The first creatures to evolve teeth didn’t have jaws. Many scientists believe these ancient fish developed the first tooth-like structures on their skin that were similar to the “denticle” scales that still cover sharks today, even after 500m years of evolution. It is thought that these denticles gradually migrated into the mouth to form oral teeth. However, research conducted by my colleagues and I suggests modern teeth – at least in sharks – may have also evolved from taste buds. In fact, we have shown that both teeth and taste buds develop from the same stem cells in an embryonic shark’s mouth.