Modern humans have large, encephalized neonates, delivered through an anteroposteriorly narrow maternal pelvis constrained by adaptation to bipedality. As a result, human birth is unusually laborious, difficult, and dangerous. The evolutionary background for these difficulties is unclear. Previous comparative studies of nonhuman primates have focused on the pelvic inlet, which is a region of constraint in humans but not in other primates. Therefore, the true obstetric constraints in other species remain unknown. This dissertation documents and quantifies human and other primate birth-canal morphology between the three traditional obstetric planes (inlet, midplane, and outlet). Computer-generated images of scanned specimens of 23 extant anthropoid species and five fossil hominins are used to compare the entire birth canals as three-dimensional entities, documenting and analyzing the functionally relevant metrics of the maternal pelvis and the fetus and their species-specific obstetric constraints. In fossil hominin species for which pelvic material is fragmentary, composite pelves were reconstructed. Measurements on these pelves allow for an estimation of the factors (fetal head and shoulders, pelvic morphology) that produce points of potential dystocia, and shed light on how the modern human birth mechanism evolved. The results of these analyses indicate that some non-human primates have obstetric constraints that exceed those of modern humans. The cephalopelvic disproportion in these species is alleviated through various mechanisms which are unattainable in humans, such as a face-first fetal presentation. Human childbirth can no longer be described as uniquely difficult compared to that of the other primates. Among fossil hominins, birth canal morphology exhibits shape variations that differ from those in modern humans and would have promoted different patterns and mechanisms of birth. The locations of maximum obstetric constraints also vary among hominin species, and the pattern of interspecific variation does not present a linear evolutionary trajectory from “easy” to “difficult” childbirth. The risk of prolapse that accompanies hominin bipedality does result in an adaptation to reduce obstetric constraints, fetal cranial molding, which may have arisen in the hominin lineage ~700,000 years earlier than previously thought.

The purpose of this study is to present the biological affinity of four Taiwanese Indigenous groups. Previous studies based on linguistics and ethnography had shown that there are differences between the indigenous groups in Taiwan (Ferrell 1969; Utsurikawa et al. 1935). Archaeological remains also indicate that there was a wide variety of groups (Tsang 1995). In order to provide some biological evidence for this issue, the present research estimated the biodistance from both cranial measurements and non-metric cranial traits between the four Taiwanese Indigenous groups (Atayal, Bunun, Babuza, and Pazeh) from modern collections. It is hypothesized that the Taiwanese Indigenous groups would have significant biological differences: the Atayal and Bunun samples (mountain indigenous) would cluster, while the Babuza and Pazeh (lowland indigenous) would cluster separately. The two hypotheses were supported from both craniometric and non-metric data in the present study. Limited comparison with groups from other areas was also performed in order to examine the possible dispersal pattern of the Taiwanese Indigenous groups. Craniometric data from three samples (South Japan, Philippines, and Hainan) from the William W. Howells Craniometric Data Set and non-metric data of four samples (Philippines, South China, Southeast Asians, and Okinawa) from Fukumine et al. (2006) were used. Since the popular hypothesis of the Austronesians’ origin suggests that there was intensive movement between Taiwan and Philippines (e.g., Bellwood 1988; Diamond 2000; Melton et al. 1995; Solheim 1988; Su et al. 2000; Trejaut et al. 2005), it is hypothesized that the Taiwanese Indigenous groups would show the closest affinity with the samples from Philippines while the other groups would be in another cluster. However, this hypothesis is not supported in the present study. The result showed that the Taiwanese Indigenous groups and those from the Philippines are relatively distant. This supports the hypothesis of Tsang (2012) that the early dispersal of Austronesian groups may have occurred several times through multiple routes to Taiwan and the Philippines.

