Thesis (Ph.D.)--Indiana University, Dept. of Anthropology, 2006. / "Title from dissertation home page (viewed July 16, 2007)." Source: Dissertation Abstracts International, Volume: 67-10, Section: A, page: 3878. Advisers: Travis R. Pickering; Kevin D. Hunt.

Temperature plays an important role in shaping the form and function of every species. Ectothermic organisms are particularly sensitive to fluctuations in their thermal environment. Their inability to produce appreciable amounts of heat through physiological mechanisms makes them particularly vulnerable to thermal shifts, and ideal for the study of temperature-mediated evolution. The central goal of this dissertation is to understand how temperature shapes the evolutionary history of terrestrial ectotherms during the colonization of novel environments. Towards this aim, I focus on a single species of lizard, the North American green anole, Anolis carolinensis. In the first chapter of my dissertation I trace the phylogeographic history of A. carolinensis in order to identify the geographic distribution of major genetic lineages within the species and its Cuban relatives, date times of divergence between these lineages, and identify geographic barriers to dispersal. In the second chapter, I use an integrated approach to identify aspects of the environment that may have influenced evolutionary adaptation within the species. I combine geo-referenced climate data, environmental niche modeling, thermal physiology, common garden experiments and genomic techniques to understand phenotypic and genomic response of this historically subtropical Cuban lizard to the more temperate regions of the American Southeast. Finally, in the third chapter I use experimental temperature manipulations and physiological testing to explore the roles of phenotypic plasticity and local adaptation in shaping latitudinal variation in thermal tolerance and identify potential systemic mechanisms involved. As a result, I have identified a Miocene origin of the initial over-water dispersal event leading to the establishment of the green anole in peninsular Florida, followed by a rapid Pleistocene range expansion of the species northward into higher latitudes. Range expansion on the mainland has led to thermal niche expansion, mediated by a combination of local adaptation of cold tolerance and genetic isolation by environment between populations from different thermal habitats. Phenotypic plasticity and canalized differentiation both shape variation in cold tolerance across latitude and energy conservation via metabolic suppression under acute and chronic cold onset may help to extend the limits of cold tolerance in this species at its northernmost latitudes. / Biology, Organismic and Evolutionary

The vertebrate head is a complex structure derived from all three embryonic germ layers. Cranial mesoderm forms most of the neurocranium, cardiovascular tissues and voluntary muscles required for intake of food and oxygenated fluid. Despite its essential role in shaping cranial and neck anatomy, long-term fate maps of cranial mesoderm are known only from the mouse and chicken, as effective labeling techniques for use in other species have been developed only recently. Data from additional species are needed to determine the embryonic origin of features absent in amniotes but present in other vertebrates and to evaluate the extent of conservation in the development of homologous structures. This dissertation examines the role of cranial mesoderm as well as its interactions with neural crest in shaping the tetrapod craniofacial and neck region, focusing on the skull and head muscles in the axolotl, Ambystoma mexicanum. I demonstrate a dual embryonic origin of the pharyngeal skeleton, including derivation of basibranchial 2 from mesoderm closely associated with the second heart field. Additionally, heterotopic transplantation experiments reveal lineage restriction of mesodermal cells that contribute to pharyngeal cartilage. The entire parietal bone is derived from mesoderm. Several structures arise from both mesoderm and cranial neural crest, including the squamosal, parasphenoid and stapes. The mesodermal contribution to the dorsal portion of the squamosal bone supports the homology of the corresponding dorsal ossification center, which fuses to the ventral center early in development, to the supratemporal, a bone lost repeatedly in tetrapods. I locate the posterior limit of myogenic cranial mesoderm, extending the head-trunk boundary to the axial level of the third somite. Using fate mapping, gene expression and comparative anatomy, I provide evidence that the cucullaris muscle, a homologue of the mammalian trapezius, is a cranial muscle allied with the gill levators of anamniotes. Finally, I generate two novel transgenic lines of Xenopus tropicalis that will be used to fate map neural crest and mesoderm. Taken together, these results add to our understanding of cranial homologies and point to a larger role for cranial mesoderm in the evolution of a mobile neck. / Biology, Organismic and Evolutionary

