So as a final statement on the evolution of the atmosphere and life, I'd like show you how both are entirely intertwined. Also please stay after for our talk on preservation of cheetah habitats. Tank you.
When gravity first pulled the earth together there was no atmosphere. Then cyano bacteria created an oxygen rich ecosystem.This allowed plants to spread to the land.This lead to increased oxygen on land. Animals then evolved onto land and that is where we've been today with an oxygen rich atmosphere.
So finally I'd like to mention some of the people who helped make this all possible. Lynn Margulis for showing us how bacteria evolved into multi cellular organisms, her work revolutionized how science thought of cellular evolution and we thank her for her contribution to science.