American Journal of Physical Anthropology

doi: 10.1002/ajpa.1330750101pmid: N/A

Hildebolt, Charles F.; Molnar, Stephen; Elvin‐Lewis, Memory; McKee, Jeffrey K.

doi: 10.1002/ajpa.1330750102pmid: 3277443

In previous epidemiological studies, it has been suggested that geochemical factors besides fluoride may affect the prevalences of dental diseases. Our objective in this study was to determine whether the prevalences of periodontal diseases, coronal caries, and root caries for prehistoric inhabitants vary between geochemical regions of the state of Missouri. Burial sites were located on unique maps that depict geochemical variation among regions of the state. Data on dental caries and alveolar bone loss were gathered from 179 of the best preserved skeletal remains of the Late Woodland (A.D. 400–900) and Mississippian (A.D. 900–1700) periods. Mean caries scores and proportions of individuals with caries were calculated for these geochemical regions. Average alveolar bone loss was regressed on age for the individuals of these regions. Significant differences in caries and bone loss were found between several regions. These differences cannot be adequately explained by fluoride concentrations or by diet. It is suggested that geochemical factors, in addition to fluoride, may have affected the prevalences of dental diseases.

Trinkaus, Erik; Churchill, Steven E.

doi: 10.1002/ajpa.1330750103pmid: 3124631

Examination of adult and immature Neandertal radii demonstrates that the medial versus anterior orientations of their radial tuberosities fall within recent human ranges of variation, but on the average their radial tuberosities are significantly more medially, as opposed to anteromedially, oriented. This more posterior positioning of their radial tuberosities implies a maintenance of an effective moment arm for M. biceps brachii through the full range of supination, an interpretation which fits with the hypertrophy of and increased moment arms for their forearm pronator muscles. It is an additional indication of the muscular hypertrophy evident elsewhere in Neandertal upper limbs.

Cook, Megan; Molto, El; Anderson, Colin

doi: 10.1002/ajpa.1330750104pmid: 3277446

A histomorphometric study of thin femoral head sections of a skeletal sample from the Dakhleh Oasis, Egypt, dated from circa 36 B.C. to 400 A.D., identified an adult female (Dk31‐A1) in her mid‐50s with a high percentage resorption surface with tunneling resorption as is typically found in hyperparathyroidism. Five static histomorphometric bone parameters were measured with the following results for this individual: 1) mean wall thickness, 41.94 μm, 2) trabecular bone volume, 18.54%, 3) surface volume, 4,070 mm2/cm3, 4) mean trabecular diameter, 132 μm, and 5) total resorption surface, 12.31%. The overall histomorphometric features and differential diagnosis support the diagnosis of hyperparathyroidism. We conclude that histomorphometry of dried bone, particularly in this case where preservation is ideal, is a valuable investigative technique for palaeopathology.

Field, L. Leigh; Surje, Sira; Ray, Ajit K.

doi: 10.1002/ajpa.1330750105pmid: 3341455

The populations of India are genetically diverse, both within and between geographic regions; immunoglobulin (GM) allotypes provide important information on genetic differences between populations, since the frequencies of combinations of allotypes (termed “haplotypes”) vary dramatically among ethnic groups. As part of a project to assess genetic diversity among defined Indian populations, we have examined eight GM allotypes in a sample of 101 unrelated Sikhs who have migrated to Toronto, Canada: Glm(1, 2, 3, 17) and G3m (5, 15, 16, 21). Sikhs are a religious group that arose in the Punjab about 1500 A.D.; most of the original converts are believed to have been middle to upper‐middle caste Hindus. Gm allotyping showed that six Gm haplotypes occurred at polymorphic frequencies (>0.01) in Sikhs: Gm3;5, Gm1,17;21, Gm1,2,17;21, Gm1,17;5, Gm1,17;15,16, and Gm1,3;5. These haplotypes have all been previously reported in Indian populations. The frequencies of the first four haplotypes resembled the published frequencies for lower‐caste Hindus of NW India more than upper‐caste Hindus. However, the last two haplotypes have been found only in upper‐caste Hindus. The frequency of one of these, Gm1,17;15,16 was higher in Sikhs (0.09) than has been reported in any Indian population with the exception of Parsis (who are descended from Iranians). We speculate that the high frequency of this haplotype may have been characteristic of some of the Hindu castes in the Punjab from which Sikhs are descended.

Masters, Judith; Lubinsky, David

doi: 10.1002/ajpa.1330750106pmid: 3341456

Several studies conducted in diverse fields indicate the presence of a genetic discontinuity within the taxon Galago crassicaudatus E. Geoffroy—the thick‐tailed bushbaby. One of these areas is morphology. This contribution details a statistical analysis of skull material classified under this taxon in order 1) to confirm the objective existence of two morphotypes, and 2) to investigate the characters that allow the skull types to be distinguished. Emphasis is placed on multivariate techniques, although univariate and bivariate techniques are included where they are felt to be appropriate. All statistical analyses point to the reality of the morphological discontinuity between the groups. This is true even when size considerations have been reduced by rescaling the data. The results support separation of the populations at a specific level: G. crassicaudatus and G. garnettii. In addition, the structural changes observed in the two taxa—including an increase in overall size in G. crassicaudatus—are indicative of a divergence in preferred habitats: G. garnettii is adapted to more mesic environmental conditions, and to a softer, less fibrous diet than is its more robust sibling.

