2 things science and human progress accomplished on this date.
1859
Darwin publishes On the Origin of Species
Charles Darwin's On the Origin of Species went on sale in London, setting out how living things change over time through natural selection. The entire first printing sold out that day, and the whole of modern biology has been built on the idea since.
Lucy, an ancestor three million years old, is found
In the Afar region of Ethiopia, Donald Johanson and Tom Gray uncovered the bones of Lucy, an Australopithecus who walked upright more than three million years ago. Her unusually complete skeleton became one of the clearest windows into how our ancestors came to stand on two feet.