Thesis (Ph. D.)--University of Sydney, 2009. / Title from title screen (viewed June 1, 2009) Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Department of Pharmacology, Faculty of Medicine. Degree awarded 2009; thesis submitted 2008. Includes bibliography. Also available in print form.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Oregon, 2002. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 104-116). Also available for download via the World Wide Web; free to University of Oregon users.

This study explored the potential impact of child temperament and daycare on behavior problems and parental sensitivity. It was expected that children with more "difficult" temperaments would exhibit more behavior problems and have less sensitive parents when experiencing high amounts of daycare. Measures from 60 families involved in the Southern Illinois Twins and Siblings Study (SITSS) were examined. Results indicated that highly active children exhibited more externalizing behaviors when experiencing less daycare. Shy children experiencing more daycare had more sensitive parents. Additionally, a temperamental difference between co-twins was related to differential parental sensitivity. Lastly, DZ co-twins were more temperamentally different when experiencing high amounts of daycare. These results demonstrate that daycare does seem to affect children; however, the specific effect depends on the child's temperament. Additionally, temperament is an important factor when examining parental sensitivity shown to twins and when determining how MZ and DZ twins react to daycare.

abstract: This study examined whether social support available to parents moderated the heritability of parent-reported social approach at 12 months (N = 286 twin pairs, 52.00% female) and social competence at 30 months (N = 259 twin pairs, 53.30% female). Genetic and environmental covariance across age is also reported. Social support consistently moderated genetic influences on children’s social approach and competence, such that heritability was highest when parents reported low social support. Shared environment was not moderated by social support and explained continuity across age. Findings provide further evidence that genetic and environmental influences on development vary across context. When parents are supported, environmental influences on children’s social competence are larger, perhaps because support helps parents provide a broadly promotive environment. / Dissertation/Thesis / Doctoral Dissertation Psychology 2017

This study used a twin and triplet sample to investigate the influence of preschoolers’ physical activity levels and internalizing problems on subsequent health outcomes (body-mass index, internalizing behavior problems, household health behaviors) in middle childhood. The potential influence of stressors salient in childhood (household chaos, socioeconomic status, stressful life events) on the hypothesized relationship between physical activity and internalizing on health was also explored. A specific focus was placed on examining the underlying genetic and environmental influences of children’s physical activity levels, as assessed by both temperamental (parent-reported) activity levels and observed (in-lab) motor behavior, using a behavioral genetic approach. By measuring physical activity in these two ways, this project also investigated the validity of the observational coding scheme developed for the current study to assess preschoolers’ overt motor behavior during laboratory testing. Data from 65 families (n = 134 children) included in the Southern Illinois Twins/Triplets and Siblings Study (SITSS) were examined from age 5 (physical activity levels, internalizing problems, and household chaos) to follow-up (body-mass index, internalizing problems, household health behavior, socioeconomic status, and stressful life events) when children were age 7-13 years old. Findings indicated that observed motor behavior and temperamental activity were not significantly correlated, suggesting that these measures assess different aspects of preschoolers’ physical activity levels. Additionally, results supported the reliability and validity of the newly developed observational coding scheme, which underscores the utility of this measure; employing this methodological tool in future studies focused on investigating motor behavior in childhood may be particularly fruitful. Genetic analyses demonstrated that approximately 66% and 34% of the variance in observed motor behavior was accounted for by additive genetic and non-shared environmental influences, respectively, whereas the variance in temperamental activity was attributable to dominant genetic effects (72%) and non-shared environmental influences (28%). These results suggest that differences in age 5 physical activity levels are largely due to genetic differences. Finally, longitudinal analyses showed that health outcomes at follow-up were significantly influenced by 5-year-old temperamental activity and internalizing problems, as well as follow-up socioeconomic status and stressful life events: 1) children who were older, were boys, and lived in a low socioeconomic status household had a higher body-mass index at follow-up; 2) children with higher age 5 internalizing problems and concurrent stressful life events had greater internalizing problems at follow-up; 3) boys and children with higher age 5 temperamental activity had lower scores for household health behaviors. The present project provides greater insight into childhood health (body-mass index, internalizing, household health behaviors) by examining factors relevant to health (physical activity levels, internalizing problems, stress) across development (i.e., from age 5 to ages 7-13 years).

