bluuebunny/crossref_metadata_2025_split huggingface dataset:
Social organization of the pygmy chimpanzee (Pan paniscus): Multivariate analysis of intracommunity associations
Authors: White Frances J. , Burgman Mark A. 
Published: February 2006

AbstractWe examined association patterns of wild, nonprovisioned pygmy chimpanzees in the central rain forest of Zaire. Associations among individuals within two communities (Hedons and Rangers) and one splinter group (Blobs) were described using two measures: the proportion of time spent together in parties, and the proportion of time spent in close proximity while feeding. Patterns were exposed using multivariate analysis and tested using nonparametric (Mantel) tests. Associations among females characterized the social interactions of both Hedons and Blobs. Associations among males, and between males and females, were common only for the Rangers. Parties of Blobs tended to be small (average size: 4), whereas parties of Hedons were of variable size (average: 7), and those of Rangers were predominantly large (average: 10). Thus, variation in association patterns corresponded loosely to differences in party size. Associations among females were most prevalent in small parties. By contrast, associations among males and between males and females were more apparent in large parties. This intracommunity correlation of social organization and party size parallels differences between the Lomako and Wamba study sites. This relationship may reflect the importance of female alliances when food is limited and the ability of single males to monopolize small, but not large, parties of associated females.
Effects of speed on forelimb joint angular displacement patterns in vervet monkeys (Cercopithecus aethiops)
Authors: Vilensky Joel A. , Gankiewicz Eva 
Published: February 2006

AbstractShoulder, elbow and wrist joint angular displacement patterns were analyzed for five vervet monkeys across increasing speed. Within symmetrical gaits, the peak positions of the pattern for each joint tended to decrease with increasing speed as did the yield angle of the elbow (more “yielding”). Across the walk(run)‐gallop transition there were no notable changes in the displacement patterns, but there was a consistent decrease in the range of elbow movements and an increase in the yield angle. Across asymmetrical gaits, there was also a tendency for some of the peak positions to decrease. These results are compared with those available for cats and dogs, and are interpreted relative to functional and neurological aspects of forelimb movements in primates.
Occlusal force and craniofacial biomechanics during growth in rhesus monkeys
Authors: Dechow Paul C. , Carlson David S. 
Published: February 2006

AbstractThe masticatory muscles in 132 anesthetized male and female rhesus monkeys ranging in age from juvenile to adult were unilaterally stimulated. Muscle forces and speeds were measured with a bite force transducer positioned at the incisors, premolars, and molars during twitch and tetanic contractions. Lateral cephalographs of all animals were used to estimate the orientation and mechanical advantage of the masticatory muscles. Results showed that maximal occlusal forces increased at a greater rate than body weight during growth. However, maximal occlusal forces increased isometrically relative to mandibular length. Mean forces at the incisors ranged from 70.3 newtons (n) in juveniles up to 139.9 n in adult males. Forces at the molars were 2–2.5 times greater than at the incisors. Time‐to‐peak tension decreased with increasing body size from 44.1 msec in juveniles to 37.4 msec in adult females to 31.0 msec in adult males. Regression analysis showed that adult males have faster muscles than adult females or juveniles even when corrected for body size. Temporalis and masseter orientation was found to change little throughout growth. The mechanical advantage of the masseter and temporalis muscles for producing occlusal forces on the distal molars improved between juveniles and adults, which is contrary to findings of Oyen et al. (Growth 43:174–187, 1979). Among adults, females had a greater mechanical advantage of the masseter muscles than males.
Stature estimation in prehistoric Native Americans of Ohio
Authors: Sciulli Paul W. , Schneider Kim N. , Mahaney Michael C. 
Published: February 2006

AbstractIn the present report we investigate stature estimation techniques in a sample of 64 (35 male, 29 female) prehistoric Native Americans from Ohio. Because living stature is unknown for these 64 individuals, we use Fully's (1956) anatomical method to provide the best estimates of living stature. In this method all osseous components of skeletal height are measured and soft tissue correction is added.Comparisons of regression equations commonly used for stature estimation in prehistoric Eastern Woodland Native American populations, but developed for East Asian and East Asian—derived populations (using lower extremity components), show that these commonly used equations consistently yield stature estimates 2 to 8 cm in excess of the best estimates from Fully's method.Based on the skeletal height measures of the 64 individuals in the present sample, we develop regression equations for the estimation of stature. These equations yield stature estimates virtually identical to estimates from Fully's method and may prove useful for stature reconstruction in other prehistoric Eastern Woodland Native American populations.
Opportunity for natural selection among the Indian populations
Authors: Reddy B. Mohan , Chopra Virendra P. 
Published: February 2006

