bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ratios as a size adjustment in morphometrics
Authors: Albrecht Gene H. , Gelvin Bruce R. , Hartman Steve E. 
Published: February 2006

AbstractSimple ratios in which a measurement variable is divided by a size variable are commonly used but known to be inadequate for eliminating size correlations from morphometric data. Deficiencies in the simple ratio can be alleviated by incorporating regression coefficients describing the bivariate relationship between the measurement and size variables. Recommendations have included: 1) subtracting the regression intercept to force the bivariate relationship through the origin (intercept‐adjusted ratios); 2) exponentiating either the measurement or the size variable using an allometry coefficient to achieve linearity (allometrically adjusted ratios); or 3) both subtracting the intercept and exponentiating (fully adjusted ratios). These three strategies for deriving size‐adjusted ratios imply different data models for describing the bivariate relationship between the measurement and size variables (i.e., the linear, simple allometric, and full allometric models, respectively). Algebraic rearrangement of the equation associated with each data model leads to a correctly formulated adjusted ratio whose expected value is constant (i.e., size correlation is eliminated). Alternatively, simple algebra can be used to derive an expected value function for assessing whether any proposed ratio formula is effective in eliminating size correlations. Some published ratio adjustments were incorrectly formulated as indicated by expected values that remain a function of size after ratio transformation. Regression coefficients incorporated into adjusted ratios must be estimated using least‐squares regression of the measurement variable on the size variable. Use of parameters estimated by any other regression technique (e.g., major axis or reduced major axis) results in residual correlations between size and the adjusted measurement variable. Correctly formulated adjusted ratios, whose parameters are estimated by least‐squares methods, do control for size correlations. The size‐adjusted results are similar to those based on analysis of least‐squares residuals from the regression of the measurement on the size variable. However, adjusted ratios introduce size‐related changes in distributional characteristics (variances) that differentially alter relationships among animals in different size classes. © 1993 Wiley‐Liss, Inc.
Linear measurements of cortical bone and dental enamel by computed tomography: Applications and problems
Authors: Spoor C. Fred , Zonneveld Frans W. , Macho Gabriele A. 
Published: February 2006

AbstractThis paper explores the potential of high‐resolution computed tomography (CT) as a morphometric tool in paleoanthropology. The accuracy of linear measurements of enamel thickness and cortical bone thickness taken from CT scans is evaluated by making comparison with measurements taken directly from physical sections. The measurements of cortical bone are taken on extant and fossil specimens with and without attached matrix, and the dental specimens studied include a sample of 12 extant human molars. Local CT numbers (representing X‐ray, attenuation) are used to determine the exact position of the boundaries of a structure. Using this technique most studied dimensions, including four of human molar enamel thickness, could be obtained from CT scans with a maximum error range of ±0.1 mm. The limitations of the method are discussed with special reference to problems associated with highly mineralized fossils. © 1993 Wiley‐Liss, Inc.
Orientation of the masseter muscle and the curve of Spee in relation to crushing forces on the molar teeth of primates
Authors: Osborn J. W. 
Published: February 2006

AbstractA highly significant correlation is demonstrated between the forward inclination of the superficial masseter muscle and the forward tilt of molar teeth in the sagittal plane, conforming to the posterior end of the curve of Spee. The skulls studied included New and Old World monkeys, anthropoid apes, man, and a selection of other mammals. There was a wide variation between the angles measured in different animals (from 54° to 115°). The tilt of the curve of Spee increases the crush/shear ratio of the force produced on food between the posterior molars. The parallel tilt of superficial masseter maximizes the efficiency with which this muscle contributes to the crush component of the bite force in the sagittal plane. © 1993 Wiley‐Liss, Inc.
Taxonomic affinity of the early Homo cranium from Swartkrans, South Africa
Authors: Grine F. E. , Demes B. , Jungers W. L. , Cole T. M. 
Published: February 2006

