Sahul Map (IMAGE) DOE/Sandia National Laboratories Caption Green lines mark primary travel routes, or "superhighways," on this map of the continent as it looked approximately 50,000 years ago. These routes emerged as a result of billions of computer simulations run at Sandia National Laboratories. Credit Meg Davidson, Sandia National Laboratories 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.