Thursday, March 21, 2013

Reviving the Woolly Mammoth: Will De-Extinction Become Reality?

This photo shows a museum worker inspecting a replica of a woolly mammoth (Mammuthus primigenius), a relative of modern elephants that went extinct 3,000 to 10,000 years ago.
 Photo by Jonathan S. Blair/National Geographic

Biologists briefly brought the extinct Pyrenean ibex back to life in 2003 by creating a clone from a frozen tissue sample harvested before the goat's entire population vanished in 2000. The clone survived just seven minutes after birth, but it gave scientists hope that "de-extinction," once a pipedream, could become a reality.

Ten years later, a group of researchers and conservationists gathered in Washington, D.C., today (March 15) for a forum called TEDxDeExtinction, hosted by the National Geographic Society, to talk about how to revive extinct animals, from the Tasmanian tiger and the saber-toothed cat to the woolly mammoth and the North American passenger pigeon.

Though scientists don't expect a real-life "Jurassic Park" will ever be on the horizon, a species that died a few tens of thousands of years ago could be resurrected as long as it has enough intact ancient DNA.

Some have their hopes set on the woolly mammoth, a relative of modern elephants that went extinct 3,000 to 10,000 years ago and left behind some extraordinarily well preserved carcasses in Siberian permafrost. Scientists in Russia and South Korea have embarked on an ambitious project to try to create a living specimen using the DNA-storing nucleus of a mammoth cell and an Asian elephant egg — a challenging prospect, as no one has ever been able to harvest eggs from an elephant.

But DNA from extinct species doesn't need to be preserved in Arctic conditions to be useful to scientists — researchers have been able to start putting together the genomes of extinct species from museum specimens that have been sitting on shelves for a century. If de-extinction research has done anything for science, it's forced researchers to look at the quality of the DNA in dead animals, said science journalist Carl Zimmer, whose article on de-extinction featured on the cover of the April issue of National Geographic magazine.

"It's not that good but you can come up with techniques to retrieve it," Zimmer told LiveScience.

For instance, a team that includes Harvard genetics expert George Church is trying to bring back the passenger pigeon — a bird that once filled eastern North America's skies. They have been able to piece together roughly 1 billion letters (Each of four nucleotides that make up DNA has a letter designation) in the bird's genome based on DNA from a 100-year-old taxidermied museum specimen. They hope to incorporate those genes responsible for certain traits into the genome of a common rock pigeon to bring back the passenger pigeon, or at least create something that looks like it.

A few years ago, another group of researchers isolated DNA from a 100-year-old specimen of a young thylacine, also known as Tasmanian tiger. The pup had been preserved in alcohol at Museum Victoria in Melbourne. Its genetic material was inserted into mouse embryos, which proved functional in live mice.


Reviving the Woolly Mammoth: Will De-Extinction Become Reality? via @LiveScience