Image (IMAGE) University of North Carolina at Charlotte Caption This tree is a summary of the selected host transformations in the clade of Betacoronavirus associated with SARS-CoV, MERS-CoV, and SARS-CoV-2. Bats have been fundamental hosts of these human coronaviruses. The host transformations indicated by dotted lines are independent events that are not important to the origins of these human coronaviruses. Credit Denis Jacob Machado Usage Restrictions available for general publication use 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.