In the last 3.8 billion years, life on Earth has evolved from single-celled prokaryotes to the dizzying array of life we have today. So how did this all happen? This video charts the story of evolution on Earth, the multi-million species battle for survival that has already said goodbye to 99.99% of competitors.
In the 1830’s, Charles Darwin sailed the world and studied a variety of previously unknown wildlife. Examining these species over two decades led eventually to Darwin’s theory of Evolution by natural selection which he offered to the public in his 1859 book, the origin of the species.
Darwin’s work allowed us to understand how life mutated and diverged from itself, creating new species, ultimately allowing scientists to work backwards and begin to discover where and how life first began.
From Crash Course: Biology on YouTube presented by Hank Green.