AbstractA critical review of data on opportunity for natural selection among the Indian populations has been made. These data on 96 populations were analysed according to regional, habitat, and socioeconomic backgrounds. The trends observed on the basis of these Indian data have been compared with worldwide data and data from industrialized nations. As in the industrialized nations, a gradual decrease in Im and It is observed with improving socioeconomic and technological status in the Indian populations. The Indian situation is similar to that of the first phase in the modern demographic transition among the industrialized nations.
Age estimation from cortical index of the human clavicle in northwest Indians
Authors: Kaur Harbir , Jit Indar 
Published: February 2006

AbstractThe proportion of the cortical thickness to the total diameter of the bone (cortical index) was calculated in paired clavicles obtained from 128 male and 82 female medicolegal postmortem subjects who were apparently healthy prior to their accidental death. The ages of the subjects varied from 15 to 85 years. The clavicles were cut either horizontally or parasagittally, and measurements were taken at midclavicle. From the ages of 15 to 30 years, the cortical index increased. It decreased steadily thereafter, with an initial sharp decrease in the age group 31–40 years in both sexes. After the age of 40 years, this rapid decrease in the index continued in the females, but became slow and gradual in the males. Differences between left and right sides were statistically insignificant in both sexes (P > 0.05). However, the sexual differences were significant (P < 0.01) in the age groups from 41 years onwards.
Reliability of age at death in the hamann‐todd collection: Validity of subselection procedures used in blind tests of the summary age technique
Authors: Meindl Richard S. , Russell Katherine F. , Lovejoy C. Owen 
Published: February 2006

AbstractThe blind test procedures used by Lovejoy et al., (Am. J. Phys. Anthropol. 68:1–14, 1985a) have been criticized because they used the Hamann‐Todd collection as their known‐age population. It has been suggested that variation within this sample was reduced by selection procedures designed to ensure accuracy of age at death. Powerful statistical tests for differences in dispersion of ages for pubic symphyseal stages were applied to comparisons between their core sample (N = 238) and those of a large autopsy‐room collection used to develop the Suchey‐Brooks System (N = 530). The variances in ages of the selected Hamann‐Todd Sample are not reduced. The careful subselection of specimens has resulted in a valid statistical core sample for use in the development of aging methodologies.
Histologic examination of age of the first African Baptist Church adults
Authors: Ericksen M. F. , Stix A. I. 
Published: February 2006

AbstractThis study applies a recently formulated method of histologic estimation of age at death to samples of anterior femoral cortex taken from adult skeletons from the First African Baptist Church cemetery and compares the results with macroscopic age estimates made by J. L. Angel and J. O. Kelley. Of the 65 samples taken, 44 were sufficiently well preserved to produce readable thin sections, although most were so fragile that they had to be embedded before sectioning. In most cases the histologic ages agreed with the macroscopic age estimations within the standard error of the estimate of the histologic method. Most cases of disagreement could be attributed to poor preservation. Despite differences between individual gross and microscopic age estimates, the two methods proved to be significantly correlated and produced the same overall demographic picture of a population whose female members were likely to die at earlier ages than the males.
Tooth dislocation: The relationship with tooth wear and dental abscesses
Authors: Clarke Nigel G. , Hirsch Robert S. 
Published: February 2006

AbstractTooth dislocation (tilting) was recorded in 1,200 skulls from 34 museum collections. The findings of dislocation by tooth type, tooth wear, and abscess location are presented. A model for dislocation based upon the progressive loss of tooth support provides a rational explanation for the phenomenon. Physiological continuous tooth eruption was considered to account for a component of the progressive loss of tooth attachment. The process of attrition, pulp perforation, and dental abscess cavity formation resulted in further, more severe loss of tooth support. Heavy functional forces, in association with greatly reduced bone support, tilted the crown lingually and root buccally. When the tooth had tilted to such an extent that the root apices protruded from the bone and, presumably (in life) through the gingival/mucosal tissues, the infected root canals were effectively isolated from the internal environment. The tooth continued to function. The more typical consequence of severe attrition and dental abscess formation was tooth loss; it also isolated an infected tooth from living tissue, but without the benefit of retaining function.
Pressure erosion of the femoral trochlea, patella baja, and altered patellar surfaces
Authors: Mann Robert W. , Roberts Charlotte A. , Thomas Michael D. , Davy Dwight T. 
Published: February 2006

AbstractAs knee flexion increases, so do tendofemoral and patellofemoral compression forces. Three cases of long‐standing uncorrected flexion contractures of the knees are presented that resulted in marked erosion of the femoral trochlea, patella baja, and remodeled patellar articular surfaces likely reflecting increased angles of flexion. It is probable that the deep femoral grooves are the result of adaptation under high‐level persistent contact loads from the quadriceps tendon. These examples expand our knowledge of bone remodeling and offer information of potential use in studying ancient skeletal samples.
Premaxillary‐maxillary suture fusion and anterior nasal tubercle morphology in the chimpanzee
Authors: Mooney Mark P. , Siegel Michael I. 
Published: February 2006

