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Publication Type
- doctoral dissertation (4) + Contains this - Excludes this
- masters thesis (2) + Contains this - Excludes this
Discipline
- Anthropology (3) + Contains this - Excludes this
- Animal Science (2) + Contains this - Excludes this
- English (1) + Contains this - Excludes this
(1 - 6 of 6)
- Title
- POSTCRANIAL EVOLUTION IN HUMANS WITH RESPECT TO TRAIT COVARIANCE AND ECOGEOGRAPHY
- Author
- Savell, Kristen Renée Rectenwald
- Publication Date
- 2018-08
- Publication Type
- doctoral dissertation
- Collection
- Graduate Theses and Dissertations
- Abstract
- Human postcranial morphology varies with climate and geography (ecogeography), a pattern that has long been associated with thermoregulatory adaptation. The thermoregulatory imperative model of postcranial evolution suggests that groups living in colder climates have evolved stouter bodies to reduce their surface area/volume ratio, while the opposite is true for groups in the tropics. Recent applications of quantitative genetics methods to human postcranial evolution have allowed researchers to move beyond testing whether limb lengths and measures of body size adhere to ecogeographic expectations, and begin disentangling the natural selection from neutral evolutionary processes. However, these have continued to model postcranial traits as if they were evolving independently. By examining human evolution on a trait-by-trait basis, researchers fail to account for evolution due to changes in correlated morphology. In addition, while these studies are able to identify the direction and magnitude of selective effects, they have yet to identify the source of that selective pressure, often relying on latitude as a problematic proxy for “climate.” In this dissertation, I use quantitative genetic methods to elucidate the role of trait covariation in the evolution of the human postcranium, as well as explore the variables that drive directional selection. Using a large, globally-dispersed sample of human skeletal material, in addition to microsatellite and temperature data, I estimate the selection gradients driving among-group differentiation, compare indices of evolvability across regions, and examine the environmental variables influencing postcranial evolution. Results indicate that 1. trait covariation plays an important role in shaping evolutionary response, 2. human groups may demonstrate emergent differentiation in evolvability across regions , and 3. the selective pressures acting on the postcranium are likely synergistic, complicating simplistic interpretations of the thermoregulatory imperative model. These findings have implications for our understanding of modern human variation, suggesting the need to develop multivariate models in which the reciprocal effects of multiple environmental variables can be examined on the covariance structure of multiple traits. Results also add to the growing evidence that population-specific trait covariance prevents evolutionary interpretations founded on modern humans to be meaningfully translated to ancient hominin lineages.
- Title
- The Evolution of the Primate Shoulder: Assessing Constraint and Evolvability
- Author
- Agosto, Elizabeth Rose
- Publication Date
- 2019-12
- Publication Type
- doctoral dissertation
- Collection
- Graduate Theses and Dissertations
- Abstract
- Observable differences among primate taxa closely align with different demands imposed by the wide range of environments they inhabit. This is reflected in the morphology of the primate shoulder girdle, which is the most variable among placental mammals. Previous research has demonstrated the morphology of the shoulder girdle reflects functional demands of the upper limb. Therefore, researchers hypothesize traits of the scapula are adaptations for specific functions related to locomotion, resource acquisition, or habitat; however, these hypotheses remain untested. In this dissertation, I use quantitative genetic approaches to assess the role of shared trait covariances on primate shoulder girdle morphology and directly test hypotheses of how this anatomical region evolved using phylogenetic comparative methods. Traits may evolve through shared responses in genetically, developmentally, or functionally covarying traits, via random genetic drift or responses to selection. In primates, the shoulder girdle shares developmental and functional relationships with traits of the basicranium, pelvic girdle, and humerus. Whether these relationships affect the evolution of the shoulder girdle, and ultimately primate morphological diversification, have not been explored. Using a broad sample of extant primate skeletal material, I estimate evolvability and conditioned covariances between the shoulder girdle, basicranium, pelvic girdle, and humerus, compare integration and evolutionary potential of these regions among primates, and directly test factors influencing shoulder girdle morphological variation. Results indicate the shoulder girdle does not evolve independently, rather its evolution is influenced by traits of the basicranium and pelvic girdle, and vice versa. Further, primate species have different patterns of covariance among these anatomical regions that affect their ability to respond to directional selection, and evolutionary covariance among these anatomical regions is not solely due to size-related variance, but also shape-related functional variance. However, no hypothesized single factor evolutionary model—locomotion, resource acquisition, or habitat—best explains what selection factors motivated evolution across all primates. These findings have implications for understanding how developmentally and functionally covariant anatomical regions may interact during evolution and their effect on morphological variation in primates and other vertebrates. Models of trait evolution should not be limited to single traits, anatomical regions, or single causes, without extreme caution.
