GEE Seminar - Dr Patricia Sanchez-Baracaldo, University of Bristol

Academic Host: John Allen
Abstarct: Primary producers transform light energy from the sun into chemical energy in the form of sugars. This fundamental process has enabled life on Earth. Once ancestral cyanobacteria evolved, they played a fundamental role in Earth’s history by enabling the rise of atmospheric oxygen paving the way for complex life. The origins of photosynthesis are still not well understood. I will give an overview about key evolutionary events in the history of Cyanobacteria: 1) the Archean origin of PSII (the photochemical reaction centre that catalyses the light-driven oxidation of water to molecular oxygen), 2) the origin of the crown group of Cyanobacteria, 3) the emergence of filamentous forms around the Great Oxidation Event (2.32 Ga), and 4) the late emergence of marine planktonic groups between 800-600 Mya.  Molecular evolution analyses overall show that there is a huge lag between the Archean origin of oxygenic photosynthesis and planktonic forms at the end of the Precambrian. By studying the ‘genomic record’ we can now unravel how oxygenic phototrophs co-evolved with the Earth’s biosphere, thereby making our planet habitable.