bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of light in human skin color variation
Authors: Quevedo W. C. , Fitzpatrick T. B. , Pathak M. A. , Jimbow K. 
Published: February 2006

AbstractThe major source of color in human skin derives from the presence within the epidermis of specialized melanin‐bearing organelles, the melanosomes. Tanning of human skin on exposure to ultraviolet light results from increased amounts of melanin within the epidermis. Melanosomes synthesized by melanocytes are acquired by keratinocytes and transported within them to the epidermal surface. In some cases, the melanosomes are catabolized en route. New information indicates that the multicellular epidermal melanin unit (melanocyte and associated pool of keratinocytes) rather than the melanocyte alone is the focal point for the control of melanin metabolism within mammalian epidermis. Gross human skin color derives from the visual impact of the summed melanin pigmentation of the many epidermal melanin units. In theory, constitutive skin color in man designates the genetically‐determined levels of melanin pigmentation developed in the absence of exposure to solar radiations or other environmental influences; facultative skin color or “tan” characterizes the increases in melanin pigmentation above the constitutive level induced by ultraviolet light. The details of genetic regulation of pigment metabolism within the epidermal melanin units are being clarified. In some mammals at least, the function of epidermal melanin units is significantly influenced by hormones which may be regulated by radiations received through the eyes. Based on an evolutionary history of the human family which exceeds ten million years, it is proposed that melanin pigmentation may have played a number of roles in human adaptations to changing biologic and physical environments.
Retinal pigmentation, visual acuity and brightness levels
Authors: Hoffman J. Michael 
Published: February 2006

AbstractThis study investigates the hypothesis that the degree of retinal pigmentation in the human eye is adaptive as it relates to the maintenance of visual acuity in optically stressful environments, deserts and snowfields. Eighty‐four subjects were examined, an estimation of their degree of retinal pigmentation made by ophthalmoscopic examination, and their binocular visual acuity tested over ten levels of brightness. The general level of retinal pigmentation did not influence mean visual acuity within the levels of brightness used in this study. The hypothesis was, therefore, rejected, but with the proviso that this study should be extended to even higher levels of brightness than were obtained here. There was no difference in mean pupil size at various levels of illumination between individuals grouped by degree of retinal pigmentation.
African fossil tali: Further multivariate morphometric studies
Authors: Lisowski F. P. , Albrecht G. H. , Oxnard C. E. 
Published: February 2006

AbstractAnalysis of measurements from the tali of 21 individual fossil primates from Africa shows that the specimens fall into five clearly defined groups. Accordingly, these specimens have been included as groups along with extant species in a subsequent canonical analysis thus allowing the fossils to play their part in the determination of the canonical separations.The results of this procedure show that the five fossil groups lie in a part of the canonical space not occupied by any extant African primate. Their positions are between the envelope of Asiatic apes (Hylobates and Pongo) and the envelope of African forms near the edge which contains Pan and Papio. One fossil group is so similar to Hylobates that its talus may have functioned in locomotion in a parallel manner. Others lie near to Pongo in directions proceeding towards Pan and Papio and it is possible that this similarity may indicate remnants of morphological adaptation for climbing in these fossils. At the same time, however, individual specimens are closer to one or another of the extant groups and this considerable spread suggests that the locomotor adaptations as evidenced by talar morphology, of the primate fauna in Africa, may have been very different from those of the present day. This would not be inconsistent with the different habitats, floras and non‐primate faunas that may have characterized the East African scene at these earlier times.Particular fossils from Olduvai and Kromdraai that are supposed to be australopithecine and therefore bipeds, are confirmed (Oxnard, '72; Lisowski et al., '74) as being totally different from man in their talar morphology and essentially rather similar to the majority of the other fossil tali examined.
Morphometric affinities of the human shoulder
Authors: Corruccini Robert S. , Ciochon Russell L. 
Published: February 2006

AbstractTo analyze differences between apes and monkeys and the affinities of man, we have studied the shoulder girdle of 327 specimens of anthropoid primates. The scapula, clavicle and humerus are viewed as an integrated functional complex on the basis of 18 measurements. Several varieties of multivariate analysis show that man is clearly closer to other hominoids than to the included monkey taxa (whether terrestrial or arboreal, Old World or New World). The marked shoulder differences between apes and monkeys and similarities between apes and man correlate with the muscular anatomy, which in hominoids allows the motions involved in their locomotion and feeding behavior. As the hominid‐pongid correspondence in shoulder morphology is especially detailed regarding the functionally important joint surfaces, it is consistent with a fairly recent period of common ancestry and behavior. No hypothetical evolutionary pathway or ancestral form of the human shoulder need look far beyond the model afforded by extant pongids. In contrast with previous studies on the primate shoulder, these results agree with information accumulating from other systems—comparative anatomy, primate behavior, and molecular biology — in suggesting very close relationship between man and extant African pongids.
Hierarchical grouping analysis and skeletal materials
Authors: Alexander Ralph W. 
Published: February 2006

