<p>This thesis deals with the evolution of individuals within a species adapted to utilize specific resources, i.e. resource polymorphism. Although a well-known phenomenon, the understanding of the mechanisms behind is not complete. Considering the ruling theories, resource polymorphism is suggested to depend on severe competition for resources, the presence of open niches to be occupied leading to a reduction in competition, and disruptive selection where generalist are out-competed due trade-offs in foraging efficiency for different prey. In order to study resource polymorphism, I have used fish as the animal group in focus and the methods I have used range over laboratory experiments, field experiments, literature surveys and theoretical modelling.</p><p>In my work, I have showed that different resource use induces different body shapes and that the rate of change is dependent of the encounter rate of different resources. The induced body changes partly led to increased foraging efficiency but surprisingly I did not find any trade-offs due to specialization. However, when studying predation risk in relation to resource polymorphism, my studies point towards that resource use and predation risk may act as balancing factors in such a way that disruptive selection can take place.</p><p>My work also shows that population feedbacks have to be explored when considering the evolution of resource polymorphism. In pond and field experiments, I found that changes in resource densities affected the actual resource use despite previous adaptations to certain resources. By performing a literature survey, I found that cannibalism indirectly by its effect on population dynamics seems to facilitate the evolution of resource polymorphism. Modelling a size-structured population, I found that resource dynamics were stabilized, and the relative availability of different resources was levelled out due to cannibalism.</p><p>Taken together, my studies strongly suggest that to understand the development of resource polymorphism in consumer populations, future studies have to include the effect of a dynamic environment both with respect to resources and predators.</p>

The human bony pelvis has evolved into its current form through competing selective forces. Bipedalism and parturition of large headed babies resulted in a form that is a complex compromise. While the morphology of the human pelvis has been extensively studied, the changes that have occurred since the adoption of the modern form, the secular changes that continue to alter the size and shape of the pelvis, have not received nearly as much attention. This research aims to examine the changes that have altered the morphology of the human bony pelvic girdle of individuals in the United States born between 1840 and1981. Secular changes in the human skeleton have been documented. Improvements in nutrition, decreased disease load, exogamy, activity, climate, and other factors have led to unprecedented growth in stature and weight. The size and shape of the pelvic canal, os coxa, and bi-iliac breadth were all examined in this study. Coordinate data from males and females, blacks and whites were digitized. Calculated inter-landmark data was analyzed using traditional metric methods and the coordinate data was analyzed using 3D geometric morphometrics. After separating the samples into cohorts by sex and ancestry, results indicate that there is secular change occurring in the modern human bony pelvis. Changes in shape are significant across the groups while only white males exhibit increases in size. The dimensions of the pelvic canal have changed over time. The birth canal is becoming more rounded with the inlet anteroposterior diameter and the outlet transverse diameter becoming longer. These diameters, once limiters, are believed to have led to an adoption of the rotational birth method practiced by modern humans. In addition, the bowl of the pelvis is becoming less flared. Childhood improvements in nutrition and decreases in strenuous activity may be the cause of the dimension changes in the bony pelvis. The similar changes across both sexes and ancestries indicate a similar environmental cause. However, it is likely a combination of factors that are difficult to tease apart. Whether the increases continue remains to be determined.

This thesis deals with the evolution of individuals within a species adapted to utilize specific resources, i.e. resource polymorphism. Although a well-known phenomenon, the understanding of the mechanisms behind is not complete. Considering the ruling theories, resource polymorphism is suggested to depend on severe competition for resources, the presence of open niches to be occupied leading to a reduction in competition, and disruptive selection where generalist are out-competed due trade-offs in foraging efficiency for different prey. In order to study resource polymorphism, I have used fish as the animal group in focus and the methods I have used range over laboratory experiments, field experiments, literature surveys and theoretical modelling. In my work, I have showed that different resource use induces different body shapes and that the rate of change is dependent of the encounter rate of different resources. The induced body changes partly led to increased foraging efficiency but surprisingly I did not find any trade-offs due to specialization. However, when studying predation risk in relation to resource polymorphism, my studies point towards that resource use and predation risk may act as balancing factors in such a way that disruptive selection can take place. My work also shows that population feedbacks have to be explored when considering the evolution of resource polymorphism. In pond and field experiments, I found that changes in resource densities affected the actual resource use despite previous adaptations to certain resources. By performing a literature survey, I found that cannibalism indirectly by its effect on population dynamics seems to facilitate the evolution of resource polymorphism. Modelling a size-structured population, I found that resource dynamics were stabilized, and the relative availability of different resources was levelled out due to cannibalism. Taken together, my studies strongly suggest that to understand the development of resource polymorphism in consumer populations, future studies have to include the effect of a dynamic environment both with respect to resources and predators.

