In the last couple of centuries, scientists have uncovered ancient fossils, prehistoric artwork, and other clues to the evolutionary origins of humankind. Here are nine of the most revealing discoveries that have changed our understanding of our early ancestors—and ourselves. Jorge Mario Álvarez Arango, UNESCO // CC BY-NDSpanning eight miles in southern Colombia, caves in Chiribiquete National Park are covered in vast prehistoric paintings. In addition to being beautiful artworks in their own right, the cave paintings are thought to have a deep spiritual meaning. Found in Slovenia in 1995, the Neanderthal-made flute was made out of the thigh bone of a prehistoric cave bear.