Lumila Paula Menéndez

Early Holocene Human Remains from the Argentinean Pampas: Cranial Variation in South America and the American Peopling

Abstract Morphological comparisons between the earliest and latest human skeletons of America have suggested the existence of a complex scenario underlying the biological diversification of American populations. In the late nineteenth and early twentieth centuries Florentino Ameghino initiated the debate on the antiquity of humans in the Argentinean Pampas, which has been reviewed recently due to new radiocarbon dates obtained. Morphometric analyses from these Argentinean Pampas samples are presented together with early samples from Chile, Brazil, and Colombia. Results show that while there is no clear separation between early and late samples from Chile, samples from Brazil, Colombia, and Argentina show more pronounced differences, the latter presenting the largest morphological variation among early American samples. However, the hypotheses that morphological differences between early and late American samples are related to evolutionary processes are difficult to support using cranial morphometric differences alone. Future studies need to consider a combination of additional evidence (e.g., archaeological and molecular).

PATOLOGÍAS BUCALES EN CRÁNEOS HUMANOS DEL NORESTE DE PATAGONIA: TENDENCIAS TEMPORALES EN LA DIETA Y ESTADO DE SALUD DE LAS POBLACIONES DEL HOLOCENO-TARDÍO DEL VALLE INFERIOR DEL RÍO NEGRO

Resumen es: El objetivo de este trabajo es contribuir, desde la bioarqueologia, a la discusion del modelo de intensificacion economica y ampliacion de la dieta de la...

Comparing Methods to Assess Intraobserver Measurement Error of 3D Craniofacial Landmarks Using Geometric Morphometrics Through a Digitizer Arm

Intraobserver error (INTRA‐OE) is the difference between repeated measurements of the same variable made by the same observer. The objective of this work was to evaluate INTRA‐OE from 3D landmarks registered with a Microscribe, in different datasets: (A) the 3D coordinates, (B) linear measurements calculated from A, and (C) the six‐first principal component axes. INTRA‐OE was analyzed by digitizing 42 landmarks from 23 skulls in three events two weeks apart from each other. Systematic error was tested through repeated measures ANOVA (ANOVA‐RM), while random error through intraclass correlation coefficient. Results showed that the largest differences between the three observations were found in the first dataset. Some anatomical points like nasion, ectoconchion, temporosphenoparietal, asterion, and temporomandibular presented the highest INTRA‐OE. In the second dataset, local distances had higher INTRA‐OE than global distances while the third dataset showed the lowest INTRA‐OE.

Spatial variation of dental caries in late holocene samples of Southern South America: A geostatistical study.

The spatial variation of dental caries in late Holocene southern South American populations will be analyzed using geostatistical methods. The existence of a continuous geographical pattern of dental caries variation will be tested.

Out of Africa by spontaneous migration waves

Hominin evolution is characterized by progressive regional differentiation, as well as migration waves, leading to anatomically modern humans that are assumed to have emerged in Africa and spread over the whole world. Why or whether Africa was the source region of modern humans and what caused their spread remains subject of ongoing debate. We present a spatially explicit, stochastic numerical model that includes ongoing mutations, demic diffusion, assortative mating and migration waves. Diffusion and assortative mating alone result in a structured population with relatively homogeneous regions bound by sharp clines. The addition of migration waves results in a power-law distribution of wave areas: for every large wave, many more small waves are expected to occur. This suggests that one or more out-of-Africa migrations would probably have been accompanied by numerous smaller migration waves across the world. The migration waves are considered “spontaneous”, as the current model excludes environmental or other factors. Large waves preferentially emanate from the central areas of large, compact inhabited areas. During the Pleistocene, Africa was the largest such area most of the time, making Africa the statistically most likely origin of anatomically modern humans, without a need to invoke additional environmental or ecological drivers.

Moderate climate signature in cranial anatomy of late holocene human populations from Southern South America

OBJECTIVE The aim of this study is to analyze the association between cranial variation and climate in order to discuss their role during the diversification of southern South American populations. Therefore, the specific objectives are: (1) to explore the spatial pattern of cranial variation with regard to the climatic diversity of the region, and (2) to evaluate the differential impact that the climatic factors may have had on the shape and size of the diverse cranial structures studied. MATERIALS AND METHODS The variation in shape and size of 361 crania was studied, registering 62 3D landmarks that capture shape and size variation in the face, cranial vault, and base. Mean, minimum, and maximum annual temperature, as well as mean annual precipitation, but also diet and altitude, were matched for each population sample. A PCA, as well as spatial statistical techniques, including kriging, regression, and multimodel inference were employed. RESULTS The facial skeleton size presents a latitudinal pattern which is partially associated with temperature diversity. Both diet and altitude are the variables that mainly explain the skull shape variation, although mean annual temperature also plays a role. The association between climate factors and cranial variation is low to moderate, mean annual temperature explains almost 40% of the entire skull, facial skeleton and cranial vault shape variation, while annual precipitation and minimum annual temperature only contribute to the morphological variation when considered together with maximum annual temperature. The cranial base is the structure less associated with climate diversity. CONCLUSION These results suggest that climate factors may have had a partial impact on the facial and vault shape, and therefore contributed moderately to the diversification of southern South American populations, while diet and altitude might have had a stronger impact. Therefore, cranial variation at the southern cone has been shaped both by random and nonrandom factors. Particularly, the influence of climate on skull shape has probably been the result of directional selection. This study supports that, although cranial vault is the cranial structure more associated to mean annual temperature, the impact of climate signature on morphology decreases when populations from extreme cold environments are excluded from the analysis. Additionally, it shows that the extent of the geographical scales analyzed, as well as differential sampling may lead to different results regarding the role of ecological factors and evolutionary processes on cranial morphology.

