Actually, there are quite a few good documentaries that lightly cover this stuff! It's a good way to introduce yourself to it. 'Miracle Planet' is a miniseries which covers the formation of the earth and the evolution of life from it's very beginning. 'The Day the Earth Nearly Died' is a single documentary focusing solely on the Permian Extinction. 'Animal Armageddon' is a short tv series which covers (I believe) the five major extinction events. Most importantly it covers the lesser known but second greatest extinction event, the Ordovician extinction. It also covers the snowball earth era. 'Walking with Monsters' is my favorite. It covers life from the first complex life forms to just before the dinosaurs. The 600 million years it shows, and the animals described, are largely unknown to many people. It's really interesting to watch!