Abstract The origins of the genus Homo have been a focus of much debate in the paleoanthropological literature due to its importance in understanding the evolutionary trajectories that led to the appearance of archaic humans and our species. On the level of taxonomic classification, the controversies surrounding the origins of Homo are the result of lack of clear classification criteria that separate our genus from australopiths, given the general similarities observed between fossils ascribed to late australopiths and early Homo. The challenge in finding clear autapomorphies for Homo has even led to debates about the classification of Homo habilis and Homo rudolfensis as part of our genus. These debates are further complicated by the scarcity of fossils in the timeframe of appearance of our genus, making any fossils dated to between 3.0 and 2.5 Ma of particular relevance in the context of this discussion. The Ledi-Geraru mandible is one such fossils, which has called the attention of researchers due to its combination of primitive traits seen in Australopithecus and derived traits observed in later Homo. Despite being fragmented and poorly preserved, it is one of the key fossil specimens available from the period mentioned above.

Resumo A região de Lagoa Santa, Minas Gerais, apresenta uma história de pesquisas que cruza as fronteiras disciplinares da antropologia, arqueologia e biologia. Neste artigo, traçamos um panorama dos debates que permeiam 180 anos de pesquisa na região. As primeiras intervenções na área foram realizadas pelo naturalista Peter Lund, no século XIX. Desde então, intervenções nacionais, como as do Museu Nacional do Rio de Janeiro, e internacionais, como as das missões Americana e Francesa, aconteceram na região. Enfatizamos neste artigo o impacto produzido na pesquisa local pelas mudanças teóricas e pela intensidade de diálogo entre as disciplinas envolvidas. Por fim, destacamos a importância de manter as pesquisas na região centradas em questões científicas interdisciplinares.

Abstract The region of Lagoa Santa, Minas Gerais, presents a research history that crosses the disciplinary boundaries of anthropology, archaeology and biology. In this article, we outline the debates that went on during more than 180 years of research in the region. The first studies in the area were carried out by the naturalist Peter Lund in the 19th century. Since then, Brazilian interventions, such as the ones sponsored by the National Museum of Rio de Janeiro, and international ones, such as the American and French missions, have taken place in the region. We emphasize in this article the impact of the theoretical changes and the intensity of dialogue between disciplines involved in Lagoa Santa research. Finally, we highlight the importance of keeping research focused on interdisciplinary scientific issues.

Systemic stress in prehispanic populations of San Pedro de Atacama (SPA) during the Middle and Late Intermediate periods was explored through cortisol analysis of hair samples of mummies from these periods. The cortisol levels in the SPA samples were similar to those in samples from present day individuals. This suggests that, in spite of the different environmental and social conditions, prehispanic populations from SPA were not exposed to higher levels of systemic stress than modern populations, possibly due to their long history of occupation and adaptation to the local environment. Individuals from the Middle period showed lower cortisol levels than those from the Late Intermediate period, thus reflecting the differences in the quality of life as shown by osteological markers as well as the cultural and environmental changes associated with the transition from one period to the other. Although cortisol levels in archaeological samples may be affected by a range of factors, they can generate cultural inferences and complement results obtained in SPA prehistoric populations using other approaches.

La presente investigación explora el grado de estrés sistémico al que estaban sometidas las poblaciones de San Pedro de Atacama durante los períodos Medio e Intermedio Tardío mediante el análisis de cortisol en el cabello de restos humanos de estos períodos. Los niveles similares de cortisol encontrados en los individuos de San Pedro de Atacama y en individuos actuales sugieren que, si bien las condiciones ambientales y sociales de las poblaciones prehispánicas fueron muy distintas a las actuales, la población prehispánica en San Pedro de Atacama no estaba sometida a niveles de estrés sistémico mayores que la actual, posiblemente debido a la larga historia de ocupación en la región que permitió que dichas poblaciones se adaptaran a sus condiciones particulares. Los niveles de cortisol de los individuos analizados del período Medio mostraron una tendencia a ser menores que los del Intermedio Tardío, congruente con las diferencias en la calidad de vida sugeridos por marcadores osteológicos y con los cambios culturales y ambientales asociados a ambos períodos. Aunque diversos factores pueden afectar los niveles de cortisol encontrados en muestras arqueológicas, este marcador muestra el potencial para complementar los resultados obtenidos sobre las poblaciones de San Pedro de Atacama utilizando otros enfoques.

During its prehistory, Chile 's desert north was occupied by numerous cultures scattered across the various ecological niches of the region. However, from the Late Archaic forward there is archaeological evidence for the sharing of resources and cultural elements across groups, a practice that intensified during the Middle and Late Intermediate Periods. We explored the dietary composition of local populations through stable carbon and nitrogen isotope analyses. Our results show a high consumption of marine protein along the coast and nearby regions as well as a possible increase in maize consumption over time. Interestingly, these results show that there was substantial dietary variety internal to these groups. This supports the idea of a regular flow of people and food between the coast and the highlands throughout the prehistoric period.

