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Coward, W. Mark; McConathy, Deirdre
doi: 10.1002/(SICI)1096-8644(199603)99:3<369::AID-AJPA1>3.0.CO;2-Spmid: 8850179
Three inferential morphometric methods, Euclidean distance matrix analysis (EDMA), Bookstein's edge‐matching method (EMM), and the Procrustes method, were applied to facial landmark data. A Monte Carlo simulation was conducted with three sample sizes, ranging from n = 10 to 50, to assess type I error rates and the power of the tests to detect group differences for two‐ and three‐dimensional representations of forms. Type I error rates for EMM were at or below nominal levels in both two and three dimensions. Procrustes in 2D and EDMA in 2D and 3D produced inflated type I error rates in all conditions, but approached acceptable levels with moderate cell sizes. Procrustes maintained error rates below the nominal levels in 2D. The power of EMM was high compared with the other methods in both 2D and 3D, but, conflicting EMM decisions were provided depending on which pair (2D) or triad (3D) of landmarks were selected as reference points. EDMA and Procrustes were more powerful in 2D data than for 3D data. Interpretation of these results must take into account that the data used in this simulation were selected because they represent real data that might have been collected during a study or experiment. These data had characteristics which violated assumptions central to the methods here with unequal variances about landmarks, correlated errors, and correlated landmark locations; therefore these results may not generalize to all conditions, such as cases with no violations of assumptions. This simulation demonstrates, however, limitations of each procedure that should be considered when making inferences about shape comparisons. © 1996 Wiley‐Liss, Inc.
Plavcan, J. Michael; Kelley, Jay
doi: 10.1002/(SICI)1096-8644(199603)99:3<379::AID-AJPA2>3.0.CO;2-Spmid: 8850180
A recently proposed model for canine reduction in hominid evolution (the “dual selection” model) suggests that canine reduction occurs as a result for incorporation of the canines into a functional incisal field. Among the evidence used to support this model are patterns of wear and occlusion of the canine teeth, particularly in female anthropoid primates. We examined wear and occlusal patterns of the canine teeth of 311 male and female anthropoid primates. We find no evidence that the canines are typically occluded tip‐to‐tip, or that they show wear patterns indicating a “gripping and pulling” function during food ingestion and processing. Furthermore, we do not find compelling evidence that the development of the mesial cristid is associated with canine reduction. While we agree that the mechanisms of selective pressures underlying canine reduction need to be investigated, the “dual selection” hypothesis is unsupported by comparative data. © 1996 Wiley‐Liss, Inc.
doi: 10.1002/(SICI)1096-8644(199603)99:3<389::AID-AJPA3>3.0.CO;2-Spmid: 8850181
Distance analysis and factor analysis, based on Q‐mode correlation coefficients, were applied to 23 craniofacial measurements in 1,802 recent and prehistoric crania from major geographical areas of the Old World. The major findings are as follows: 1) Australians show closer similarities to African populations than to Melanesians. 2) Recent Europeans align with East Asians, and early West Asians resemble Africans. 3) The Asian population complex with regional difference between northern and southern members is manifest. 4) Clinal variations of craniofacial features can be detected in the Afro‐European region on the one hand, and Australasian and East Asian region on the other hand. 5) The craniofacial variations of major geographical groups are not necessarily consistent with their geographical distribution pattern. This may be a sign that the evolutionary divergence in craniofacial shape among recent populations of different geographical areas is of a highly limited degree. Taking all of these into account, a single origin for anatomically modern humans is the most parsimonious interpretation of the craniofacial variations presented in this study. © 1996 Wiley‐Liss, Inc.
Fox, C. Lalueza; Martín, A. González; Civit, S. Vives
doi: 10.1002/(SICI)1096-8644(199603)99:3<413::AID-AJPA4>3.0.CO;2-Xpmid: 8850182
A multivariate analysis of four prehistoric and nine historic populations from the Iberian Peninsula and Balearic Islands with large sample sizes (n > 30 individuals for the neurocranium and n > 15 for the facial skeleton) is presented, considering 874 male and 557 female skulls and using 20 craniometric measurements. Cluster analyses have been undertaken using the squared Euclidean distance as a measure of proximity and the average linkage between groups (UPGMA), and neighbor‐joining algorithms as a branching method, and a bootstrap analysis was used to assess the robustness of the clustering topology. The study was complemented with a principal coordinate analysis and with the application of the Mantel test to measure the degree of correspondence between the information furnished by the female and the male samples. The analyses show that the main source of morphometric variability in the Iberian Peninsula is the Basque population. The second source of variation is provided by two populations (Muslims and Jews), different from the rest from an archaeological and cultural point of view, and can probably be attributed to influences from sub‐Saharan Africa. The massive deportations of the Jews in 1492 and of the Moors between the 15th and 17th centuries may have erased this source of variability from the present population of the Iberian Peninsula. The remaining studied populations, including samples from Castile, Cantabria, Andalusia, Catalonia and Balearic Islands, are grouped together, showing a notable morphological homogeneity, despite their temporal and geographic heterogeneity. These results are in general agreement with those obtained in synthetic maps, by analyzing multiple genetic markers. In such studies, the Basque population is described as the main source of genetic variability, not only in the Iberian Peninsula, but also in Western Europe. © 1996 Wiley‐Liss, Inc.
