A grant has been awarded to Drs. James Marden and Ilkka Hanski to examine variation in physiological traits of an insect that is a model organism for population dynamics. As with most species, populations of checkerspot butterflies are scattered across a landscape of distinct, isolated patches of suitable habitat. Individual populations frequently go extinct, but this is balanced by an approximately equal number of instances of the founding of new populations in previously unoccupied patches of suitable habitat. This project will test the hypothesis that old stable populations consist of butterflies of poor flight ability and high fecundity, whereas newly founded populations consist of butterflies of strong flight ability and reduced fecundity. Measurements of flight ability and the tradeoff between flight and fecundity will be incorporated into mathematical models to predict the evolution and spatio-temporal dynamics of these traits. Functional genomic approaches (DNA microarrays and proteomics) will be used to examine the genetic mechanisms responsible for variation in flight ability and fecundity. Results will provide an integrative understanding of how gene function affects organismal traits that determine spatial population dynamics and landscape ecology. The NSF Biocomplexity program was motivated by the understanding that "research on the individual components of environmental systems provides only limited information about the behavior of the systems themselves". This project will overcome that problem by integrating data from multiple levels of biological complexity, from genes to landscapes, in order to understand the behavior of a large and complex ecological system.
Results of this work will enhance understanding of processes that maintain genetic variation in fragmented populations; this is a topic of keen interest for management and conservation of biodiversity. The results will also provide information and methods that will be applicable to management of insect pests that migrate among fields and regions in agricultural landscapes.
The project will enhance the infrastructure for research and education by forging a new partnership between U.S. scientists expert in functional genomics and integrative organismal biology with a research group in Finland that is at the forefront of population research and theory. Long-term benefits will include opportunities for student exchange and development of material resources including a characterized cDNA library and a microarray that will bring genomic tools to one of the ecologically best known species. Training of students will enhance the pool of young scientists capable of using functional genomics in an ecological context. Participation of women and minorities will be accomplished in part by an outreach partnership with an NSF EPSCoR institution (Mississippi State University) that will bring underrepresented minority undergraduates to the project each year.