- Title
- Biochemical and Microbial Biomarkers Mediating Feed Efficiency in Cattle
- Author
- Clemmons, Brooke Ashley
- Publication Date
- 2018-05
- Publication Type
- masters thesis
- Collection
- Graduate Theses and Dissertations
- Abstract
- Beef cattle are the primary red meat consumed in the United States and provide greater than $105 billion in retail value each year. In the beef industry, feed represents approximately 60% of the total input costs. Thus, finding novel ways of improving feed efficiency in order to reduce that cost is imperative. This research assesses several aspects of the ruminal microbiome in relation to feed efficiency in steers, including stability of the ruminal bacteriome following transition to feed, serum metabolites in steers differing in feed efficiency, as well as potential microbial and biochemical biomarkers of feed efficiency. In this study,50 Black Angus steers of 7 months of age were acclimated to the GrowSafe© feeding system and fed a step-up receiving diet before receiving a growing ration. Steers were maintained on the diet for 70d. Weekly BW was measured, serum collected, and rumen content was obtained via gastric tubing. The average RFI was calculated and steers were divided into low- (n=14) and high-RFI (n=15) groups based on 0.5 SD below and above the mean RFI, respectively. Untargeted serum metabolomics was conducted utilizing LC-MS. Genomic DNA was extracted from rumen content and the amplified V1-V3 hypervariable region of the bacterial 16S rRNA gene was sequenced for analyses. Missing values were approximated through matrix completion and data was normalized using a centered log-ratio transformation. Random Forests supervised machine learning and feature selection was performed on the bacterial compositions. Ruminal bacteria diversityfluctuated over the course of the trial, and was lower at the end of the trial compared to the beginning (P<0.05). Low-RFI steers were associated with decreased bacterial α [alpha]-(P=0.03) and β-[beta] diversity (R2=1, P=0.001), and greater abundances of pantothenate (0.375; P=0.04) as well as reduced abundances of glucose-6-phosphate (2.13; P=0.02) and glucose-1-phosphate (2.13; P=0.03). Fold change Flavobacteriia abundances were greater with increased pantothenate contrasted to reduced pantothenate (5.06; P=0.04). Greater abundances of pantothenate-producing bacteria, such as Flavobacteriia, may result in improved nutrient utilization in low-RFI steers. Pantothenate and/or Flavobacteriia may serve as potentially novel biomarkers to assess or predict feed efficiency in Black Angus steers on a backgrounding diet.
- Title
- "I sing of cruelty and compassion together": Reading Thomas Nashe's Religious Rhetoric through Kenneth Burke's Perspective by Incongruity
- Author
- Moody, Charles Jeffrey
- Publication Date
- 2019-08
- Publication Type
- doctoral dissertation
- Collection
- Graduate Theses and Dissertations
- Abstract
- This study considers the late 16th - early 17th century English writer Thomas Nashe’s various texts through a rhetorical lens as informed by the 20th century rhetoric scholar Kenneth Burke’s works. Nashe remains an enigmatic character in English literature as he presses the boundaries of appropriateness in various ways, and, despite his attempts to guide his readers to Christian application, the texts present problems for reconciliation with a Christian motive. However, Burke’s discussion of perspective by incongruity and the dramatistic pentad provide a helpful set of terms for understanding how Nashe’s texts work to accomplish such a motive. This study primarily considers three of Nashe’s most well-known texts, Christs Teares over Jerusalem, Pierce Penilesse, and The Unfortunate Traveller, along with the lesser known The Terrors of the Night to present Nashe as consistently pressing the boundaries of rhetorical appropriateness to prompt his readers to a reconsideration of their interior motives. His texts accomplish this goal by developing incongruous perspectives that seek to disrupt the readers’ expectations of each of these types of texts. This study also serves as a working example for combining the disciplines of literary and rhetorical studies in effective ways.
