Tasmanian Devils Evolving Resistance to Tumors
Genetic changes suggest some animals are fighting back against the lethal, transmissible cancer called devil facial tumor disease.
Is there hope yet for the beleaguered Tasmanian devil in its fight against the deadly condition known as devil facial tumor disease (DFTD)?
Researchers from Washington State University (WSU) say they have identified a genetic resistance to DFTD evolving in some populations of the animal.
Tasmanian devils, the well known marsupials that live exclusively on the island of Tasmania off southern Australia, have been decimated in recent years by DFTD, a transmissible cancer that is almost always fatal and has taken out an estimated 80% of the devils.
The brutal condition, which spreads among devils through bites or food sharing, causes cancers to form in the animal's mouth, making it hard to eat and eventually bringing about death by starvation.
Now, though, a WSU team has found two devil genome regions that suggest there may be a way forward for the species, one that does not include extinction.
The scientists took note of devil populations that persisted in areas that had long since been overrun by DFTD and investigated whether there might be a genetic reason the animals had not contracted it.
By comparing devil DNA samples taken before and after the emergence of DFTD, the scientists found two genome regions that had changed significantly following the spread of the disease.
Several genes in those regions, the team observed, are associated with cancer or immune system function in other mammals, which told them the surviving devils may indeed be evolving a resistance to the lethal condition.
The scientists are now looking more closely at the genome regions, with the ultimate goal of breeding DFTD-resistant devils.
"Our study suggests hope for the survival of the Tasmanian devil in the face of this devastating disease," said Andrew Storfer, WSU biology professor, in a statement. "Ultimately," he added, "it may also help direct future research addressing important questions about the evolution of cancer transmissibility and what causes remission and re-occurrence in cancer and other diseases."
Complete findings of the study have been published in the journal Nature Communications.
VIEW PHOTOS: Wombats So Cute You Can't Look Away
As we ease into the weekend, what better way to wind down than by looking at photos of cute wombats? We begin with the closest thing the world has to a celebrity wombat, Patrick. A resident and top attraction at Ballarat Wildlife Park in Victoria, Australia, Patrick comes by his fame thanks to his size. As you can see he's just honking enormous. He's also old, and fat -- oldest and fattest among all wombats, in fact, at 29 years old and 88 pounds at last check. Patrick has his own Facebook page, and he even has his own merchandise line . As tempting as it is to devote an entire gallery to Patrick, we promise we'll move on now and show you other wombats.
OK, we lied. He's too cute for just one slide. Here's Patrick not even hardly trying to look cute but succeeding at it anyway. The Ballarat Wildlife Park people say Patrick is so famous he's even been visited by actor Nicolas Cage. We'll pause a moment while you picture that for yourself.
OK, we lied, again. Last time, though, we promise. Here's Patrick chowing down. A wombat's gotta eat, after all. Wombats are herbivores and dine on various types of roots, bark and grass.
A sleeping wombat is a cute wombat. They're nocturnal creatures, so they catch most of their Zzzzs while it's light out.
Wombats are marsupials, toting around their young in pouches. Baby wombats spend nearly half of their first year in the mother's pouch. By the latter half of the year, though, they're ready to leave the pouch and make it on their own.
Wombats have razor-sharp incisors that grow throughout their lives, getting whittled back down to size when they're used to gnaw on rougher vegetarian fare.
Your run-of-the-mill wombat will be a bit more than 3 feet long and will weigh around 55 pounds.
There are two type of wombat: hairy-nosed and bare-nosed (also called common). They can live for anywhere from around 5 years in the wild to 30 years if they're in captivity. They're native strictly to Australia and a few nearby islands.
Wombats make their homes in burrows. They're strong and have very sharp claws that allow them to build often elaborate tunnel and chamber complexes, like the adjoining rooms of a house.
Unfortunately, their innate drive to make burrows makes wombats vulnerable to angry farmers and ranchers who take umbrage and the stocky little mammal's accidentally destructive ways. For this reason, they're often hunted. Watch your six, little fellas.