Our research examines genetic and functional diversity of bacteria in the natural environment, especially in the context of symbiotic associations.  Among the most pervasive and intimate symbioses, those between bacteria and eukaryotic hosts combine the biochemical capabilities of two domains and represent key evolutionary innovations in the history of Life.  We are interested in untangling the fundamental evolutionary and ecological processes that shape such associations.

Broad questions motivating our projects include:

  • How do fundamental evolutionary processes — mutation, selection, and genetic drift — shape bacterial genomes?
  • How does the transition to a symbiotic lifestyle influence bacterial evolution?
  • What population genetic processes shape variation within bacterial groups? Is observed variation functionally significant?
  • What roles do bacterial symbionts play in their host’s responses to environmental variability?

Much of our work focuses on bacterial symbionts that influence the remarkable evolutionary success of insects hosts.  These bacteria include obligate mutualists that synthesize amino acids and other nutrients to their hosts, as well as bacterial parasites that can hijack their hosts’ reproduction.  As representatives of distinct symbiotic lifestyles, these microbial partners are useful models to examine the genomic consequences of symbiotic relationships.  Current projects focus on genome evolution of Blochmannia, an obligate endosymbiont that has coevolved with ant hosts in the tribe Camponotini.