Collaborative Research/RUI: The Role of Frequency Dependent Selection in the Evolution of Color Pattern Polymorphism in Guppies

Lake Forest College, Lake Forest IL

Investigators

Abstract

Naturally occurring populations of guppies (Poecilia reticulata) exhibit striking genetically based variability in the color patterns of males. Each male has a unique color pattern or one that is shared with one or very few other fish in the population. How this polymorphism is maintained remains a mystery despite decades of study on this model organism. Laboratory studies have suggested that the mating success of males may depend on how rare or common their color pattern is, and theory suggests that such frequency dependent selection could maintain genetic variation. This study will examine the role of frequency dependent selection in maintaining color pattern variation in naturally occurring guppy populations. It will use new techniques for molecular paternity analysis and permanent marking of fish to examine patterns of survival and mating success of individual fish in streams. Understanding how genetic variation can persist in natural populations has long been a goal of research in evolutionary biology and more empirical study is needed. Dwindling populations of organisms often suffer from loss of genetic variation. Thus, this is an increasingly important topic for investigation and application to conservation strategies. This research involves an international collaboration between research and undergraduate institutions, and research participation by undergraduates and a high school teacher.