In case you haven’t been following this story, the Tasmanian Devil population has been ravaged by a contagious tumor. As a BBC report earlier this year explained:
Devil facial tumor disease (DFTDA) was first documented by a wildlife photographer in 1996. The animals have powerful jaws able to crunch through the bones of much larger animals and are known to bite each other’s faces during fights and courtship behaviour.
The devils usually have a life expectancy of about five years, but it is now unusual to see an animal over the age of three. Researchers estimate the wild population has fallen from 140,000 in the 1990s to 80,000.
A severely diseased devil is a grotesque sight: large tumours protrude from the face and neck, sometimes pushing out teeth and invading eye sockets.
As the tumours interfere with feeding, the animals become emaciated and usually die within six months of showing lesions.
But while many scientists had suspected a virus, Anne-Marie Pearse, a researcher for the state of Tasmania who co-wrote the article in Nature, found abnormalities in the chromosomes of the cancer cells were the same in every tumor.
Pearse and her colleague Kate Swift discovered that, while the normal complement of chromosomes in the devil is 14, the tumours contained 13, which were grossly abnormal. These chromosomal rearrangements were identical in tumours from all 11 animals studied by the scientists.
This offers support for the idea that the disease apparently began with a single sick devil, probably in the mid-1990s, that directly spread the cancer cells by biting other animals. The authors propose that cancer cells are dislodged from one animal and essentially transplanted to another as a result of bites inflicted around the mouth.
“Devils jaw wrestle and bite each other a lot, usually in the face and around the mouth, and bits of tumor break off one devil and stick in the wounds of another,” said Ms Pearse.
“We’ve found out how the disease is transmitted, which is a breakthrough in how we manage the wildlife population.
She added: “Finding a vaccine would be the ultimate goal.”
While that report offered some hope, more recent findings suggest that the devil is likely to be severely afflicted by other infections due to a lack of genetic diversity, which in turn means its prospects for long-term survival are poor. From PhysOrg:
Australian scientists say the ongoing fight to save Tasmanian devils from extinction may be doomed.
Researchers have been battling to find a cure for a deadly facial tumor disease that has decimated the numbers of the rare animals — found only in Australia’s island state of Tasmania.But now scientists at Sydney University have suggested a lack of genetic diversity because of inbreeding will doom the devils in any case.
Geneticist Kathy Belov, leader of the university scientific team, told the Australian Broadcasting Corp. the devils had been found to have “very low levels of genetic diversity in really key immune genes.”
“What this means is that they are going to be susceptible, not only to this horrible cancer that is decimating them at the moment, but potentially to all sorts of other diseases, because they simply don’t have the genetic diversity in their genes, which will enable them to respond to any new diseases that are thrown at them,” she said.
A deadly facial cancer already has killed half of the devil population because the animals have no resistance to the disease which they catch from biting each other — fighting over food or mates at breeding time.
Belov said even though scientists hoped to save the Tasmanian devil from extinction through breeding a captive “insurance” population, it would be hard to protect them from any epidemic in the future.
