Two non-specific indicators of stress: Enamel hypoplasia and Harris lines

Harris lines (HL) and enamel hypoplasia (EH) are two non-specific indicators of stress, commonly used in the reconstruction of the health status in past and present populations. The aim of this study was to determine if there is a correlation between these two markers. To achieve this aim, a sample of 136 individuals from two archaeological sites (Az-71 and Az-l40) from northern Chile was analyzed. HL and EH showed no correlation in terms of presence absence at the individual level. In addition, HL and EH, by age of the individual at the time of the defect formation, showed a completely different distribution. The results indicate no correlation between these two indicators at any level. Instead, the distribution of Harris lines, by age of the individual at the time of their formation, show that this indicator is associated with growth and not with arrested or slowed associated with stressful conditions

Análisis bioantropológico de un enterratorio humano del Holoceno Tardío en Cabo Nose, Tierra del Fuego, Chile Bioanthropological analisys of a Late Holocene human burial from Cabo Nose, Tierra del Fuego Chile

Se presenta el hallazgo fortuito, excavación y análisis de un enterratorio humano en Cabo Nose, Tierra del Fuego, Chile. El enterratorio se encontraba depositado en un conchal compuesto principalmente de choritos y mauchos, así como de algunos huesos de pescados, aves y mamíferos (lobo marino y guanaco). Los restos esqueletales correspondían a un individuo adulto joven de sexo masculino, fechado en 980 +/-40 años AP (Holoceno tardío). El esqueleto presenta hiperostosis porótica y espina bífida oculta, que posiblemente fueron consecuencia de una dieta rica en alimentos de origen animal pero pobre en vegetales y por tanto en folatos. Esta carencia nutritiva habría afectado al individuo durante el periodo gestacional (espina bífida oculta) y durante la niñez (hiperostosis porótica). Sin embargo, es también posible que un defecto genético haya causado los problemas congénitos (espina bífida y coaliciones tarsales) identificados en este individuo. El análisis isotópico indica un claro predominio de dieta marítima, lo cual concuerda con la evidencia paleopatológica.The discovery, excavation and analysis of a burial in Cabo Nose, Tierra del Fuego, Chile, is presented. The burial was deposited in a shell midden composed mostly of mussels and Nacella sp., as well as some fish, birds and mammal bones (sea lion and guanaco). The remains corresponded to a young adult male dated to BP 980+/-40 (Late Holocene). The skeleton showed porotic hyperostosis, spina bifida occulta, and deformities in the tarsal bones of the left foot. These anomalies were most likely the result of a folate dietary deficiency caused by the ingestion of a diet that was rich in meats, but poor in leafy-green vegetables. This dietary deficiency affected the individual during the gestational period (spina bifida occulta) and childhood (porotic hyperostosis). It is also possible, however, that the congenital defects seen in this individual (spina bifida occulta and tarsal coalitions), were the result of a genetic condition. The isotopic analysis shows that this individual consumed a diet that was predominantly maritime, which is in agreement with the paleopathological evidence

Maize (Zea mays) consumption in the southern andes (30 degrees-31 degrees S. Lat): stable isotope evidence (2000 BCE-1540 CE)

Objectives: The timing and dietary role of maize agriculture is central to archaeological discussions in the Andean region. In the semi-arid region of northern Chile (SARNC), archaeological models propose that maize was adopted during the Early Ceramic period in tandem with pottery and sedentism. Through stable isotope (SI) analyses, of bone collagen and apatite, this study assesses the timing of maize introduction, diachronic changes (2,000 BCE to 1,540 CE.), and synchronic dietary variability in the prehistoric SARNC. Materials and Methods: Fifty-two prehistoric individuals from SARNC were analyzed for delta C-13(ap), delta C-13(col), and delta N-15. Descriptive statistics were used to characterize the results by period and location (inland and coast). Between-periods (ANOVA or Kruskal-Wallis tests), and synchronic comparisons (inland vs. coast; Student's t-tests), were conducted. A SIAR model was run to further evaluate dietary changes. Dietary interpretations are based on food web data. Results: Coastal groups show significant changes in the diet during the Middle (900-1,000CE; enrichment in delta C-13), and Late Intermediate periods (100-1450CE; when the Delta(13C)(ap-col) is above 5.2 parts per thousand). In the inland, significant changes in SI occurred in the Late Intermediate period (delta C-13 enrichment). In the Late period, the inland diet became enriched for delta C-15. Synchronic comparisons showed coastal individuals to have higher delta N-15. Discussion: The popularization of maize in the SARNC was not associated with the appearance of pottery and/or sedentism, and its role as a dietary staple was a late phenomenon (c.a. 1,000CE). The results obtained in this study show that the adoption and consumption of maize varied dramatically in the Southern Andes.Fondecyt 1110125 1150776 Direccion de Bibliotecas, Archivos y Museos Ministerio de Educacion, Chil

Early human dispersals within the Americas

Studies of the peopling of the Americas have focused on the timing and number of initial migrations. Less attention has been paid to the subsequent spread of people within the Americas. We sequenced 15 ancient human genomes spanning from Alaska to Patagonia; six are ≥10,000 years old (up to ~18× coverage). All are most closely related to Native Americans, including those from an Ancient Beringian individual and two morphologically distinct "Paleoamericans." We found evidence of rapid dispersal and early diversification that included previously unknown groups as people moved south. This resulted in multiple independent, geographically uneven migrations, including one that provides clues of a Late Pleistocene Australasian genetic signal, as well as a later Mesoamerican-related expansion. These led to complex and dynamic population histories from North to South America

A Paleogenomic Reconstruction of the Deep Population History of the Andes.

There are many unanswered questions about the population history of the Central and South Central Andes, particularly regarding the impact of large-scale societies, such as the Moche, Wari, Tiwanaku, and Inca. We assembled genome-wide data on 89 individuals dating from ∼9,000-500 years ago (BP), with a particular focus on the period of the rise and fall of state societies. Today's genetic structure began to develop by 5,800 BP, followed by bi-directional gene flow between the North and South Highlands, and between the Highlands and Coast. We detect minimal admixture among neighboring groups between ∼2,000-500 BP, although we do detect cosmopolitanism (people of diverse ancestries living side-by-side) in the heartlands of the Tiwanaku and Inca polities. We also highlight cases of long-range mobility connecting the Andes to Argentina and the Northwest Andes to the Amazon Basin. VIDEO ABSTRACT