Books by Tyler G O'Brien
Papers by Tyler G O'Brien
Thesis (M.A.)--University of Tennessee, Knoxville, 1994. Vita. Includes bibliographical reference... more Thesis (M.A.)--University of Tennessee, Knoxville, 1994. Vita. Includes bibliographical references (leaves 74-79).
Thesis (Ph. D.)--State University of New York at Binghamton, Department of Anthropology, 2003. In... more Thesis (Ph. D.)--State University of New York at Binghamton, Department of Anthropology, 2003. Includes bibliographical references (leaves 113-142). Photocopy.
Growth, development, and aging : GDA, 2008
Available techniques for determining age from human cranial remains are limited. This study exami... more Available techniques for determining age from human cranial remains are limited. This study examines the efficacy of Meindl and Lovejoy's (1985) method of determining age based on ectocranial suture closure patterns as compared to a baseline of ages developed from a multifactorial approach employing various age determining factors from across the skull. What makes this study different is that the sample upon which this comparison is performed contains a large number of artificially deformed crania. Our hypothesis is that aging techniques that rely on suture closure patterns as markers are complicated by the results of artificial modification of the cranial vault. The study is conducted on adult, human crania from prehispanic archaeological sites in South America. Results demonstrate a significant difference between the two aging methods, more particularly when applied to deformed skulls. We conclude that when a skull is deformed age should be estimated utilizing multiple factors...
The Postmortem Fate of Human Remains, 1996
International Journal of Osteoarchaeology, 2010
... skull and (2) the intentional deformation involves the anatomical milestones of the neuroskul... more ... skull and (2) the intentional deformation involves the anatomical milestones of the neuroskull and the face.' A study ... present work is to analyse the modifications during the morphogenesis of the cranium through the influence of the different cranial deformation models which ...
Advances in Anthropology, 2013
The expression of sexual dimorphism may vary across time and space, as well as within and between... more The expression of sexual dimorphism may vary across time and space, as well as within and between populations depending on genetic and environmental factors that influence growth and development. The objective of the present work is to contribute to the knowledge of factors that determine the physical characteristics of ancient human groups in the eastern valleys of Cochabamba-a key region for cultural development, interregional interaction with northern Chile and northwest Argentina, and their noticeable role in the settlement of the south central Andean region. This paper analyzes the differences between males and females crania representing ancient human groups that inhabited the eastern valleys of Cochabamba, Bolivia. Thirty-one craniometric variables are analyzed from a sample of 234 individuals. Differences are evaluated using univariate analysis by ANOVA and multivariate discriminant analysis. The results indicate the existence of higher mean values in males compared to females in most cranial measurements (mean difference 5.3%). The discriminant analysis also reveals a significant morphological difference exists between sexes. Furthermore, by means of the discriminant function, the reclassification of correct sex was 99% of cases. This information indicates that members of this population could live in optimal conditions, with adequate resources to ensure growth and development and normal expression of the phenotype of each sex.
Advances in Anthropology, 2013
One of the most interesting problems facing the interpretation of south central Andean prehistory... more One of the most interesting problems facing the interpretation of south central Andean prehistory is to decipher the genetic relationships among ancient groups that inhabited this region. This study evaluates the biological relationships between the ancient inhabitants of the coast and interior valleys of the Azapa region in northern Chile and the Cochabamba valleys of Bolivia, with reference to highland Tiwanaku groups. Craniometric data (N = 299) were statistically evaluated to compute group means using Mahalanobis (D 2) values. Results demonstrate that there is a notable difference between coastal and interior valley populations of the Azapa region; whereas a close biological association exists between groups from the Cochabamba valleys and the interior Azapa valleys, especially for those associated with the Formative and Tiwanaku Periods.
International Journal of Osteoarchaeology, 2011
... et al., 1993; Dean, 1995a, 1995b; O'Loughlin, 1996; Pomatto et al., 2006); its influ... more ... et al., 1993; Dean, 1995a, 1995b; O'Loughlin, 1996; Pomatto et al., 2006); its influence on cranial ... we discuss the relationships among the measurements as they apply to the two deformation types and ... skulls (please refer to Figures 1 and 2). We first begin with cranial breadth (B ...
American journal of physical anthropology, 2008
The peopling of the south-central Andean region can be determined by exploring a combination of c... more The peopling of the south-central Andean region can be determined by exploring a combination of cultural, economic, and biological factors that influence the structure of populations and determine particular dispersals of gene frequencies. Quantitative characters from 1,586 adult crania of both sexes from northern Chile, northwestern Argentina, and the Cochabamba valleys in Bolivia were analyzed employing multivariate statistical analyses. Biological distances, representing phenotypic variation between these regions and their subregions, were studied within a population genetics framework. An analysis of Mahalanobis D(2) distances establishes two principle directions of interaction: the first between the Cochabamba valleys and northern Chile, and the second between the Cochabamba region and northwestern Argentina. The Chile and Argentina regions are shown to be less related to each other than each is to the Bolivian region. A higher mean genetic divergence is found for the entire re...
American Journal of Physical Anthropology, 2014
The existing biocultural links are analyzed among ancient inhabitants of the Cochabamba valleys (... more The existing biocultural links are analyzed among ancient inhabitants of the Cochabamba valleys (Bolivia) from the Formative and Tiwanaku periods, coastal and inland Azapa region (Chile) from the Late Archaic to the Late periods, and the Atacama Desert oases (Chile) from the Formative period to the time of European contact. Craniometric information obtained from a sample of 565 individuals from different sites of the studied regions was evaluated using methods derived from quantitative genetics and multivariate statistical analysis techniques. It is shown that during the Formative and Tiwanaku periods inhabitants of the Cochabamba valleys maintained contact with the population of northern Chile. This contact was more fluid with the people from the interior valley of Azapa than it was with the settlers of San Pedro Atacama (SPA). An important biological affinity in the Late Period between the inhabitants of the Azapa valley and the late SPA groups is also examined. The Late-Inca Catarpe SPA sample shows a broad genetic variability shared with the majority of the groups studied. The results reaffirm the differences between the coastal and interior Azapa valley groups and strengthen the hypothesis of two pathways to populating the south central Andean area. The divergence observed among subpopulations can be explained by the spatiotemporal dispersion between them, genetic drift dispersion compensated by the action of gene flow, and cultural norms that regulate within group mating.
Journal of forensic sciences, 2007
ABSTRACT: When postmortem environmental conditions are just right, according to the Goldilocks... more ABSTRACT: When postmortem environmental conditions are just right, according to the Goldilocks Phenomenon, soft tissues (and associated fatty acids) are converted into and preserved as adipocere. To better understand this conversion process and the ...
American Journal of Physical Anthropology, 2008
The peopling of the south-central Andean region can be determined by exploring a combination of c... more The peopling of the south-central Andean region can be determined by exploring a combination of cultural, economic, and biological factors that influence the structure of populations and determine particular dispersals of gene frequencies. Quantitative characters from 1,586 adult crania of both sexes from northern Chile, northwestern Argentina, and the Cochabamba valleys in Bolivia were analyzed employing multivariate statistical analyses. Biological distances, representing phenotypic variation between these regions and their subregions, were studied within a population genetics framework. An analysis of Mahalanobis D 2 distances establishes two principle directions of interaction: the first between the Cochabamba valleys and northern Chile, and the second between the Cochabamba region in Wiley InterScience (www.interscience.wiley.com).
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Books by Tyler G O'Brien
Papers by Tyler G O'Brien