Fossa
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Post by Fossa on Jul 2, 2013 19:59:09 GMT
...or, how not to, according to the article below... I expect Thylacine is familiar with all the material mentioned here, but for the others (all two of you at present!) Apologies if this has come up elsewhere, I couldn’t see anything about this on Discover Wildlife – but maybe I wasn’t looking hard enough... Incidentally, Thylacine, your new avatar bears a passing resemblance to a fossa! * There are currently hopes (by some) that the thylacine could be brought back by cloning. The leader in this field is Professor Mike Archer, professor of palaeobiology at the University of New South Wales in Sydney. Apparently (as recently as March this year) he said he expected to see thylacines roaming Tasmanian bush within his lifetime, after being brought back to life using gene technology. He said an important step was taken recently when a research team he was working with managed to create embryos of the gastric brooding frog, which became extinct in Australia during the 1980s. (The frog incubated its young in its stomach and gave birth through its mouth. ) He said the embryos containing the DNA of the extinct frog were created by using tissue from a frog that had been frozen before the species became extinct. Researchers injected DNA from the frozen frog into eggs from living frogs of a similar species and produced cloned embryos that lasted for a few days (obviously the last four words of that sentence are significant. But he hopes an actual brooding frog will be created within a year, once the reasons for the embryos dying has been discovered and corrected.) Professor Archer began a project in 2000 to bring back the thylacine and said the ‘brooding frog success’ showed extinct animals could be brought back to life. He said that success could then be applied to the thylacine (with much of the work of identifying all the necessary genes already done through his earlier work). However, the thylacine will be more challenging as there is no frozen sample – he just has a specimen that has been stored in alcohol for more than 100 years, so is therefore not in ‘top condition’. His plan is to put thylacine DNA into the egg cell of a Tasmanian devil – “now that would be the way this would almost certainly work”. Looking on Google, it seems Mike Archer’s work has been well publicised, which makes it sound very encouraging. But the guy writing the following article – Greer - is very scathing and sceptical, to say the least. I sense he holds a bit of a grudge, as the article gets more and more bitter as it goes on (and it goes on and on). The article was written in 2009 i.e. before Archer’s statements above, but is still very relevant. I would suggest skim-reading about the first 40% and last 10% of the article, which I think are the most interesting parts, and giving the rest a miss. www.quadrant.org.au/magazine/issue/2009/7-8/cloning-the-thylacineGreer starts off by describing Archer’s initial attempts to extract thylacine DNA (from the aforementioned pup, which he says here had been preserved in alcohol since its death in 1866) and the issues that arose – for example, contamination with micro-organisms – and the colossal failure in terms of genome sequencing (there was virtually anything to work with). It’s clear that Archer does not give up easily. There were a few things I found particularly interesting towards the end. First is the potential use of Tasmanian devils or numbats as surrogate mothers for the cloned thylacine embryo. These last shared a common ancestor with the thylacine about 28 million years ago, so Greer questions whether the devil and numbat reproductive physiology and immunology would be compatible with a thylacine embryo. Secondly, because the egg would contain the surrogate species’ mitochondrial DNA in its cytoplasm, the embryo and eventual pup would not be 100% thylacine. Also, how would the thylacine learn to hunt in the absence of other individuals of its own kind? Is this behaviour innate? National Geographic also quotes Archer as saying that bringing back the thylacine would have benefits for Tasmanian devils, which are currently threatened by devil facial tumour syndrome: “If the thylacine could be put back, it would compete with the Tasmanian devil for food as it once did, keeping smaller devil populations under control and hence less capable of spreading disease across the whole of Tasmania.” I personally would love to see the thylacine brought back, but am highly sceptical that this can ever happen after reading Greer’s article. Millions have been spent already – is it really worth continuing? Would there really be benefits for Tasmanian devils? (I think the chances are that all the wild ones will have died out well before this could ever happen – or become resistant, hopefully.) What do others think? I would do a poll if there were more than four of us! * NB I should acknowledge this website (http://www.examiner.com.au/story/1381582/thylacine-can-return-from-dead/) as this is almost verbatim!
