LTREB: Sexual selection over time: evolutionary dynamics and outcomes of intense male competition and female mate choice in a lek mating system

Florida State University, Tallahassee FL

Investigators

Abstract

The purpose of this project is to understand how evolution by sexual selection occurs. It analyzes how differences in which individuals produce offspring and how many offspring they produce lead to population-wide changes in behavior or morphology. In natural populations, some individuals are often more successful than others at producing offspring. This is especially true in “lek” mating species, where males display to many females in one location, and females visit many males before mating. Iconic examples of such behavior occur in peacocks, birds-of-paradise, and small tropical birds called manakins. This project builds on long-term monitoring of behavior in the lance-tailed manakin to investigate patterns of individual reproductive success. By following the fate of individual manakins and linking individual behavior and other traits to genetically measured reproductive success, researchers will measure the strength of both natural and sexual selection in a wild population. Broader impacts of this work include intensive independent research opportunities for undergraduate students, internationally and on the university campus. A collaboration hosts a live stream of manakin display activity with supporting in-depth and accurate content about evolution and behavior. The work produces training opportunities for post-graduates and graduate students, who will take part in data collection and outreach. This project advances three key areas of research in evolution and animal behavior. First, it characterizes temporal variation in the potential for sexual selection to occur (measured as standardized reproductive variance). To do so, the work investigates three hypothesized sources of this variation: breeding synchrony, climactic variation, and variation in the availability of preferred mates. Second, it draws on strengths of the long-term dataset to incorporate changes that occur across individual lifespans into analyses of sexual selection. This allows for the separation of developmental from selective processes to more accurately characterize targets of selection. Long-term data include video of displays by the same males across their breeding tenure, and these will be analyzed to objectively measure changes in display performance over time. Finally, this study directly quantifies genetic changes in the population over time. These data will be used to assess the relative contribution of multiple sources of evolutionary change, including viability selection, gene flow, and drift as well as sexual selection. Samples archived during this study build potential for later genomic analysis to understand the genes underlying sexual selection. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.