I am intrigued by the two-way interaction between single celled photosynthesising algae (phytoplankton) in the ocean and the carbon cycle, trace metals and climate. Firstly, the evolution and production of phytoplankton act to pump carbon dioxide from the atmosphere to the ocean, so variations in phytoplankton success and access to trace metals can drive climate; this forms one major thread of my research aiming to reconstruct productivity, and other carbon system parameters in the ancient oceans. Furthermore, the impact of phytoplankton on the atmosphere and ocean environment, can also drive their own evolution. The photosynthesising mechanisms of these algae have had to adapt to the ever declining levels of carbon dioxide over the geological history of Earth, via either adaptive change in the enzyme Rubisco, or via the emergence of so called carbon concentrating mechanisms. A second aim, is to chart the evolutionary history of photosynthesis (and other biochemical processes) through genetics and biomarker molecules both as a means of constraining past levels of carbon dioxide in the atmosphere, but also to understand and predict different species responses to anthropogenic change.