The investigation reported here involved an analysis of some of the biological factors affecting tonic immobility in young Japanese quail. Both duration and incidence of tonic immobility were measured on each bird at six days and again at 12 days of age. A significant line effect was found at both ages, and rankings of these lines for duration and incidence followed a similar pattern. Number of inductions and duration of immobility were inversely related, while the percentage incidence was positively associated with duration of immobility. A large maternal effect found at six days of age disappeared by 12 days of age. Additive genic effects were low to moderate which is indicative that tonic immobility is associated with fitness. / Master of Science

The aim of this study is to place a wide variety of two-phenotype frequency-dependent selection models into a unified population-genetic framework. This work is used to illuminate the possible genetic constraints that may exist in such models, and to address the question of evolutionary modification of these constraints. The first part of Chapter 1 synthesizes from the literature a general framework for applying a genetic structure to a simple class of two-phenotype models. It shows that genetic constraints may prevent the population from achieving a predicted phenotypic equilibrium, but the population will equilibrate at a point that is as close as possible to the phenotypic equilibrium. The second part of Chapter 1 goes on to ask whether evolutionary modification of the genetic system might be expected to remove these constraints. Chapter 2 provides an example of the application of the framework developed in Chapter 1. It presents re-analysis of a model for the evolution of social behavior by reciprocation (Brown et al. 1982). The genetic results of Chapter 1 apply to this model without modification. I show that Brown et al. were unnecessarily restrictive in their assumptions about the types of genetic systems that support their conclusions. Chapter 3 discusses some models for the evolution of altruism that do not fit the assumptions of Chapter 1, despite their two-phenotype structure. These models violate the fundamental assumption of Chapter 1, this being the way in which individual fitness is derived from the behavioral fitnesses. The first part is a complete, in-depth analysis of diploid sib-sib kin selection. I show that some results from the basic model can be used, provided the behavioral inclusive fitness functions are substituted for the true behavioral fitnesses. The second part is an analysis of the validity of the concept of behavioral structure, as introduced by Michod and Sanderson (1985). I show that this concept is flawed as a general principle. Chapter 4 extends the basic model to the case of sex-allocation evolution. I show how many of the central results of sex-allocation theory can be derived more simply using a two-phenotype framework.

It is now well accepted, through the use of mutational studies, that genes influence behavioural variation. However, we have little knowledge of the cellular and neuronal mechanisms underlying the effects of specific genes. This thesis broadens our understanding of the neurogenetic underpinnings of naturally occurring differences in behaviour using the genetically tractable model organism Drosophila melanogaster. The thesis focuses on allelic variation at the foraging (for) gene which influences both larval and adult behaviour. In particular, for’s cellular/neural contributions to food-related behaviours and learning and memory is investigated. In the first study, we map FOR protein distribution patterns in the adult brain and use this knowledge to demonstrate a neural-specific function for the for gene in adult food-related behaviour. In the second study we demonstrate a novel role for for in the regulation of naturally existing differences in fly learning and memory in the mushroom bodies of the fly brain. In the third study, I explore FOR distribution patterns in larval tissues. I show that FOR is expressed both in neural and non-neural tissues suggesting a distributed function for FOR in food-related behaviours in the larva. In the last study, I describe naturally existing differences in fat metabolism in the Drosophila larva fat storage tissue. FOR is expressed in the fat storage tissue and may regulate lipid packaging, a trait linked to foraging. In general, my thesis is a cellular and neurogenetic analysis of natural variation in behavioural and physiological traits of D. melanogaster. The functions of FOR in food-related behaviours, nutrient physiology and cognition are conserved across taxa. The findings of this thesis should provide a framework to understand these phenomena in a wide range of organisms.

It is now well accepted, through the use of mutational studies, that genes influence behavioural variation. However, we have little knowledge of the cellular and neuronal mechanisms underlying the effects of specific genes. This thesis broadens our understanding of the neurogenetic underpinnings of naturally occurring differences in behaviour using the genetically tractable model organism Drosophila melanogaster. The thesis focuses on allelic variation at the foraging (for) gene which influences both larval and adult behaviour. In particular, for’s cellular/neural contributions to food-related behaviours and learning and memory is investigated. In the first study, we map FOR protein distribution patterns in the adult brain and use this knowledge to demonstrate a neural-specific function for the for gene in adult food-related behaviour. In the second study we demonstrate a novel role for for in the regulation of naturally existing differences in fly learning and memory in the mushroom bodies of the fly brain. In the third study, I explore FOR distribution patterns in larval tissues. I show that FOR is expressed both in neural and non-neural tissues suggesting a distributed function for FOR in food-related behaviours in the larva. In the last study, I describe naturally existing differences in fat metabolism in the Drosophila larva fat storage tissue. FOR is expressed in the fat storage tissue and may regulate lipid packaging, a trait linked to foraging. In general, my thesis is a cellular and neurogenetic analysis of natural variation in behavioural and physiological traits of D. melanogaster. The functions of FOR in food-related behaviours, nutrient physiology and cognition are conserved across taxa. The findings of this thesis should provide a framework to understand these phenomena in a wide range of organisms.