The second major event was the Permian extinction at the end of the Paleozoic Era. It was the largest mass extinction in Earth's history killing 80% of all life. This loss of life was necessary for the explosion of new life that happened afterwards. The absence of many species allowed dinosaurs to occupy the empty niches and start the era of Dinosaurs.
The third important event happened in the tertiary period when birds, mammals and flowering plants began to dominate. This happened when the dinosaurs went extinct after the cretaceous and the evolution of mammals led to the first humans. Without this event humans may not exist or be much different than what we are today.
The scale of Earth's history is incredibly massive. It surprised me looking at the timeline that all the eras and periods we talk about are all in the span of only about a meter. The Earth was barren with little to no life for most of history. When reading about it it seems that all the eras and periods are roughly the same length but looking at it you can see that the Precambrian Era is most of Earth's history.
Humans have had such a great impact on Earth in just a few hundred years. And most of our impact has happened in the last hundred. We are destroying ecosystems that took hundreds of millions of years to evolve in just years. Humans have existed for just a few thousand years, and have done more in a blink than any other species has done in millions of years.
Some questions I have are why did it take so long for life to take off and start evolving? Why did some species go extinct? Where there intelligent species in the past that went extinct? Why did the planet evolve the way it did?
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