Lisa M. Angeloni, Ph.D. - US grants

Behavior has often been argued to be the first level of response of animal populations to new environments, changing before other traits. A great deal of previous research has documented existing geographic and environmental variation in behavior, but there have been relatively few opportunities to examine the role of behavior changes during contemporary shifts of populations to new environments. This project will take advantage of an unprecedented opportunity to monitor changes in reproductive behavior during an experimental introduction of Trinidadian guppies (Poecilia reticulata) from one ecological environment where predation pressure is relatively high to another environment where predation pressure is relatively low. There is a deep comparative literature exploring the way that reproductive traits of guppies, such as male color patterns, male mating tactics and female preferences for male traits, vary with predation pressure across streams, setting up a predictive framework for this work. The results of this project are expected to highlight the way that behavioral changes, through both flexible modification and genetic evolution, allow animals to adapt to new environmental conditions. The findings of this research will have implications for biological invasions and conservation biology as animal populations respond behaviorally to increasingly modified environments caused by human disturbance and global change. This work will have broader implications for the participation of minorities in science, not only through the involvement of a Hispanic principle investigator, but more importantly through graduate advising, undergraduate mentoring and education at the K-12 level. This project will help to increase the participation of minority students in the biological sciences at Colorado State University and will include the development of a workshop program to bring guppy behavior and experimental biology to K-12 classrooms in Colorado.

This project tests the effects of gene flow, the movement of genes from one population to another by immigrants, on local adaptation and population dynamics in Trinidadian guppies. On the one hand, gene flow may break down local adaptation and reduce fitness by introducing maladapted genes. On the other hand, gene flow may increase fitness by adding genetic variation to small, inbred populations. Moreover, gene flow may have important effects on population growth and dynamics. The researchers will test the effects of gene flow using experiments in wild populations and in controlled mesocosms (experimental pools). First, they will determine how immigration of fish adapted to a different environment affects traits and fitness in wild populations. Next, they will test how these changes in traits and fitness affect population dynamics. Lastly, they will experimentally test how the effects of gene flow vary with the degree of adaptive differentiation between populations and the level of inbreeding.

This study takes advantage of a rare opportunity to examine populations before and after the onset of gene flow in the wild and in mesocosms. Results of this project will inform conservation programs since a commonly used, but rarely tested, conservation strategy is to artificially increase gene flow. Alongside the research, the investigators will expand their innovative "guppy kit" program to expose elementary and middle school students to experimental evolutionary biology using guppies in the classroom in both the US and in Trinidad. The research will also provide training in field, experimental, and molecular research for underrepresented minorities and Trinidadian undergraduate students. Co-funding for the international component of the research has been provided by OISE.