A lo largo de su prehistoria, el norte árido de Chile fue ocupado por una gran diversidad de culturas dispersas por todos los pisos ecológicos de la región. Sin embargo, desde el Arcaico Tardío se encuentran evidencias de intercambio de recursos y elementos culturales entre estas zonas, práctica que se intensificó durante los Periodos Medio e Intermedio Tardío. En este trabajo se evaluó la composición de la dieta de las poblaciones locales, por medio del análisis de isótopos estables de carbono y nitrógeno. Los resultados muestran gran consumo de proteínas marinas en las poblaciones costeras y de regiones cercanas, junto con un posible aumento en el consumo de maíz a lo largo del tiempo. También se demuestra una considerable variedad en la dieta de los individuos de cada grupo, apoyando la idea de un constante flujo de personas y alimentos entre la costa y el altiplano durante la prehistoria de la región.

Vertebral osteophytosis was studied as a marker for physical stress in prehistoric populations of San Pedro de Atacama from the Middle (400 - 1.000 A.D.) and Late Intermediate (1.000 - 1.450 A.D.) periods. The mean degree of osteophytosis was recorded in each vertebral segment of 154 individuals from four sites: Solcor 3, Coyo 3, Quitor 6 and Toconao Oriente. Osteophytosis prevalence was more severe in older individuals, corroborating its degenerative nature. However, after correction for age impact in osteophytosis prevalence, significant differences were observed between sites. Differences in osteophytosis prevalence between sexes were not significant. The results show that during the Late Intermediate period populations of both sexes suffered less vertebral stress than during the Middle period, particularly during the its end. Changes in activity patterns (amount of energy invested, intensity or type of activities undertaken) could account for the differences found.

Se estudió la osteofitosis vertebral como indicador de estrés físico en grupos humanos prehistóricos de San Pedro de Atacama, durante los períodos Medio (400 DC - 1000 DC) e Intermedio Tardío (1000 DC - 1450 DC). Se registró el grado promedio de osteofitosis vertebral de cada segmento vertebral en 154 individuos adultos de cuatro sitios: Solcor 3, Coyo 3, Quitor 6 y Toconao Oriente. Se comprobó el carácter degenerativo de la osteofitosis vertebral, ya que el grado promedio de osteofitosis fue mayor en el rango etario más viejo. Se observaron diferencias significativas entre sitios sólo en este rango. No se encontraron diferencias en el grado de osteofitosis entre sexos. Los resultados indicaron que durante el período Intermedio Tardío, tanto hombres como mujeres, sufrieron un estrés físico sobre la espalda menor que las poblaciones que vivieron durante el período Medio, especialmente a finales de este período, posiblemente por cambios en los patrones de actividad, ya sea en la energía invertida en sus actividades y por consecuencia, en la intensidad de las actividades físicas desarrolladas, o en diferencias en el tipo de actividades desarrolladas.

A região cárstica de Lagoa Santa tem sido de suma importância para as discussões sobre o tempo e o modo da dispersão dos primeiros americanos. A Lapa do Santo, escavada na última década, originou uma das maiores coleções de esqueletos humanos desta região. Neste trabalho, investigamos as afinidades morfológicas dos esqueletos da Lapa do Santo com outras amostras esqueletais de Lagoa Santa e da Colômbia, contextualizando-as dentro da variação morfocraniana existente hoje no planeta. Nossas análises, realizadas sobre um total de 2.059 crânios (1.071 masculinos e 988 femininos), estão baseadas em duas abordagens multivariadas, com o objetivo de caracterizar a variabilidade intra e intergrupos das 24 séries incluídas no trabalho. Nossos resultados mostram que os crânios da Lapa do Santo, bem como de outras séries de Lagoa Santa, não mostram níveis mais elevados de variabilidade intragrupal do que as séries modernas usadas como comparação, sugerindo que elas representam uma mesma população biológica. Concluímos também que os esqueletos mais antigos da América do Sul, incluindo os da Lapa do Santo, mostram fortes afinidades morfológicas com as populações australo-melanésias e da ilha de Páscoa. Tais resultados sugerem que houve um aumento na diversidade biológica no continente americano durante o Holoceno Médio, possivelmente devido ao influxo de diversidade extracontinental após a colonização inicial das Américas.

