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Previous studies have demonstrated that cranial base anatomy is influenced primarily by three different characteristics: brain shape, positional behavior, and facial growth (Lieberman et al. 2000). Although the timing of cranial base growth is not fully understood, features of the cranial base are frequently used to interpret the hominin fossil record (Guy et al. 2005; White et al. 1994; Brunet et al. 2002). While specific aspects of cranial base morphology may be species-specific, there is sparse information on the developmental mechanisms driving these adult morphologies. The aim of this study is to 1) examine changes in the human cranial base form throughout ontogeny and 2) determine their relationship to the development of positional behavior and brain growth. This research asks: to what extent does human cranial base morphology vary before and after adult positional behavior is acquired? The null hypothesis is that there is no relationship between features of the cranial base and the development of positional behavior. Data are collected using 3D landmarks on n=35 human crania and analyzed with both Morphologika (O'Higgins and Jones 1999) and MorphoJ (Klingenberg 2011) to identify age related changes in shape. Results of this study demonstrate that most of the changes in cranial base form occur between dental eruption stages N and NJ1 between 0 and 2 years of age. These changes consist of a relative shortening of the anterior-posterior cranial base length, a more posterior positioning of the foramen magnum, and a more anterior position of the occipital condyles and separate the N and NJ1 dental development groups from other groups. This change coincides with the transition to upright posture in human children (Abitbol 1993), a significant period of brain growth (Neubauer 2009) and has implications for reconstructing positional behavior in fossil hominins. Despite new insights into the development of cranial base morphology, the utility of the cranial base in assigning hominin taxonomy remains inconclusive.
ContributorsMcgechie, Faye Rachele (Author) / Kimbel, William (Thesis director) / Schwartz, Gary (Committee member) / Hill, Cheryl (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2015-05
Description
Isotopic analyses of archaeological and modern materials are commonly used to reconstruct diet, climate, and habitat. This study analyzes 15 camelid samples from three sites (two archaeological, one modern) in South America to determine their carbon and nitrogen isotopic values to further explore the relationship between stable isotopes and environments. Camelid individuals in the modern site of Cuenca, Ecuador had a diet of almost entirely C3 vegetation, while those in Chen Chen, Peru had slightly higher values, still consistent with C3 plants. Those in the higher altitude site of Pumapunku, Bolivia had higher δ13C values than expected, indicating they may have been foddered with a mixed diet. These isotopic data indicate that vegetation, and therefore herbivore diets, are influenced by altitude. Additionally, it was found that a positive linear relationship exists between δ15N values and aridity of a site. Results indicate that aspects of the environment such as aridity are reflected in isotopic signatures. These results contribute to the increasing amount of data on isotopic variation in South American camelids, both modern and archaeological.
ContributorsSpencer, Katherine Clare (Author) / Knudson, Kelly (Thesis director) / Reed, Kaye (Committee member) / School of Human Evolution and Social Change (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Scalping has been practiced by the Native Americans since pre-Columbian times in North America and is observed as cut-marks in the form of a rough circle on the superior aspect of the cranium of the individual. For this study, there are 7 crania with cut-marks evident of scalping from the Southwest population of Chavez Pass. These crania were excavated from the site of Nuvakwewtaqa located in north-central Arizona, in the middle of the Coconino National Forest. Unfortunately, the site was heavily looted through pot-hunter activity, leading to a large collection of commingle remains. The objectives of this study are summarized into three basic question words: Who? Where? And, How? More specifically: [1] whether there is a relationship between age or sex and being a victim of scalping; [2] whether there is a relationship between the burial location and having been scalped; and, [3] whether the age or sex of an individual affected the manner in which they were scalped. For this analysis of scalping, three statistical tests were used: Fisher's exact test, Chi-Square test and two-sample t-tests.
ContributorsBeyens, Anne Marie (Author) / Simon, Arleyn (Thesis director) / Stojanowski, Christopher (Committee member) / Schwartz, Gary (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2014-05
Description
Many of the derived features of the human skeleton can be divided into two adaptive suites: traits related to bipedalism and traits related to encephalization. The cervical spine connects these adaptive suites and is itself unique in its marked lordosis. I approach human cervical evolution from three directions: the functional significance of cervical curvature, the identification of cervical lordosis in osteological material, and the representation of the cervical spine in the hominin fossil record.