<p> Captive animals demonstrate a number of differences compared to their wild counterparts, with the suite of some of the most common, and arguably deleterious, referred to collectively as domestication syndrome. Scholars have proposed a number of different variables and mechanisms for the changes, with captive diet being one of the prominent explanations. This thesis explores the effects of captivity on the skulls and mandibles of Malagasy lemurs (predominantly ring-tailed lemurs <i>Lemur catta</i>) using relative linear measurements and selected ratios, gathered from natural history museum collections. I predicted that captive and wild individuals would show differences in cranial measurements related to mastication, which would be driven by their different diets and the exploitation of the kily fruit <i>Tamarindus indica</i> (H1_A). I also predicted that wild individuals would show more overall variation due to consumption of broader, less consistent diets (H1_B). Finally, I predicted that a multivariate model would be able to properly predict captivity status in <i>Lemur catta</i> using linear variables. Captive <i> Lemur catta</i> showed significantly (p = 0.0126) shorter relative post-palatal lengths than their wild counterparts, supporting H1_A, and significantly (p = 0.0374) smaller variance in the inio-orbital (post-facial) region, supporting H1_B. However, captive individuals showed significantly (p = 0.0390) greater variance in anterior flexion of the angular process, which refuted H1_B. A step-wise discriminant function model was able to properly predict captivity status in a sample of n = 18 <i>Lemur catta</i> using four linear variables (R² = 0.9336). Descriptive statistics across sex and other lemur species revealed differences that should be noted by scholars, specifically significantly (p = 0.0250) longer alveo-orbital AO (pre-facial) regions in male <i>Lemur catta</i>. The findings of this thesis, including its critique of physical and intellectual conservation of data, should be taken into account by museum professionals, animal husbandry personnel, and morphologists alike, and all measurements and findings shall be published on open access servers.</p><p>

abstract: This study examined the ontogeny of body mass (i.e. "growth") of Otolemur garnettii and Galago senegalensis. Growth is a proximate causal mechanism for adult size variation and growth patterns themselves can be the target of selection with adult size being the end result. Therefore, growth patterns of species can be the result of adaptation to species-specific social system, ecology, and life-history. The goals of this study were to: (1) Assess whether interspecific body mass variation was due to differences in growth rate, growth duration, a combination of the two, or neither; (2) test the hypothesis that sexual size dimorphism is attained by differences in relative growth rate as predicted by sexual selection theory; and (3) test the hypothesis that frugivorous O. garnettii grow at a relatively lower rate than gummivorous Go. senegalensis as predicted by an ecological risk aversion hypothesis. Growth rates and durations of Otolemur garnettii and Galago senegalensis males and females were compared both interspecifically and intraspecifically. The hypotheses regarding the ontogeny of sexual size dimorphism and the risk aversion hypothesis were not supported. O. garnettii males and females grow at an absolutely higher rate and for a longer duration compared to Go. senegalensis males and females respectively. O. garnettii females grow at a relatively higher rate compared to Go. senegalensis females as well. This may relate to weaning habits. O. garnettii infants are weaned during the dry season when feeding competition would be presumably high making large mass at weaning advantageous. While the growth of females might be strongly influenced by natural selection and competition for resources following weaning, the growth of males may be more strongly influenced by sexual selection relating to contest competition for females. Sexual size dimorphism results from differences in growth duration in O. garnettii and from differences in both growth duration and growth rate in Go. senegalensis. The results of this study highlight the need for more data on the growth patterns, mating and social systems, feeding competition, and life history schedules for these and other galagids. Study of how and why growth patterns have diverged through evolution is important in discerning the evolutionary history of each species. / Dissertation/Thesis / Ph.D. Anthropology 2011

<p> The femoral bicondylar angle is often associated with bipedality in the fossil record because it forms during ontogeny as the result of biomechanical stress. However, the exact mechanisms responsible for its formation remain unknown. Two dominant theories based on static models are assumed in the literature, one focused on skeletal architecture at the proximal femur and one on architecture at the distal femur. The proposed relationships have never been statistically analyzed. This study aims to investigate several of the skeletal measurements at the proximal and distal femur often associated with the theories on the formation of the bicondylar angle, in order to determine if correlations do exist between them and the degree of bicondylar angle in adulthood.</p><p>

This thesis focuses primarily on hypotheses about the causes, extent, and nature of Ancestral Pueblo violence from the tenth through the fourteenth centuries using information gleaned from human biological remains from two regions, La Plata and Chaco Canyon. Hypotheses surrounding the use of violence in Ancestral Pueblo Cultures from the San Juan Basin (A.D. 900 to 1200) were tested using a multidisciplinary scientific approach that includes osteological and bioarchaeological data in conjunction with available archaeological data. The archaeological theories are derived from broad patterns of evidence based on reconstructions of the paleoenvironment, regional settlement patterns, site construction, and local contexts. This complex analysis of violence is accomplished through the examination of human remains from three pre-Columbian sites in the American Southwest, La Plata (LA 37592 and LA 37593) and Peñasco Blanco. Through the use of taphonomic science, marks on the skeletal material were identified as either abiotic or biotic and their causes discussed. Those marks produced from violence and warfare were examined in association with the complex social and cultural interactions that can lead to violence. Violence and warfare are both defined, and the idea of violence as a cultural performance is advocated through the concept of the Politicization of the Dead. This work revises recently proposed patterns of violence in the prehistoric Southwest and offers an alternative hypothesis for the multiple types of cultural taphonomic processing seen on the various human skeletal assemblages throughout the prehistoric American Southwest.

