The 'True Frog' Rana igorota (image) University of Kansas Share Print E-Mail Caption To establish the actual timing of true frogs' diversification, Chan and Brown performed phylogenetic analysis of 402 genetic samples obtained from an online database called GenBank. These samples represented 292 of the known 380 true frog species in the world. Credit Courtesy of Rafe Brown 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.