Bipedalism is commonly assumed to be an adaptive convergence because it has evolved independently three times in small desert rodents. However, the functional benefits of bipedality in this ecosystem have long been unclear. In this thesis I integrate phylogenetics, functional morphology, biomechanics, information theory, and behavior to investigate whether and how bipedality increases fitness in desert ecosystems, and whether bipedal rodents convergently evolved to have the role in their respective ecosystems. Based on the diversity of extant dipodid rodents, I begin by statistically reconstructing the pattern of morphological evolution in jerboas. I find that the strongest indicator of bipedality is metatarsal to humerus length, and that changes in this ratio are associated with increased rates of speciation, supporting a punctuated equilibrium pattern of evolution in this clade. Furthermore, the distinct patterns of morphological evolution suggest that a complex suite of genetic and developmental mechanisms governs the acquisition of bipedality in jerboas. I then use an inverse dynamics approach to characterize the biomechanics of bipedal hopping in a derived jerboa. I find that the dynamics of jerboa hopping are generated predominantly by muscular contractions, rather than tendon--based elastic energy storage and return between strides. Therefore hopping in small rodents favors rapid production and absorption of forces, rather than sustained bouts of steady--state locomotion. By reviewing predator--prey studies in biomechanics, ecology, and evolution I hypothesize that ricochetal locomotion enhances the ability of small rodents to evade predators that hunt via ballistic interception. I then develop Information Theoretic techniques to measure the unpredictability of escape trajectories in sympatric bipedal and quadrupedal rodents. As expected, bipedal rodents use significantly more unpredictable escape trajectories, likely enhancing predator evasion ability and enabling foraging in exposed areas with higher predation risk. I then found that bipedal rodents exhibit a stronger preference for exploring open spaces, matching previously established foraging patterns. These findings suggest that the evolution of bipedality enables spatial resource partitioning to limit interspecific competition in desert rodents. Based on the functional studies in my thesis, I evaluate ecological models to predict the occurrence of convergent bipedal rodents in Myomorpha. I show that diet specialization and aridity are insufficient to predict the locomotor morphology of these rodents and develop novel hypotheses for the convergent evolution of bipedalism in desert rodents. My thesis investigates the functional consequences of morphological evolution in the context of evolutionary ecology. By considering the interconnectedness of ecology, behavior, and evolution, studies in biomechanics can be designed to inform each of these fields. This interdisciplinary approach is necessary to study the adaptive nature of behavioral traits that are governed by myriad genetic, developmental, and environmental factors. / Biology, Organismic and Evolutionary

Although young children can sometimes produce words in a near perfect form at a very early stage, several diary studies revealed that these correct first productions are usually followed by less faithful renditions, only to be returned later to relative accuracy. In order to investigate if this nonlinear pattern of children vocal production called “phonological regression” might also be shared with birds, we examined here the trajectory of vocal development of a young African Grey parrot (Athena) who is learning referential English. Parrots are excellent model systems for the study of speech acquisition as they possess advanced cognitive skills and are expert imitators of the human voice. By tracking Athena’s acquisition of vowel-like sounds over the course of fifteen months using audio recordings and acoustic software programs, we analyzed her vocal development over time, from her first squeaks to her more distinct pronunciations, and compared her progress with human children and other parrots in the lab. Not one, but multiple U-shaped curves characterized her acquisition of isolated labels. Our results indicate that, like human children, parrots can experience the phenomenon of phonological regression.

Rabies virus, a negative sense single-stranded RNA virus, is the type member of the genus Lyssavirus of the Rhabdoviridae . The glycoprotein (G), which projects from the surface of the lyssavirus particle, is the only protein known to be capable of eliciting the production of neutralizing antibodies and knowledge of the antigenic nature of this protein is therefore important. Five different antigenic sites have been mapped on the G protein. In this study, the isolation of mutants resisting antibody neutralization (escape mutants) was attempted by a selection strategy employing three distinct strains of rabies: Evelyn Rokitnicki Abelseth (ERA), Big Brown Bat (BBB), and Silver Haired Bat (SHB). No escape mutants were generated from BBB and SHB but a total of seven independent ERA mutants were recovered using monoclonal antibodies (Mabs) directed against antigenic sites I and IIIa of the glycoprotein. (Abstract shortened by UMI.)

acase@tulane.edu

acase@tulane.edu

The Osa Peninsula is one of Costa Rica's most biodiverse areas with more large mammals than anywhere else in the country. During the last two decades, however, mammal species have been subject to illegal hunting pressure of unknown amounts. The goal of this dissertation is to investigate the knowledge and attitudes of villagers and local leaders of Osa Peninsula regarding large mammals and their use, and to compare various estimates of wildlife abundance to assess potential effects of human activities during recent years. From surveys, 58% the 359 interviewees from 15 communities believe that in 1993 there were more wild animals than 2008. Paca is the most poached species, and second in importance is the white-lipped peccary. The main motivation for poaching is for local consumption, but 62% of interviewees strongly disagreed with the notion of poaching being a legitimate activity. Interviews with local leaders indicated that 63% strongly agreed that wildlife persistence is important for the development of the area. They believe that deforestation, poaching, and gold mining are the main activities negatively affecting wildlife species on the Osa Peninsula. During 2001 and 2002 I estimated Relative Abundance Indices (RAI) of nine species of vertebrates from tracks in three sectors differing in human activity: gold mining, farming, and indigenous people's activities. I found that jaguar, puma, white-lipped peccary, tapir, and great curassow had lower RAIs in the mining sector. Other species such as collared peccary, red brocket deer, agouti, and paca were just as common outside the Park as inside. I set up camera trap stations in the core and toward the edge of the CNP during 2003 and in the core of the park in 2008. There were few significant differences in the RAIs of the nine species near vs. far from the park, but abundance some species differed between years, likely a result of an increase in amount of patrolling by park rangers during that time. The results of this study provide insights into perceptions and behaviors of local residents, and into wildlife population changes, that can be used in the conservation of the mammals species in the Osa Peninsula.

No description available.