AbstractThe technique of hierarchical grouping analysis is examined with respect to its use as a tool in grouping skeletal remains, utilizing both continuous and certain types of discontinuous anthropometric variables. The method is found to be useful when tested with Amerind skeletal materials at the micro‐evolutionary level, and as a technique for sexual differentiation within human and non‐human primate populations. The application of this form of cluster analysis to dental data is examined.
Hominid taphonomy: Transport of human skeletal parts in an artificial fluviatile environment
Authors: Boaz N. T. , Behrensmeyer A. K. 
Published: February 2006

AbstractFlume experiments demonstrate that human skeletal parts sort into lag and transportable groups in a current flow of 31 cm/sec. Orientations, rates and types of movement, and stable positions are recorded. Density of a skeletal part is correlated with the average rate of movement, whereas wet weight in air, weight in water, and volume are not. Shape is an important but unquantifiable factor. Complete crania are the fastest moving elements; individual cranial fragments are in the lag group. Omo fluviatile deposits show a preponderance of hominid lag elements, whereas Olduvai and East Rudolf perilacustrine deposits present a mixture of transportable and lag elements.
The use of inverse sine transformations in the analysis of non‐metric cranial data
Authors: Green Richard F. , Suchey Judy Myers 
Published: February 2006

AbstractIn recent years osteologists have frequently used non‐metric (dichotomous) cranial data to measure biological distance between skeletal samples of Homo sapiens. Applying methods used earlier by biologists, these workers begin by attempting to stabilize the variance of the measures used by transforming the observed trait frequencies using some type of inverse sine transformation. The frequently used Grewal‐Smith transformation doesn't work well for small samples of the size often considered by osteologists. As a consequence the mean measure of divergence between populations determined by this method is strongly influenced by a bias which depends on sample size. This paper compares several transformations in terms of how close the actual variance of the transformed frequency corresponds to its nominal value. It is suggested that the traditional (Grewal‐Smith) inverse sine transformation not be used, and several alternatives are considered.
The legend of Prince Vijaya — a study of Sinhalese origins
Authors: Kirk R. L. 
Published: February 2006

AbstractAncient chronicles relate the origin of the Sinhalese people of Sri Lanka to the arrival of Prince Vijaya from an area either in north‐east or north‐west India, and his subsequent affiliation with people from south India. Students of Indian history argue that the Vijayan legend should be interpreted to favor either one or the other of the northern origins, or a mixture of peoples from both areas. Genetic distance analysis however, despite the limitations imposed by the data, shows that modern Sinhalese populations are closer to the Tamils and Keralites of south India and the upper caste groups of Bengal than they are to populations in Gujarat or the Panjab.
Knuckling behavior in captive orangutans and a wounded baboon
Authors: Susman Randall L. , Tuttle Russell H. 
Published: February 2006

AbstractWith this communication we hope to clarify the usage of behavioral information from apparently non‐pathological orangutans and a pathological baboon to elucidate problems of hominoid locomotor evolution, particularly the problem of knuckle‐walking. We suggest that Hausfater's ('75) report on “knuckle walking” in the wounded baboon “Dutch” is at best marginally relevant to the problem of hominoid knuckle‐walking because Dutch is a pathological subject and because the report lacks quantification and sufficient descriptive detail to support the claim that his knuckling behavior is essentially the same as knuckle‐walking by extant African apes.Because we cannot observe the behavior of antecedent African apes and because of the relatively close morphological and genetic affinities of orangutans, chimpanzees, and gorillas, spontaneously knuckling and knuckle‐walking orangutans are the best available subjects to test certain hypotheses about the evolution of pongid knuckle‐walking.
Genetic structure and heterozygosity in the kuru region, Eastern Highlands of New Guinea
Authors: Wiesenfeld Stephen L. , Gajdusek D. Carleton 
Published: February 2006

AbstractGenetic structure of 20 of the 37 linguistic groups in the Eastern Highlands of New Guinea including the kuru region is analyzed using information on blood groups and serum protein polymorphisms. The average individual is heterozygous at 28.6% of loci and the average number of alleles per locus is 1.234. Coefficients of kinship for linguistic groups range from 0.005 for the sweet potato cultivating North Fore to 0.075 for the isolated Pawaians whose dietary staple is sago and who depend more on hunting and gathering. As one selects linguistic groups with smaller and smaller population size and increasing isolation, one finds that kinship coefficients rise as much as tenfold, but there is no concomitant loss of heterozygosity or trend toward fixation of alleles. Genetic relationships established by genetic distance trees and by principal components analysis are comparable and are consistent with other anthropological observations.
A preliminary anatomical diagnosis of the first Plio/Pleistocene hominid discoveries in the central Afar, Ethiopia
Authors: Johanson D. Carl , Coppens Yves 
Published: February 2006