Conodonts are important biostratigraphic tools for the delineation and calibration of the geochronological boundaries within the Carboniferous and used generally as stage-boundary markers for the Lower Carboniferous (Mississippian). The studied successions in the Central and Eastern Taurides were mainly deposited in a shallow marine environment during the Carboniferous time and they comprise less abundant and diversified conodont fauna. The conodont fauna represented by twenty-four species belonging to ten genera have been described from the studied sections (AS / AAO / BSE and HB) in the Taurides (Turkey). Regarding the first occurrences and last occurrences of biostratigraphically significant species within these sections, the following zones have been established across the Lower Carboniferous successions: (1) Polygnathus inornatus Zone (Hastarian-Lower Tournaisian) / (2) Gnathodus cuneiformis &ndash / Polygnathus communis communis Zone (Ivorian-Upper Tournaisian) / (3) Polygnathus mehli mehli Zone (Ivorian-Upper Tournaisian) / (4) Gnathodus girtyi girtyi Zone (Brigantian-Upper Visean) / (5) Gnathodus girtyi simplex Zone (Pendelian-Lower Serpukhovian) / (6) Rhachistognathus muricatus Zone (Zapaltyubinsky-Upper Serpukhovian) and (7) Declinognathodus inaequalis - Declinognathodus noduliferus Zone (Bogdanovsky-Lower Bashkirian). Based on the recovered conodont assemblages, Visean - Serpukhovian boundary has been recognized by the first occurrence of Gnathodus girtyi simplex and the Mid-Carboniferous boundary is delineated by the first occurrence of Declinognathodus inaequalis, which is an index taxon for the basal part of the Bashkirian. Based on the microfacies studies it can be concluded that conodont elements essentially obtained from the crinoidal bioclastic packstone-grainstone, crinoidal packstone-grainstone, coated bioclastic grainstone, intraclastic grainstone and spiculite packstone facies in the studied sections. It can be concluded that that the occurrence of abundant crinoids are indicative criteria for the presence of conodonts. Additionally, geometric morphometric analyses of biostratigraphically important genus, Gnathodus, on the basis of data available in the literature emphasize the importance of numerical taxonomy and reveal that taxonomic revision of this genus is needed.

The Terminal Middle Period (3000 to 2000 B.P.) and the Transitional Late Period (2000 B.P. to 1500 B.P.) contain a number of diverse projectile point styles belonging to several cultural complexes. The cultural complexes studied here include: Pelican Lake, Besant, Outlook, Bracken, Sonota and Sandy Creek. The point styles associated with these complexes have been in the past separated on largely visual or subjective bases. Clarifying the projectile point morphologies during this period will allow for better interpretations of archaeological sites on the Northern Plains. To aid in this clarification, twelve projectile point assemblages from nine previously excavated sites on the Saskatchewan and Alberta Plains were studied. These assemblages were subjected to geometric morphometric and discriminate function analysis. Beyond these two avenues of analysis, the assemblages were also subjected to metric testing to determine if the point styles were more consistent with arrow or dart projectiles. During this time period, the technological transition from the atlatl and dart to bow and arrow appears to have occurred. As a result of the arrow/dart testing, a pattern of robustness was seen in the kill site assemblages as compared to the habitation site assemblages. This resulted in larger points being found in communal kill sites in the study suggesting a link between game size and hunting methods. The result from this analysis recommends a reduction in the independent point styles suggested by other researchers. The data trends towards the finding that two major cultural complexes existed in the Terminal Middle / Transitional Late periods in the studied region of Northern Plains, Pelican Lake and Besant. A third minor group morphologicaly between the two major groups.

