The history and composition of the Raymond A. Dart Collection of Human Skeletons at the University of the Witwatersrand,Johannesburg, South Africa

The Raymond A. Dart Collection of Human Skeletons (Dart Collection) is housed in the School of Anatomical Sciences at the University of the Witwatersrand, Johannesburg, South Africa, and comprises one of the largest documented cadaver‐derived human skeletal assemblages in the world. This collection originated in the early 1920s as a result of the efforts of Raymond Dart and continues to grow. The skeletons included represent varied indigenous and immigrant populations from southern Africa, Europe and Asia. This contribution documents the history of the collection and provides an updated inventory and demographic assessment of this valuable research collection. According to a recent inventory the Dart Collection currently comprises 2,605 skeletons representing individuals from regional SA African (76%), White (15%), Coloured (4%) and Indian (0.3%) populations. A large proportion of the skeletons (71%) represent males. The recorded ages at death range from the first year to over 100 years of age, but the majority of individuals died between the ages of 20 and 70. The Dart Collection has been affected by collection procedures based on availability. All of the cadavers collected before 1958, and large proportions subsequently, were derived from unclaimed bodies in regional South African hospitals. Some details of documentation (age at death, population group) are estimates and some aspects of the collection demographics (sex ratios) do not closely reflect any living South African population. Our inventory and analysis of the Dart Collection is aimed to assist researchers planning research on the materials from this collection. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.     

A blind test of mandibular morphology for sexing mandibles in the first few years of life

Loth and Henneberg ([2001] Am. J. Phys. Anthropol. 115:179-186) proposed that consistent shape differences exist between male and female juvenile mandibles which can be used to predict sex with an accuracy of 81%. A sample of known sex and age from the Spitalfields Collection was examined blind twice and resulted in an overall accuracy of only 64%. The tests also showed that: 1) the method sexed males more reliably than females; and 2) consistency was low.     

Historical sex-specific distribution of Atlantic walrus (<Emphasis Type="Italic">Odobenus rosmarus rosmarus</Emphasis>) in Svalbard assessed by mandible measurements

We developed a discriminant function based on measurements of known-sex mandibles of walrus from the Canadian Arctic collected between 1983 and 1998 and used it to explore the sex ratio in the catches of walrus in Tusenøyane, south-eastern Svalbard, during the nineteenth century. Canadian mandibles older than 5 years of age of known sex were classified into correct sex with 100% accuracy by using two measurements. Applying the same discriminant function to 80 mandibles from Svalbard older than 5 years of age classified 48 (60%) as males and 32 (40%) as females. It also classified 584 aged and un-aged mandibles from Svalbard 67% (390) as males and 33% (194) as females. Eight of the aged jaws (10%) and 41 (7%) of the un-aged jaws had probabilities of classification into sex <80%. We stress the importance of being cautious in applying a discriminant function developed from Canadian mandibles to classify the sex of old weathered mandibles from Svalbard. However, we believe our results indicate that female walrus were once more common in south-eastern Svalbard than they are now.     

The frequency and anatomical features of torus mandibularis in a Black South African population.

Torus mandibularis is a rounded bony protuberance on the lingual surface of the mandible and usually found above the myolohyoid line, medial to the molar roots. This report describes the frequency and morphology of torus and also proffers the likely cause among black South Africans. A total of 284 modern skeletal specimens were obtained from the Raymond Dart Collection of Human Skeletons at the School of Anatomical Sciences, University of the Witwatersrand. The mandibles were classified into dentate and edentulous, while those with torus, especially in dentate mandibles, were reviewed for side location, type and shape. No measurements were made, consistent with the view that these characteristics are non-metrical and should be assessed by means of a standard observatory procedure. Out of 246 dentate mandibles, 60 (24.4%) were found to have torus and only 1 (4.3%) out of the 23 male edentulous mandibles; the difference is statistically significant (P=2.8%). The torus distribution among males and females was 48 (80%) and 12 (20%), respectively, and again statistically significant (P< 0.05). Prevalence of torus was highest in the 40–60 years age group. The morphology of the torus showed that 37 (61.7%) were bilateral in location, 42 (70%) were of the solitary type and 31 (51.7%) were round in shape. The formation of torus follows the threshold model which holds that this is primarily a genetic trait, but with environmental factors such as mechanical stress necessary for its development.     

