Mate choice for nonadditive genetic benefits and the maintenance of genetic diversity in song sparrows

The lek paradox asserts that strong directional selection via female choice should deplete additive genetic variation in fitness and consequently any benefit to females expressing the preference. Recently, we have provided a novel resolution to the paradox by showing that nonadditive genetic effects such as overdominance can be inherited from parent to offspring, and populations with females that express a mating preference for outbred males maintain higher genetic variation than populations with females that mate randomly. Here, we test our dynamic model using empirical data previously published from a small island population of song sparrows (Melospiza melodia). The model assumes that fitness and male trait expression display overdominance effects. The results demonstrate that female choice for outbred males mediated by directional selection on song repertoire size provides a heritable benefit to offspring through reduced inbreeding depression. Within the population, we estimate the heritability of the inbreeding coefficient to be 0.18 +/- 0.08 (SD). Furthermore, we show that mate choice for outbred males increases fitness-related genetic variation in the population by 12% and thereby reduces inbreeding depression by 1% per generation in typical years and upwards of 15% in severe years. Thus, mate choice may help to stave off population extinction in this and other small populations

Predicting Body Mass Index in Northern Plains American Indian Children

Obesity has become a major health concern for American Indians. Obesity prevalence is higher for minority groups, however American Indians consistently have higher rates than any other U.S. population. Of more concern is the trend towards higher rates of overweight and obesity in American Indian children. Obesity has been associated with many health concerns such as coronary heart disease, high blood pressure, and type 2 diabetes mellitus in both American Indian adults and children. The purpose of this study is to identify predictor variables that may be contributing to the development or possibly maintenance of obesity in American Indian children. The sample consisted of 291 tribally enrolled American Indian students (grade 3-5). In addition, a smaller sample of 80 parents/caregivers participated in this study. Child participants completed several questionnaires pertaining to the following topics: demographics, diet and physical activity, weight-related attitudes, psychological/emotional, and cultural identity. Parents/caregivers completed a similar research packet and most items were related to parent/caretaker\u27s personal attitudes and behaviors. Two multiple regression analyses were conducted to observe the predictive power of independent variables on child BMI scores. The first data analyses were structured hierarchically to investigate the contributions of the following five blocks or sets of predictor variables: (a) demographic variables (i.e., gender and SES), (b) food selection and physical activity measures (i.e., food choice intention, knowledge of fatty foods, food self-efficacy, physical activity, and sedentary behavior), (c) attitudes about body size (i.e., body dissatisfaction, attitudes toward body size, attempted weight loss), ( d) emotional eating variables (i.e., self-esteem and emotional eating), and ( e) cultural identity. A simultaneous multiple regression was also conducted on a pre-selected set of parental/caretaker variables (adult/caretaker BMI, birth weight of 1st child, and parent/caretaker body dissatisfaction) to assess their relationship to the dependent variable (child BMI). This study found that 33% of Northern Plains American Indian children were overweight and 20% were at risk for becoming overweight. Results also revealed that demographics, diet and physical activity, and weight-related attitudes explained a significant amount of variance ( 41.5%) in child BMI. Statistically significant unique contributions were observed for gender, food choice intentions, sedentary behaviors, attitudes towards body size, body dissatisfaction, and attempted weight loss. In addition, results showed that parent/caretaker BMI, birth weight of 1st child, and parent/caretaker body dissatisfaction explained a significant amount of variance (15%) in child BMI scores; however, none of the predictors accounted for a significant unique contribution to the overall model

Adolescent and Adult Perceptions of Adolescent Diet, Physical Activity, Body Size, and Obesity Prevention in Botswana

