Contagious Cancer May Send Endangered Tasmanian Devil Into Extinction
Tasmanian Devils are facing a devilish disease that could wipe them out within decades. Called the Devil Facial Tumour Disease (DFTD), the problem is a contagious cancer that causes huge lesions to form on the face. It has killed more than 80% of Tasmanian devils since 1996 and there has been an 84% decrease in devil sightings across Tasmania as of February 2011. The Tasmanian devil has been listed as an endangered species.
According to Save the Tasmanian Devil, DFTD is one of only three known cancers that can spread like a contagious disease. Tasmanian devils are biters, as anyone familiar with the species quickly learns, and the disease is spread from the many bites they deliver to one another. Once infected, a devil typically won't live longer than six months and usually die of starvation because the tumors make it so difficult to eat.
Now, researchers are finding that the cancer is evolving in an unexpected way.
Live Science reports on Yahoo News that "rather than changing their genes, a new study finds, Tasmanian devil tumors are altering on an epigenetic level — meaning the basic gene sequences stay the same, but the genes that get switched on and off are different. Some of the epigenetic variants may help the cancer spread more easily or evade the immune system, said study researcher Katherine Belov, an animal geneticist at the University of Sydney."
In essence, what researchers though were tumors that cloned themselves, they've found that the cancer is actually evolving. It might mean that the cancer will get more aggressive, but it might also mean that the tumors will become benign. Save the Tasmanian Devil notes that a PhD student has been studying a population of devils where the cancer is not as deadly as in other populations.
"Although DFTD has spread through this population at the same rate that it is spreading elsewhere, abundance throughout the population has not plummeted, the full age structure is still intact and tumours appear to grow slower, regress and take longer to kill the animal."
This could mean that indeed the cancer is evolving to be less aggressive, but whether or not there is still hope for the species remains to be seen.