Mandibular ramus flexure: A new morphologic indicator of sexual dimorphism in the human skeleton

In the skeleton, male and female characteristics lie along a continuum of morphologic configurations and metric values. Size alone is not the best indicator of sex. In contrast, morphologic differences that arise from genetically sex-linked growth and development allow better separation of the sexes. This study presents a new morphologic indicator of sexual dimorphism in the human mandible. A sample of 300 mandibles from adults of known sex primarily from the Dart collection was analyzed. Of these, 100 were found to have obvious bony pathologies and/or excessive tooth loss (“pathologic” sample). Thus, the normative sample consisted of 200 individuals (116 males, 84 females). Examination of morphologic features led to the discovery of a distinct angulation of the posterior border of the mandibular ramus at the level of the occlusal surface of the molars in adult males. Flexure appears to be a male developmental trait because it is only manifest consistently after adolescence. In most females, the posterior border of the ramus retained the straight juvenile shape. If flexure was noted, it was found to occur either at a higher point near the neck of the condyle or lower in association with gonial prominence or eversion. In the normative sample, overall prediction accuracy from ramus shape was 99%. When the “pathologic” sample was analyzed separately, 91.0% were correctly diagnosed. Because the African samples were overwhelmingly black, this trait was also tested on American samples (N = 247) of whites (N = 85), Amerinds (N = 66), and blacks (N = 96) that included a mix of healthy individuals and those with extensive tooth loss and evidence of pathology. The results were nearly identical to those of the “pathologic” African sample, with accuracies ranging from about 91% in whites and blacks to over 92% in Amerinds. Total accuracy for all African and American samples combined (N = 547) is 94.2%. In conclusion, at 99%, sexing from the shape of the ramus of a healthy mandible is on a par with accuracy attainable from a complete pelvis. Moreover, there is no record that any other single morphologic or metric indicator of sex (that has been quantified from the adult skeleton) surpasses the overall accuracy attained from the more representative mixed sample produced by combining all groups assessed in this study. The usefulness of this trait is enhanced by the survivability of the mandible and the fact that preliminary investigations show that the trait is clearly evident in fossil hominids. © 1996 Wiley-Liss, Inc.     

Talking heads: Morphological variation in the human mandible over the last 500 years in the Netherlands

The primary aim of this paper is to assess patterns of morphological variation in the mandible to investigate changes during the last 500 years in the Netherlands. Three-dimensional geometric morphometrics is used on data collected from adults from three populations living in the Netherlands during three time-periods. Two of these samples come from Dutch archaeological sites (Alkmaar, 1484–1574, n = 37; and Middenbeemster, 1829–1866, n = 51) and were digitized using a 3D laser scanner. The third is a modern sample obtained from MRI scans of 34 modern Dutch individuals.Differences between mandibles are dominated by size. Significant differences in size are found among samples, with on average, males from Alkmaar having the largest mandibles and females from Middenbeemster having the smallest. The results are possibly linked to a softening of the diet, due to a combination of differences in food types and food processing that occurred between these time-periods. Differences in shape are most noticeable between males from Alkmaar and Middenbeemster. Shape differences between males and females are concentrated in the symphysis and ramus, which is mostly the consequence of sexual dimorphism. The relevance of this research is a better understanding of the anatomical variation of the mandible that can occur over an evolutionarily short time, as well as supporting research that has shown plasticity of the mandibular form related to diet and food processing. This plasticity of form must be taken into account in phylogenetic research and when the mandible is used in sex estimation of skeletons.     

The relation between external dimensions of the human mandible and cortical bone morphology as determined with the aid of CT scans

Computerized tomographs were taken of 22 mandibles, selected from an early Arab population and aged between 17 and 60 years. A specially designed holder was used to define specific locations along the mandible, namely symphysis, mid sagittal section through the corpus, midpoint of the first molar (M1), gonion and ramus. Cortical cross sectional area and principal moments of inertia were then calculated for the locations specified, to obtain estimates of the resistance of the bone to deformation. They were analyzed in relation to age, sex, side and external dimensions of the mandible. The error of measurement calculated from (i) repeated CT scans (ii) repeated measurements (iii) from comparison of CT scans with a sectioned mandible, were of the same order of magnitude. All values were greater in males than in females; they were only slightly affected by age and were unaffected by side. Mandibular length and ramus height accounted for most of the variation observed in moments of inertia. We consider that these results can best be interpreted in accordance with the hypotheses put forward by Hylander (1975, 1985) according to which the mandible acts as a third degree lever, with “wishboning” forces acting at the symphysis and parasagittal bending at the first molar. We now plan to apply this method to study the “strength” of the mandibles of past populations with different dietary adaptations.     

