Mobility Highways (IMAGE) Washington University in St. Louis Caption Simulated “mobility highways” of farmer-herder interactions overlaid with the geolocated archaeological sites dated between ca. 3600 and 2200 before present (Credit: X. Chen) Credit Xinzhou Chen Usage Restrictions None License Original 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.