Err Tasmanian Devil that is. I had better make that clear before someone adds devil worshipping to the usual snobbish or elitist description of the wombats.
So what's up with Taz? Well, the real life animal that inspired the Warner Bros cartoon character is in danger of going extinct from a contagious cancer. The real life Tasmanian Devil is a predator about the size of a small dog. It lives only in Tasmania. It's a marsupial and a distant cousin of us Wombats.
Unfortunately, the problem that Taz Devil is having now may spell the end of a lot of species that seem to have been pulled back from extinction. As I mentioned earlier the Devil is in danger of extinction from a cancer. That cancer spreads from animal to animal during their frequent fights over food. Normally cancers can’t spread from one animal to another because the next animal’s immune system recognizes it as foreign tissue and attacks it. Unfortunately, Taz Devil immune systems can’t seem to do that with this cancer. The Tasmanian Devil population went through a severe bottleneck near the end of the last ice age—probably down to 500 or so animals. The population expanded to over 20,000, but the animals are so closely related that their immune systems can’t tell the difference between tissue from one animal and another.
That’s apparently a problem with other animals too. Cheetahs had a similar bottleneck and expansion, and similar reaction from their immune systems. Fortunately Cheetahs haven’t run into a cancer like this as far as we know. This could have wide implications in terms of endangered species. Keeping a few hundred animals alive may not be enough to keep a species viable in the long run. If genetic diversity gets low enough a species will be vulnerable to this kind of thing, as well as to other diseases. If one animal is vulnerable to a disease, they all will be.
Hopefully we can figure out some way to save the devil. Hopefully we can keep in mind that having a few animals from a species survive doesn't guarantee the survival of a species.
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Comments: 6
Can be savage little devils! i think it is a shame that a lot of animals are on the endangered list and our great grandchildren won't know animals as we do. i can't imagine a world without them.
I've read a few stories about zoo-based attempts to boost dwindling animal populations, and why they don't always work. I also heard recently that actor Robert Culp has filed a lawsuit to stop the L.A. Zoo's new elephant habitat. Have you heard anything about that, or are you strictly marsupial? ;-)
Sounds like scientists have a tough nut to crack with this one. I didn't realize their populations had been so reduced and the genetic pool narrowed thus.