- Title
- Impact of nutritional management strategies on semen quality of developing bulls
- Author
- Proctor, Jarret
- Publication Date
- 2019-08
- Publication Type
- masters thesis
- Collection
- Graduate Theses and Dissertations
- Abstract
- Nutritional management and semen collection method are thought to influence semen quality parameters evaluated during a breeding soundness examination. Therefore, the objective of this experiment was to evaluate the effects of two feeding strategies on growth performance and semen quality of developing bulls. A secondary objective was to quantify the effects of two semen collection methods on semen quality. Angus bulls (n = 48; 332 ± 47 d of age) were stratified into one of sixteen drylot pens before random assignment to one of two iso-caloric diets: a total mixed ration (TMR; n = 8 pens) or a component-based ration (COMP; n = 8 pens). Bulls were assigned to either electroejaculation (EE; n = 24) or trans-rectal massage (RM; n = 24) and each collection method occurred twice throughout an 84-d feeding period. Rumen pH was continuously monitored via rumen boluses and dry matter intake (DMI) was measured daily. Backfat thickness and hoof conformation were measured on d 0 and 84, with body weight measured and semen collected at 21-d intervals. Semen was assessed for progressive motility, total sperm per ejaculate, and sperm cell morphology. Bulls fed the COMP ration had a greater DMI (P < 0.01) and ADG (P < 0.01), but similar feed efficiency (P = 0.19) when compared to TMR-fed bulls. Bulls fed COMP had a lower mean rumen pH (P < 0.01). Additionally, COMP-fed bulls had greater backfat thickness (P < 0.01) but similar hoof conformation scores (P ≥ 0.55) when compared to TMR-fed bulls on d 84. Bulls fed the COMP had greater semen volume (P < 0.05) but feeding management did not affect progressive motility (P = 0.42), total sperm per ejaculate (P = 0.86), or percent morphologically-normal sperm (P = 0.59). However, bulls collected via RM had greater total sperm per ejaculate (P < 0.05), and semen volume (P < 0.01), but lower percent morphologically-normal sperm (P < 0.05) and progressive motility (P < 0.01). Neither diet nor semen collection method affected BSE passage rate (P ≥ 0.34), suggesting minimal influence on BSE outcomes in developing bulls.
- Title
- Embodying Mycenaean Cultural Identity in Late Bronze Age Central Greece: A Bioarchaeological Analysis
- Author
- Stiles, Kaitlyn Elizabeth
- Publication Date
- 2019-12
- Publication Type
- doctoral dissertation
- Collection
- Graduate Theses and Dissertations
- Abstract
- This research is a bioarchaeological examination of the biocultural manifestation of Mycenaean cultural identity in the Late Bronze Age (ca. 1600-1100 BCE) rock cut chamber tomb cemetery of Golemi Agios Georgios (“Golemi”) in central Greece. Biological correlates for Mycenaean cultural identity were identified from current archaeological narratives of Mycenean cultural identity. A biological profile including the minimum number of individuals, age, sex, cranial and dental non-metric traits, non-specific indicators of disease, activity markers, and evidence for cranial trauma was developed for each tomb. The results of these analyses were used to explore the extent to which the mortuary community of Golemi embodied the archaeologically defined Mycenaean cultural identity. Hierarchical Bayesian analysis was used to examine whether some tombs demonstrated significantly more or less of a given skeletal trait. Chi-square and Fisher’s exact tests for independence investigated possible relationships between age, sex, social status, and various indicators of health. The results of all analyses were combined to identify potential spatial relationships between tombs in the cemetery. The results of these analyses indicate that the individuals of Golemi do embody Mycenaean cultural identity, but the extent to which each tomb expresses this identity is variable. Contrary to the overt image of male dominance in Mycenaean cultural identity, females and males are equally represented in the cemetery and female individuals, on average, survived longer than did male individuals. The special treatment of some juveniles and their variable presence in tombs indicates that including juveniles was a highly individualized decision. A significant relationship between non-specific indicators of disease and status was observed suggesting a spectrum of social statuses existed among the tomb groups. The location of wealthy, healthy tomb groups next to relatively poor, less healthy groups may indicate that social networks dictated burial placement rather than familial relationships, thereby reflecting the networked nature of Mycenean culture. Finally, the persistence of Golemi throughout tumultuous periods of the Late Bronze Age suggests that the community was able to successfully adapt to the changing social climate.