Written language, the hallmark of human civilization, didn't just suddenly appear one day. Thousands of years before the first fully developed writing systems, our ancestors scrawled geometric signs across the walls of the caves they sheltered in. Paleoanthropologist and rock art researcher Genevieve von Petzinger has studied and codified these ancient markings in caves across Europe. The uniformity of her findings suggest that graphic communication, and the ability to preserve and transmit messages beyond a single moment in time, may be much older than we think. TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design -- plus science, business, global issues, the arts and much more. Find closed captions and translated subtitles in many languages at http://www.ted.com/translate Follow TED news on Twitter: http://www.twitter.com/tednews Like TED on Facebook: https://www.facebook.com/TED Subscribe to our channel: null