This dissertation examines the relationship of form and function in the foot of four species of hominoid; Homo sapiens, Pan troglodytes, Gorilla gorilla, and Pongo pygmaeus. The study is both analytic and comparative; that is, objectives include both analysis of the funtioning of the anatomical system of the foot, and comparison of this system in several closely related organisms exhibiting very different types of positional behavior. The investigation utilizes the joint-link approach of Dempster, and focuses on the functional complex rather than the single structure. Analysis of a particular complex, such as a joint, integrates anatomical data relating to muscle and ligament size and disposition and joint configuration, with osteometric data pertaining to the size of articular surfaces and the shape and proportions of the osseus structures. Several new osteometric measurements have been derived which are more relevant in assessing function than previously used linear measures. The four species with which this study is concerned exhibit very different types of positional behavior. Chimpanzees exhibit the widest range of behavior, being at home in the trees or on the ground. Gorillas are more terrestrial but are also capable of arboreal activities. The foot of these African pongids is more "generalized" than that of humans or orangs. The mobile tarsus can be stabilized in certain positions, and the powerful hallux can be used in a wide range of prehensile and non-prehensile activities. Humans use the foot as a base of support and as a propulsive organ in bipedal striding and running. The stabilized tarsus and adducted hallux are used as levers in raising the center of gravity and are unsuited for activities in which the foot is used as a prehensile organ. The high, narrow tarsus, which adds resiliency to this part of the foot, necessitates a number of "balancing" adaptations to maintain body weight over the base of support and prevent uncontrolled movement and consequent strain at the talo-crural joint, in particular. For similar reasons, the long axes of the tibiae are parallel, and the plane of the talo-crural and subtalar joints are perpendicular to the line of gravity during bipedal activities. Orangs are highly arboreal, usually supporting the body using the limbs in tension in a small branch setting. The highly prehensile foot emphasizes the lateral digits rather than the hallux in grasping the substrate. The tarsus is extremely mobile, especially in inversion, in order to allow foot placement in a wide variety of positions. Increased mobility, which occurs at the talo-crural as well as the subtalar and transverse tarsal joints, is a result of differences between this and the other species in both osseus and soft-part (especially ligamentus) morphology. As a consequence, the tarsus is ill-suited for compressive weight-bearing, or for use as a lever for the plantar flexors of the foot in this species. In keeping with the emphasis on digital prehension, the lateral metatarsals and phalanges are extremely elongated, and the hallux is reduced in the orang. When the total morphological pattern of the foot is considered, it is apparent that humans and African pongids are more similar to each other than they are to orangs. Somewhat different conclusions may be drawn if single structures only are compared. Generalizations regarding both habitus and heritage are commonly made from limited comparisons of anatomical structures. Problems with this practice are discussed in this dissertation.

Bone remodeling activity was assessed on a large and homogeneous skeletal population. The association of remodeling and bone maintenance with age, sex, and gross pathologies was examined. Microstructural analysis of the femur was used to evaluate health for 234 skeletal individuals spanning three cultural horizons from Sudanese Nubia (350 B.C.-A.D. 1300). Frost's Triple Surface System was used to systematically collect data from the endosteal, middle, and periosteal envelope of the cortical cross sections. Measurements of bone quantity (rate of skeletal turnover) and bone quality (frequency of growth arresting and recovery, size of osteons) were used. Females have a more rapid rate of skeletal turnover than males for all age categories by decades. Younger females (18-29) remodel bone at a greater rate than elderly females (50+). Both young and old females have a low percent cortical area (less than 69%), and exhibit more porosity. Two different mechanisms are operating which contribute to the bone loss in two subgroups at risk. Young adult females have a decrease in formation and mineralization, but do not show an increase in resorption. Elderly females lose bone primarily at the endosteal envelope due to an increase in resorption, and are able to maintain the integrity of the cortex. Both males and females have the least variability in microstructural features (intact osteons, forming osteons, resorption spaces, fragments) at the periosteal envelope. Sites of active mineral regulation and homeostasis (double zone osteons, high density inner lamellae osteons, and Type II osteons) are found most frequently at the middle and endosteal envelopes. Individuals with well maintained bone (percent cortical areas above 70%) have higher frequencies of hypermineralized double zone osteons and osteons with high density inner lamellae. Individuals with decreased cortical area do not have the ability to regulate mineral exchange, and are at risk for poorly mineralized bone and bone loss. In the Nubian population, young adult females are at risk due to nutritional stress and reproductive stress, and evidence for this has come from the microstructural analysis combined with the archaeological reconstruction of diet and modern epidemiological studies.

