Matching Items (146)
Description
Despite the critical role that the vertebral column plays in postural and locomotor behaviors, the functional morphology of the cervical region (i.e., the bony neck) remains poorly understood, particularly in comparison to that of the thoracic and lumbar sections. This dissertation tests the hypothesis that morphological variation in cervical vertebrae reflects differences in positional behavior (i.e., suspensory vs. nonsuspensory and orthograde vs. pronograde locomotion and postures). Specifically, this project addresses two broad research questions: (1) how does the morphology of cervical vertebrae vary with positional behavior and cranial morphology among primates and (2) where does fossil hominoid morphology fall within the context of the extant primates. Three biomechanical models were developed for the primate cervical spine and their predictions were tested by conducting a comparative analysis using a taxonomically and behaviorally diverse sample of primates. The results of these analyses were used to evaluate fossil hominoid morphology. The two biomechanical models relating vertebral shape to positional behaviors are not supported. However, a number of features distinguish behavioral groups. For example, the angle of the transverse process in relation to the cranial surface of the vertebral body--a trait hypothesized to reflect the deep spinal muscles' ability to extend and stabilize the neck--tends to be greater in pronograde species; this difference is in the opposite of the direction predicted by the biomechanical models. Other traits distinguish behavioral groups (e.g., spinous process length and cross-sectional area), but only in certain parts of the cervical column. The correlation of several vertebral features, especially transverse process length and pedicle cross-sectional area, with anterior cranial length supports the predictions made by the third model that links cervical morphology with head stabilization (i.e., head balancing). Fossil hominoid cervical remains indicate that the morphological pattern that characterizes modern humans was not present in Homo erectus or earlier hominins. These hominins are generally similar to apes in having larger neural arch cross-sectional areas and longer spinous processes than modern humans, likely indicating the presence of comparatively large nuchal muscles. The functional significance of this morphology remains unclear.
ContributorsNalley, Thierra Kénnec (Author) / Kimbel, William H. (Thesis advisor) / Reed, Kaye (Committee member) / Shapiro, Liza (Committee member) / Arizona State University (Publisher)
Created2013
Description
Arguments of human uniqueness emphasize our complex sociality, unusual cognitive capacities, and language skills, but the timing of the origin of these abilities and their evolutionary causes remain unsolved. Though not unique to primates, kin-biased sociality was key to the success of the primate order. In contrast to ancestral solitary mammals, the earliest primates are thought to have maintained dispersed (non-group living) social networks, communicating over distances via vocalizations and scent marks. If such ancestral primates recognized kin, those networks may have facilitated the evolution of kin-biased sociality in the primate order and created selection for increased cognitive and communicative abilities. I used the gray mouse lemur (Microcebus murinus) to model whether vocalizations could have facilitated matrilineal and patrilineal kin recognition in ancestral primates. Much like mouse lemurs today, ancestral primates are thought to have been small-bodied, nocturnal creatures that captured insects and foraged for fruit in the thin, terminal ends of tree branches. Thus, the mouse lemur is an excellent model species because its ecological niche is likely to be similar to that of ancestral primates 55-90 million years ago. I conducted playback experiments in Ankarafantsika National Park, Madagascar testing whether mouse lemur agonistic calls contain matrilineal kin signatures and whether the lemurs recognize matrilineal kin. In contrast to large-brained, socially complex monkeys with frequent coalitionary behavior, mouse lemurs did not react differently to the agonistic calls of matrilineal kin and nonkin, though moderate signatures were present in the calls. I tested for patrilineal signatures and patrilineal kin recognition via mating and alarm calls in a colony with known pedigree relationships. The results are the first to demonstrate that a nocturnal, solitary foraging mammal gives mating calls with patrilineal signatures and recognizes patrilineal kin. Interestingly, alarm calls did not have signatures and did not facilitate kin recognition, suggesting that selection for kin recognition is stronger in some call types than others. As this dissertation is the first investigation of vocal kin recognition in a dispersed-living, nocturnal strepsirrhine primate, it greatly advances our knowledge of the role of vocal communication in the evolution of primate social complexity.