AbstractA quantitative analysis that employs randomization methods and distance statistics has been undertaken in an attempt to clarify the taxonomic affinities of the partial Homo cranium (SK 847) from Member 1 of the Swartkrans Formation. Although SK 847 has been argued to represent early H. erectus, exact randomization tests reveal that the magnitude of differences between it and two crania that have been attributed to that taxon (KNM‐ER 3733 and KNM‐WT 15000) is highly unlikely to be encountered in a modern human sample drawn from eastern and southern Africa. Some of the variables that differentiate SK 847 from the two early H. erectus crania (e. g., nasal breadth, frontal breadth, mastoid process size) have been considered to be relevant characters in the definition of that taxon. Just as the significant differences between SK 847 and the two early H. erectus crania make attribution of the Swartkrans specimen to that taxon unlikely, the linkage of SK 847 to KNM‐ER 1813, and especially Stw 53, suggests that the Swartkrans cranium may have its closest affinity with H. habilis sensu lato. Differences from KNM‐ER 1813, however, hint that the South African fossils may represent a species of early Homo that has not been sampled in the Plio‐Pleistocene of eastern Africa. The similarity of SK 847 and Stw 53 may support faunal evidence which suggests that Sterkfontein Member 5 and Swartkrans Member 1 are of similar geochronological age. © 1993 Wiley‐Liss, Inc.
Interpretation of low body mass indices: Australian aborigines
Authors: Norgan N. G. 
Published: February 2006

AbstractLow body mass index (BMI kg/m2) has been proposed as a practical measure of energy undernutrition although it has some well‐known limitations. Some reports have suggested that those Australian Aborigines living a largely traditional way of life have low BMI without compromised health status and may have paradoxically high levels of subcutaneous adipose tissue.The evidence for low BMI, in Australian Aborigines is reviewed from the mean data of 1,174 individuals in 26 groups of adults and from the individual data of 349 of these individuals, collected before 1970. Three of the nine groups of women had mean BMI less than 18.5 kg/m2 and 4% of the individual men and 14% of the individual women had values less than 16kg/m2, a value regarded as indicating severe chronic energy deficiency. Skinfold thicknesses were greater than expected from the BMI, suggesting paradoxically high subcutaneous fatness. The contribution of long‐leggedness to low BMI was estimated from the regression of BMI on the sitting height to stature ratio (SH/S). For the 26 groups, this was estimated to be 2 kg/m2, r2 = 31%. The relationship was weaker with the individual data, r2 = 15%. Body shape as evinced by low SH/S does contribute to low BMI in these Australian Aborigines. Single cut‐offs of BMI are not applicable to all population groups and allowance may have to be made for body form when using BMI to assess nutritional status. © 1994 Wiley‐Liss, Inc.
Morphological adaptation to diet in platyrrhine primates
Authors: Anapol Fred , Lee Sarah 
Published: February 2006

AbstractMorphological features of the jaws and teeth are examined in eight species of platyrrhine monkeys that coexist in the Suriname rainforest. Z‐scores calculated from geometric predictions for several features of the feeding apparatus thought to have some functional significance (e. g., tooth dimensions, jaw robusticity, leverage of primary jaw elevators) are compared to a profile of the naturalistic dietary behavior of these species (i. e., proportions of fruit mesocarp, seeds, leaves, and fauna eaten).Several features are found exclusively in those platyrrhines whose dietary preferences are the most limited. Such specializations appear to be associated with a particular protein source exploited by a species to supplement a largely frugivorous diet. Ateles paniscus, which feeds primarily on the mesocarp of ripe fruit, has an adaptive morphology that emphasizes broad incisors. Chiropotes satanas (and to a slightly lesser extent, Pithecia pithecia) is a frugivore/seed predator with large upper and lower canines and a robust mandible. The frugivore/folivore Alouatta seniculus has a relatively large total molar area and effective mandibular condyle height. In all four of these strictly vegetarian species, the leverage of the masseter muscle is greater than that of temporalis.Of the omnivorous species, Cebus apella and C. nigrivittatus exploit both fauna and seeds for protein and exhibit an array of many of the above features, such as large teeth and thick mandibles. Saimiri sciureus, not particularly known for seed predation, departs from Cebus in having less robust canines and a more gracile mandible. All three cebid omnivores have a temporalis with greater leverage than the masseter, indicating a requirement for resisting anteriorly directed forces, for example, using the jaws for vigorous foraging. The lack of any enlarged features, other than incisors, in the omnivorous Saguinus midas may be attributable to the functional constraints of small body size. Because the small size of the gape limits the size of the food parcel ingested, a requirement to enlarge other dentomandibular structures for trituration is alleviated.
The skull attributed to Mozart—craniosynostosis or not?
Authors: Hauser Gertrud , Kritscher Herbert 
Published: February 2006

