Why is there life on Earth?

A visual history of the Earth through 5 milestones which explain the great changes that have made life on our planet possible: How did we get here? Do you like this topic? Read more here: http://bbva.info/2GSzgv1 Follow a path of more than 4.5 billion years, from its birth as a fireball to the present Blue Planet. Discover what has made the Earth so special, a world in constant change. In the last few years, our idea of the Earth’s history has changed, as new research has shown that it cooled down much faster that we thought. New and surprising stages have been unveiled on this winding road: the emergence of oxygen, the engine of evolution, first caused a mass extinction and a brutal climate change, that turned our world into a snowball.