ContributorsKessler, Sharon E (Author) / Nash, Leanne (Thesis advisor) / Reed, Kaye (Thesis advisor) / Radespiel, Ute (Committee member) / Zimmermann, Elke (Committee member) / Arizona State University (Publisher)
Created2014
Description
Modern primate diet is well-studied because of its considerable influence on multiple aspects of morphology, including the shape of the facial skeleton and teeth. It is well-established that differences in craniofacial form influence feeding abilities by altering the nature of bite force production. Tooth morphology, likewise, has been shown to vary with diet across primates, particularly in the details of occlusal form. It has also been suggested that tooth form (e.g., tooth root size and shape and crown size) reflects, in part, the demands of resisting the stresses generated during feeding. However, while they are central to our efforts to infer diet in past species, the relationships between bite force production, craniofacial morphology and tooth form are not well-established. The current study is separated into two parts. In Part I, the hypothesis that crown size and root surface area are adapted to resist masticatory stress is evaluated by testing whether these features show correlated variation along the tooth row in a taxonomically diverse sample of primates. To further explore the adaptive nature of this correlation, pair-wise comparisons between primates with mechanically resistant diets and closely-related species consuming less resistant foods are performed. If crown size and root surface area covary along the tooth row, past research suggests they may be related to bite force. To test this hypothesis, Part II examines the variation of these dental characteristics in comparison to theoretically-derived bite force patterns along the tooth row. Results suggest that patterns of maximum bite force magnitude along the tooth row are variable both within and between species, underscoring the importance of individual craniofacial variation on masticatory force production. Furthermore, it is suggested that some adaptations traditionally associated with high bite force production (i.e., facial orthognathy) may increase anterior biting force at the expense of posterior biting force. Taken together, results from the current study reveal that both tooth root and crown size vary in conjunction with the mechanical properties of diet and with bite force patterns along the tooth row in anthropoids.
ContributorsLucas, Lynn (Author) / Spencer, Mark (Thesis advisor) / Schwartz, Gary (Committee member) / Kimbel, William (Committee member) / Arizona State University (Publisher)
Created2012
Description
Geology and its tangential studies, collectively known and referred to in this thesis as geosciences, have been paramount to the transformation and advancement of society, fundamentally changing the way we view, interact and live with the surrounding natural and built environment. It is important to recognize the value and importance of this interdisciplinary scientific field while reconciling its ties to imperial and colonizing extractive systems which have led to harmful and invasive endeavors. This intersection among geosciences, (environmental) justice studies, and decolonization is intended to promote inclusive pedagogical models through just and equitable methodologies and frameworks as to prevent further injustices and promote recognition and healing of old wounds. By utilizing decolonial frameworks and highlighting the voices of peoples from colonized and exploited landscapes, this annotated syllabus tackles the issues previously described while proposing solutions involving place-based education and the recentering of land within geoscience pedagogical models. (abstract)
ContributorsReed, Cameron E (Author) / Richter, Jennifer (Thesis director) / Semken, Steven (Committee member) / School of Earth and Space Exploration (Contributor, Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
East African extensional basins have played a crucial role in revealing the evolution and characteristics of the early stages of continental rifting and for providing the geological context of hominin evolution and innovation. The numerous volcanic eruptions, rapid sedimentation and burial, and subsequent exposure through faulting and erosion, provide excellent conditions for the preservation of tectonic history, paleoenvironment data, and vertebrate fossils. The reconstruction of depositional environments and provision of geochronologic frameworks for hominin sites have been largely provided by geologic investigations in conjunction with paleontological studies, like the Ledi-Geraru Research Project (LGRP). High-resolution paleoclimate records that can be directly linked to hominin fossil outcrops have been developed by the Hominin Sites and Paleolakes Drilling Project (HSPDP) which collected sedimentary-paleolake cores at or near key hominin fossil sites.
Two chapters of this dissertation are a result of research associated with the HSPDP. For HSPDP, I establish a tephrostratigraphic framework for the drill cores from the Northern Awash (Afar, Ethiopia) and Baringo-Tugen Hills-Barsemoi (Kenya) HSPDP sites. I characterize and fingerprint tephra through glass shard and feldspar phenocryst geochemistry. From tephra geochemical analyses, I establish chronostratigraphic ties between the HSPDP cores’ high-resolution paleoclimate records to outcrop stratigraphy which are associated with hominin fossils sites.
