Biodistance Analysis

RESUMEN Los modelos bioantropológicos y arqueológicos proponen cambios en la demografía, en la organización social, en las dinámicas poblacionales y en las redes de interacción social entre los grupos cazadores-recolectores del norte de la Patagonia y del sur pampeano durante los últimos 1000 años. El objetivo de este trabajo es explorar, desde la
perspectiva de la antropología dental, si los individuos recuperados en el curso inferior del río Colorado (transición pampeano-patagónica oriental, provincia de Buenos Aires), inhumados durante el Holoceno tardío (ca. 3000-250 años AP), pertenecieron a diferentes poblaciones biológicas o si, por el contrario, compartieron un pool génico común a lo largo
de ese período. Para alcanzar este objetivo se realizaron
análisis métricos de la dentición permanente de 21 individuos adultos de ambos sexos, procedentes de tres sitios arqueológicos.
Los resultados indican una similitud en la dispersión de
los valores obtenidos, lo que permitiría inferir cierta continuidad fenotípica. En este sentido, no se observan segregaciones claras entre grupos de individuos, de manera que es posible plantear que no habrían existido divergencias biológicas entre los grupos humanos que inhumaban a sus ancestros en el área durante todo el lapso considerado. Estos datos contrastan con la información generada en áreas vecinas (p. ej., Pampa
occidental), lo que indicaría que durante el Holoceno tardío final (ca. 1000-250 años AP) se habrían desarrollado diferentes procesos y dinámicas poblacionales (p.ej., regionalización) a nivel macro-regional.

ABSTRACT Bioanthropological and archaeological models propose changes in demography, social organization, population dynamics, and social network interactions among hunter-gatherer groups of northern Patagonia and southern Pampas over the last 1000 years BP. Following this argument, the aim of this paper is to examine, from a dental anthropological perspective, whether the individuals recovered in the lower course of the Colorado river (Eastern Pampean-Patagonian transition, Buenos Aires province, Argentina), buried during the late Holocene (ca. 3000-250 years BP), belonged to different biological populations or, on the contrary, whether they shared a common gene pool
throughout this period. To achieve this goal, dental metrics were performed on adults from both sexes, recovered from three archaeological sites. The results indicate a similarity in the dispersion of the values obtained, which would allow the inference of certain phenotypic continuity. In this sense, no clear segregations among groups of individuals are
observed, so that it is possible to argue that biological differences would not have existed among the human groups that buried their ancestors in the lower course of the Colorado river during the period considered. These data contrast with the information generated in neighboring areas (e.g., western Pampas), indicating that during the final late Holocene (ca. 1000-250 years BP) different processes and population dynamics (e.g., regionalization) developed at a macro-regional level.

Though the term Hyksos commonly refers to the rulers of the Egyptian Second Intermediate Period, it is also used to describe the larger population from which these rulers rose from. Archaeological, artistic and textual sources suggest a Levantine origin to the ‘Hyksos people’, however whether this was a single homogenous group or several groups from a wider area, has remained uncertain.
Nonmetric traits, also called epigenetic or quasi-continuous traits, are normal variation of the human skeleton that remain hidden during life. The traits, though seemingly random in a single person, often have a genetic component that links biologically closely related people together, enabling an exploration of biological affiliations not only within but between populations.
As a non-invasive method, nonmetric trait analysis can be used to study biological closeness when there is no wish or possibility to use DNA analysis. An increasing number of nonmetric trait analyses are being conducted to skeletal human remains, creating trait distribution maps for a wider exploration of biological closeness. As part of the Hyksos Enigma project, nonmetric traits from skeletal human remains from Tell el-Daba, the ancient Hyksos capital of Avaris, are recorded. The results help to understand familial relationships within the site but also compare the site and its subgroups to Levantine sites, potentially offering new insight into the Hyksos origin and the wider migration of people in the Levantine area.

The use of dental metrics as a reliable tool for the assessment of biological distances has diversified dramatically in the last decades. In this paper, some of the basic assumptions on this issue and the potential of cervical measurements in biodistance protocols are discussed. A sample of 1173 permanent teeth from 57 male and female individuals, recovered in Chenque I site (Western Pampas, Central Argentina), a Late Holocene hunter-gatherer cemetery, is examined in order to test the impact of exogenous factors that may have influenced the phenotypic manifestation and affected dental crown sizes. The statistical association between dental metric data, obtained by measuring the mesiodistal and buccolingual diameters of the crown and cervix, and the quantification of hypoplastic defects as a measure to evaluate the influence of the environment in the dental phenotypic expression is evaluated. The results show that socioenvironmental stress did not affect dental metrics and that only the more stable teeth (first incisors, canines, first premolars and first molars) and three variables (buccolingual diameter of the crown and both mesiodistal and buccolingual measurements of the cervix) should be included in multivariate analyses. These suggestions must be strengthened with additional studies of other regional samples to identify factors of variation among populations, so as to develop general guidelines for dental survey and biodistance analysis, but they are a first step for discussing assumptions usually used and maximizing the available information for low-density hunter-gatherer societies.

Stepwise discriminant function analysis and Mahalanobis's generalized distance are applied to 36 measurements recorded in crania from Australasia and Oceania for assessing biological relationships and possible origins of these populations. Craniofacial variation in Australia is found to be clinal. There is extreme diversity in the Murray River Valley and southern Queensland cranial series. Multiple origins of the Australians are not supported by these results. Although selection and other processes cannot be completely ruled out, gene flow and restrictions to the exchange of genes can explain most of the morphological patterning observed. Breadth and length dimensions of the vault, interorbital breadth, biorbital breadth, palate length, and upper facial height are among the most important discriminators. Viewed within the broader context of Asia and the Pacific, Australians represent a biologically distinct population, one sharing ancestral ties with Melanesians but not with the recent populations of Asia and the rest of the Pacific. The latter represent a second major population complex.