Why do some reproductive patterns persist despite their costs to the health of females? The evolutionary consequences of social behavior variation of nonhuman-animal females are unknown, but important for understanding why some patterns of mating within populations are more common than others. The investigators will complete a comparative experimental study of behavioral and demographic variation of females in multiple species of Drosophila (model organisms) for which phylogenetic relationships and ecology are known, but social and mating behavior unknown. The investigators will collect flies from the wild, culture them and perform controlled experiments in the laboratory to evaluate whether multiple matings confer benefits to the health of females and their offspring; females will be allowed to mate only one time or multiple times with one or multiple males and the health of the females and their offspring will be measured. Data will be deposited to an online repository, to FLYBASE, and available in published papers coauthored by undergraduate collaborators, postdoctoral associates, and senior personnel. Undergraduate participants will contribute substantially and collaboratively as research partners to the programmatic enterprise in a broader impacts activity, a scientific research immersion, that is an integrated part of the research, designed to introduce students to experimental research science from project implementation, execution, data acquisition, analysis, primary-report production, and response to the critiques of their colleagues before submission to scientific journals. The study will provide large data sets for efficient testing of hypotheses, producing general insights. Thus, it is important in providing controlled experimental data in comparative perspective about a general puzzle, currently unanswerable in other longer-lived model organisms or humans.