Three chapters of this dissertation are a result of field work with the LGRP. I report new geological investigations (stratigraphic, tectonic, and volcanic) of two previously unmapped regions from the eastern Ledi-Geraru (ELG), Asboli and Markaytoli. Building upon this research I present interpretations from tephra analyses, detailed stratigraphic analyses, and geologic mapping, of the Pleistocene (~2.6 to < 2.45 Ma) basin history for the LGRP. My work with the LGRP helps to reconstruct a more complete Early Pleistocene depositional and geologic history of the lower Awash Valley.
Overall, this dissertation contributes to the reconstruction of hominin paleoenvironments and the geochronological framework of the Pliocene and Pleistocene faunal/hominin records. It further contributes to rift basin history in East Africa by elaborating the later structural and stratigraphic history of the lower Awash region.
Two chapters of this dissertation are a result of research associated with the HSPDP. For HSPDP, I establish a tephrostratigraphic framework for the drill cores from the Northern Awash (Afar, Ethiopia) and Baringo-Tugen Hills-Barsemoi (Kenya) HSPDP sites. I characterize and fingerprint tephra through glass shard and feldspar phenocryst geochemistry. From tephra geochemical analyses, I establish chronostratigraphic ties between the HSPDP cores’ high-resolution paleoclimate records to outcrop stratigraphy which are associated with hominin fossils sites.
Three chapters of this dissertation are a result of field work with the LGRP. I report new geological investigations (stratigraphic, tectonic, and volcanic) of two previously unmapped regions from the eastern Ledi-Geraru (ELG), Asboli and Markaytoli. Building upon this research I present interpretations from tephra analyses, detailed stratigraphic analyses, and geologic mapping, of the Pleistocene (~2.6 to < 2.45 Ma) basin history for the LGRP. My work with the LGRP helps to reconstruct a more complete Early Pleistocene depositional and geologic history of the lower Awash Valley.
Overall, this dissertation contributes to the reconstruction of hominin paleoenvironments and the geochronological framework of the Pliocene and Pleistocene faunal/hominin records. It further contributes to rift basin history in East Africa by elaborating the later structural and stratigraphic history of the lower Awash region.
ContributorsGarello, Dominique Ines (Author) / Arrowsmith, Ramon (Thesis advisor) / Campisano, Chris J (Thesis advisor) / Reed, Kaye (Committee member) / Feary, David (Committee member) / Wittmann, Axel (Committee member) / Arizona State University (Publisher)
Created2019
Description
As the junction between the head and the trunk, the neck functions in providing head stability during behaviors like feeding to facilitating head mobility during behavior like grooming and predator vigilance. Despite its importance to these vital behaviors, its form and function remain poorly understood. Fossil hominin cervical vertebrae preserve a striking diversity in form despite the commitment to orthograde bipedality. Do these differences in cervical vertebral form correspond to functional variations among our recent ancestors? This dissertation attempts to understand 1) how does the neck function in head stability and mobility 2) how do these functions relate to cervical vertebral form. Kinematic and passive range of motion studies were conducted in several species of primate to obtain measures of function which were subsequently related to skeletal form.
Results show that cervical vertebral morphology does not significantly covary with differences in joint mobility. Rather, they implicate the critical role of ligaments and muscles in facilitating head mobility. Results of the kinematics study show that the neck plays a role in maintaining head stability during locomotion. However, the kinematic data do not significantly correlate with morphological variation among primate species. Given the negative results of the extant morphological analyses, it is difficult to apply them to the fossil record. As such, the functional significance of the disparate morphologies found in the hominin fossil record remain ambiguous.
