Climate evolution (IMAGE) Johannes Gutenberg Universitaet Mainz Caption Climate evolution in the Greenland/North Atlantic/Central Europe region: Megafauna were present during all phases with their largest population density some 15,000 years ago. They migrated when thick pine and birch forests began to extend 11,000 years ago. Credit ill./©: ELSA-Projekt Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND 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.