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Post by Thylacine on Jul 2, 2013 21:24:01 GMT
Hi Fossa/Lefty/H, This is interesting stuff. Yes I think it will be possible to clone a thylacine within the next 30 years or so but not in the next 10. As I've said, the big big benefit would be to the habitat in western Tasmania which would have to be conserved. The thylacine would as you rightly say, not be a 100% thylacine from 1800 but it could be close. Mitochondrial DNA is unlikely to be a major stumbling block and using a Tassie Devil ovum as a carrier is an easy option. (Numbat is a more disimilar creature and quite a bit smaller than a thylacine). You could probably guess 95% of the thylacine genome is identical to the Devil anyway. We will never know the innate hunting instinct of a thylacine as compared to how much of it's behaviour is learnt from its parent. A cat's innate behaviour is strong and can hunt without any parental input. How can we know when this species is so different to most things we know. Financially, it's a dead loss when we should be conserving the Tasmanian habitat but this is similar to many other projects - including many fancy zoo enclosures eg Antwerp zoo elephant house cost millions for 5 elephants when this money could have helped thousands of wild elephants in Africa. Flagship species can command these funds. And this is nothing when compared to wages for football players. Which would you rather have a reserected thylacine or Torres playing up front for Chelsea for a season? Maybe my avatar photo was originally a Fossa..... but it looks close enough for me to do a double take! Archie is going to reprimand you for posting this in the "Mammals" section when it should go into the "Extinct pages"!
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Post by Admin on Jul 3, 2013 17:52:04 GMT
Which would you rather have a reserected thylacine or Torres playing up front for Chelsea for a season? I see you invoked Torres' law, nice and early there, Thylacine! And Torres will never work until Chelsea's plastic fans swallow their pride and rip off LFC's Na-na na-na na-na song. Whilst waving plastic blue flags, of course! Regards the linked article (and I struggled with lasting the pace for just your recommended amount, Fossa, sorry ), I've got to say the project appeared to have been a great white elephant, total folly imho (a bit like Torres at Chelsea). What they should be doing down under is creating a stockpile of Thylacine material. Unless they want a single specimen resurrected for an Andy Warholesque five minutes, they're going to need all the material they can get their hands on. For it to succeed long-term, they'll need cloning techniques to be really, really improved imho and they'll need lot of Tazzie devil's eggs to inject the nuclear DNA into. Surrogate Tazzie mothers would be great and the little beasts could hunt like Tazzies, sniffing out each other (not Tazzies), when it comes to finding a mate. Of course, this will be problematic in itself, but relative childsplay to creating a sufficiently sized founder population with sufficient genetic variation. Leaving Tazzie mitochondria in the first generation eggs would be the very least of the problem, I'd expect. Bringing a mammal back, going off what I inferred from the link, will require a freshly extinct species. So, until the tiger or the giant panda are no more and then brought back successfully, we'll never see another live Thylacine. At least not, imho. Sorry guys.
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Fossa
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Post by Fossa on Jul 4, 2013 19:49:02 GMT
Yes, it's surprising that the numbat was mentioned, that sounds like a C-section waiting to happen - that's if it could ever even accommodate a thylacine foetus in its abdomen to begin with! Presumably these are supposed to give birth naturally? I would have thought that, at present, the priority with Tassie Devils would be to produce more of their own species, rather than trying to resurrect an already-extinct one. I agree with what you have said about the mitochondrial DNA (I was just quoting the article! ) It wouldn't be of ecological significance. How many thylacine specimens are likely to be out there - particularly considering it became extinct in the 1930s? The occasional specimen might have been kept as a curio, but they're likely to be poorly-preserved. There is a faded, manky stuffed thylacine specimen at the Natural History Museum in London, but I wouldn't have thought that would be any use, for example.
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Post by cabbage on Jul 4, 2013 21:15:04 GMT
I think I kind of agree, you could probably bring back an animal that looks like a Thylacine via cloning - but would it be a Thylacine?
I guess one answer is that we'd never know so would it be worth doing just to having something to fill that Thylacine shaped hole in the universe?
The current attempts to breed a 'Quagga' has the same issue - all they're really doing is breeding a Zebra that looks a bit like a Quagga.
Michael Crichton foresaw this issue in the novel of Jurassic Park - there the scientists eventually admit that the creatures they've cloned aren't actually dinosaurs, they're just animals that look like a bit like they think dinosaurs should have looked.
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ollie
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Post by ollie on Jul 10, 2013 14:44:32 GMT
An animal that looks like a Thylacine but isn't one, cabbage? That you'd expect to live a full life? Sorry, but I'm pretty sure there wouldn't be a cat in hell's chance of that being a success. With your quagga example, I can see there being much more chance of successfully creating a poor imposter. All horses tend to have roughly the same body form but what comes close to the thylacine on the evolutionary tree and has a similar body form?