<p>Fossil taxa are crucial to studies of brain evolution, as they allow us to identify evolutionary 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 evolution, by evaluating variation in the endocranial morphology of extant primates and their fossil representatives. I use a comparative approach to examine the relationships between interspecific adult endocranial volume and shape, and brain evolution and cranial form among extant primate clades and their fossil representatives. The associations are evaluated via phylogenetically informed statistics perfomed on volumetric measurements and three-dimensional geometric morphometric analyses of virtual endocasts constructed from micro-CT scans of primate crania. Fossil taxa included in these analyses are: 1) anthropoids Parapithecus, Aegyptopithecus (Early Oligocene, Egypt), Homunculus and Tremacebus (Early Miocene, Argentina), and 2) Eocene euprimates Adapis and Leptadapis (Eocene adapoids, France), and the Rooneyia (Eocene omomyoid, Texas). </p><p>The first part of this work (Chapter 2) explores variation in residual mass of brain components (taken from the literature) among primates, and evaluates the correlated evolution of encephalization and brain proportions with endocast shape, quantified via three-dimensional geometric morphometric techniques. Analyses reveal a broad range of variation in endocast shape among primates. Endocast shape is influenced by a complex array of factors, including phylogeny, body size, encephalization, and brain proportions (residual mass of brain components). The analysis supports previous research, which concludes that anthropoids and tarsiers (Haplorhini) share the enlargement of several key brain regions including the neocortex and visual systems, and a reduction of the olfactory system. Anthropoids further differ from strepsirrhines in endocranial features associated with encephalization--a more flexed brain base, an inferiorly deflected olfactory fossa--and those associated with brain proportions--a small olfactory fossa, and a more caudally extended cerebrum that extends posteriorly past the cerebellar poles. Tarsiers are unique in having a mediolaterally broad and rostro-caudally short endocast with an attenuated anterior and middle cranial fossae. This morphology is likely related to the extreme orbital enlargement in this taxon, which limits anterior expansion of the endocranium. Finally, despite the correlation between residual endocranial volume and endocast shape among modern primates, early anthropoid fossils demonstrate a disconnect between these factors in sharing key features of endocast shape with extant anthropoids at a relatively small brain size. </p><p>The second part of this thesis (Chapter 3) explores the relationship between craniofacial organization--cranial base angle, facial size, facial hafting--and encephalization via the lens of the Spatial Constraints and Facial Packing Hypotheses. These hypotheses predict that interspecific adult variation in encephalization correlates with endocranial shape such that a larger brain for a given body size will be more "globular" or spherical in shape. These hypotheses futher predict that basicranial angle covaries with encephalization and that the relative size of the endocranium and facial skeleton will have an antagonistic effect on basicranial angle and facial hafting. Results show that various measures of globularity have inconsistent and weak relationships to phylogeny, encephalization, and basicranial flexion, owing to a diversity of clade-specific scaling patterns between the maximum length, breadth, and width of the endocast. Among extant primates, there is weak but significant evidence to suggest that both facial size and encephalization influence variation in basicranial flexion. Considering the fossil specimens in isolation, their relative ranks in encephalization, basicranial flexion, and midline facial size and shape follow the pattern expected from the Spatial and Facial Packing Hypotheses outlined above; however, relative to modern species, the early fossil anthropoids have more flexed cranial bases and shorter facial skeletons at much smaller level of encephalization than seen in modern anthropoids. </p><p>Together, the extant data suggest a moderately conserved pattern of correlated evolution among endocranial size, endocranial shape, brain proportions, and craniofacial organization, which may explain differences in endocranial and facial shape between extant strepsirrhine and anthropoid primates; however, the fossil record for early anthropoid evolution demonstrates that a shift towards key anthropoid-like traits of the endocranium, basicranium, and facial skeleton were initiated early in anthropoid evolution, with subsequent encephalization occurring within and among members of this clade. Thus, these anthropoid cranial traits evolved in tandem with changes in the relative size of brain components, rather than absolute or relative brain size alone. Basicranial flexion, facial length and orientation are influenced by both: 1) shifts in endocranial shape associated with changes in brain proportion--accounting for the initiation of the anthropoid-like craniofacial plan early in the evolution of the clade--and 2) encephalization, which influenced subsequent morphological divergence among extant anthropoid groups.</p> / Dissertation

