Prehistoric Food Globalization GIF (IMAGE) Washington University in St. Louis Caption Animation illustrates how four of the ancient world's most important domesticated grain crops spread across the Old World between 7,000 and 3,500 years ago. https://media.giphy.com/media/5YhLYT0OTG11uiY648/giphy.gif Credit Data source: Xinyi Liu; Animation by Javier Ventura/Washington University in St. Louis. Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.