doi: 10.1002/(SICI)1096-8644(199603)99:3<429::AID-AJPA5>3.0.CO;2-Rpmid: 8850183
Fiber architecture of the extensor musculature of the knee and ankle is examined in two African guenon species—the semiterrestrial Cercopithecus aethiops, and the arboreal C. ascanius. Using histologic and microscopic techniques to measure lengths of sarcomeres, the original lengths of muscle fasciculi and angles of pinnation in quadriceps femoris and triceps surae are reconstructed from direct measurements on cadavers. Calculations of reduced physiological cross‐sectional area, mass/predicted effective tetanic tension, maximum excursion, and tendon length/fasciculus + tendon lengths are correlated to preferred locomotor modalities in the wild.
Blackwelder, Torina L.; Golub, Mari S.
doi: 10.1002/(SICI)1096-8644(199603)99:3<449::AID-AJPA6>3.0.CO;2-Rpmid: 8850184
In order to describe the timing and extent of accelerated pubertal weight gain in female rhesus, we examined a large colony data base consisting of over 10,000 weight records for animals between 1.5 and 3.0 years of age (menarche occurs at about 2.6 years). Average colony weights were determined by week of age from information on age at weighing. Cross‐sectional analyses with linear regression demonstrated an acceleration in weight increase from 196 to 231 weeks (28–33 months) when colony weights increased 381 g/12 weeks as opposed to an average of 193 and 203 g, respectively, during the preceding and succeeding age intervals of the same length. Longitudinal analyses (n = 428) indicated that maximum individual growth velocity averaged 499 ± 18 g/12 weeks and occurred at 119 ± 5.6 weeks (29.7 ± 0.2 months) of age. Nonlinear modeling with the Gompertz function indicated that decelerating growth rates seen at earlier ages were not characteristic of the period of accelerated pubertal growth. © 1996 Wiley‐Liss, Inc.
doi: 10.1002/(SICI)1096-8644(199603)99:3<455::AID-AJPA7>3.0.CO;2-Vpmid: 8850185
Iron profiles of communities of hunter‐gatherers and former hunter‐gatherers conducted between 1969 and 1987 at Dobe in the Kalahari Desert of Botswana exhibited pronounced differences during periods of rapid culture change. The loss of good health and particularly the increase in anemia through time was attributed to notable changes in diet, although changes in mobility patterns were considered a secondary cause. In 1988 and 1989, studies were conducted at Kutse, also in the Kalahari Desert of Botswana, to ascertain the frequency of anemia at a recently sedentary community in which residents still relied primarily on wild animals for meat. Although not identical, the hematological presentation in 1989 was similar to that in 1988. The studies together suggest that our findings characterize the pattern of health and disease at Kutse, which is unrelated to any specific year or to diet. Additional measures of disease, specifically ESR (erythrocyte sedimentation rate) and oral temperatures, support an interpretation of anemia of chronic disease as the cause of hypoferremia at Kutse. Morbidity is high, in spite of adequate diets, because the residents are transitional from a nomadic to a sedentary lifestyle and from a relatively dispersed to an aggregated settlement pattern. These changes have introduced new health problems. © 1996 Wiley‐Liss, Inc.
Loth, Susan R.; Henneberg, Maciej
doi: 10.1002/(SICI)1096-8644(199603)99:3<473::AID-AJPA8>3.0.CO;2-Xpmid: 8850186
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.
Conroy, Glenn C.; Senut, Brigitte; Gommery, Dominique; Pickford, Martin; Mein, Pierre
doi: 10.1002/(SICI)1096-8644(199603)99:3<487::AID-AJPA9>3.0.CO;2-Tpmid: 8850187
Miocene primates from southern Africa are extremely rare. For this reason we wish to place on record several interesting new fossil primate specimens recently recovered from the Miocene sites of Berg Aukas and Harasib in the Otavi Mountain region of northern Namibia. The new finds consist of a virtually complete atlas vertebra from Berg Aukas attributable to the hominoid Otavipithecus namibiensis and two teeth and four postcranial fragments from Harasib referrable to Cercopithecoidea. The atlas vertebra exhibits anatomical characteristics intermediate between those of modern cercopithecoids and hominoids which may be indicative of a transition from pronograde to orthograde postures. The cercopithecoid remains show that the earliest Old World monkeys known from southern Africa were small, approximately the size of vervet monkeys. These new specimens are important because they provide the first evidence relating to possible positional behaviors of Otavipithecus and the earliest fossil record of cercopithecoids from southern Africa. © 1996 Wiley‐Liss, Inc.
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