AbstractFive fragmentary hominid specimens including four associated postcranial (lower limb) bones and a temporal bone of another individual from the Plio/Pleistocene of the central Afar, Ethiopia, are described. These remains represent the primary discoveries of fossil hominids by an international team working since 1972 in recently recognized paleontological exposures in the Afar triangle. The descriptions presented are purely anatomical and no taxonomic assessment is intended.The postcranial material is comprised of two fragmentary proximal femurs, a right and a left, a right distal femur, and a right proximal tibia. The close association and morphological similarities of these four fragments strongly suggests that they are from the same individual.An eroded and fragmentary left temporal bone, from another locality, was also found.Both the cranial and postcranial material are from roughly equivalent stratigraphic horizons and may be of nearly the same geological age.
Arch form, tooth size, and occlusomandibular kinesis in the Ceboidea
Authors: Zingeser M. R. 
Published: February 2006

AbstractCorrelations between dental morphology, arch configuration, and jaw movement patterns were quantitatively investigated in 23 ceboid species to elucidate integrative aspects of occlusal functional anatomy in an adaptive and evolutionary context. Differential maxillary‐mandibular arch widths are primary in guiding lateral jaw movements. These movements are characterized according to their associated condylar shifts as either predominantly translatory or rotational. Predominantly translatory movements result from peripheral contact relationships between maxillary arches which are considerably wider posteriorly than their opposing mandibular arches. The greatest degree of mandibular movement is in the molar region in functional association with wide “primitive” maxillary molars, narrow mandibular molars, constricted maxillary intercanine widths, and narrow maxillary incisors. In contrast, predominantly rotational masticatory jaw movements result from differential arch widths which are greatest in the maxillary canine and incisor regions. Here most jaw movement is in the anterior segment and this is reflected in small maxillary‐mandibular molar width differences, a high degree of premolarization, wide‐set maxillary canine teeth, and wide maxillary incisors. Possible selectional factors in the putative evolution of rotational predominance in mastication from the more primitive translatory pattern are discussed.
A comparative study of metric and non‐metric traits in a series of modern crania
Authors: Carpenter James Culver 
Published: February 2006

AbstractThe purpose of this study is to question the utility of non‐metric traits as predictors of age, race, and sex by comparing a group of non‐metric variables with a group of metric variables. Twelve metric variables and 15 nonmetric variables were scored on 317 crania from the Terry Collection at the U. S. National Museum, and later statistically evaluated with a number of multivariate analysis programs and a stepwise discriminant program. The metric variables were found to be significant sex and race discriminators, where‐as the non‐metric variables were non‐significant. The non‐metric variables were found to be better age discriminators than the metric variables, even though neither could be classified as highly significant. It was concluded that non‐metric traits by themselves have very little discriminatory value and should be used instead to supplement other osteological measurements and observations.
Temporal variation in prehistoric Nubian crania
Authors: Carlson David S. 
Published: February 2006

AbstractMuch of the earlier work on the prehistory of Sudanese Nubia has emphasized discontinuity between early Nubian populations. However, recent investigations suggest the converse ‐ that a remarkable degree of cultural and biological continuity exists among indigenous Nubian groups, perhaps as far back as the Paleolithic. Thus, cultural and biological differences between Nubian populations can be most effectively perceived as the result of in situ evolutionary development.The present analysis has two major purposes: (1) to describe the morphological differences in the craniofacial complex between indigenous Nubian populations extending from the A‐Group (c. 3,400 B.C.) through the Christian (c. 1,500 A.D.) horizons; and (2) to account for these differences within an evolutionary framework. The multiple discriminant analysis of radiographically derived variables revealed a trend from a substantially lower and more elongated cranial vault to a shorter and taller vault throughout the almost 5,000 year time span. Associated with this pattern was a tendency for the face to become more inferiorly‐posteriorly located with respect to the vault in the latter groups. Finally, the masseter and temporalis muscles underwent a reduction and slight relocation through time. We speculate that this trend may be associated with behavioral changes associated with transition from a hunting and gathering to a totally agricultural subsistence pattern.
Structural harmony and Neandertäl speech: A reply to Le May
Authors: Lieberman Philip 
Published: February 2006

