Salty Layers (image) Earth Institute at Columbia University Share Print E-Mail Caption Study authors Jay Quade (left) and Jordan Abell (right) looking for optimal samples at the site of an ancient Turkish settlement where salts left behind by animal and human urine give clues about the development of livestock herding. Credit Güneş Duru Usage Restrictions Credit must be given. 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.