AbstractThe anterior nasal spine (ANS) is considered by some to be a unique characteristic of modern humans; however, it has been reported to occur in chimpanzees. Among human populations, ANS size correlates with facial prognathism and timing of premaxillary‐maxillary sutural fusion, which may have implications for models of midfacial growth. To investigate these questions, skulls from 55 chimpanzees (Pan troglodytes) (29 male, 26 female), ranging in age from infants to adults, were examined. None of the 55 specimens examined had a true ANS, but a number of specimens exhibited raised anterior nasal prominences or tubercles (ANT) on the nasal surface of the premaxilla. Female specimens had significantly (P < .05) more ANTs and more extensive fusion of both the palatal and facial components of the suture than did the male specimens. Results from the present study document the presence of an ANT in a sample of chimpanzee crania and are consonant with associations predicted by a septal‐traction model of midfacial growth.
Masticatory‐stress hypotheses and the supraorbital region of primates
Authors: Hylander William L. , Johnson Kirk R. , Picq Pascal G. 
Published: February 2006

AbstractThe purpose of this study is to test various masticatory‐stress hypotheses about the evolution and function of well‐developed browridges of higher primates. This was done by measuring and analyzing patterns of in vivo bone strain recorded from three‐element rosette strain gages bonded to the supraorbital region and to other portions of the bony face of Macaca fascicularis and Papio anubis during mastication and incision. The magnitude and direction of the principal strains recorded support Endo's hypothesis that the supraorbital region during mastication and incision is bent in the frontal plane (Endo, 1966). Our data do not, however, support his hypothesis that the supraorbital region is bent more during incision than during mastication. The data also demonstrate that overall levels of supraorbital strain are not larger in more prognathic subjects. Most importantly, the data indicate that the supraorbital region of nonhuman catarrhines is strained very little during mastication and incision. This indicates that there is much more supraorbital bone than is necessary both to counter masticatory loads and to provide an adequate safety factor to failure for these loads. This in turn suggests that the macaque and baboon browridges can be considerably reduced in size and still maintain these required structural characteristics.Thus, our experiments provide no support whatsoever for those hypotheses that directly link browridge morphology to masticatory stress (cf. Endo, 1966; Russell, 1983, 1985). A recent review of Endo's original work indicates that this latter statement is also true for humans (Picq and Hylander, 1989). We conclude, therefore, that there is no good reason to believe that enlarged browridges in living and/or fossil primates are structural adaptations to counter intense masticatory forces.The evolution of browridge morphology in primates is best explained on the basis of factors related to the position of the brain relative to the orbits (Moss and Young, 1960). When these structures are widely separated, as in gorillas, the large intervening space must be bridged with bone. In addition, enough bone must be present within the supraorbital and bridged regions to prevent structural failure due to non‐masticatory external forces associated with highly active primates (e.g., accidental traumatic forces applied to the orbits and neurocranium). This requirement results in both pronounced browridges and in much more supraorbital bone than is necessary to counter routine cyclical stress during mastication and incision. This in turn explains why bone strains recorded from the supraorbital region are extremely small relative to other portions of the primate face during mastication and incision.
Effects of age and gender on the location and orientation of the foramen magnum in rhesus macaques (Macaca mulatta)
Authors: Masters Anne V. , Falk Dean , Gage Timothy B. 
Published: February 2006

AbstractEndocasts from 378 rhesus macaque skulls from the Cayo Santiago skeletal collection were measured to determine the effects of age and gender on the position and orientation of the foramen magnum. The foramen magnum migrates from a rostral to a caudal position and its angle changes during postnatal development. The angles and relative positions of the foramen magnum are similar for both genders of infants and for both genders of adults. However, analyses of linear response and plateau (LRP) functions reveal significant differences between males and females in the timing of reorientation of the angle and migration of the foramen magnum. The mean adult angle and relative position of the foramen magnum are reached by 4.7 years in females, but they do not achieve their adult values until 7.1 years in males. A similar pattern is observed for the brainstem region of the basicranium. Mean adult lengths of the brainstem region are reached at 5.2 years in females and 7.1 years in males. The relationships between cranial capacity, the growth pattern of the brainstem, and the pattern of change for the angle and the relative position of the foramen magnum are examined. Quantification of the effects of age and gender on the location of the foramen magnum in a large sample of endocasts from one species of higher primate has potential implications for research on human development, and for interpretation of juvenile specimens in the hominid fossil record.
Dental development in South African australopithecines. Part II: Dental stage assessment
Authors: Conroy Glenn C. , Vannier Michael W. 
Published: February 2006

