Secrets of the narwhal tusk
To Martin Nweeia, the narwhal — a mysterious whale with an off-center tusk — is much more interesting than the mythical unicorn. Now, eight years after he described the narwhal’s distinctive tusk as a sensory organ, the fascinating creature is coming into focus. Nweeia and his colleagues have mapped a sensory pathway between that spiral tooth and the narwhal brain, along the way showing how the animal may use its tusk to suss out its environment. A practicing dentist in Connecticut and a clinical instructor in the Department of Restorative Dentistry and Biomaterials Sciences at the Harvard School of Dental Medicine (HSDM), Nweeia calls himself “just a curious kid” whose interest in dental anthropology — teeth in people across evolutionary history — spurred him to look at, for example, the elephant tusk and other variants of teeth in animals. But for more than a dozen years he has been chasing narwhals in...