Evolution of gills (IMAGE) University of British Columbia Caption Well before evolving to help vertebrates breathe underwater, gills played an early and equally important role regulating the salt and pH balance of blood, according to surprising new research from University of British Columbia zoologists. Credit Rashpal Dhillon, Rush Studio. Usage Restrictions n/a 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.