Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 35 for “"shape variation"”.
-
Endocranial volume and shape variation in early anthropoid evolution
… trends in relative brain size and brain shape that may not otherwise be identifiable in comparative studies using only extant taxa, owing to multiple events of parallel encephalization among primate clades. This thesis combines indirect and direct approaches to understanding primate …
-
Geometric morphometric analysis of skeletal shape variation across the pleuronectiformes
1 PDF file (vii, 94 pages)
-
Assessing primate skull shape variation in relation to habitat: a 3D geometric morphometric approach
… adaptation as an evolutionary response. Shape-space data and multivariate statistics quantify shape variation patterning and, therefore, consolidate hominoid systematic procedures. This thesis identifies ecomorphological patterns of variation within extant primates. Through a comparative, …
-
Reproductive Life History and Shell Shape Variation of Three Species of Elimia (Pleuroceridae) in the Lower Etowah River Basin
… where egg deposition could be monitored. Shell shape was assessed using Geometric Morphometrics. Although there was some overlap, shell shapes differ significantly among the three forms. Shell sculpture differences appear early in juvenile forms and the three species are distinguishable by the …
-
Investigating the functional and adaptive significance of leaf size and shape variation in Jamesbrittenia (Scrophulariaceae (s.s). tribe Manulae) : an experimental and comparative approach
… the functional significance of leaf size and shape variation, as well as the patterns of leaf form variation in the genus Jamesbrittenia within the context of phylogenetic history. Leaf sizes 63-measured Jamesbrittenia varied between 0.006cm² (in J. microphylla) and 6.52cm² (in J. megaphylla). …
-
Human Physiology and Acheulean Handaxe Design
… designed to study handaxe design and sources of shape variation using novel methodological approaches. The main goal is to examine their shape variation from a physiological perspective since most studies focus on functional and/or cultural aspects of handaxe manufacture and use. This is …
-
Modelling non-linearity in 3D shapes: A comparative study of Gaussian process morphable models and variational autoencoders for 3D shape data
The presence of non-linear shape variation in 3D data is known to influence the reliability of linear statistical shape models (SSM). This problem is regularly acknowledged, but disregarded, as it is assumed that linear models are able to adequately approximate such non-linearities. Model …
-
The Interactive Effects of Multiple Stressors on Lithobates catesbeianus and Anaxyrus americanus
… Glyphosate caused significant anatomical shape variation in <em>L. catebeianus</em>, while increased temperature caused significant anatomical shape variation in <em>A. americanus</em>. The shape variations caused by the different stressors may lead to further developmental and behavioral …
-
The shape of diversity: a morphometric analysis of late archaic bifaces from Lamoka Lake
… of community of practice, I have shown that tool shape variation could indicate distinct social groups. Using computer software to digitally outline bifaces I compared the shape of over 400 bifaces from Lamoka Lake and statistically analyzed their morphologies in order to provide material …
-
Visual object tracking
… the tracker will predict the location and the shape of the target in the following frames. Despite the significant research effort that has been dedicated to this area for several years, this field remains challenging due to a number of issues, such as occlusion, shape variation and drifting, …
-
An automated computer-assisted approximation of the nose in South Africans from CBCT (Cone Beam Computed Tomography) scans
… models for predicting nasal soft-tissue shape from information about the underlying skull substrate. The acquisition and extraction of the relevant anatomical structures (hard- and soft-tissue) were performed using an automatic dense landmarking procedure and analysed by geometric …
-
The Effect of Isolation by Waterfalls and Dams on Stream Fish Morphology
… were used to quantify differences in fish body shape based on species-specific landmarks. Significant intraspecific differences between stream populations and between above-barrier and below-barrier populations were found in three species. The majority of body shape variation was associated with …
-
Dental morphology and variation across holocene Khoesan people of Southern Africa
… people. There have been many studies of dental variation in Holocene populations of Europe and the Americas, but few of African populations. Despite the Khoesan being the focus of much osteological research over the last two decades, their dental morphology is understudied and we know little …
-
Fatal Restrictions: Exploring State-Level Abortion Laws, Sociodemographic Contexts, and Maternal Mortality in the United States
… public assistance, unemployment, and income, shape variation in MMR across U.S. states from 2018 to 2022. Using a state-level analysis, I classify abortion laws along a restrictive-protective continuum and use multiple linear regression models to assess the independent effects of …
-
Bat Skull Evolution: the Impact of Echolocation
… for the Phyllostomidae family). Morphological variation related to other drivers of adaptation (in particular echolocation) remains understudied. In this thesis, I investigated the relationship between bat skull morphology (i.e., size and shape) and functional traits (i.e., feeding and …
-
Effects of environmental change on species: Marvacrassatella lineage and the Plio-Pleistocene record of sea level change
… valve. Principal-components analysis assessed shape variation within the Marvacrassatella lineage. Canonical discriminant analysis on geometric means produced two canonical variables that explain the separation among species. Most changes in shell and muscle shape occurred in adductor muscle …
-
Phylogeographic and morphometric studies on the Eurasian pygmy shrew Sorex minutus: insights into its evolutionary history and postglacial colonisation in Europe
… but skulls showed no evident trend in size variation. Shape variation was significant but modest when analysing the sample divided into phylogeographical groups. However, the samples from different islands within the British Isles show that island evolution played an important role in …
-
A comparison of the subspecific divergence of two sympatric African monkeys, Papio hamadryas & Chlorocebus aethiops: morphology, environment, diet & phylogeny
… and both exhibit extensive subspecific variation corresponding to geotypic forms. This thesis compares these two subspecific radiations, using skull morphology to characterise the two taxa, and attempts to determine if the two have been shaped by similar selective forces.The baboon …
Page 1 of 2