Kelly J. Knudson

Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change

Background Approximately two hundred human burials were discovered on the edge of a paleolake in Niger that provide a uniquely preserved record of human occupation in the Sahara during the Holocene (∼8000 B.C.E. to the present). Called Gobero, this suite of closely spaced sites chronicles the rapid pace of biosocial change in the southern Sahara in response to severe climatic fluctuation. Methodology/Principal Findings Two main occupational phases are identified that correspond with humid intervals in the early and mid-Holocene, based on 78 direct AMS radiocarbon dates on human remains, fauna and artifacts, as well as 9 OSL dates on paleodune sand. The older occupants have craniofacial dimensions that demonstrate similarities with mid-Holocene occupants of the southern Sahara and Late Pleistocene to early Holocene inhabitants of the Maghreb. Their hyperflexed burials compose the earliest cemetery in the Sahara dating to ∼7500 B.C.E. These early occupants abandon the area under arid conditions and, when humid conditions return ∼4600 B.C.E., are replaced by a more gracile people with elaborated grave goods including animal bone and ivory ornaments. Conclusions/Significance The principal significance of Gobero lies in its extraordinary human, faunal, and archaeological record, from which we conclude the following: The early Holocene occupants at Gobero (7700–6200 B.C.E.) were largely sedentary hunter-fisher-gatherers with lakeside funerary sites that include the earliest recorded cemetery in the Sahara. Principal components analysis of craniometric variables closely allies the early Holocene occupants at Gobero with a skeletally robust, trans-Saharan assemblage of Late Pleistocene to mid-Holocene human populations from the Maghreb and southern Sahara. Gobero was abandoned during a period of severe aridification possibly as long as one millennium (6200–5200 B.C.E). More gracile humans arrived in the mid-Holocene (5200–2500 B.C.E.) employing a diversified subsistence economy based on clams, fish, and savanna vertebrates as well as some cattle husbandry. Population replacement after a harsh arid hiatus is the most likely explanation for the occupational sequence at Gobero. We are just beginning to understand the anatomical and cultural diversity that existed within the Sahara during the Holocene.

Tiwanaku influence in the South Central Andes: Strontium Isotope Analysis and Middle horizon migration

Although the presence of Tiwanaku-style material culture throughout southern Peru, northern Chile, and western Bolivia is well documented, the nature of Tiwanaku influence during the Middle horizon (A.D. 500-1100) is variously attributed to imperial expansion or economic and/or religious relationships. Strontium isotope data from archaeological human remains from Tiwanaku-affiliated sites identified first-generation immigrants from the Lake Titicaca basin outside of the Tiwanaku heartland at the Peruvian site of Chen Chen. These data provide an important component to studies that demonstrated close biological relationships during the Middle horizon but could not demonstrate the direction of population movement. How ever, no immigrants from the Lake Titicaca basin were identified at the San Pedro de Atacama cemeteries of Coyo Orien tal, Coyo-3, and Solcor-3. At the sites of Tiwanaku, Tilata, Iwawe, and Kirawi, strontium isotope ratios were also variable, and demonstrate movement within the Lake Titicaca basin. This demonstrates that Tiwanaku influence involved direct col onization in the Moquegua Valley but that in other regions, like San Pedro de Atacama, local inhabitants adopted Tiwanaku style material culture. This elucidates the complex and highly variable relationships between the Tiwanaku heartland and peripheral sites during the Middle horizon.

Investigating cultural heterogeneity in San Pedro de Atacama, northern Chile, through biogeochemistry and bioarchaeology

Individuals living in the San Pedro de Atacama oases and the neighboring upper Loa River Valley of northern Chile experienced the collapse of an influential foreign polity, environmental decline, and the appearance of a culturally distinct group during the Late Intermediate Period (ca. AD 1,100-1,400). We investigate cultural heterogeneity at the Loa site of Caspana through analyses of strontium and oxygen isotopes, cranial modification styles, and mortuary behavior, integrating biological aspects of identity, particularly geographic origins, with cultural aspects of identity manifested in body modification and mortuary behavior. We test the hypothesis that the Caspana population (n = 66) represents a migrant group, as supported by archeological and ethnographic evidence, rather than a culturally distinct local group. For Caspana archeological human tooth enamel, mean (87)Sr/(86)Sr = 0.70771 +/- 0.00038 (1sigma, n = 30) and mean delta(18)O(c(V-PDB)) = -3.9 +/- 0.6 per thousand (1sigma, n = 16); these isotopic data suggest that only one individual lived outside the region. Material culture suggests that the individuals buried at Caspana shared some cultural affinity with the San Pedro oases while maintaining distinct cultural traditions. Finally, cranial modification data show high frequencies of head shaping [92.4% (n = 61/65)] and an overwhelming preference for annular modification [75.4% (n = 46/61)], contrasting sharply with practices in the San Pedro area. Based on multiple lines of evidence, we argue that, rather than representing a group of altiplano migrants, the Caspana population existed in the region for some time. However, cranial modification styles and mortuary behavior that are markedly distinct from patterns in surrounding areas raise the possibility of cultural heterogeneity and cultural fissioning.

