Enhancing the learning of evolutionary anthropology skills by combining student-active teaching with actual and virtual immersion of Master's students in fieldwork, laboratory practice, and dissemination.

Higher education in evolutionary anthropology involves providing students with in-depth knowledge of biological and cultural heritage sites and collections that are frequently inaccessible. Indeed, most sites, fossils, and archaeological remains can be visited or manipulated only rarely and solely by specialists with extensive experience. Owing to the development of 3D and medical imaging techniques, this fragile heritage is now more widely accessible, and in a dynamic way. However, exclusive adoption of virtual teaching and learning has a negative impact on student engagement and, naturally, on exchanges with instructors, and thus cannot be used without some reservations. In the ITAP (Immersion dans les Terrains de l'Anthropologie biologique et de la Préhistoire) project of the higher education STEP (Soutien à la Transformation et à l'Expérimentation Pédagogiques) transformation program at the University of Bordeaux, we combine student-active teaching with Master's students fully immersed in ongoing fieldwork, laboratory study, and dissemination of research results in order to develop more individually shaped learning curricula and to foster both professional and new interdisciplinary skills. Here, we present examples of experiments conducted in the ITAP project using both authentic and virtual collections of archaeological, experimental, and reference materials that help to break down the barriers between research activities and higher education, as well as providing a more general appraisal of the appropriate use of virtual tools in higher education by combining them with real-life situations.

Complex mortuary dynamics in the Upper Paleolithic of the decorated Grotte de Cussac, France.

The Mid-Upper Paleolithic (Gravettian) karstic Grotte de Cussac (France) contains two areas of human remains in the context of abundant (and spectacular) parietal engravings. The first area (loci 1 and 2) includes the skeleton of a young adult male in a bear nest, rearranged by postdecomposition inundation, and the variably fragmentary remains of at least two individuals distributed across two bear nests, sorted anatomically and with most of the elements constrained to one side of one nest. The second area (locus 3) retains remains of two adults and an adolescent, in upper hollows and variably distributed down the slope, largely segregated into upper versus lower body groups. The only decoration associated with the human remains is red pigment on some of the bones or underlying sediment. The human remains indicate variable nonnatural deposition and manipulation of human bodies, body portions, and skeletal elements of at least six individuals. Moreover, Cussac is unusual in the association of these remains with exceptional parietal art. The complex Cussac mortuary pattern joins growing evidence from other Gravettian sites of variable treatment of individuals after death, within and across sites, in terms of formal deposition of the body versus postmortem manipulation versus surface abandonment. It provides a window onto the social diversity and the complex interactions of the living and the dead among these successful Late Pleistocene foragers.

Validation and reliability of the sex estimation of the human os coxae using freely available DSP2 software for bioarchaeology and forensic anthropology.

OBJECTIVES: A new tool for skeletal sex estimation based on measurements of the human os coxae is presented using skeletons from a metapopulation of identified adult individuals from twelve independent population samples. For reliable sex estimation, a posterior probability greater than 0.95 was considered to be the classification threshold: below this value, estimates are considered indeterminate. By providing free software, we aim to develop an even more disseminated method for sex estimation. MATERIALS AND METHODS: Ten metric variables collected from 2,040 ossa coxa of adult subjects of known sex were recorded between 1986 and 2002 (reference sample). To test both the validity and reliability, a target sample consisting of two series of adult ossa coxa of known sex (n = 623) was used. The DSP2 software (Diagnose Sexuelle Probabiliste v2) is based on Linear Discriminant Analysis, and the posterior probabilities are calculated using an R script. RESULTS: For the reference sample, any combination of four dimensions provides a correct sex estimate in at least 99% of cases. The percentage of individuals for whom sex can be estimated depends on the number of dimensions; for all ten variables it is higher than 90%. Those results are confirmed in the target sample. DISCUSSION: Our posterior probability threshold of 0.95 for sex estimate corresponds to the traditional sectioning point used in osteological studies. DSP2 software is replacing the former version that should not be used anymore. DSP2 is a robust and reliable technique for sexing adult os coxae, and is also user friendly.

Human tuberculosis predates domestication in ancient Syria.

The question of pre-neolithic tuberculosis is still open in paleopathological perspective. One of the major interests is to explore what type of infection could have existed around the early stage of animal domestication. Paleopathological lesions evoking skeletal TB were observed on five human skeletons coming from two PPNB sites in Syria, which belongs to the geographical cradle of agriculture. These sites represent respectively pre-domestication phase (Dja'de el Mughara, Northern Syria, 8800-8300 BCE cal.) and early domestication phase (Tell Aswad, Southern Syria, 8200-7600 BCE cal.). MicroCT scan analyses were performed on two specimens (one per site) and revealed microscopic changes in favor of TB infection. Detection of lipid biomarkers is positive for two specimens (one per site). Initial molecular analysis further indicates the presence of TB in one individual from Dja'de. Interestingly, no morphological evidence of TB was observed on animal remains of wild and newly domesticated species, discovered in these sites. These observations strongly suggest the presence of human tuberculosis before domestication and at its early stages.

