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Cenozoic Park: Cloning the Tasmanian Tiger
Mirk writes "The
Australian Museum
reports a breakthrough in their plans to clone the Tasmanian Tiger. The ``tiger'', actually a carnivorous marsupial, became extinct in 1936, when the last known
specimen died in captivity. Er, did I say ``extinct''?
Now it looks like what everyone thought was an extinction may be
``a 70-year hiccup'', to quote the press release. The museum's Evolutionary Biology Unit have successfully replicated individual Tasmanian Tiger genes using a process known as
PCR (Polymerase Chain Reaction)."
Scientists don't go around cloning every extinct animal. Not every animal died because of evil humans, some died because they weren't fit to survive in this world. Bringing them back now, when other species have evolved, could throw everything off balance and screw up the world even more.
Just because you can do something, doesn't mean you should.
...and don't want to rehash the whole 'Jurassic Park' cliche'. I have to believe that a species is extinct for a reason. Yes, maybe it's because Man destroyed their habitat or hunted them to extinction, but the fact remains, they're extinct, they could not adapt for survival. Surely there's a reason for that? This can't end well.
Don't park drunk, accidents cause people.
Couple of comments on the ever-so-brief-and-simple press release:
(1) No mention of the increasing research into why cloning large mammals if more difficult than thought. See recent New Scientist magazines for pop coverage.
(2) No mention of host animals. The Tiger can't be brought back whole and entire, something needs to act as a host - 90% close relative, 10% recovered DNA. Then work up.
(3) No mention of gene pools and viable population sizes. Pick one human - clone a breeding population from them. Fancy working with them? Didn't think so.
Still, interesting project!
It is an obvious must that any animal that would be restored using this procedure should be considered carefully, and the main critera should be based upon several points:
1. Is the animal extinct today due to human interference?
2. Can the animal re-establish itself in todays ecology?
3. Is it practical to re-introduce the animal back into the wild?
If the answer to all of these major questions (and many more minor questions) is yes, then I can see no good reason not to undo the damage humans have caused to these species.
The breakthrough here is that PCR confirmed that there was very little damage to the ethanol preserved specimen. The next step is that they are planning on using PCR amplified DNA to "rebuild" the genome of the Tasmanian Tiger. To my knowledge, all other cloning involves injecting cell nuclei into oocytes (eggs). This has the advantage of preserving genes in the proper context. This is probably not possible with the preserved specimens.
Trying to re-build the entire Tasmanian Tiger genome, essentially from scratch, to produce artificial chromosomes is a huge undertaking - by the researcher's estimates, this could take 10-15 years.
All you really need to do is look at the track record of the introduction of foreign species into environments that had not evolved with them.
;) -- the introduction of the mongoose to fight the rat population in the sugar cane fields has had a negative impact on the native bird populations.
Take Hawaii (okay, share it with the rest of us
Or to quote my favorite Jeff Goldblum line:
"You were so busy trying to see if you could do it that you didn't stop to think about whether you should."
Old age and treachery almost always overcome youth and skill.
That's like saying "Go ahead and fry that mission critical server, I have backups!" Sure, it'll save your ass, but its no way to run things.
Or we could:
a) Manage wildlife conservation at a reasonable level. (Control poaching, destruction of environment, etc).
b) Accept that fact that species become extinct, regardless of whether by human hands or not. Why bring them back just for the sake of doing it. (See Jurassic Park for an extreme example).
We should never mess with nature. Something as simple as introducing a new species in a different environment has caused havok around the world. (Like Zebra mussels in the great lakes). Can you imagine some genetically altered species roaming around, interbreeding and the like?
We can't even get rid of Zebra mussels, this is an ecological nightmare waiting to happen!
PCR is a technique that is successful in replicating even very small pieces of DNA. It 'amplifies' extremely small samples of material into amounts that are detectable. Essentially, this group in Australia has determined that they have some DNA from the Tasmanian Tiger, but they have no idea how much of the genome. It is highly likely that there just isn't enough enact DNA to be useful for the creation of an animal.
Assume for a moment that they are exceptionally lucky and have an intact genome from two individuals, one male and one female. The scientists then pass the substantial hurdle of cloning these individuals (no marsupials have been cloned yet). What do they have: two individuals. This would amount to a 'population bottleneck' of the worst magnitude. Who will these animals' offspring mate with?
I don't think this is the example you are looking for. The reason the Tasmanian Tiger became extict is that the Tasmainian state government put a bounty on them because the state's farmers believed they were killing sheep (which thay may have been but certainly not in great numbers). So I can hardly see how reintroducing them on the island would damage "Earth's delicate balance", and they couldn't possibly do more damage than the introduced sheep currently do. Although the Tasmanian wilderness seems to have survived without the this particular animal, I'm sure the human race, and the earth as a whole, would be better off with anything that helps reduce the dramatic decline in bio-diversity. BTW like most Australian native fauna, I wouldn't call the Tasmanian Tiger "cutesy-wootsy", nor a marsupial a "puddy-tat". You should come visit and have a look at some of our animals face-to-face.
"Not every animal died because of evil humans, some died because they weren't fit to survive in this world."
Fitness to survive in the world has nothing to do with it. A meteor falls, and everything with a body mass greater than 100kg dies out. Were the larger animals less fit? A volcano erupts. A species dies. A flood wipes out a nesting ground. Chalk up another one. Human sailors bring in rats, goats and row plants, destroying practically all native flora and fauna of whole island chains.
Were any of these things destroyed because they were less fit? Of course not. If your building catches on fire, are the survivors more "fit" or are they simply lucky enough to be working on the first floor?
Despite the pitifully bad dialog of Jurassic Park, natural history does not represent some featureless plain on which species struggle against each other and the best win out. Catastrophes happen. Climates make sudden, radical shifts. Disease runs rampant. New vegetation suites are established. Chance is everywhere.
And chance is all it takes. Abandon any idea that the creatures you see around you are "better" than what came before. Different? Sure. Better? By what standards? They're here because of chance built on chance, built on chance. Feedback loops tend to enforce the status quo, keeping many species stable over millions of years (a feature generally absent for the last 12,000 years) but the best predator on Earth can't live if all the prey die and forest dwellers die when the forest goes bye.
The Thylacine happened to be a predator on an island where humans decided to raise sheep. It was fully "fit" in the environment before this point. Afterwards, it was "unfit" in the sense that it's hide was not bulletproof and it had an unfortunate predilection for traps.
Should we worry about the return of extinct species? At some point, yes, but not because some anthropomorphic "nature" selected them for extinction. We should worry because these creatures may be all too "fit" and have behaviors, breeding strategies, or feeding habits that are exceptionally successful in a modern setting.
Do you oppose the return of Grey Wolves to the Yellowstone Basin, or the reintroduction of Grizzlies to their historic range? Like the thylacine, these are creatures that have been absent from these territories for multiple generations. And the areas to which they are being "returned" have often experienced radical changes in the intervening years. Watching the ups and downs of these "reintroduction" projects should give us a good preview of the pitfalls to avoid when someone wants to put just a few Mastadons in Missouri.
This is just the atheist's version of the religious argument that science should "not play God." Something infinitely wiser than us has not ordained that something should be, therefore man should not rightly make it be.
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