AbstractDental development stages of six immature Australopithecus robustus individuals from Swarktrans (SK 61, SK 62, SK 63, SK 64, SK 438, SK 3978) and seven immature Australopithecus africanus individuals from Taung, Sterkfontein, and Makapans (Taung 1, Sts 2, Sts 8, Sts 18, Sts 24, Stw 327, MLD 2) are described. These stages were assessed using the system devised by Demirjian and colleagues and were based on a data set comprising over 350 computed tomographic (CT) scans taken at 1 and 2 mm slice intervals. It is concluded that patterns of dental development may have differed between A. robustus and A. africanus even though the chronology of development (i.e., the length of time for dental development to occur) may have proceeded relatively rapidly in both species. These data provide unique information regarding the timing and pattern of dental maturation in austral‐opithecines and can be used to compare and contrast developmental patterns among early hominids, modern humans, and nonhuman primates.
Perinatal dental development in the chimpanzee (Pan troglodytes)
Authors: Siebert Joseph R. , Swindler Daris R. 
Published: February 2006

AbstractThe synthesis of both ontogenetic and phylogenetic data should provide the ideal explanation of morphologic variation, but for the primate dentition, this has not yet occurred. Information concerning growth and development of primate teeth is lacking, in part because of the paucity of specimens. We have therefore examined the deciduous second molars (dm2) and tooth buds of the permanent first molar (M1) of 12 chimpanzees (Pan troglodytes), aged 6.5 months of gestation to 4 postnatal months. The ordering of cusp calcification was identical to that of other primates. By regression analysis, correlations of mesial and distal widths with buccal, lingual, and mesiodistal lengths were low, most probably because of decreased rates of change (slopes) and the relatively small sample size. Correlations were, however, greater for mandibular than for maxillary dentition and higher for age than for body weight; for both the dm2 and M1, distal moieties increased faster and were more highly correlated with other dental variables and age than were mesial ones. Comparison with data from humans revealed both differences and similarities in the absolute size and growth rate of dental moieties during the perinatal period. As the reasons for ontogenetic variation become understood for individuals, species, and higher taxa, the phylogenetic implications of differential growth should become clearer as well.
On thick and thin enamel in hominoids
Authors: Beynon A. D. , Dean M. C. , Reid D. J. 
Published: February 2006

AbstractMartin (1983, 1985) reviewed the significance of enamel thickness in hominoid evolution. He studied cut faces of hominoid teeth using the scanning electron microscope and related enamel prism packing patterns to both enamel formation rates and enamel thickness, although he did not present primary data on formation rates, which he summarised as being either “fast” or “slow.” Martin concluded that thick enamel formed at a fast rate represented the ancestral condition in the human and great ape clade. Thin enamel in African apes reflected a secondary reduction in secretion rates, with outer enamel being formed at a slow rate. The present study on ground sections of great ape and human teeth, using polarised light microscopy, was designed to measure the spacing between incremental growth lines in enamel, including striae of Retzius and prism cross striations, to determine rates of enamel formation in hominoids. Measurements on stria spacing showed that striae generally diverged as they passed outwards through enamel in all taxa. Cross‐striation spacings also increased from inner to outer enamel. Secretion rates did not fall into two exclusive categories but varied, giving a spectrum of values generally increasing from within outwards at any one crown level and reducing in cervical enamel. There was no evidence for a reduction in enamel formation rates in outer enamel among African apes. These findings cast doubt on the proposition that the common ancestor of great apes and man had thick enamel formed at a fast rate. It is possible that thin enamel was the primitive condition, in which case thick enamel in humans and in Sivapithecus is derived, suggesting that thick enamel on low cusped teeth evolved on more than one occasion.
Characteristics of hamadryas‐like male baboons living in anubis baboon troops in the Awash hybrid zone, Ethiopia
Authors: Phillips‐Conroy Jane E. , Jolly Clifford J. , Brett Frederick L. 
Published: February 2006

AbstractIn the twenty‐two years since the Awash baboon hybrid zone was first described, about 25–30 hamadryas or hamadryas‐like hybrid males have taken up residence in anubis baboon groups. Most enter as mature adults, though some may immigrate as juvenile followers. Long‐term tracking of known immigrants indicates that they may reside for four years or more in their adopted troop, during which time they establish a series of comparatively short‐term harems, and probably sire hybrid offspring. “Abductions” of anubis females to hamadryas troops, as postulated by early observers, were not seen, though their occurrence cannot be ruled out. Younger, more recent immigrants tend to be “purer” hamadryas in phenotype, perhaps reflecting a more distant origin, or a change in the composition of neighboring hamadryas populations: Coexisting hamadryas and anubis show no signs of reproductive isolation by behavioral barriers, and evidently belong to a single “recognition species”.