Research

Our research into metapopulation genetics focuses on two fundamental questions regarding the process of evolution in spatially structured populations. First, what are the forces that generate and destroy population structure? Second, given that there is population structure, how does it affect the process of evolution?

The theory of interconnected populations (metapopulations) has shown that conclusions regarding ecological and evolutionary dynamics derived from single populations can be radically different when considered in a spatial context. Nevertheless there is a deficit of long-term field data on spatially distributed populations to guide and focus this theory. We have been studying the metapopulation biology of the plant Silene latifolia and its associated pathogen, Microbotyrum violaceum for more than 30 years, collecting data on population demographics, sex ratio and disease incidence data in more than 800 populations. This project combines these long-term data with population genetic data to investigate how within population processes (selection, drift) and among population processes (founder effects, gene flow, and inter-demic selection, extinction and recolonization) combine to influence the genetic composition of (and divergence among) demes. Of particular interest is how metapopulation structure may enhance or retard adaptive evolution at different levels of selection.

This data and myriad resources from this project are freely available. Please see our long-term research page at [link, coming soon, silenemetapopulation.org].

The primary defining characteristic of eukaryotes is the presence of membrane-bound organelles, including mitochondria and plastids, that have retained their own genomes.  Basic cellular processes depend on these genomes and their functional coordination with the nucleus, and understanding how and why organelle genomes are maintained represents a fundamental evolutionary question.

The rate of mutation has been hypothesized to be a driving force in organelle genome evolution, particularly with respect to genome size and architecture, the functional transfer of genes to the nucleus, and the origins of cyto-nuclear incompatibilities. Within the genus Silene, we have identified a handful of species have experienced recent mitochondrial rate accelerations of >100-fold and remarkably divergent genome structure (genome size, gene content, organization of repeats, RNA editing).  We are using comparative genomics to explore the relationship between mitochondrial genome mutation rate and genome structure, and how these processes affect the relationship between the mitochondrial genome and the nucleus.

The primary defining characteristic of eukaryotes is the presence of membrane-bound organelles, including mitochondria and plastids, that have retained their own genomes.  Basic cellular processes depend on these genomes and their functional coordination with the nucleus, and understanding how and why organelle genomes are maintained represents a fundamental evolutionary question.

The rate of mutation has been hypothesized to be a driving force in organelle genome evolution, particularly with respect to genome size and architecture, the functional transfer of genes to the nucleus, and the origins of cyto-nuclear incompatibilities. Within the genus Silene, we have identified a handful of species have experienced recent mitochondrial rate accelerations of >100-fold and remarkably divergent genome structure (genome size, gene content, organization of repeats, RNA editing).  We are using comparative genomics to explore the relationship between mitochondrial genome mutation rate and genome structure, and how these processes affect the relationship between the mitochondrial genome and the nucleus.