I am interested in the co-evolution of Earth and life. My PhD focussed on Cyanobacteria, ancient oxygenic phototrophs which first appeared more than 2.3 billion years ago. They are now widespread from cold glacial habitats to to temperate agricultural soils, geothermal vents and warm tropical oceans near the equator. Many species are important ecosystem engineers, generating organic nitrogen and carbohydrates which facitate the growth of animals and plants higher in the food chain. My research investigates how Cyanobactria have grown to prosper in their varied and changing environments. This draws upon methods of phylogenetic analyses, bayesian molecular clocks, microbial culture and genome assembly. Particular topics of focus include antioxidant evolution, superoxide dismutase gene expression and diversification of cold-tolerant strains.