Abitbol, M. Maurice

doi: 10.1002/ajpa.1330750107pmid: 3124632

Study of the pelvis in 143 different mammals reveals that in quadrupeds the ischial spines are barely noticeable and are located posteriorly near the sacrum. In humans, the ischial spines are prominent and more anteriorly located. As a consequence of their position and size, the ischial spines in humans become an obstacle to parturition. Herein a theory is proposed to account for what appears to be an incongruous development and orientation of the ischial spines in humans. The pelvic diaphragm is a vertical pelvic “wall” in tailed mammals and is composed of muscles involved mostly with the motion of the tail. In humans, the muscles of the pelvic diaphragm have a very different anatomical orientation. They form a horizontal pelvic “floor,” and their functions are first to support the abdominopelvic organs and resist intra‐abdominal pressure that is exerted from above, and second, as levator ani, to control the anal sphincter. In humans the muscles and fascias of the pelvic diaphragm are inserted on the ischial spines either directly or indirectly through the sacrospinous ligament and the tendinous arch of the pelvic fascia. The result is a medial pull on the ischial spines to produce a more rigid and narrower pelvic floor. An inconstant ossification center for the ischial spines make them more prominent. The backward tilt of the sacrum placed the bispinal line in a diameter position. Pongids and even fossil hominids occupy an intermediate postion between tailed mammals and Homo sapiens. The present form of the pelvis in Homo sapiens may be determined by a significant genetic component but may also be partly acquired during childhood and adolescence.

Bräuer, Günter; Mehlman, Michael J.

doi: 10.1002/ajpa.1330750108pmid: 3124633

Three hominid molars were recovered from a depth of 7.0–7.1 meters in the Mumba Shelter at Lake Eyasi, northern Tanzania. Geological context of the finds and archaeological data indicate that people with a Middle Stone Age technology were using the Mumba locality intermittently whenever retreat of lake waters allowed access to the site. Uranium series dates suggest an age on the order of 130,000 years bp for the teeth and stone tools. Based on morphological analyses, the dental remains probably belonged to one individual and appear to be the crowns of two upper permanent M2s and one lower permanent M2. Crown areas are very small, even in comparison to the variation exhibited by recent African populations. Crown patterns have no archaic features. These teeth are smaller than any verifiable archaic Homo sapiens examples; thus, they may represent early anatomically modern Homo sapiens.

Greksa, Lawrence P.; Spielvogel, Hilde; Paz‐Zamora, Mario; Caceres, Esperanza; Paredes‐Fernández, Luis

doi: 10.1002/ajpa.1330750109pmid: 3341457

The forced vital capacity (FVC), forced expiratory volume in one second (FEV), and ratio of FEV to FVC (%FEV) of 161 male and 158 female youths of European ancestry who were born at high altitudes and who were residing in La Paz, Bolivia (average altitude of 3,600 m) were examined and compared with those for lowland Europeans and highland Aymara Amerindians. FVC and FEV were significantly larger (p < .001) in the La Paz Europeans than in two lowland control samples of European ancestry, with the relative differences between samples varying from small (1.5–4.1%) to moderate (7.7–11.9%). It could not be determined whether the enhanced lung volumes of the La Paz European children were acquired through an accelerated development of lung volumes relative to stature during adolescence, as is the case for Amerindian highlanders. After controlling for body and chest size, FVC and FEV were significantly smaller in the La Paz Europeans than in highland Aymara (p < .001), suggesting that the lung volumes of the Aymara are influenced by factors other than simply growth and development at high altitude. Finally, as found in Amerindians, chest size is an important determinant of intra‐individual variation in lung function among highland Europeans.

Harris, Edward F.; Bailit, Howard L.

doi: 10.1002/ajpa.1330750110pmid: 3341458

It has long been recognized that tooth crown diameters in hominoids are all positively intercorrelated one with another. This study reports on sex‐specific correlation matrices derived from 2,650 individuals from the Solomon Islands, Melanesia. Mesiodistal and buccolingual diameters of all permanent teeth from one side are used, excluding third molars. Analysis discloses significant sex dimorphism in the strengths of the intercorrelations, with females being better integrated. Principal components analysis (PCA) provides an objective means of data reduction (shown here to be preferable to simple size summation methods) and decorrelation of the resulting linear combinations. Four components are extracted (with results being virtually identical in the two sexes) and arguments are put forth that varimax rotation to “a simpler solution” may be counterproductive. Before rotation, the four components are 1) overall size, 2) buccolingual widths contrasted with mesiodistal lengths, 3) anterior (I,C) contrasted with posterior (P,M) teeth, and 4) premolars contrasted with molars. Most of the explained (shared) variance (63%) extracted by PCA is in overall size of the dentition. There is a strong urge to view the results of these principal components analyses as reflective of biologically and genetically meaningful entities.