I'd say "nothing".
If you want something that looks like a thylacine, I think it'd be for all intents and purposes safe to say it is one (if you can do it - which I'm pretty sure we'll never be able to).
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Post by cabbage on Jul 10, 2013 15:13:53 GMT
An animal that looks like a Thylacine but isn't one, cabbage? That you'd expect to live a full life? Sorry, but I'm pretty sure there wouldn't be a cat in hell's chance of that being a success. With your quagga example, I can see there being much more chance of successfully creating a poor imposter. All horses tend to have roughly the same body form but what comes close to the thylacine on the evolutionary tree and has a similar body form? I'd say "nothing". If you want something that looks like a thylacine, I think it'd be for all intents and purposes safe to say it is one (if you can do it - which I'm pretty sure we'll never be able to). I guess I'm making the old nature vs nurture argument really. Is the sum of an animal more than just the chemicals that make up its DNA? Is a cloned Thylacine which has the same (or close to the same) genetic code as an extinct forebear - but which doesn't know how to behave like a Thylacine, still a Thylacine? If it looks like a duck, walks like a duck and quacks like a duck, its a duck. But what if it doesn't know how to quack?
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Post by Admin on Jul 10, 2013 17:19:10 GMT
Or even when to quack? It could quack at all the wrong times? Surely, some abilities are hardwired into an animal by virtue of its anatomy and physiology - a pretty much direct product of its genes (though I accept nutrition / excretion will still be essential). To turn your argument on its head though cabbage, if I'd managed to teach my cat to walk on its hind legs all these years ago, would it have magically changed species as it was doing a trick (read: behaviour) that no other cat could do?
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Fossa
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Post by Fossa on Jul 10, 2013 19:26:49 GMT
It's interesting, there are currently plans to 'bring back' aurochs by selectively breeding domestic cattle, in which auroch genes survive. These would then be used to establish free-range populations in Europe. Would these really be aurochs? I think the consensus is that they would be 'indistinguishable from the former aurochs'. But would they behave in the same way? Would they fill the same 'ecological niche'? I think this probably isn't such an issue for cattle, which are essentially grazers. But if there were a such a hypothetical situation for a predator, I can't see it working. Surely some of the natural behaviour would have been lost in the domestication process?
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Post by cabbage on Jul 10, 2013 21:45:23 GMT
We're straying towards the realms of philosophy here but I think there's a decent argument to be made that if you teach your cat to live its life on its hind legs then, yes it isn't a cat anymore. There's an author (apologies I can't remember who!) who writes a fair bit about this kind of thing in his/her books. Their premise is that dogs are basically a schizophrenic Human/Wolf 'hybrid'. We took wolves, moulded them into the physical shapes we desired and injected them with a whole host of (good and bad) human personality traits. A dog isn't a wolf anymore because we've taught them to think like a person. I think I agree with what Fossa is saying. An Auroch isn't a cow, no matter how much it may look like one, or how many genes it shares. Yes it might satisfactorily fill the grazer ecological niche, it might happily survive, breed and be a viable animal, it might look like we think an Auroch should have looked. But what about its social interactions? What about how it deals with predators and how it interacts with humans? Aren't they part of what makes it an Auroch? Are they brought along with its genetic code? How would we even know? As a hypothetical, say we reproduced a herd of Aurochs and discovered that they were incredibly hostile and aggressive towards humans, to the extent that those who are supposed to look after them cannot do so. The temptation would be to try and use this initial stock and breed more docile, 'friendly', Aurochs for ease of working with/keeping (I guess something similar maybe happened one day in our prehistory). At what point do these more and more docile animals stop being Aurochs and start being Cows?
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Fossa
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Posts: 77
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Post by Fossa on Jul 15, 2013 21:03:23 GMT
I would edit my typo in the thread title, but I don't seem to be able to.
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Post by cabbage on Jul 17, 2013 23:47:56 GMT
I would edit my typo in the thread title, but I don't seem to be able to. There's a typo?
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Fossa
Junior Member
Posts: 77
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Post by Fossa on Jul 24, 2013 20:11:03 GMT
There was a typo - I wrote 'thlyacine' - but Admin obviously corrected it once I made that post.
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