Over a billion years ago, jewel-like cyanobacteria caused the Great Oxygenation Event. Thanks to Cyanobacteria, we have air to breathe. Cyanobacteria have played an astoundingly fundamental role in shaping life on Earth today. Over a billion years ago, they caused the Great Oxygenation Event which created our oxygen-rich atmosphere and transformed the planet. Cyanobacteria are also believed to be the precursors responsible for photosynthesis and multicellularity as a whole. These photosynthesizing chains of bacteria are found in many environments, including freshwater ecosystems. This video was made in collaboration with Jared Leadbetter, Professor of Environmental Microbiology at the California Institute of Technology.