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Friday, February 24, 2012

Cloning Our Way Back to the Deep Past

Image Source: Wiki via I09.

Woolly Mammoths have been extinct for at least four millennia (most Mammoth populations died 10,000 years ago, but a small pocket survived on an island in the Arctic Ocean until about 1,700 BCE). Several specimens of these great Ice Age elephant cousins are so well preserved in Arctic ice that there is a lot of speculation that they could be successfully cloned within five years.


I09 remarks that this is probably impossible because cloning is so difficult:
A team of Russian and Japanese scientists recently announced that they have discovered pristine DNA samples of woolly mammoths, and they will clone a living mammoth within five years. It's tremendously exciting...but almost certainly not going to happen. ...

Honestly, cloning a mammoth isn't that much harder than any other species, assuming you've got the required materials. Of course, that's a pretty big assumption to make for a species that has been extinct for at least 4,500 years. Since our cloning technology is in place, all you really need is some pristine mammoth DNA. To get that, we have to find undamaged cell nuclei from a mammoth that we can insert into the egg cells of a surrogate parent, most likely its living relative the African elephant.

That's why this recent discovery is potentially exciting. Global warming has thawed some parts of eastern Russia that ordinarily remain permanently frozen, and the newly uncovered ground has yielded a startling discovery: a bunch of well-preserved mammoth carcasses, including at least two calves that are well-preserved enough to donate cell nuclei from their bone marrow, at least according to a joint team of Russian and Japanese researchers.

Now, to be perfectly honest, we can't even be really sure about that part of this story - considering how even the slightest imperfections could render the cloning process impossible, there's every chance that this bone marrow DNA will prove unsuitable for cloning. Still, let's just assume that the scientists at Japan's Kinki University can successfully extract the cell nuclei and place them in the wombs of African elephants. What then are the chances that we'll end up with a baby mammoth?

Unfortunately, they're still not very good. At this point, it has less to do with the particular difficulties of cloning a species that's been extinct for millenniums - scientist overcame the main challenges of that part when they found the (presumably) pristine bone marrow - and more to do with how difficult it is to clone any species. Cloning remains a frustratingly inexact process, one where a single successful fertilization out of hundreds of failed attempts would be considered a massive achievement. Indeed, as recently as 2006, one review of cloning declared it a still entirely experimental technology, and that any successful attempt should be considered purely a matter of chance and luck."
I09 describes years of failed attempts to clone the Pyrenean Ibex, which became extinct only 12 years ago. One clone was born in 2009, only to die minutes later. This raises the question on whether extinct animals such as Mammoths, which belonged to another age on our planet (let alone 12 years ago), should be resurrected across an ocean of time by our science. It is a strange reflection on how radically the planet's lifeforms change with her successive eras. It also shows how we use our science to wrestle with death - and seek mastery over time.

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