This great piece by Carl Zimmer of National Geographic delves into the question “What is the purpose of a narwhal’s tusk?” This has been debated for centuries. The newest hypothesis comes from Martin Nweeia, a Connecticut dentist and a clinical instructor at the Harvard School of Dental Medicine. He believes it is a sensory organ, since it has nerves running throughout its length. This tusk could conceivably assist the animal in making sense of its surroundings. His findings are published in The Anatomical Record.
Kristin Laidre, from University of Washington, who has done her own fair share of narwhal research, believes that the tusk has more of a macho function. Male deer and elk have antlers, male rhinos have horns, male narwhals have tusks.
This is a good debate. Perhaps they’re both correct. We shall see.