<p>Primates and many other animals that move in an arboreal environment often cling, sometimes for long periods, on vertical supports. Primates, however, face a special challenge in that almost all primates bear nails on the tips of their digits rather than claws. Squirrels and other arboreal animals possess claws and/or adhesive pads on their digits in order to hold their weight on vertical substrates. Assuming the ancestral primate was arboreal and lost claws prior to the radiation of primates this paradox has important implications and raises a significant question about living primates and early primate evolution: how can primates maintain vertical postures without claws and how did early primates meet this challenge? Primate vertically clinging and grasping postures (VCG) have been studied in the wild and theoretical models of VCG postures have been described. This dissertation builds on this work, by studying the biomechanics of VCG postures in primates. Based on mechanical models, it was hypothesized VCG posture in primates will vary in three ways. </p><p>Hypothesis 1: Species with different morphological features associated with different locomotor modes will vertically cling and grasp in different ways. </p><p>Hypothesis 2: As substrate size increases, primates will place their arms to the side of the support and adjust posture and muscle recruitment in order to maintain a necessary tangential to normal force ratio to resist gravity. </p><p>Hypothesis 3: On substrates of the same relative size, larger animals should be less effective at maintaining VCG postures due to scaling relationships between muscle strength and body mass. </p><p>The sample consisted of multiple individuals from eight strepsirrhine species at the Duke Lemur Center. The sample varied in locomotor mode--habitual vertical clinging and leaping (VCL) compared to less specialized arboreal quadrupeds--and body mass--100 to 4,000 grams. Subjects were videorecorded while holding VCG postures on substrates of increasing size. Substrate preference data were calculated based on frequency and duration of VCG postures on each substrate. Qualitative kinematic data were recorded for a maximum of thirty trials per individual, per substrate. Angular data were calculated for forelimbs and hindlimbs from these videos for ten trials per individual per substrate. In addition, kinetic data from an imbedded force transducer were collected for two species that vary in locomotor mode, but not body mass. </p><p>There are several significant and relevant results from this study that address both primate functional anatomy and locomotor evolution. Hypothesis one was supported by hand and hindlimb joint postures, shown to be highly sensitive to locomotor mode. VCL primates exhibited deeply flexed limbs and more hand grasping (wrapping around the substrate) versus parallel hand postures and use of bowed finger postures compared to less specialized primates. Kinetically, species were shown to bear the majority of their weight in their hindlimbs relative to their forelimbs. The forelimb joints and foot showed little variation by habitual locomotor mode. Hypothesis two found support in that species tend to prefer smaller substrates, clinging less frequently for shorter durations as substrate size increases. Hand posture changed as size increased, as primates (except for the slow lorises) in this study grasped with their pollex on smaller substrates, but the pollex disengaged in grasping on larger substrates. Hypothesis three was not supported; body mass did not influence VCG postures. </p><p>Taken together, the finding that the forelimb held a wide range of postures on each substrate size for all species and played a limited role in weight-bearing suggests the forelimb free to move (to adjust posture and or forage). The hindlimb plays a more specific role in weight-bearing and is more sensitive to variations in primate anatomy. Additionally, these findings lead to hypotheses concerning the relatively short pollexes of primates, and that the ancestral primate was smaller than 100g and preferred small substrates as found in a fine-branch niche.</p> / Dissertation

Thesis (M.A.)--Ohio State University, 2009. / Title from first page of PDF file. Includes vita. Includes bibliographical references (p. 42-50).

Adolescence is a life history transition of individual and evolutionary importance: the body begins to allocate energy available above maintenance costs away from somatic growth and towards reproductive function. This study investigates how both distal, intergenerational effects and proximal, seasonal changes in energy availability impact the way adolescent female bodies allocate energy among linear growth, fat and lean mass, activity, and metabolic function. The research follows up on a prenatal supplementation study conducted by the British Medical Research Council in rural Gambia between 1989 and 1994. Pregnant women were randomized to receive daily supplements of 1015 kcal either from week 20 of pregnancy until delivery or during the first 20 weeks of lactation. The 67 adolescent daughters included in the follow up study were born to women in both groups during the rainy agricultural season, the period of the year associated with weight loss, poor perinatal outcomes, and high impact of the pregnancy supplement on birth weight. Anthropometry, body composition, daily saliva, weekly serum, and weekly fasting urine samples for C-peptide of insulin were collected during one month each in the 2009 rainy agricultural season, the 2010 dry harvest season, and the 2010 rainy agricultural season. Participant heart rates were calibrated to oxygen consumption each season, and 24-hr accelerometer and heart rate data were recorded to estimate free-living energy expenditure. It was found that pregnancy supplementation status did not predict infant or adolescent phenotype in the study sample. Maternal postpartum weight, however, was a powerful positive distal predictor of adolescent size. The daughters of heavier mothers produced less leptin per unit fat mass. Under conditions of high energy expenditure and low intake, adolescent women who were growing in height mobilized adipose stores and acquired lean mass, while developmentally older women maintained fat stores at the expense of lean mass. Married adolescents in the sample were older, had lower fasting C-peptide of insulin, had higher absolute energy expenditure, and spent more of their total energy budgets in activity than did unmarried peers. / Human Evolutionary Biology

No description available.