Pathology of Bedouin skeletal remains from two sites in Israel

Frequency of pathology and of some anomalies in skeletons of Bedouin living about 200 BP, uncovered in the Israeli Negev, is considered in relation to particular bone, sex, age-group, and kinds of defects. The environment of the Bedouin in relation to his “health-status” is noted. Two-thirds of the skeletons had one or more different bones with defects. Incidence of crania with defects was: males, 26%; females, 18%; the highest incidence occurred at age 35–49. Alveolar abscesses occurred in 28% of maxillae, 9% of mandibles. Of the long bones, the tibia was most frequently affected (15%): swelling of the shaft, relatively common, was apparently caused by bejel, a non-venereal form of syphilis, similar to yaws, endemic to the Bedouin. Forty-eight percent had defective vertebrae, usually an arthritic manifestation of one kind or another; half of this group had defects in more than one region of the spine. Defects also occurred relatively frequently in the innominata, sacrum, scapula, and clavicle, mostly arthritic lesions except in the sacrum in which the percentage with sacral hiatus was high. Average age at death was, males, 43 years, females, 33 years (adults only), and 28 years for all ages.     

Chromosome aberrations in lymphocytes of residents living in buildings constructed with radioactively contaminated rebars

Using the G-banding technique, we examined lymphocytes from 90 individuals (43 males and 47 females, median age 31 years) living in buildings constructed with radioactively contaminated rebars. Forty-five nonexposed control subjects (22 males and 23 females, median age 30 years), matched to the radiation-exposed individuals by sex and age, were selected for comparison. At least 500 metaphases were checked for each individual. All recognizable structural aberrations of chromosomes or chromatids were recorded. After adjusting for age and smoking status, both the percentage of cells with aberrant chromosomes (PCAC) and the number of aberrant chromosomes per 100 cells (NAC) were found to be significantly higher in the radiation-exposed females than in the control females (p < 0.05 for PCAC and NAC). This difference, however, was not observed in the comparison of radiation-exposed and control males. This suggests a possible interaction between sex and radiation exposure in their effects on chromosome aberrations.     

Sexual dimorphism of root length on a Greek population sample

Sexual dimorphism in teeth has been an area of research for osteoarchaeologists and forensic anthropologists studying human skeletal remains. As most studies have been based on the mesiodistal and buccolingual crown measurements, sexual dimorphism from root length dimensions remains “neglected” by comparison to crown dimensions. The aim of the present study was to test the existence of sexual dimorphism in the root length of single-rooted teeth with the purpose of investigating whether maximum root length can be reliably used to determine sex. A total of 774 permanent teeth in 102 individuals (58 males and 44 females) from the Athens Collection were examined. The maximum root length of each tooth was measured on the mesial, distal, buccal, and lingual side. Almost all teeth presented a high degree of sexual dimorphism with males showing numerically higher values in root length than females. The most dimorphic teeth were the maxillary second incisors followed by maxillary canines. The percentage of sexual dimorphism reached 16.56%, with maxillary teeth showing the highest degree of dimorphism. The classification results show that the overall correctly specified group percentage ranged from 58.6% to 90.0%. The data generated from this study suggest that root length measurements offer a reliable method for determining sex and are therefore useful in osteoarchaeological studies, particularly in cases of fragmented or cremated material, but also in forensic contexts. Moreover, root length can be used to separate the remains of female and male subadult individuals with a high level of accuracy thus addressing one of the most problematic issues in human osteoarchaeology and anthropology as immature skeletons are the most difficult to sex.     

Sexually dimorphic pelvic morphology in South African whites and blacks

It is well known that there is metric and morphologic variation in the expression of sexual dimorphism between racial phenotypes and populations. Therefore, the purpose of this research is to assess morphologic sex differences in the pelves of South African whites and blacks. Results will be used to improve the identification of human skeletal remains by producing group specific standards. Morphologic features of both left and right os coxae were studied in a sample of 400 known sex/race individuals from the Pretoria and Dart collections. Bones that were clearly pathologic or visibly deformed were excluded from the study. Data were subjected to SPSS analysis.

Results indicated that overall, pubic bone shape was the easiest to assess and was the most consistently reliable morphological indicator of sex in both sexes and population groups. At 88% average accuracy, the most discriminating traits in whites were pubic bone shape and subpubic concavity form. In blacks, greater sciatic notch form allowed the highest separation, averaging 87.5%, followed by pubic shape at 84.5%. Important findings included the fact that there were significant differences in the accuracy of sex determination from pelvic morphology between both males and females and whites and blacks.