AbstractThe results of a detailed morphological analysis of the skull attributed to Mozart are presented which refute a recent claim that the skull as well as several of Mozart's portraits show indications of uncomplicated trigonocephaly. These indications according to the present analysis are within the limits of normal variation and derive from retention of part of the long arm of the anterior fontanelle.
Locomotion in captive Leontopithecus and Callimico: A multimedia study
Authors: Rosenberger Alfred L. , Stafford Brian J. 
Published: February 2006

AbstractVideo studies, gait analysis, footprint tracks, and observational scan sampling show that, in comparably furnished enclosures, Leontopithecus rosalia and Callimico goeldii are superficially similar in their use of predefined locomotor patterns but differ profoundly in many underlying details which reflect differences in postcranial morphology. Each uses pronograde arboreal quadrupedal walking, quadrupedal bounding, and vertical climbing with comparable frequency, and both shift to bounding while moving quadrupedally at high speeds. In walking, both species use a diagonal sequence gait. However, in Callimico the distance per bout traveled while walking or running is shorter than in L. rosalia and there is an emphasis on leaping (from a stationary position) and bounding‐leaps (saltational extensions of pronograde quadrupedalism), in contrast with the basically quadrupedal style of L. rosalia. This dichotomy is consistent with anatomical specializations, such as forelimb elongation in Leontopithecus and hindlimb elongation in Callimico. In vivo hand‐ and footprint studies demonstrate grasping halluces in both species while walking. Limb stances in L. rosalia during “transaxial bounding” involve an overstriding hindlimb, a predominance of oblique rather than in‐line travel, and unique hand and foot positions. Anatomically, this locomotor style may be associated with reduced dexterity of the elongate hands and a relatively short hallux. The captive locomotor profiles for both species probably reflect biased samples of the locomotor repertoire of their wild counterparts. Nevertheless, these data reflect species‐specific integrations of locomotor behavior and morphology, and corroborate expectations of locomotor diversity among callitrichine primates, even those of similar body size. It is suggested, however, that conventional quantitative studies of locomotor profiles may prove inadequate for resolving subtle aspects of locomotor morphology and behavior. © 1994 Wiley‐Liss, Inc.
Articular structure and function in Hylobates, Colobus, and Papio
Authors: Rafferty Katherine L. , Ruff Christopher B. 
Published: February 2006

AbstractIt has been demonstrated in clinical and experimental studies that subarticular trabecular bone responds to mechanical loads transmitted across joints through changes in mass and structural organization. We investigated differences in mass, volume, and density of subarticular trabecular bone of the humeral and femoral head in Hylobates syndactylus, Colobus guereza, and Papio cynocephalus. Our hypothesis was that variations in trabecular properties between taxa may reflect differences in mechanical loading associated with different locomotor repertoires. A nondestructive method for measuring trabecular properties using optical luminance data measured from radiographs was developed. We also examined the relationship between internal trabecular properties and the external size and surface area of the humeral and femoral heads in these taxa. Our results suggest that internal and external articular structure are relatively independent of each other and may be adapted to different aspects of the mechanical environment. Differences in trabecular mass between taxa appear to correspond to differences in the magnitudes of mechanical loads borne by the joint, whereas aritcular volume and surface area are related primarily to differences in joint mobility. Because of the apparent physiological “de‐coupling” of articular mass and volume, variations in articular density (mass/volume) are difficult to interpret in isolation. Comparisons of internal and external articular structure may provide new ways to reconstruct the locomotor/positional behavior of extinct taxa. © 1994 Wiley‐Liss, Inc.
Human dento‐gnathic metric variation in mesolithic/neolithic Ukraine: Possible evidence of demic diffusion in the Dnieper Rapids region
Authors: Jacobs Kenneth 
Published: February 2006