The karstic region of Lagoa Santa has been highly important for the discussion about the tempo and mode of the initial human dispersal into the Americas. Lapa do Santo rockshelter, excavated during the past decade, represents to date one of the largest collections of early Holocene human remains recovered from the region. Here we analyze the morphological affinities of Lapa do Santo individuals with other early series from Lagoa Santa and Colombia, contextualizing them within the modern human cranial variation across the planet. Our analyses, performed on a total of 2,059 skulls (1,071 males and 988 females), are based on complementary multivariate approaches, aiming to characterize the within-group variance and the between-group morphological affinities of the 24 series included in the analyses. Our results indicate that Lapa do Santo, and other Lagoa Santa, individuals do not present higher levels of within-group variation than modern human groups, supporting the idea that they represent a single biological population. When compared to worldwide series, the early South American groups, Lapa do Santo included, share high morphological affinities among themselves and with Australo-Melanesian and Easter Island groups. Taken together, these results suggest an increase of biological diversity in the continent during the Holocene, possibly a result of the influx of new extra-continental diversity after its initial settlement.

Between the 1950s and 1970s Father Gustavo Le Paige excavated one of the largest osteological collections of Latin America, attracting the attention of numerous researchers over the past 40 years. In his field notes, Le Paige recorded the excavation of 5482 skulls and human bodies deposited in the Instituto de Investigaciones Arqueológicas y Museo of the Universidad Católica del Norte (San Pedro de Atacama). However, cumulative processes of abandonment and the lack of preventive conservation resulted in the loss of context and a decrease in the quality of preservation of a significant portion of this skeletal collection. Here, we present the current state of preservation of this collection, and 50 new radiocarbon dates that helps the chronological contextualization of 21 of the larger and more representative cemeteries in the Le Paige collection.

Entre 1950 y 1970 el sacerdote Gustavo Le Paige excavó una de las mayores colecciones osteológicas de América Latina, que ha llamado la atención de muchos investigadores en los últimos 40 años. En sus notas de terreno Le Paige consigna la exhumación de 5482 cráneos y cuerpos humanos, depositados en el Instituto de Investigaciones Arqueológicas y Museo de la Universidad Católica del Norte, en San Pedro de Atacama. Sin embargo, procesos acumulativos de abandono y falta de conservación preventiva produjeron serios daños en el estado de una parte significativa de esta colección, así como la pérdida de sus contextos. Aquí, presentamos el actual estado de conservación de la colección, al mismo tiempo que ofrecemos 50 nuevas dataciones radiocarbónicas que sitúan cronológicamente en forma más precisa a 21 de los cementerios más representativos de donde proviene nuestro objeto de estudio.

We examine four prehistorical moments in San Pedro de Atacama with the purpose of qualifying the impact that Tiwanaku had on the local population. To this end, we carried out osteobiographic studies on 161 individuals from the cemeteries of Solcor-3, Coyo-3 and Quitor-6, which are representative of pre-Tiwanaku (Sequitor and Quitor Phases), Tiwanaku (Coyo Phase; with a rise of altiplano influence), Final Tiwanaku (final Coyo Phase) and post-Tiwanaku (Yaye-Solor Phase). The results for three of the indicators that we used, suggest an improvement in the biological quality of life of the local population, expressed in greater height and sexual dimorphism, the lesser occurrence of caries, occlusal abrasion and loss of teeth during the individual's life, all of this possibly owing to the increase in the consumption of animal protein that took place under Tiwanaku influence. Although, on a first impression, hyperostosis and the systemic hypoplasia of tooth enamel would indicate a negative impact on the population, it is conceivable that the greater incidence of these variables results from an improved diet that made individuals more resistant to attacks by pathogenic agents. The last indicator we used relates to body use, which reveals that, notwithstanding the changes that would have been propitiated by altiplano influence, the local population kept to its traditional daily activities throughout.

Se examinan cuatro momentos de la prehistoria de San Pedro de Atacama, con el objeto de calificar el impacto de la influencia Tiwanaku en una población local. Fueron realizados estudios osteobiográficos en 161 individuos de los cementerios Solcor-3, Coyo-3 y Quitor-6, representativos de los períodos pre-Tiwanaku (Fases Sequitor, Quitor), Tiwanaku (Fase Coyo; auge de influencia altiplánica), Tiwanaku Final (final Fase Coyo) y post-Tiwanaku (Fase Yaye-Solor). Los resultados de tres de los marcadores usados apuntan a que se verifica una mejoría en la calidad de vida biológica de la población local, traducida en mayor estatura y dimorfismo sexual, menor ocurrencia de caries, de desgaste oclusal y de pérdida de dientes durante la vida del individuo, ello posiblemente debido al incremento en el consumo de proteína animal durante el momento de influencia de Tiwanaku. La hipoplasia sistémica del esmalte dental y la hiperostosis indican, a primera vista, un cuadro opuesto al de un impacto positivo en esta población; sin embargo, es posible pensar que la mayor incidencia de estas variables se deba a que, como resultado de una mejor dieta, los individuos eran más resistentes a los ataques de agentes patogénicos. El último indicador se relaciona con el uso del cuerpo, el cual señala que, al margen de cualquier cambio propiciado por la influencia altiplánica, la población local mantuvo sus tradicionales actividades cotidianas a lo largo de todo el tiempo