In conclusion, this study provides quantification of individual morphological traits in the os coxae of white and black South Africans that will be of value in forensic and archaeological analyses, especially when dealing with fragmentary remains. It also demonstrates that population differences affect the expression of sexual dimorphism and must be accounted for to develop the most effective methods of analysis.     

The density of long limb bones and the percentage ash weight of the skeleton of Macaca mulatta

The gravimetric density of humeri, radii, femora and tibiae from a series of 274 male and female skeletons of rhesus monkeys, Macaca mulatta, was determined for fetal, young and adult periods. The ages of 171 of the animals were known: they ranged from 57 days of gestation to 13.6 years; the ages of an additional 103 skeletons were estimated. The mean density of the fetal bones was found to increase linearly with age and was higher for males than females, and higher for the superior than for the inferior limb bones. During the young period the pattern of increase in density can be represented by a power-type curve, and the density is significantly higher in females than in males and in superior than in inferior limb bones. The densities of the long limb bones of the adult skeletons show a slight, but not significant, negative trend with increasing age. In this age group the mean densities are higher for males than females and higher for the superior than for the inferior limb bones. The percentage ash weight was determined for the total skeleton and for 21 subdivisions of 23 postnatal skeletons with estimated ages. The skull and long limb bones were found to have higher mean percentage ash weights than the vertebral segments and the sternum. Both the density and the percentage ash weight of the Macaca mulatta skeletons examined exceed those found in our earlier studies of the human skeleton.     

Has the transition to agriculture reshaped the demographic structure of prehistoric populations? New evidence from the Levant

This paper presents the demographic changes that followed the transition from a hunting-gathering way of life (Natufian) to an agricultural, food-producing economy (Neolithic) in the southern Levant. The study is based on 217 Natufian (10,500-8,300 BC) skeletons and 262 Neolithic (8,300-5,500 BC) skeletons. Age and sex identification were carried out, and life tables were constructed. A five-parameter competing hazard model developed by Siler ([1979] Ecology 60:750-757) was used to smooth life-table data. No indication of increased mortality with the advent of agriculture was noted. On the contrary, both life expectancy at birth (24.6 vs. 25.5 years) and adults' mean age at death (31.2 vs. 32.1 years) increased slightly from the Natufian to the Neolithic period (assuming stationary populations). Yet the transition to agriculture affected males and females differently: mean age at death in the Natufian was higher for adult females compared to adult males, while in the Neolithic, it was the reverse. One interpretation given to the distribution of female ages at death is that with the onset of the Neolithic period, maternal mortality increased as a result of a concomitant increase in fertility. If the adoption of agriculture in the Levant increased the rate of population growth at the beginning of the Neolithic, expectation of life may have increased dramatically.     

Patella measurements of South African whites as sex assessors.

This study uses metrical characteristics of the patella to derive population specific equations for sex determination in South Africa. Six measurements were taken from 120 normal and undamaged left patellae in a sample of known race, equally distributed by sex, obtained from the Raymond A Dart collection of human skeletons. These data were subjected to discriminant analysis. Maximum height and maximum breadth were selected in the stepwise analysis with an average accuracy of 83% in correct sex classification. Four functions were derived from the direct analysis with a range of average accuracy between 77% and 85%. While most individual variables showed high misclassification rates and may not be useful on their own, maximum height and maximum breadth have an average accuracy of 85 and 79%, respectively.     

Sex determination using the scapula in medieval skeletons from East Anatolia

Sex determination from skeletal human remains by discriminant function analysis is one of the methods utilized in the forensic and osteoarcheological sciences. The purpose of the present study is to establish metric standards for sex determination for medieval Anatolian populations using scapular measurements. The database for this research consisted of 93 adult skeletal remains (47 males and 46 females) from the Dilkaya medieval collection. Four measurements were taken: maximum scapular height, maximum scapular breadth, glenoid cavity height, glenoid cavity breadth, and subjected to discriminant function analysis. All measurements demonstrated some degree of sexual dimorphism, with the highest accuracy of sex determination (94.8%) obtained using maximum scapular breadth. Overall accuracies of the functions ranged from 82.9% to 95.0%, with a higher accuracy rate obtained for female skeletons than for males. Population specific discriminant formulas were developed using combinations of measurements, which can be used in ancient Anatolian populations.     

