The songs of birds, the hums and grunts of toadfish, and the lofty speech of humans all use the same ancient brain circuit, despite an evolutionary split 400 million years ago, reports National Geographic. Researchers have discovered that the base of the hindbrain and upper spinal cord is the starting point for all vocalizations.
Scientists believe the brain mechanism can be found even in silent creatures like sharks—which may not be so silent after all. The same section of the brain, however, drives sounds in different ways. In the toadfish, for example, the brain regulates swim bladder muscles that control the creature's strange calls. "There's this fundamental similarity in brain circuits, but then there's this beautiful diversity on top of it," said a researcher. (Read more animal stories.)