Obesity is a worldwide health problem affecting developed and developing nations. Botswana is an upper-middle income nation experiencing rapid urbanization, economic, and nutritional change. The combined prevalence of adolescent overweight and obesity has now surpassed underweight. Little is known regarding the adolescent and adult perceptions of adolescent diet, physical activity, body size, the meaning of obesity, and obesity prevention interventions. This qualitative-descriptive study uses Ecological Systems Theory to analyze and interpret data from 15 focus groups (12 adolescent and 3 parent focus groups of unrelated participants) conducted in Gaborone, Botswana. The purpose of this study is to describe the factors that influence adolescent and adult perceptions and attitudes related to adolescent diet, physical activity, body size, obesity and potential obesity interventions. Prolonged data immersion, clustering of analogous data into themes, and direct reporting of participant voices were used to provide a rich description of the shared experiences and perceptions of the study participants. Results indicate that adolescents identify healthy versus unhealthy foods, yet choose unhealthy foods based on taste preferences, social pressures, and the perceived affordability of unhealthy foods. Parents prefer a healthy diet for their adolescent children, although they acknowledge purchasing unhealthy foods for their children based on adolescent taste preferences and social pressures. Adolescent and parent participants suggest a body size analogous to normal weight is most desirable for adolescents themselves and most attractive in the opposite sex. Obese body sizes are associated with perceived laziness, isolation, and negative social stigma. Additionally westernized preferences are replacing the historical notion that a large body size is consistent with wealth, strength, and prosperity. Participants also perceive thinness to be related to illness, specifically suspected HIV infection due to the relatively high prevalence of HIV infection in Botswana. Adolescents and parents of adolescents show a willingness to participate in obesity prevention programs. Participants suggest that any school-based program be voluntary, entertaining, informative, involve parents, take into consideration peer influence, and increase healthy food offerings while not eliminating individual choice. An ecological, school-based obesity prevention program with parent involvement should be developed for this adolescent population

The Role of Homework in a Mathematics Classroom

Research Topic: The topic I researched is assignment grading techniques. I would studied which type of grading works best for students to learn. Participants: Participants in this study came from a lower class public middle school and high school. The population is 90% white with 60% of students qualifying for free and reduced lunches. The size of the study will be approximately 15 students in the 9th grade. 65% of the students come from a single parent home or have divorced parents. Instrument: Tests that I have created on the topic will be the measuring instrument. The test will only cover the topics covered in class and each class will take the exact same test. The test had 15 questions covering each topic. They will not be multiple choice questions and will be problems where they are open ended where the students have to show work. At the end of the tests, I will also attach a survey for students to state how they felt the homework helped them on the test. Hypothesis Statement: If grading assignments using various strategies, then grading assignments by grading for completion will show the most growth

'On the Application of Hierarchical Coevolutionary Genetic Algorithms: Recombination and Evaluation Partners'

This paper examines the use of a hierarchical coevolutionary genetic algorithm under different partnering strategies. Cascading clusters of sub-populations are built from the bottom up, with higher-level sub-populations optimising larger parts of the problem. Hence higher-level sub-populations potentially search a larger search space with a lower resolution whilst lower-level sub-populations search a smaller search space with a higher resolution. The effects of different partner selection schemes amongst the sub-populations on solution quality are examined for two constrained optimisation problems. We examine a number of recombination partnering strategies in the construction of higher-level individuals and a number of related schemes for evaluating sub-solutions. It is shown that partnering strategies that exploit problem-specific knowledge are superior and can counter inappropriate (sub-) fitness measurements

Runtime Analysis of the (1+(λ,λ))(1+(\lambda,\lambda)) Genetic Algorithm on Random Satisfiable 3-CNF Formulas

The $(1+(\lambda,\lambda))$ genetic algorithm, first proposed at GECCO 2013, showed a surprisingly good performance on so me optimization problems. The theoretical analysis so far was restricted to the OneMax test function, where this GA profited from the perfect fitness-distance correlation. In this work, we conduct a rigorous runtime analysis of this GA on random 3-SAT instances in the planted solution model having at least logarithmic average degree, which are known to have a weaker fitness distance correlation. We prove that this GA with fixed not too large population size again obtains runtimes better than $\Theta(n \log n)$, which is a lower bound for most evolutionary algorithms on pseudo-Boolean problems with unique optimum. However, the self-adjusting version of the GA risks reaching population sizes at which the intermediate selection of the GA, due to the weaker fitness-distance correlation, is not able to distinguish a profitable offspring from others. We show that this problem can be overcome by equipping the self-adjusting GA with an upper limit for the population size. Apart from sparse instances, this limit can be chosen in a way that the asymptotic performance does not worsen compared to the idealistic OneMax case. Overall, this work shows that the $(1+(\lambda,\lambda))$ GA can provably have a good performance on combinatorial search and optimization problems also in the presence of a weaker fitness-distance correlation.Comment: An extended abstract of this report will appear in the proceedings of the 2017 Genetic and Evolutionary Computation Conference (GECCO 2017