Skeletal morphology and pathology are frequently used to support theories of activity patterns in prehistoric populations. In this study, the adult forearm (n = 307 radii and ulnae) and wrist bones (n = 500 scaphoid and lunate) from the Tell Abraq tomb, United Arab Emirates (ca. 2300 BC), were assessed for morphological variations and pathologies. Specifically, musculoskeletal attachment sites (MAS) were evaluated for indications of stress and articular surfaces were assessed for the presence of osteoarthritis (OA). OA was prevalent on the distal forearm bones (radius 40% and ulna 35%). Additionally, OA at the proximal ulna (73%) strongly correlated with (MAS) stress marker scores of elbow joint flexion (brachialis: rs = .323, p<.01) and extension (triceps: rs = .473, p<.01; anconeus: rs = .330, p<.01) as well as forearm rotation (supinator: r s = .373, p<.01; pronator teres: rs = 344, p<.01). The medial head of the triceps, anconeus and supinator muscles provide medial stability at the humeroulnar joint. Musculoskeletal attachment site stress indicators for the thumb were indicative of repeated or strained movements in extension and abduction and correlated strongly with proximal OA at the ulna (extensor pollicis longus: rs = .452, p<.01). Side did not correlate with OA, probable sex or any of the MAS stress markers. An unusual finding of an elevated transverse ridge was observed at the trochlear notch of the ulna. Presence of the transverse midtrochlear ridge (TTR) (58%) was positively correlated with proximal elbow joint OA (r s = .330, p<.01) and assigned sex (rs = .263, p<.01). Eighty-five percent of assessed radii had a depressed facet for the attachment site of the volar carpal ligament and 34% of the scaphoid bones had an exaggerated dorsal ridge for attachment of the dorsal carpal ligament of the wrist. The high levels of OA at the distal radius and proximal ulna in conjunction with the MAS data lend support to the theory that the individuals from the Tell Abraq tomb were engaged in regular heavy and repetitive bimanual activities with their upper extremities.

This comparative study of growth and development in 16 diverse primate species includes intra- and interspecific comparisons of the sequence and timing of (1) eruption of the deciduous and permanent teeth, (2) fusion of craniofacial sutures, and (3) closure of postcranial epiphyses. Although the primary focus of this research is the relative timing of dental, craniofacial, and postcranial development, metric data were also collected to assess the growth in size accompanying different patterns of maturation. The underlying premise is that evolutionary change is associated with changes in the developmental programs of descendants relative to those of their ancestors. For the purposes of this study, the degree to which the ontogenies of two groups are similar is judged by how closely the relative timing of development of same traits conforms in the groups. Novel treatments of the data include constructing “relative maturation” scales and introducing discriminant function analysis to analyze developmental timing data. ^ I assess both the phylogenetic and adaptive significance of similarities and differences in maturational timing. The developmental data assembled here can be used to assign individuals of all ages to their correct taxon, indicating that temporal patterns of maturation contain a wealth of phylogenetic information. Furthermore, like phylogenies, the taxonomic signals in developmental data are hierarchically nested: haplorhines are developmentally distinct from strepsirrhines, monkeys from apes, African apes from Asian apes, and gorillas from chimpanzees. ^ Conspecific males and females are found to differ in their temporal patterns of maturation regardless of how sexually dimorphic they become. Striking developmental dimorphism exists even in species exhibiting only minimal adult body size and canine dimorphism, such as Hylobates lar. Possible functional explanations for differences in the relative timing of development of postcranial traits are also explored. Cross-group differences occur less frequently among postcranial features intimately involved in joint function than in those that are not. No strong correlation was found between the relative timing of postcranial development and postcranial growth. In discussing the life-history implications of developmental timing parameters, I conclude that the relative timing of dental, craniofacial, and postcranial development, and of growth in size differs in species with “fast” life histories versus those with “slow” life histories. ^ I highlight instances where these results differ from those previously reported and suggest directions in which further elucidation of primate ontogenies might profitably be pursued. Finally, I illustrate how the methods and data presented in this dissertation can be applied to the interpretation of extinct primates, such as Archaeolemur. ^