Mongel Horsemen (image) National Institute for Mathematical and Biological Synthesis (NIMBioS) Share Print E-Mail Caption These are Mongol horsemen. Intense warfare is the evolutionary driver of large complex societies, according to a new mathematical model whose findings accurately match those of the historical record in the ancient world. Credit None Usage Restrictions None Share Print E-Mail 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.