This BBC link offers a simple overview of how our planet and its life forms evolved: The 25 Biggest Turning Points in Earth’s History | BBC Earth
Our species, Homo sapiens, is ridiculously young. We have only existed for a fifth of a million years. In that time we have expanded from our African birthplace to reach every continent, and even outer space. Our activities have precipitated the sixth mass extinction and unleashed the fastest episode of climate change in Earth’s history. Yet we are also the only species that has ever managed to piece together the history of Earth.