Social Identities and Geographical Origins of Wari Trophy Heads from Conchopata, Peru

The Wari empire (600–1000 CE) of the pre‐Hispanic Andes engaged in ritual practices that included the modification and display of human trophy heads, but it is unknown from whom these heads were taken. Of 31 trophy heads from Conchopata, the majority are of adult males, and 42% exhibit cranial trauma, indicating that people whose heads were transformed into trophies commonly experienced violence. Strontium isotope analysis of five adult trophy heads indicates that at least three of these individuals consumed foods grown in a geological zone outside the Wari heartland. These data, combined with information on age, sex, and violent life histories and iconography showing bound prisoners and warriors wearing trophy heads, suggest that at least some trophy heads represent individuals from nonlocal areas who may have been perceived as enemies.

Diet, Tuberculosis, and the Paleopathological Record

Osseous manifestation of infectious disease is of paramount importance to paleopathologists seeking to interpret ancient health, but the relationships among infectious agent exposure, development of disease, and skeletal involvement are complex. The outcome of an exposure strongly depends on multiple factors, including ecology, diet, nutrition, immune function, and the genetics of pathogen and host. Mycobacterial diseases are often studied in ancient remains but also are especially influenced by these factors; individual and population differences in severity and course are apparent following onset of active disease. The osteological record for these diseases represents the complex interplay of host and pathogen characteristics influencing within‐ and among‐individual skeletal lesion prevalence and distribution. However, many of these characteristics may be assessed independently through the archaeological record. Here, we explore the contributions of dietary protein and iron to immune function, particularly the course and outcome of infection with Mycobacterium tuberculosis. We emphasize how nutrition may influence the dissemination of bacilli to the skeleton and subsequent formation of diagnostic lesions. We then generate models and hypotheses informed by this interplay and apply them to four prehistoric New World areas. Finally, discrepancies between our expectations and the observed record are explored as a basis for new hypotheses.

EXAMINING THE LIFE HISTORY OF AN INDIVIDUAL FROM SOLCOR 3, SAN PEDRO DE ATACAMA: COMBINING BIOARCHAEOLOGY AND ARCHAEOLOGICAL CHEMISTRY

Informacion detallada sobre la vida de un individuo, integrando multiples lineas de evidencia que incluye identificacion del origen geografico, condiciones de salud e indicadores de usos funcionales del cuerpo, puede ser utilizada para aclarar el complejo proceso de la aculturacion en los oasis de San Pedro de Atacama, norte de Chile durante el Horizonte Medio. Este trabajo presenta los resultados de analisis bioantropologicos y quimicos de un individuo (tumba 50, numero de catalogo 1948) del cementerio de Solcor 3 (ca. 500-900 d.C.) en San Pedro de Atacama. Las proporciones de los isotopos de estroncio en el esmalte dentario humano revelan informacion acerca de donde una persona vivio durante su ninez, cuando el esmalte se forma. El individuo 1948 muestra proporciones de isotopos de estroncio claramente fuera del rango que caracteriza a las poblaciones locales de San Pedro de Atacama. Estos datos muestran que el individuo 1948 fue originalmente de un lugar foraneo. El analisis de su salud, rol social y contexto mortuorio nos permite conocer el tratamiento social aplicado a los extranjeros en la region de San Pedro de Atacama durante el Horizonte Medio. Nuestros datos sostienen la idea que la condicion de extranjero del individuo 1948 no fue una limitacion para su asimilacion en la sociedad atacamena. El fue enterrado en un cementerio local, a la moda local, sin que se resaltara su posible origen foraneo. Ademas, los datos con respecto a su salud y estilo de vida no lo distinguen del resto de la poblacion local. Por lo tanto, nuestros analisis sugieren una total aculturacion de este individuo en la sociedad atacamena durante su vida adulta, por lo que retuvo poca o ninguna indicacion de suprobable nacimiento en un area foranea

Issues of affinity: exploring population structure in the Middle and Regional Developments Periods of San Pedro de Atacama, Chile.

The Middle Period (AD 400-1000) in northern Chiles Atacama oases is characterized by an increase in social complexity and regional interaction, much of which was organized around the power and impact of the Tiwanaku polity. Despite the strong cultural influence of Tiwanaku and numerous other groups evident in interactions with Atacameños, the role of immigration into the oases during this period is unclear. While archaeological and bioarchaeological research in the region has shown no evidence that clearly indicates large groups of foreign immigrants, the contemporary increase in interregional exchange networks connecting the oases to other parts of the Andes suggests residential mobility and the possibility that movement of people both into and out of the oases accompanied these foreign influences. Here, we analyze biodistance through cranial non-metric traits in a skeletal sample from prehistoric San Pedro de Atacama to elucidate the extent of foreign influence in the oases and discuss its implications. We analyzed 715 individuals from the Middle Period (AD 400-1000) and later Regional Developments Period (AD 1000-1450), and found greater phenotypic differences between Middle Period cemeteries than among cemeteries in the subsequent period. We argue that this greater diversity extends beyond the relationship between the oases and the renowned Tiwanaku polity and reflects the role of the oases and its different ayllus as a node and way station for the Middle Periods myriad interregional networks.

