3 Billion years ago cyanobacteria appeared on the planet, changing the course of life on earth. Scientists call this event the Oxygen Catastrophe.
This video discusses the appearance of cyanobacteria and the effect it had on the evolution of life over the next 3 billion years.
Suitable for an introduction to evolution, endosymbiosis and the appearance of photosynthesis and oxygen. The video includes an introduction to iron strata formation and the relationship between cyanobacteria and chloroplasts.