What are the biggest turning points in Earth's history? BBC Earth has put together this really cool website ‬ with details of what, according to them, mark key times in the 4.5 billion years since Earth came to be. From the first forms of life about 3.5 Ga (or earlier) to the origin of plate tectonics, onwards to multicellular life forms and mass extinctions which resulted in some of the most beautiful fossils we know today. Do you think the most crucial events have been covered here? For the very nice info graph follow the following link: http://goo.gl/D7Dtmz