No description available.

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 259-261).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

The aim of this study was to test the accuracy of two methods for age estimation in non-adults, Cameriere’s European formula and AlQahtani’s London Atlas, on a multi-ethnic American sample. Radiographs of European, Hispanic and American Indian children (166 girls and 194 boys) aged between 6 and 17 years were analyzed following both methods. The accuracy of each method was assessed using the mean difference and the mean of the absolute values of the residuals (mean prediction error). Categories relating to ethnicity, sex and age were applied to the assessment of accuracy in order to compare these two approaches. Results indicate that Cameriere’s European formula significantly underestimated age for both sexes (p < 0.001), with a mean difference of -1.19 years for girls and -1.32 years for boys, prompting the first author to create an American specific formula. The American formula slightly overestimated age but this difference was not significant (p>0.05). Using Cameriere’s European formula the mean prediction error (ME) was 1.51 years for girls and 1.58 years for boys while the ME was 1.24 years for girls and 1.13 years for boys, using the American formula. The London Atlas underestimated age with a mean difference of -0.18 for girls and -0.16 for boys. The absolute mean difference was 1.04 years for girls and 1 year for boys. For both methods, differences in accuracy based on sex or ethnic group were not significant (P>0.05). The results indicate that both methods may be useful for estimating age in a forensic context.

abstract: Unanswered questions about the evolution of human gender abound and are salient across the anthropological disciplines and beyond. Did adult sex-typed behavioral tendencies actually evolve? If so, when? For what purpose? The best way to gain insight into the evolution of human gender is to understand the evolution and development of sex-typed behavior in comparative primate taxa. Captive research indicates that there are many proximate factors likely to shape the development of sex-typed behavior in non-human primates&mdash;prenatal and postnatal endocrinological experience, social experience, ecological factors, and their interactions. However, it is largely unknown how sex-typed behavior proceeds and is shaped by those factors in evolutionarily salient environments. This study investigated one&mdash;whether extrinsic sexually differentiated social interactions are likely influential in the development of adult sex-typed behavior in wild-living Lemur catta. Little is known about sex-typed development in this species or in strepsirrhines in general. This research therefore addresses an important phylogenetic gap in our understanding of primate sex-typed development. Behavioral observations were carried out on mixed cross-sectional sample of adult females (n=10), adult males (n=8), yearling females (n=4), yearling males (n=4), and newborn females (n=16) and males (n=14) at Beza Mahafaly Special Reserve in southwest Madagascar from September 2008 to August 2009. Twenty-three sex-typed behaviors were identified in adults using linear mixed effects models and models of group response profiles through time. Of those, only eight had a pre-pubertal developmental component. Infants did not exhibit any sex differences in behavior, but juveniles (prepubertal, weaned individuals) resembled adults in their (relatively few) patterns of expression of sex-typed behavior. Most adult sex-typed behaviors in this species apparently develop at or after puberty and may be under gonadal hormone control. Those that develop before puberty do not likely depend on extrinsic sexually differentiation social interactions for their development, because there is no clear evidence that infants and juvenile male and females are not treated differently by others according to sex. If sexually differentiated social interactions are important for sex-typed behavioral development in subadult ,italic>Lemur catta, they are likely intrinsically (rather than extrinsically) driven. / Dissertation/Thesis / Ph.D. Anthropology 2012

abstract: Modern primate diet is well-studied because of its considerable influence on multiple aspects of morphology, including the shape of the facial skeleton and teeth. It is well-established that differences in craniofacial form influence feeding abilities by altering the nature of bite force production. Tooth morphology, likewise, has been shown to vary with diet across primates, particularly in the details of occlusal form. It has also been suggested that tooth form (e.g., tooth root size and shape and crown size) reflects, in part, the demands of resisting the stresses generated during feeding. However, while they are central to our efforts to infer diet in past species, the relationships between bite force production, craniofacial morphology and tooth form are not well-established. The current study is separated into two parts. In Part I, the hypothesis that crown size and root surface area are adapted to resist masticatory stress is evaluated by testing whether these features show correlated variation along the tooth row in a taxonomically diverse sample of primates. To further explore the adaptive nature of this correlation, pair-wise comparisons between primates with mechanically resistant diets and closely-related species consuming less resistant foods are performed. If crown size and root surface area covary along the tooth row, past research suggests they may be related to bite force. To test this hypothesis, Part II examines the variation of these dental characteristics in comparison to theoretically-derived bite force patterns along the tooth row. Results suggest that patterns of maximum bite force magnitude along the tooth row are variable both within and between species, underscoring the importance of individual craniofacial variation on masticatory force production. Furthermore, it is suggested that some adaptations traditionally associated with high bite force production (i.e., facial orthognathy) may increase anterior biting force at the expense of posterior biting force. Taken together, results from the current study reveal that both tooth root and crown size vary in conjunction with the mechanical properties of diet and with bite force patterns along the tooth row in anthropoids. / Dissertation/Thesis / Ph.D. Anthropology 2012