Informacion morfometrica en estudios interpoblacionales: una comparación de técnicas basadas en proporciones y coordenadas Procrustes/Interpopulation morphometric studies: a comparison between techniques based on proportions and Procrustes coordinates

RESUMEN Este trabajo se centra en el analisis de cambios osteoartrosicos observados en esqueletos del cementerio de Rincon Chico 21 (Santa Maria, Catamarca), con el objeto de intentar la reconstruccion de los habitos corporales mas probables y explorar su vinculacion con eventuales divisiones del trabajo en la poblacion que genero este cementerio precolombino. Las manifestaciones osteoartrosicas en los principales sistemas articulares de 56 individuos adultos de ambos sexos fueron registradas, analizadas y comparadas. Los resultados sugieren que en esta comunidad con una economia de subsistencia principalmente basada en la practica de agricultura de regadio y pastoreo de camelidos (Desarrollos Regionales), habria existido una division de tareas y/o actividades potencialmente relacionadas con el sexo de los individuos. Asimismo, los analisis estadisticos aplicados entre los grupos etarios considerados estarian indicando que la edad constituiria un factor determinante en la expresion final de la enfermedad degenerativa articular tanto en las articulaciones de los miembros inferiores como en las del esqueleto axial. ABSTRACT This research is centered on the skeletal analysis of osteoarthritic changes observed in individuals from Rincon Chico 21, a prehistoric burial site at Santa Maria, Catamarca, Argentina. The aim was to try the reconstruction of the most probable corporal behaviours, as well as the possible relationships with labour divisions among individuals from the population that generated the prehistoric cemetery. Osteoarthritic manifestations on the main articular systems of 56 systematically excavated adult skeletons of both sexes were registered, analyzed and compared. Results suggested that in this prehistoric community, with subsistence economy based on agriculture and pastoralism (Regional Developments Period), there may have existed a sexual division of the daily activities. In addition, the results of the statistical analysis applied among the age groups indicate that the age would be an important factor for determining the final expression of the degenerative joint disease, both in the joints of the lower extremities and in the axial skeleton.RESUMEN El estudio de las poblaciones humanas antiguas es complejo y requiere de un enfoque interdisciplinario. La arqueologia argentina esta promoviendo el desarrollo de nuevas lineas de evidencias que incluyen espacios muy activos de interaccion con la biologia. Numerosos estudios biologicos se efectuan sobre los depositos sedimentarios asociados al contexto arqueologico. Los sedimentos asociados a los restos humanos constituyen un recurso de informacion poco explorado y en general, escasamente contemplado en el diseno previo de la excavacion. El presente trabajo aborda el examen de sedimentos de foramenes sacrales de esqueletos humanos pertenecientes al Museo Regional Monsenor Fagnano, Tierra del Fuego, una clase de material arqueologico poco estudiado. La recuperacion de rotiferos, artropodos y parasitos justifica el esfuerzo de muestreo sobre materiales sin asignacion temporal y con escasa referencia espacial. Se puede concluir que el estudio de microfosiles presentes en este tipo de deposito permite maximizar la informacion obtenida del registro bioarqueologico debido a que albergan valiosa informacion paleoambiental, bioantropologica y tafonomica. Asi, el estudio exhaustivo y no destructivo de las muestras arqueologicas resulta un punto crucial en la estrategia de investigacion. ABSTRACT The study of ancient human populations is complex and requires an interdisciplinary approach. The Argentinean archaeology is promoting the development of new research fields, including areas of active interaction with biology. Numerous biological studies are conducted on the sedimentary deposits in association to the archaeological context. The sediments associated to human remains constitute an unexplored source of information. Nevertheless, this material is frequently overlook during excavations and/or insufficient number of samples are taken. The present study analyzes the sediments found in sacral foramina of human skeletons belonging to the Monsenor Fagnano Regional Museum, Tierra del Fuego this is a kind of archaeological material rarely studied. The recovery of rotifers, arthropods and parasites justified the sampling effort on this unusual sediments characterized by a low temporary and spatial reference. It can be concluded that the study of microfossils found in this type of deposit maximized the information obtained from the bioarchaeological registry because it harbors valuable palaeoenvironmental, bioanthropological and taphonomic data. Therefore, the exhaustive and non-destructive study of the archaeological samples is a crucial point in the research strategy