AbstractThe Neandertäl supralaryngeal vocal tract reconstruction reported by Lieberman and Crelin ('71) is based on the methods of comparative anatomy. Normal adult‐like humans have a skeletal morphology in harmony with the soft tissue of their vocal tracts. This is also the case for non‐human primates and human newborns who have a different skeletal morphology in harmony with a different vocal tract. The “bits and pieces” that together constitute functional complexes are under separate and complex genetic control. The conditions discussed by Le May ('75) can result in the retention of some features of the skeletal morphology of a newborn in association with an adult‐like supralaryngeal vocal tract. However, these examples cannot show how the soft tissue of the supralaryngeal hominid vocal tract would match the skeletal structure of a fossil hominid, if the fossil hominid population were subject to the same selectional forces operant on all living primates. The Neandertäl supralaryngeal tract is thus probably in harmony with its skeletal morphology and similar to that of a human newborn.
Primate models for australopithecine sexual dimorphism
Authors: Wolpoff Milford H. 
Published: February 2006

AbstractSeveral different models of sexual dimorphism in the South African australopithecines are compared with sexual dimorphism in the living primates. Australopithecine dimorphism is placed in an evolutionary context, and contrasting trends in the hominid and pongid lineages are shown. Evidence suggesting that the australopithecines were an extremely polytypic taxon is presented, and a high level of both inter‐ and intra‐population variation is indicated.
A note on craniofacial sutural growth
Authors: Koskinen Leena , Isotupa Kauko , Koski Kalevi 
Published: February 2006

AbstractThe paper presents and discusses some features of sutural structures. Fibre orientation in sutures seems to be quite variable and associated with minute local growth phenomena. Trabecular patterns in bones, reflecting growth, appear to support the idea of the outside determination of growth. The bevelled and interdigitated structures seen in many sutures may be interpreted as an expedient solution to the problem of fast growth.
Physical Anthropology and the dental and medical specialties
Authors: Krogman Wilton Marion 
Published: February 2006

AbstractThe rise of two sub‐specialties in Physical Anthropology traces back to the Anatomy Departments of Schools of Medicine in Germany and France during the nineteenth century. The study of human diversity in bones and bodies was largely by medically‐trained anatomists. There developed Medical Anthropology and Dental Anthropology, employing osteometry and craniometry on the skeleton, somatometry and cephalometry on the living body. As a result cross‐sectional studies gave way to longitudinal studies and X‐ray techniques were added to purely mensurational procedures.In Medical Anthropology the specialties most directly concerned are pediatrics, plastic surgery, endocrinology, and orthopaedics. In Dental Anthropology the specialties most directly concerned are pedodontics, orthodontics, oral surgery, and prosthodontics. The contributions of Physical Anthropology to each is discussed.
Some aspects of aging in the lumbar spine
Authors: Ericksen Mary Frances 
Published: February 2006

AbstractI measured the bodies of vertebrae L3 and L4 of 338 skeletons from the Terry collection in the Smithsonian Institution, including Blacks and Whites, males and females, aged from 20 to 90 years. Transverse breadths of the upper and lower endplates (excluding osteophytes) and minimum transverse breadths all increase with age. In general, the greater broadening occurs in the endplates, but the middle of the body also broadens to such a degree that there is no demonstrable increase in vertebral “flaring” with age. In males, posterior body height decreases relative to anterior height, so that the lumbar bodies become more wedge‐shaped with age, but females show essentially no change. Anterior height decreases in proportion to minimum breadth, so that the lumbar bodies become relatively lower and broader, and this change is significantly correlated with age in all groups. Midbody height decreases relative to anterior height, so that Nordin's biconcavity index is reduced with age. The increase in biconcavity remains evident even when average anterior‐posterior height is used to calculate the index. At all age levels a high percentage of individuals have biconcavity indices of 80% or less, indicating that Nordin's standard of normality for this index, established from measurement on radiographs of the living, should be revised downward for use in evaluating osteoporosis in skeletal populations.
The structure of the human symphysis pubis with special consideration of parturition and its sequelae
Authors: Putschar Walter G. J. 
Published: February 2006

AbstractReview of the structure of the symphysis pubis, based on my extensive study of the pelvic joints ('31) shows changes from age, function, pregnancy hormones and stress of parturition. Primary physiologic shearing clefts and secondary traumatic clefts in cartilage are more frequent in females. Inter‐digitations in the young osteocartilaginous border secure the vulnerable growth cartilage against increasing shearing forces. The retropubic eminence, ligamentous or cartilaginous, forms earlier in females, later, due to bony lipping in males, secondary to extrusion of disc cartilage. Ovarian and placental hormones in pregnancy cause remodeling and resorption of the posterior margin of the pubic facette and adjacent cortex, making a (variably) deep bony groove for greatly hypertrophied transverse ligaments. Delivery of a mature infant produces traumatic changes leading to extrusion of torn fibrocartilage in any direction, progressively loosening the symphysis, producing cartilage nodules, cysts and reactive bone formation. Older age degenerative arthritis is more frequent in parous females.