AbstractDental and gnathic metrics from a series of Mesolithic and Neolithic cemetery samples in the Dnieper River valley (Ukraine) are compared. Both male and female Neolithic samples have larger dental dimensions, wider dental arcades, and a more robust mandibular corpus than do the Mesolithic samples. In addition, the relative variances (RVs) of bucco‐lingual dental breadths (as measured by modified Levene's Tests) show an intriguing pattern of change from the Mesolithic into and through the Neolithic. Female RVs show a clear tenency to increase through time, while male RVs show more mixed tendencies. Such a pattern indicates that the increases in Ukrainian Neolithic dento‐gnathic dimensions are plausibly attributable to low intensity gene flow (demic diffusion). Seen in the light of new chronometric, paleodietary, and paleolinguistic information, as well as in the context of recent archaeological models for agro‐pastoralist origins in the North Pontic, these data suggest that gene flow via population interactions originating in or transient through the circum‐Caucasus may have played an important role in producing the Ukrainian Neolithic dental increase. © 1994 Wiley‐Liss, Inc.
Maternal mortality or prolonged growth: Age at death and pelvic size in three prehistoric Amerindian populations
Authors: Tague Robert G. 
Published: February 2006

AbstractThis study evaluates the relationship between age at death and pelvic size among adults in three prehistoric Amerindian populations. The issue is to identify if the pelvis continues to grow and remodel in adulthood, or if there is differential survivorship among adults, particularly among females, based on pelvic size. The samples used in this study are Indian Knoll, Pecos Pueblo, and Libben. Twenty‐one measures of the pelvis are analyzed. A correlational analysis among individuals 18 years of age and older shows that the subpubic angle narrows with advancing age in both sexes. The suggested etiology is osteophytic growth on the ischiopubic ramus among older adults. A two‐sample test comparing younger (ages 18–24) and older (25 years of age and older) adults shows that the linea terminalis (which represents the pubic and iliac components of the pelvic inlet) is significantly shorter in the younger age group, but this pattern is seen only in females. Two interpretations are consistent with this result. First, a female with a short linea terminalis (i. e., small pelvic inlet) may have died at a young age due to childbirth‐related complications. In prehistory, maternal mortality may have been a leading cause of death, with pelvic inlet capacity being a determinant of survivorship among parturients. Second, the linea terminalis may be unique by continuing to grow in early adulthood in females but not in males; the growth occurs at the medial border of the pubis. Longitudinal growth studies of modern humans provide support for the second interpretation. The selective advantage of a later age at maturation of the pubis in females than males is that the period of growth is prolonged, thereby contributing to sexual dimorphism in pubic length and, correspondingly, linea terminalis length and pelvic inlet circumference. © 1994 Wiley‐Liss, Inc.
Craniometric variation among modern human populations
Authors: Relethford John H. 
Published: February 2006

AbstractPrevious studies of genetic markers and mitochondrial DNA have found that the amount of variation among major geographic groupings of Homo sapiens is relatively low, accounting for roughly 10% of total variation. This conclusion has had implications for the study of human variation and consideration of alternative models for the origin of modern humans. By contrast, it has often been assumed that the level of among‐group variation for morphological traits is much higher. This study examines the level of among‐group variation based on Craniometric data from a large sample of modern humans originally collected by W. W. Howells. A multivariate method based on quantitative genetics theory was used to provide an estimate of FST — a measure of among‐group variation that can be compared with results from studies of genetic markers. Data for 57 Craniometric variables on 1,734 crania were analyzed. These data represent six core areas: Europe, Sub‐Saharan Africa, Australasia, Polynesia, the Americas, and the Far East. An additional set of analyses was performed using a three‐region subset (Europe, Sub‐Saharan Africa, and the Far East) to provide comparability with several genetic studies.The minimum FST (assuming complete heritability) for the three‐region analysis is 0.065, and the minimum FST for the six‐region analysis is 0.085. Both of these are less than the average FST from genetic studies (average estimates of 0.10–0.11). The smaller value of the minimum FST estimates is expected since it provides an estimate of FST expected under complete heritability. Using an estimate of average craniometric heritability from the literature provides an estimate of FST of 0.112 for the three‐region analysis and 0.144 for the six‐region analysis. These results show that genetic and craniometric data are in agreement, qualitatively and quantitatively, and that there is limited variation in modern humans among major geographic regions. © 1994 Wiley‐Liss, Inc.
Altitude, language, and class I HLA allele frequencies in Papua New Guinea
Authors: Smith Tom , Bhatia Kuldeep , Prasad Madhuri , Koki George , Alpers Michael 
Published: February 2006