Evaluation of the suchey–brooks method of age estimation in an Australian subpopulation using computed tomography of the pubic symphyseal surface

Despite the prominent use of the Suchey–Brooks (S–B) method of age estimation in forensic anthropological practice, it is subject to intrinsic limitations, with reports of differential interpopulation error rates between geographical locations. This study assessed the accuracy of the S–B method to a contemporary adult population in Queensland, Australia and provides robust age parameters calibrated for our population. Three‐dimensional surface reconstructions were generated from computed tomography scans of the pubic symphysis of male and female Caucasian individuals aged 15–70 years (n = 195) in Amira® and Rapidform®. Error was analyzed on the basis of bias, inaccuracy and percentage correct classification for left and right symphyseal surfaces. Application of transition analysis and Chi‐square statistics demonstrated 63.9 and 69.7% correct age classification associated with the left symphyseal surface of Australian males and females, respectively, using the S–B method. Using Bayesian statistics, probability density distributions for each S–B phase were calculated, providing refined age parameters for our population. Mean inaccuracies of 6.77 (±2.76) and 8.28 (±4.41) years were reported for the left surfaces of males and females, respectively; with positive biases for younger individuals (<55 years) and negative biases in older individuals. Significant sexual dimorphism in the application of the S–B method was observed; and asymmetry in phase classification of the pubic symphysis was a frequent phenomenon. These results recommend that the S–B method should be applied with caution in medico‐legal death investigations of Queensland skeletal remains and warrant further investigation of reliable age estimation techniques. Am J Phys Anthropol, 2013. © 2013 Wiley Periodicals, Inc.     

广东佛山河宕新石器时代晚期墓葬人骨

本文对佛山河宕新石器晚期墓葬中出土的人骨进行了形态观察和测量比较,认为这些古代人在体质上仍有不特别强烈的蒙古人种性质,并显示出一些同赤道人种相似的特证。还指出了该墓群的性别年龄分布,因性别而异的埋葬头向和拔牙风俗。     

Loss of molar occlusion and mandibular morphology in adults in an ancient human population consuming a coarse diet

The purpose of the study is to investigate the link between number of molar teeth retained in occlusion and mandibular morphology in adults in an ancient, high dental wear human population. The study material comprises skeletons from Mediaeval Wharram Percy, England (N = 50 female, 69 male adults). It was hypothesized that adults retaining fewer occluding molars would show reduction in mandibular dimensions, particularly in the ascending ramus and gonial regions where the main muscles of mastication have their insertions. Molar occlusal status is assessed using the concept of functional units. Mandibular morphology is assessed using a suite of ten linear measurements plus the mandibular angle. Results show no evidence for any association between number of molars retained in occlusion and mandibular angle. There was an association between mandibular size and number of molars retained in occlusion, with smaller mandibular dimensions in those retaining fewer occluding molars. Some measurements were affected more than others so that there was also some shape alteration. Alteration of mandibular dimensions was more clearly demonstrable in females than in males. Only in females could significant reduction in the ascending ramus and gonial regions be demonstrated. Reasons for the apparent difference in response to loss of molar occlusion between male and female mandibles are unclear, but sex differences in bony metabolism mediated by hormonal factors may be implicated. Results suggest that care should be exercised when including mandibles from individuals showing loss of molar occlusion in morphological studies. Am J Phys Anthropol 152:383–392, 2013. © 2013 Wiley Periodicals, Inc.     

Morphological variation in adult chimpanzees (Pan troglodytes verus) of the Taï National Park, Côte d'Ivoire

Twenty five adult chimpanzee skeletons (Pan troglodytes verus) of known age and sex (15 females, 10 males) from a long‐term study site in Taï National Park, Cote d'Ivoire present new data on variation. These skeletons provide a rare opportunity to measure the cranium and postcranium from the same individuals. We compare measurements and indices of the Taï sample with those of relatively complete Pan troglodytes schweinfurthii skeletons from Gombe National Park, Tanzania. Measurements of Pan paniscus are included as an outside comparison. The Taï and Gombe samples are analyzed by sex; combined sex samples are compared between the two groups, and the two sexes to each other. Taï females and males do not differ in most long bone lengths or in pelvic dimensions, but do differ significantly in cranial capacity, facial measurements, clavicle length, scapular breadth, and femur length. Gombe females and males differ significantly in some facial measurements and in scapular breadth. In combined sex samples, Taï individuals have lower cranial capacity, longer palate and mandible, and greater dimensions in the trunk and limb lengths. Taï females account for most of the variation; males differ from each other only in greater length of humerus and femur. The Taï skeletons provide new data for assessing individual variation and sexual dimorphism within and between populations and species. The combination of cranial and postcranial data provides a clearer picture of chimpanzee intraspecific and interspecific variation than can be gained from either data set alone. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.