Results show that cervical vertebral morphology does not significantly covary with differences in joint mobility. Rather, they implicate the critical role of ligaments and muscles in facilitating head mobility. Results of the kinematics study show that the neck plays a role in maintaining head stability during locomotion. However, the kinematic data do not significantly correlate with morphological variation among primate species. Given the negative results of the extant morphological analyses, it is difficult to apply them to the fossil record. As such, the functional significance of the disparate morphologies found in the hominin fossil record remain ambiguous.
ContributorsGrider-Potter, Neysa (Author) / Kimbel, William (Thesis advisor) / Raichlen, David (Committee member) / Schwartz, Gary (Committee member) / Ward, Carol (Committee member) / Arizona State University (Publisher)
Created2019
Description
Accurately predicting local ranges of isotopic signatures in human populations is essential for answering questions about past migrations and mobility. While local ranges of δ18O can be estimated using modern baseline samples and precipitation models, there are many environmental and anthropogenic drivers that can cause these ranges to deviate from the ranges seen in human populations. This study performs a geostatistical meta-analysis on a large dataset (n = 1,370) of spatially contextualized archaeological δ18O samples from 30 publications in order to generate a predictive model of local human δ18O ranges in the Central Andes. Two models were generated, one using archaeological samples of both humans and fauna, and the other using only humans. The model using only human samples makes more accurate predictions, cautioning against the incorporation of faunal δ18O samples in studies of human provenance. The models are also compared against a model of δ18O values found in precipitation across the study area, and significant differences lead to the conclusion that precipitation models are insufficient for predicting local human δ18O ranges.
ContributorsHatley, Camden Miller (Author) / Knudson, Kelly (Thesis director) / Scaffidi, Beth (Committee member) / School of Earth and Space Exploration (Contributor) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
In this study, the packaging and labeling of milk and coffee was compared between Walmart and Sprouts. The pricing, the sourcing, the certifications and the overall shelf presence of the items was taken under consideration. After studying the packaging of both, a new design incorporating the applicable labels, customer appeal and appropriate green marketing was created for both the commodities.
ContributorsBhatt, Rashi Hitesh (Author) / Collins, Shari (Thesis director) / Keahey, Jennifer (Committee member) / School of International Letters and Cultures (Contributor) / School of Earth and Space Exploration (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Einstein's theory of special relativity has been used by accomplished science fiction authors since its discovery in 1905, allowing intrepid adventurers to reach far away worlds without having to fear time's passage. By traveling near light speed, these fictional travelers experience a different passage of time as the universe ensures the commonality of the speed of light in all reference frames. In the here and now, this method of travel has been proposed to assist in interstellar and interplanetary exploration. This paper will investigate the practicality of this method of travel by proposing a mission utilizing a craft with this type of velocity.
ContributorsWaaler, Mason Duran (Author) / Jacob, Richard (Thesis director) / Covatto, Carl (Committee member) / Foy, Joseph (Committee member) / School of Life Sciences (Contributor) / School of Earth and Space Exploration (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The giant green sea anemone, Anthopleura xanthogrammica, hosts two different endosymbiotic algae. One is a unicellular chlorophyte, Elliptochloris marina; the other is Symbiodinium muscatinei, a dinoflagellate. Hosting these different symbionts influences the life history strategy of A. xanthogrammica's congener A. elegantissima, directly impacting its reproductive strategy (asexual vs. sexual). My study sought to examine whether the type and density of symbiont also affects the reproductive condition of A. xanthogrammica, which reproduces only sexually. Gonad development was measured in anemones from Slip Point, Clallam Bay, WA and Tongue Point, WA along with symbiont type and density per mg of anemone protein. The results indicate a trend towards brown anemones having more developed gonads, especially in males. This may mean that A. xanthogrammica anemones that host zooxanthellae are more reproductively fit than zoochlorellate anemones. Thus, it may be favorable for anemones to host zooxanthellae. This is especially true in summer months when the high temperatures and mid-day low tides coincide with the period of most rapid gonad development.
ContributorsGasbarro, Ryan Patrick (Author) / Neuer, Susanne (Thesis director) / Rutowski, Ronald (Committee member) / Bingham, Brian (Committee member) / Barrett, The Honors College (Contributor) / School of Earth and Space Exploration (Contributor) / School of Life Sciences (Contributor)
Created2015-05