This is a study of the factors that affect face shapes, and the techniques that can be used to measure variations in two dimensional representations of faces. The materials included thirty photographs of people in natural poses and thirty portraits that were based on the pose photographs. Visual assessors were asked to score the photographs and portraits in terms of pose (cant, turn and pitch) and also to compare the portraits to the photographs and score them in terms of likeness in the depiction of the face and its component features. Anthropometric indices were derived and used to score the images for the pose variables as well as for aspects of individual variation in external face shape and the spatial arrangement of the features. Geometric morphometric analysis was also used to determine the shape variation occurring in the photographs, the variation within the portraits, and to specifically discern where the portraits differ from the photographs in the depiction of head pose and individual differences in facial morphology. For the analysis of pose it was found that visual assessors were best at discerning the extent of head turning and poorest at discerning head pitch. These tendencies occurred in the visual assessments of both the photographs and the portrait drawings. For the analysis of the individual variation in face shapes it was found that external face shape varies according to upper face dimensions and the shape of the chin, and that vertical featural configurations are strongly linked to external face shape. When the portrait and photograph data were placed in the same geometric morphometric analysis the inaccuracies in the portrait drawings became evident. When these findings were compared to the visual assessments it transpired that, on average, visual assessment was generally congruent with the geometric morphometric analysis, but were possibly confounded by patterns of dysmorphology in the portraits that were contrary to what this study suggests are normal patterns of face shape variation. Overall this study has demonstrated that while anthropometric and visual assessments of facial differences are quite good, both were comparatively poor at assessing head pitch and tended to be confounded by the dysmorphologies arising in the portrait drawings. Geometric morphometric analysis was found to be very powerful in discerning complex shape variations associated with head pose and individual differences in facial morphology, both within and between the photographs and portraits.

In the past few decades, an area of skeletal research focusing on shape analyses has gained popularity in the field of physical anthropology, and subsequently forensic anthropology. Known as geometric morphometrics, this type of analysis allows the researcher to place the morphological shape of bones into a statistical framework to answer questions on a variety of topics, including sexual dimorphism. Sex assessment from the long bones has been traditionally conducted using traditional morphometric methods (Iscan and Miller-Shaivitz 1984; Steyn and Iscan 1997), and as a result, relies mainly on size differences and has not considered how joint morphology and shape affect sex. For this project, a geometric morphometric analysis of the proximal tibia in a modern Caucasian American population was conducted using a sample of 100 male and 100 female tibiae from the William M. Bass Donated Skeletal Collection at the University of Tennessee at Knoxville. The proximal tibia's effectiveness as an indicator of sex in a modern American population was evaluated via generalized Procrustes, principal components, and discriminant function analyses. Principal components revealed a lack of separation between males and females in terms of proximal tibia shape. The discriminant function analysis was successful at discriminating males from females, but cross-validation yielded a low total accuracy rate of 58%. The shape of the proximal tibia contributes to sexual dimorphism in a Caucasian American population, but is only slightly useful in a discriminant function. Further research should be conducted on different populations and using different skeletal landmarks.

