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Beardless Bdale

Beardless Bdale

Posted Jan 23, 2009 11:34 UTC (Fri) by jhs (guest, #12429)
Parent article: Beardless Bdale

That's good news. I've been hearing about the Tasmanian Devil situation in some of my non-technical podcasts.

There is a very nasty infectious cancer that has killed out nearly half of the wild devil population. It's great to hear that the free software community is helping with this effort.


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Beardless Bdale

Posted Jan 23, 2009 19:58 UTC (Fri) by jd (guest, #26381) [Link]

I've been monitoring the news outlets for stories on the Tasmanian Devil and it doesn't look good for them. They have a low variation in their DNA, there appears to be a very slight resistance but no actual immunity in a handful of cases, and the best the Australians have come up with is to build a gigantic fence keeping the infected population away from the known uninfected clusters. (Now all they have to do is teach Taz to read.)

This does assume, however, that they know where every Devil is, so that no infected ones are on the wrong side. It also assumes that, since the virus can be spread through saliva, that the fence will stop other methods of transmission.

From an ecological perspective, this is a problem that could exterminate all wild Tasmanian Devils and make re-instroduction via captive breeding programs extremely difficult. Those of us geeks interested in ecology thus care a lot about the situation from that perspective.

But it's not the only one. Trying to find a cure whilst trying to keep new infections from happening requires someone knowledgable on Game Theory and the Byzantine General's Problem. Trying to do so within the miniscule budgets ecologists get (especially in a recession) requires a genius at SIMPLEX and other optimization methods. Trying to maximize genetic diversity is another optimization problem (which Taz' to try and save, say by surgery). Trying to do all this in the timeframe left is going to take hefty computer resources (maybe a BOINC project?) and skillful coders.

Beardless Bdale

Posted Jan 23, 2009 21:12 UTC (Fri) by nix (subscriber, #2304) [Link]

You call it a 'virus'. It isn't a virus, it's a cancer. Totally different
beasties.

They're in considerable trouble. The only way I can see to save them
involves moving some to another island and writing off those you leave
behind :(

Beardless Bdale

Posted Jan 24, 2009 1:30 UTC (Sat) by i3839 (guest, #31386) [Link]

The Tassie people I'm visiting think that it has something to do with some kind of poisonous stuff that's used by the forestry for one thing or the other, but I forgot the details.

Bdale looked a lot better with his beard intact. :-/

Beardless Bdale

Posted Jan 24, 2009 2:13 UTC (Sat) by jd (guest, #26381) [Link]

The cancer is indeed a cancer, but cancers aren't in themselves contagious, so it's clear that the cancer is induced by a pathogen that can be transmitted. This is not that unusual. The bacteria that cause stomach ulcers are linked to inducing stomach cancer, and so on. In the case of Taz, there is a virus which is the transmissible agent. This then causes the cancer in the Devils with the virus. This is why the researchers were so interested in the immune response that some Devils gave to the virus. If the immune response was strong enough, then breeding programs might have been a possibility and vaccinations could have become a consideration. It turns out that the immune response isn't nearly strong enough.

Contagious cancers

Posted Jan 24, 2009 2:42 UTC (Sat) by corbet (editor, #1) [Link]

Getting way off topic, but what the heck...

The way the guy explained it at the event, the cancers themselves are contagious. In particular, the tumor cells are not the victim's cells; they come from outside. The lack of genetic diversity in the devil population makes that sort of propagation possible. It's weird (and nasty) stuff.

Contagious cancers

Posted Jan 24, 2009 13:29 UTC (Sat) by nix (subscriber, #2304) [Link]

This is not unique. There is a contagious cancer of dogs that's still
going: because it's non-lethal it's kept going more successfully, and is
still hopping from dog to dog perhaps a thousand years after its
progenitor died.

Yes, mammalian cell, you too can be an immortal unicellular organism.

Beardless Bdale

Posted Jan 25, 2009 15:05 UTC (Sun) by mjg59 (subscriber, #23239) [Link]

In the general case, but given:

1) An immune system that isn't triggered
2) The ability to encourage blood vessel growth
3) Easy transmission of immortal cells

then cancer itself is transmissable. Human cancers have (to the best of our knowledge) failed to achieve these three, so we haven't seen anything similar so far. Tasmanian Devils live in a small and physically constrained ecosystem and so are fairly inbred, which limits their genetic diversity and thus ability to have immune responses to cells derived from near-identical organisms.

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