A long-standing question in evolutionary biology is how organisms adapt to novel environments. We investigate the mechanisms of adaptation to high temperature in cyanobacteria from geothermal environments, which include the most thermotolerant phototrophs on Earth.

Acaryochloris marina is a recently discovered cyanobacterium that is unique in its utilization of the far-red light absorbing Chlorophyll d as the major pigment in photosynthesis. As a result, it occupies a solar niche that is invisible to most other phototrophs. We use Acaryochloris to understand the origin of novel traits and the consequences for diversification.

Diatoms in the Rhopalodiales possess cyanobacterial endosymbionts that have lost the ability to photosynthesize but fix nitrogen for their host. We are studying the mechanisms of symbiont genome evolution and metabolic integration with its diatom host, as well as the costs and benefits of symbiosis.