Three-dimensional imaging of past skeletal TB: From lesion to process.

3D imaging has become an essential tool in the field of biological anthropology, notably for human evolution purposes. High resolution virtual 3D reconstructions of original specimens contribute to their preservation and broaden the ability for research, teaching and exchanges. Paleopathology can get substantial benefit from these methods, among others for reconstructing infectious pathological processes on ancient bones. Tuberculosis is frequently diagnosed on ancient human remains; however, some osseous expressions are difficult to interpret using classical methods. We illustrate here the interest of 3D methods for reconstructing processes involved in pathological bone changes due to Mycobacterium tuberculosis infection. Four paleopathological specimens attributed to this infection, dating from different time periods and concerning diverse parts of the skeleton have been analyzed using a specific 3D digital chain we have previously developed. These 3D analyses allow to virtually reconstruct the initial location and aspect of the infectious process, its extension as well as its possible diffusion to the surrounding soft tissues. This possible virtual follow-up of the disease leads to the concept of processual paleopathology that we would like to introduce in the field. The 3D methodology can help to improve our knowledge of natural history and evolution of ancient human infections such as tuberculosis.

Anthropological facial approximation in three dimensions (AFA3D): computer-assisted estimation of the facial morphology using geometric morphometrics.

This study presents Anthropological Facial Approximation in Three Dimensions (AFA3D), a new computerized method for estimating face shape based on computed tomography (CT) scans of 500 French individuals. Facial soft tissue depths are estimated based on age, sex, corpulence, and craniometrics, and projected using reference planes to obtain the global facial appearance. Position and shape of the eyes, nose, mouth, and ears are inferred from cranial landmarks through geometric morphometrics. The 100 estimated cutaneous landmarks are then used to warp a generic face to the target facial approximation. A validation by re-sampling on a subsample demonstrated an average accuracy of c. 4 mm for the overall face. The resulting approximation is an objective probable facial shape, but is also synthetic (i.e., without texture), and therefore needs to be enhanced artistically prior to its use in forensic cases. AFA3D, integrated in the TIVMI software, is available freely for further testing.

Facial soft tissue depths in French adults: variability, specificity and estimation.

Facial soft tissue depths (FSTD) are used in facial approximation to render the shape of the face, and are traditionally published specifically to population, corpulence, and sex amongst other factors. This paper investigates the variability of FSTD collected at 37 landmarks on 500 CT (computed tomography) scans of French living individuals. The specificity of the sample is evaluated by comparing values with six published datasets of various populations and recording techniques. Apart from a significant influence of the corpulence, FSTD show negligible variations with age and sex. The differences between the French sample and other datasets contradict the hypothesis of major influence of population, and underline sample specificity linked with technique and methodology of data measurement. Regression equations were computed to estimate FSTD using age, sex, facial build, and craniometrics, leading to more accurate results if such factors are known. Nevertheless, application of the pooled T-table (Tallied-Facial-Soft-Tissue-Depth-Data) has been validated according to the French sample.

Anatomical placement of the human eyeball in the orbit--validation using CT scans of living adults and prediction for facial approximation.

Accuracy of forensic facial approximation and superimposition techniques relies on the knowledge of anatomical correlations between soft and hard tissues. Recent studies by Stephan and collaborators (6,8,10) reviewed traditional guidelines leading to a wrong placement of the eyeball in the orbit. As those statements are based on a small cadaver sample, we propose a validation of these findings on a large database (n = 375) of living people. Computed tomography scans of known age and sex subjects were used to collect landmarks on three-dimensional surfaces and DICOM with TIVMI. Results confirmed a more superior and lateral position of the eyeball relatively to the orbital rims. Orbital height and breadth were used to compute regression formulae and proportional placement using percentages to find the most probable position of the eyeball in the orbit. A size-related sexual dimorphism was present but did not impact on the prediction accuracy.

Three-dimensional computer-assisted craniometrics: a comparison of the uncertainty in measurement induced by surface reconstruction performed by two computer programs.

Digital investigation of anthropological material through computed tomography (CT) offers several new opportunities in morphometrics. However, an object measured with computer-assisted methods does not necessarily exactly match the original one. The scanning and surface reconstruction of the object induce some alterations, and data acquisition is prone to measurement uncertainty. The purpose of this research is to evaluate the intra- and inter-observers variations in medical CT scan measurements of a known-size phantom and two dry crania. Two software packages, AMIRA and Treatment and Increased Vision for Medical Imaging (TIVMI), which use different techniques of surface reconstructions, were compared. The mean difference between the measurements was lower for TIVMI, using an objective algorithm based on the half-maximum height (HMH) protocol in three dimensions (3D). AMIRA can induce up to a 4% error in known measurements and 5% uncertainty in dry skull measurements. This study emphasises the risk of object shape alteration in each step of its digitisation.