A Timescale for the Evolution of Life on Planet Earth (image) University of Bristol Share Print E-Mail Caption A timescale for the evolution of life on planet Earth summarising the findings of Betts et al. study. Credit University of Bristol Usage Restrictions Image is for single use only to illustrate this press release and must not be archived 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.