As published in Current Biology and reported in Science Magazine and BBC news, James Cotton, Steve Rossiter and colleagues in China have revealed that bats and dolphins both hone in on their prey using a process called echolocation, even though they are very distantly related. Involved in the process is the motor protein prestin found in mammalian outer hair cells (OHCs) and thought to confer high frequency sensitivity and selectivity in the mammalian auditory system. By examining the prestin gene, the study shows that this protein evolved in the same way in both bats and whales. Dr Rossiter said: “We were surprised by the strength of the evidence for convergence between these two groups of mammals, and, related to this, by the sheer number of convergent changes in the DNA that we found."