(Phys.org)—A team of researchers from several institutions in China and one in Ireland has found evidence in the ears of developing bat fetuses that suggests all bats evolved from a common ancestor that had developed echolocation. In their paper published in the journal Nature Ecology & Evolution, the researchers outline their study and results and explain why they believe they have found evidence of some bats losing their echolocation abilities. M. Brock Fenton and John Ratcliffe with Western University and the University of Toronto respectively offer a News & Views piece in the same journal issue on the work done by the team and offer opinions regarding the results.