The evolution of photosynthesis forever transformed our planet’s geochemical cycles and left a lasting impact on life for billions of years. Studying the role of early life and metabolism across geological timescales has proven challenging, as ancient biological events have traditionally only been accessible through the fossil and geological records which do not provide a window into the biochemical properties of early microbial life. My research utilizes a combination of evolutionary biology and synthetic biology to “resurrect” aspects of ancient life to test longstanding questions concerning the origins of photosynthesis and some of the earliest evidence for life on Earth. The proposed work will provide insight into how photosynthesis evolved in the face of changing atmospheres in the past. This may in turn help us understand how life will respond to the changing climates we face today, as well as provide novel approaches to engineer and improve upon photosynthesis.