Stone tools reveal a critical transition in the lives of our early human ancestors. Learn about how technological advances went hand-in-hand with human evolution in this educational video by HHMI BioInteractive. Though tool use is not unique to humans, the sophistication of our tools and our degree of reliance upon them is unique, and sets us apart from other species. So when did human tool-making begin, and why? And what does it tell us about the evolution of our ancestors? Paleoanthropologist Tim White reveals the answers in this short video also featuring evolutionary biologist Sean Carroll. Download this movie and find classroom resources on human evolution at http://www.hhmi.org/biointeractive/tool-making-animal