AbstractClass I HLA gene frequencies show considerable variation over short geographical distances in Papua New Guinea. Hypotheses to account for this invoke natural selection, population structure, the pattern of population movement, or past demographic changes. To determine the role of the various factors in shaping this distribution, we have studied correlations between HLA‐based genetic distances, geographical distances, altitude, and linguistic differences in Papua New Guinea. Linguistic differences at the family or stock level within the Trans‐New Guinea Phylum generally correspond to genetic differences. However, on the basis of their HLA gene frequencies, speakers of Austronesian (AN) languages do not form a distinct group of populations. Linguistic variation and spatial autocorrelation do not fully account for the altitudinal cline differences noted in gene frequencies, particularly at the HLA‐A locus. We propose that the distribution of HLA gene frequencies in Papua New Guinea is partially under the control of selection operating differentially along the altitude gradient. © 1994 Wiley‐Liss, Inc.
Early ontogeny of the human femoral bicondylar angle
Authors: Tardieu Christine , Trinkaus Erik 
Published: February 2006

AbstractThe presence of a femoral bicondylar angle consistently and significantly greater than 0° has been a hallmark of hominid bipedality, but its pattern of development has not been documented. We have therefore compiled cross‐sectional data on the development of the articular bicondylar angle for a clinical sample of modern humans and of the metaphyseal bicondylar angle for two Recent human skeletal samples, one predominantly European in origin and the other Amerindian. All three samples exhibit a pattern of a bicondylar angle of 0° at birth and then a steady average increase in the angle from late in the first year postnatal, through infancy, and into the juvenile years. The two skeletal samples reach low adult values by approximately 4 years postnatal, whereas the clinical sample with a lowered activity level appears to attain consistent adult values slightly later (approximately 6 years postnatal). In addition, two modern human individuals, one nonambulatory and the other minimally ambulatory, show no and little development, respectively, of a bicondylar angle. These data, in conjunction with clinical and experimental observations on the potential and form of angular changes during epiphyseal growth, establish a high degree of potential for plasticity in the development of the human bicondylar angle and the direct association of a bipedal locomotion and (especially) posture with the developmental emergence of a human femoral bicondylar angle. © 1994 Wiley‐Liss, Inc.
Social implications of gummivory in marmosets
Authors: Harrison Mary L. , Tardif Suzette D. 
Published: February 2006

AbstractGummivory or exudate feeding is a major dietary specialization which has received relatively little attention in the literature. While plant exudates contribute to the diet of many primate species, we suggest that the callitrichid speciesCebuella pygmaeaandCallithrix jacchus are obligateexudate feeders under free‐ranging conditions.Callithrix jacchusprovides an excellent model for examining the effects of exudate feeding and foraging upon social behavior, since other callitrichid species of similar body size do not share this dietary specialization. We review the effects of exudate foraging on specific social behaviors observed both in field and laboratory populations ofC. jacchus. By comparing this species to closely related species, exudate foraging is seen to (1) be retained under laboratory conditions, (2) increase the frequency of territorial marking behavior while decreasing the frequency of overt aggression in males, (3) decrease the duration of infant care, and (4) increase the number of nonadults in social groups but not affect group size. The evidence presented supports the hypothesis that the consequences of exudate foraging inC. jacchusare fundamental and socially complex. © 1994 Wiley‐Liss, Inc.