A new study is offering hope for Tasmanian devils, an endangered species battling a contagious cancer. Devil facial tumor disease is a nasty condition causing deep mouth sores that eventually lead to starvation. Since it was first discovered in 1996, researchers have feared the disease would prompt the extinction of the Australian marsupial, now restricted to the island state of Tasmania, and for good reason. The facial cancer, which spreads through biting, a common practice when devils breed or fight over carcasses to eat, has already caused the population to plummet from 140,000 to 20,000, reports National Geographic. But a study published Friday in Science suggests the critters have rounded a corner. It shows the infection rate for one of two genetically distinct cancers that make up the disease has dropped significantly since the turn of the century.
Devil facial tumor disease is actually two conditions, DFT1 and DFT2. In this study, researchers looked at how DFT1 spreads, which involved collecting samples from 51 Tasmanian devil tumors beginning around 2003. Early on, sampling showed each infected devil would spread the disease to 3.5 others on average. But by 2018, the spread factor had dropped to 1. "This is potentially really exciting, because this means the disease is not racing through natural populations the way it used to," study author and evolutionary biologist Austin Patton tells NatGeo. It also means extinction as a result of the cancer is unlikely. Indeed, "the tumor itself might eventually go extinct," a researcher tells Science News. That's especially good news for the captive-bred devils recently released on mainland Australia, who may not have the disease resistance of their chum on Tasmania. (Read more Tasmanian devil stories.)