ABSTRACT PI: Gowaty PROPOSAL NUMBERS 9631801 The hypothesis that the research is designed to test is that female choice of mates for traits that affect the viabilities of females offspring affects females preferences for particular mates even in social systems in which females seem unable to chose or in which females options are ecologically or socially modified. Social behavior that can interfere with a female s ability to achieve mating s with her preferred partners include male- male- interactions female-female s interactions, and interactions between the female and those males that attempt to manipulate or modify her choice via forced copulation, aggressive conditioning, affiliative conditioning, or brokering of food resources in exchange for matings. The research is specifically designed to test the generality of this hypothesis and will include comparisons of outcomes from nearly identical experimental protocols on six well- known and frequently studied species representing phylongenetically diverse taxa. This research is collaborative and cooperative. It will include experiments on laboratory populations of Drosophila pseudoobscura, Drosophilia hydei at the university of Georgia, guppies, Poecilea reticulata, at Trondheim University Cockroaches, Nauphoeta cinerea, at the University of Kentucky, mallards, Anas platyrhynchos at the Delta Waterfowl and Wetlands Research Station, and wild house mice, Mus musculus, at the University of Southern Illinois at Carbondale. The research protocol involves exposing females to sets of males, which researchers will pick at random with respect to phenotypic variation of individuals from populations consisting of virgin males from diverse sources. Test females will demonstrate preferences in choice arenas. After Establishing her preferred mate, half of the test females will be placed in breeding chambers with preferred males and half with non preferred. The viability (surv ival to adulthood or independence) of offspring from several types of control manipulations including those from an identical series of male choice trials. The significance of this research lies in the rarity of studies of the effects of freely expressed mate choice by females or males on offspring viability or quality. It will be the first to evaluate 1) the theoretical assumption that the effects of female choice outweigh the effects of male choice for species with typical post-fertilization investments in offspring: 2. the prediction that for a species (D. hydei) with relatively equal post-fertilization investments that male and female choice are equally important to offspring viability; 3. how viabilities of offspring vary under freely- expressed mate choice (By females and males) compared to non preferred matings; and 4. differences in offspring viability as a function of whether matings are managed or represent choices made by freely-acting individuals.