical and theoretical evidence that artificial mummification appeared during a period of increased coastal freshwater availability and marine productivity, which caused an increase in human population size and accelerated the emergence of cultural innovations, as predicted by recent models of cultural and technological evolution. Under a scenario of increasing population size and extreme aridity (with little or no decomposition of corpses) a simple demographic model shows that dead individuals may have become a significant part of the landscape, creating the conditions for the manipulation of the dead that led to the emergence of complex mortuary practices.

Possible influence of the ENSO phenomenon on the pathoecology of diphyllobothriasis and anisakiasis in ancient Chinchorro populations.

Current clinical data show a clear relationship between the zoonosis rates of Diphyllobothrium pacificum and Anisakis caused by the El Niño Southern Oscillations (ENSO) phenomenon along the Chilean coast. These parasites are endemic to the region and have a specific habitat distribution. D. pacificum prefers the warmer waters in the northern coast, while Anisakis prefers the colder waters of Southern Chile. The ENSO phenomenon causes a drastic inversion in the seawater temperatures in this region, modifying both the cool nutrient-rich seawater and the local ecology. This causes a latitudinal shift in marine parasite distribution and prevalence, as well as drastic environmental changes. The abundance of human mummies and archaeological coastal sites in the Atacama Desert provides an excellent model to test the ENSO impact on antiquity. We review the clinical and archaeological literature debating to what extent these parasites affected the health of the Chinchorros, the earliest settlers of this region. We hypothesise the Chinchorro and their descendants were affected by this natural and cyclical ENSO phenomenon and should therefore present fluctuating rates of D. pacificum and Anisakis infestations.

Possible influence of the ENSO phenomenon on the pathoecology of diphyllobothriasis and anisakiasis in ancient Chinchorro populations

Current clinical data show a clear relationship between the zoonosis rates of Diphyllobothrium pacificum and Anisakis caused by the El Niño Southern Oscillations (ENSO) phenomenon along the Chilean coast. These parasites are endemic to the region and have a specific habitat distribution. D. pacificum prefers the warmer waters in the northern coast, while Anisakis prefers the colder waters of Southern Chile. The ENSO phenomenon causes a drastic inversion in the seawater temperatures in this region, modifying both the cool nutrient-rich seawater and the local ecology. This causes a latitudinal shift in marine parasite distribution and prevalence, as well as drastic environmental changes. The abundance of human mummies and archaeological coastal sites in the Atacama Desert provides an excellent model to test the ENSO impact on antiquity. We review the clinical and archaeological literature debating to what extent these parasites affected the health of the Chinchorros, the earliest settlers of this region. We hypothesise the Chinchorro and their descendants were affected by this natural and cyclical ENSO phenomenon and should therefore present fluctuating rates of D. pacificum and Anisakis infestations.

Microevolution in prehistoric Andean populations: chronologic mtDNA variation in the desert valleys of northern Chile.

Archeological evidence suggests that the iconographic and technological developments that took place in the highlands around Lake Titicaca in the Central Andean region had an influence on the cultural elaborations of the human groups in the valleys and the Pacific coast of northern Chile. In a previous communication, we were able to show, by means of a distance analysis, that a craniofacial differentiation accompanied the process of cultural evolution in the valleys (Rothhammer and Santoro [2001] Lat. Am. Antiq. 12:59-66). Recently, numerous South Amerindian mtDNA studies were published, and more accurate molecular techniques to study ancient mtDNA are available. In view of these recent developments, we decided 1) to study chronological changes of ancient mtDNA haplogroup frequencies in the nearby Lluta, Azapa, and Camarones Valleys, 2) to identify microevolutionary forces responsible for such changes, and 3) to compare ancient mtDNA haplogroup frequencies with previous data in order to validate craniometrical results and to reconstruct the biological history of the prehistoric valley groups in the context of their interaction with culturally more developed highland populations. From a total of 97 samples from 83 individuals, 68 samples (61 individuals) yielded amplifications for the fragments that harbor classical mtDNA markers. The haplogroup distribution among the total sample was as follows: 26.2%, haplogroup A; 34.4%, haplogroup B; 14.8%, haplogroup C; 3.3%, haplogroup D; and 21.3%, other haplogroups. Haplogroup B tended to increase, and haplogroup A to decrease during a 3,900-year time interval. The sequence data are congruent with the haplogroup analysis. In fact, the sequencing of hypervariable region I of 30 prehistoric individuals revealed 43 polymorphic sites. Sequence alignment and subsequent phylogenetic tree construction showed two major clusters associated with the most common restriction haplogroups. Individuals belonging to haplogroups C and D tended to cluster together with nonclassical lineages.