The use of geometric morphometrics (GM) in physical anthropology has increased markedly over the recent years. In current studies of secular change, anthropologists have more frequently turned to this technique as it provides scientists with a powerful tool for shape analysis. Secular change is defined as changes in the skeletal biology, usually seen in a population, resulting from shifts in living standards or exposure to a new environmental factor over a short timeframe (Jantz and Meadows Jantz 2000; Weisensee and Jantz 2011). Studies conducted in Europe, Asia, and the United States have shown significant signs of secular change in craniofacial morphology. This thesis will utilize GM analyses of 57 craniofacial landmarks from 313 individuals to determine secular change in the European male populations of the Raymond A. Dart and Pretoria Skeletal Collections located in Johannesburg and Pretoria, South Africa, respectively, with birth years ranging from 1850 to 1956. Craniofacial data points were collected using a 3D Microscribe digitizer, upon which the Generalized Procrustes Analysis (GPA) was used to align all landmarks into one coordinate reference plane. In order to determine the presence of shape change, a Principal Components Analysis (PCA) was run on the Procrustes coordinates of all individuals. Then, a multivariate regression of shape score on year of birth was conducted to determine the magnitude of change as explained over time. Following the multivariate regression, various Canonical Variates Analyses (CVA) were performed to determine whether secular change was occurring. In addition to collecting metric data, ultimate and proximate causes are explored to provide a more holistic understanding of the potential reasons for the changing or unchanging nature of the crania in the ancestrally European South African population. This study hypothesizes these collections will exhibit craniofacial secular change resulting from greater exposure to increased nutrition over time, greater access to healthcare, and socioeconomic and political stability. Additionally, genetic factors could be affecting the development of the crania through time. As many studies use the Dart and Pretoria collections in tandem to understand population-specific traits of modern South Africans, the presence of secular change will greatly affect the way researchers utilize samples for their studies. Forensic anthropologists study collections to create better estimations for elements of the biological profile such as stature, age, and sex. However, failure to take into account secular change would provide erroneous results. This study provides answers regarding the need to account for secular change if necessary. This research indicates that there are some changes occurring in the craniofacial morphology as see by the PCA, but the results of the CVA indicate that this is not necessarily due to secular change. The results do not clearly indicate the presence of secular change. There are many possibilities dictating potentially why. The first possibility is that there are small changes occurring in the craniofacial morphology; however, this is not caused by secular change. There are other variables, potentially genetic, that are influencing these slight changes that we see. Despite other nations with similar economic development trajectories experiencing a definite presence of secular change, the unique history and population structure of European South Africans could be contributing to the lack of secular change present. Another possible reason is the lack of passage of time from the industrialization of the nation. Furthermore, there is potentially not enough data tested to warrant a reliable conclusion that secular change is or is not occurring. With the cranium, the possibility exists that a minimum threshold of specimens is needed in order to have a reliable conclusion.

This project analyzes the sexual dimorphism of the femur and tibia using geometric morphometrics. The study sample includes 250 individuals of known sex and age at death with complete, non-damaged, non-pathological skeletal remains from the William M. Bass Donated Skeletal Collection at the University of Tennessee, Knoxville. Ages range from 19-96 for males (mean=56.92 years) and 29-97 for females (mean=59.48 years). A combination of landmarks and semi-landmarks were collected on the proximal and distal epiphyses of each bone using a Microscribe, which helps capture the overall size and shape variation present in the sample. Only individuals from one population, White, where analyzed in order to eliminate population variation bias. Classification rates for males and females for the proximal femur were 80.8% and 78.4% respectively, for the distal femur 92.6% and 89.6% respectively, for the proximal tibia 80.8% and 83.2% respectively, and the distal tibia 81.6% and 80.8% respectively, all with a p<0.0001. These rates created a classification model for which epiphysis gave the most accurate assessment of sex: the distal femur, followed by the proximal tibia, then the distal tibia, and lastly the proximal femur. This study indicates the knee joint is the most dimorphic, followed by the ankle and then the hip. The results fall in line with another study indicating the knee is more sexually dimorphic in a modern White population (Spradley and Jantz 2011), though in contrast to their results this study found the distal femur was more dimorphic than the proximal tibia. This method indicates that in comparison to standard measurements, geometric morphometrics may provide a more reliable method for sex estimation when used, specifically on the knee. Certain landmarks were then selected based on the standard taphonomic process of coffin wear and postmortem damage (Pokines and Baker 2014) for exclusion to determine the usability of the method on fragmented or damaged skeletal remains. When combinations of landmarks were removed, the distal femur still possessed the highest classification rates with over 80% accuracy.