Childhood lost: Abductions, sacrifice, and trophy heads of children in the wari empire of the ancient andes

This study examines isolated child skeletal remains from ritual structures at the Wari site of Conchopata (A.D. 600–1000) to evaluate how they were modified into trophy heads and whether the children were sacrificed. The skeletal remains represent at least seven children. Strontium isotope ratios are examined to determine whether children were taken from foreign locales. Results show that the children’s skulls exhibit a hole on the apex of the cranium and on the ascending ramus of the mandible, identical to the adult Wari trophy heads. At least one child may have been sacrificed. 87 Sr/ 86 Sr demonstrate that two of the four sampled child trophy heads were nonlocal, suggesting that children were occasionally abducted from distant communities, perhaps for sacrifice and certainly to transform some into trophy heads. The similar child and adult trophy heads suggest that the ritual treatment of children was not uniquely designed, at least as it related to their processing, display, and destruction. Furthermore, it is suggested that the child trophy heads were not simply passive symbols of pre-existing authority by the head-takers and trophy head-makers. The trophy heads simultaneously imbued those agents with authority—they did not merely reflect it—demonstrating the “effective agency” of the trophy head objects themselves. Finally, we suggest that prisoner-taking and trophy head-making by military and ritual elites served to legitimate the authority of those individuals while simultaneously serving larger state goals that enhanced Wari state authority and legitimated its policies and practices.

Cultural Diversity and Paleomobility in the Andean Middle Horizon: Radiogenic Strontium Isotope Analyses in the San Pedro De Atacama Oases of Northern Chile

Despite a long history of research, interactions between the Tiwanaku polity of the Andean Middle Horizon (ca.A.D. 500-1100) and the San Pedro de Atacama oases of northern Chile remain controversial. Here, we investigate Middle Horizon interactions through an isotopic identification of the geographic origins of individuals buried in San Pedro de Atacama cemeteries and present the largest radiogenic strontium isotope dataset generated, to date, for the Andes. For individuals in Middle Horizon San Pedro de Atacama cemeteries ofCasa Parroquial, Coyo Oriental, Coyo-3, Larache, Quitor-5, Solcor-3, Solcor Plaza, Solor-3, and Tchecar Tumulo Sur, mean tooth enamel and bone 87Sr/86Sr = .70834 ± .00172 (2σ, n = 273). Overall, the mean 87Sr/86Sr values from Middle Horizon San Pedro de Atacama cemeteries support the idea that interactions between Atacamenos and inhabitants of other regions varied by ayllu, an Andean kin-based community structure, with some ayllus incorporating individuals with a wider variety of geographic origins than others. When our interpretations of the radiogenic strontium isotope data are contextualized with analyses of mortuary behavior and recent biodistance analyses, we argue that the San Pedro de Atacama oases appear to be have been inhabited by culturally and biologically diverse groups, rather than by large numbers of colonists from the Tiwanaku capital and the Lake Titicaca Basin.

Changing patterns of mobility as a response to climatic deterioration and aridification in the middle Holocene southern Sahara

The African Humid Period witnessed a rapid human re-occupation of the Sahara as numerous lakes formed during the Holocene climatic optimum circa 10-5 kya. Permanent waters attracted a variety of aquatic and terrestrial fauna allowing for long-term occupation of specific paleolake basins. The Gobero paleolake in central Niger was one such location that preserves a unique mortuary record from the southern Sahara. Here, we use radiogenic strontium isotope analysis to investigate how human communities adapted to aridification throughout the Holocene. In particular, we examine the effects of increasing climate instability on patterns of human mobility. Results of radiogenic strontium isotope analysis of enamel and bone samples from Middle Holocene burials (∼7.2-4.9 kya) indicate predominantly local values with no evidence for sex-based variation. Comparisons of radiogenic strontium isotope data with previously published (Stojanowski and Knudson: Am J Phys Anthropol 146 (2011) 49-61) Early Holocene burials (∼9.7-8.3 kya) indicate significant differences in both enamel and bone values. Middle Holocene individuals demonstrate a predominantly non-local signature for enamel values and a predominantly local signature for bone values. Those individuals with non-local bone values always demonstrated non-local enamel values; however, the opposite was not the case. This suggests a divergence of mobility strategies during the Middle Holocene with a minority of individuals maintaining a more mobile existence throughout their life and others maintaining a similar strategy as Early Holocene hunter-gatherers that was tied to the paleolake basin. The more mobile individuals likely lived during the terminal phase of the lakes occupation. One response to aridification by Saharan peoples, then, was increasing mobility.