Kertu Liis Krigul (IMAGE) Estonian Research Council Caption Kertu Liis Krigul, the first author of the paper Credit Karl Erik Piirimees Usage Restrictions Please mention the author of the photo (Karl Erik Piirimees). 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.