ContributorsFatica, Lawrence Martin (Author) / Kimbel, William (Thesis director) / Reed, Kaye (Committee member) / Schwartz, Gary (Committee member) / Barrett, The Honors College (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor)
Created2014-05
Description
Teratomas are germ cell tumors that can generate a broad spectrum of biological tissues including: hair, oil glands, bones, and teeth. Little research has focused on the detailed comparison of teeth from growing within teratomas to teeth that grew normally within the oral cavity. Broad similarities in the overall pattern of dental growth have previously been observed using average enamel thickness, a measurement of enamel height, comparisons. Enamel thickness is used to infer functional aspects of dentition. Relative enamel thickness values have not been used in previous studies to account for the difference in size of the teeth.
ASU’s Bioarchaeology of Nubia Expedition (BONE) led by Dr. Brenda Baker discovered the remains of a female individual from the Classic Kerma period with a preserved large teratoma containing hard tissue components including two molariform teeth. There are only three previous recorded instances of teratomas in a paleopathological setting.
This study analyzed the characteristics of teeth found within a teratoma and compared them to permanent oral dentition to ascertain the degree to which dental development is affected by local growth environment. Permanent (oral) molars from multiple individuals and 2 teratoma teeth from a singular individual from the BONE site were analyzed alongside a comparative sample of permanent (oral) molars from an unrelated, more modern population. MicroCT scans were used to create digital renditions of the teeth to create 3D and 2D models to analyze the enamel and dentine of the teeth to measure their morphological characteristics. The relative enamel thickness and the absolute occlusal enamel volumes were calculated. The study found that there are significant differences in enamel thickness between the teratoma teeth and any of its oral cavity counterparts.
This study is unique in that it is the first study to analyze teeth from a teratoma to permanent teeth from the oral cavity using 2D and 3D digital dental models created from microCT data. It is also the first study to analyze these morphological characteristics in an archaeological sample.
ASU’s Bioarchaeology of Nubia Expedition (BONE) led by Dr. Brenda Baker discovered the remains of a female individual from the Classic Kerma period with a preserved large teratoma containing hard tissue components including two molariform teeth. There are only three previous recorded instances of teratomas in a paleopathological setting.
This study analyzed the characteristics of teeth found within a teratoma and compared them to permanent oral dentition to ascertain the degree to which dental development is affected by local growth environment. Permanent (oral) molars from multiple individuals and 2 teratoma teeth from a singular individual from the BONE site were analyzed alongside a comparative sample of permanent (oral) molars from an unrelated, more modern population. MicroCT scans were used to create digital renditions of the teeth to create 3D and 2D models to analyze the enamel and dentine of the teeth to measure their morphological characteristics. The relative enamel thickness and the absolute occlusal enamel volumes were calculated. The study found that there are significant differences in enamel thickness between the teratoma teeth and any of its oral cavity counterparts.
This study is unique in that it is the first study to analyze teeth from a teratoma to permanent teeth from the oral cavity using 2D and 3D digital dental models created from microCT data. It is also the first study to analyze these morphological characteristics in an archaeological sample.
ContributorsSchander-Triplett, Katherine (Author) / Schwartz, Gary (Thesis director) / Baker, Brenda (Committee member) / Ortiz, Alejandra (Committee member) / School of Human Evolution & Social Change (Contributor) / Department of Psychology (Contributor) / Barrett, The Honors College (Contributor)
Created2019-12
Description
This study was conducted in order to determine whether the lagomorphs of 111 Ranch- Aztlanolagus agilis, Hypolagus arizonensis, and Sylvilagus cunicularius- could be distinguished based on femora. This is because while there is a large quantity of disarticulated lagomorph postcranial fossils from 111 Ranch, the chief diagnostic traits of A. agilis and H. arizonensis are the enamel patterns on their third premolars, leaving a large swath of specimens unidentifiable by diagnostic traits alone. Specimens from the Arizona Museum of Natural History were measured and compared to specimens known to be from these genera. Additionally, morphological traits in mandibles were used to identify mandible specimens, which in turn were used to identify fossils with the same specimen label. Statistical tests such as t-tests and principal components analyses were used to examine the distributions of sizes and locate clusters of datapoints likely corresponding to each genus. Some of these could be linked to a genus based on one particular specimen, P15156, which had been identified as Hypolagus based on its mandible morphology and size. The majority of the Museum'a specimens were thus associated with one of the three species, save for those which were too damaged and intermediate in size to confidently categorize.
ContributorsTkacik, Stephanie Marie (Author) / Farmer, Jack (Thesis director) / Reed, Kaye (Committee member) / McCord, Robert (Committee member) / School of Earth and Space Exploration (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05