Tasmanian devils suffer from an unusual cancer, which is contagious and causes tumors that grow so large on the face and neck that the animals eventually can’t eat:
The furry black animals spread a fast-killing cancer when they bite each other’s faces. Since the disease’s discovery in 1996, their numbers have plummeted by 70 percent.
Genetic studies suggest an origin:
It didn’t jump from another species, said Murchison. Tasmanian devils, for unknown reasons, are prone to various types of cancer. This tumor’s genetic signature suggests that probably no more than 20 years ago, mutations built up in some animals’ Schwann cells — cells that produce the insulation, called myelin, crucial for nerves — until the first devil fell ill with this new type.Those mutations went far beyond a typical cancer. When one sick animal bites another, it transplants living cancer cells that form a copy of the first animal’s tumor. Murchison’s team tested 25 tumors gathered from devils in different parts of Tasmania, and found the tumors were essentially identical to one another.
It’s one of only two forms of cancer known to spread this way, Murchison said; the other is a sexually transmitted cancer in dogs. (That’s quite different than people’s transmission of a few cancer-causing viruses, such as the human papillomavirus that causes cervical cancer.)