|Alexander Svalov, an official of the Ice Age Museum, inspects a mammoth bone (Photo: Sergei Karpukhin/Reuters)|
Would you pay $100 to see a woolly mammoth munching on grass?
How about Neanderthals building a fire, or a sabre-toothed tiger streaking across the prairie?
The genetic blueprints for such extinct creatures and humans are emerging from labs around the world. U.S. researchers recently unveiled the mammoth genome and a German team is putting the finishing touches on the genome of our Neanderthal cousins, which is expected early in 2009. Scientists, who once dismissed reviving extinct creatures as little more than science fiction, now find themselves with the tools that might make it possible.
The thought of woolly mammoths, extinct for thousands of years, once again thundering across the tundra certainly fires up the imagination, says evolutionary geneticist Hendrik Poinar of McMaster University in Hamilton, who finds his public audiences are fascinated with the idea of bringing the shaggy beast back from the dead.
The flightless dodo bird and other animals driven to extinction in the last few hundred years also are popular picks for resurrection. Less so, he says, for the giant short-faced bear, a ferocious "hyper carnivore" almost twice the size of today's grizzly, that used to prowl around North America.
The technical challenges of reviving creatures are daunting, but Poinar and many of his colleagues no longer see them as insurmountable. Give enough time and money to a clever, motivated research team, they say, and extinct creatures might walk the Earth again.
"For all practical purposes, you could have something that looks like a mammoth," says Poinar. He sees "no scientific reason" to do it, but says the "wow" appeal of a mammoth could prove irresistible to entrepreneurs looking to start a theme park. "If there was one in a zoo outside Toronto, wouldn't you go?"
Stephan Schuster at Pennsylvania State University has estimated a mammoth look-alike could be created for as little as $10 million US. His team made headlines in November when it announced the near-completion of the mammoth genome. The researchers extracted the DNA from hair snipped from mammoths frozen for thousands of years in the Siberian permafrost.
It is not possible to whip up a baby mammoth from scratch using the genome. But scientists can envision, at least in theory, genetically engineering something that resembles the real thing.
By comparing the mammoth genome to that of its modern relative, the elephant, scientists say they should be able to identify and isolate genes that set the creatures apart. The genes for big tusks, woolly coats and other key mammoth features could then be added to the elephant genome, installed in an embryo and implanted into an elephant surrogate.
Schuster has suggested the technique could someday be used to recreate any creature that lived within the last 100,000 years, as long as it got trapped in permafrost and had hair, because low temperatures and hair shafts protect DNA.
Dinosaurs are too far-gone - degradation of the DNA over millions of years should keep Tyrannosaurus Rex on the shelf indefinitely. The more recently vanished dodo bird, great auk, and ancient bears, wolves and tigers are possible candidates for revival, as is the Neanderthal, which died out about 30,000 years ago.
Whether it's a good idea is another matter altogether. "It could be done," Schuster told reporters when he unveiled the mammoth genome. "The question is: Just because we might be able to do it one day, should we do it?"
Many observers say the time and effort would be better spent conserving the wild animals still roaming the Earth. "What would be the point? (Of bringing the extinct back to life)." "We'd be recreating an animal whose habitat has disappeared," said Adam Lister at the British Natural History Museum.
McMaster's Poinar shares the sentiment, but figures it is just a matter of time before someone tries it. "I think it is eventually going to happen if people don't close it down ahead of time," he says of mammoth revival.
The creature's remains have been found across the Northern Hemisphere, but some of the best specimens are stored in a sub-zero underground museum in Khatanga, Siberia, that has been carved out of the permafrost.
Poinar and his European, Russian and American colleagues have taken samples from several of the frozen remains, under permit from Russian authorities, and fed the specimens into the gene machines to read the genome and to tease out information on the evolution and demise of the mammoth.
Japanese scientists have had a long-running interest in bringing the iconic creature back to life. They have been searching for viable mammoth sperm preserved in the Siberian permafrost in the hope of creating an embryo, which could be implanted into an elephant.
That approach has yet to deliver, but the technology is advancing. Teruhiko Wakayama, at the Center for Developmental Biology in Kobe, Japan, recently reported the successful cloning of mice from cells that had been in the deep freeze for 16 years.
Wakayama's team salvaged intact nuclei from the neurons of their frozen mice and used them to clone healthy mouse pups. Wakayama suggested in the U.S. Proceedings of the National Academy of Sciences in November that the same technique might be used to "resurrect" animals, such as the mammoth, from frozen tissues.
Genetic engineering might be the easier way to go, but the Japanese effort points to the tremendous interest in reviving the extinct creature, says Poinar.
Poinar and his peers, meanwhile, keenly are awaiting the publication of the Neanderthal genome being extracted from bones found in Europe. They will pour over the DNA sequence to see what set the Neanderthals apart from modern humans, and hunt for clues to explain why they died off toward the end of the last ice age.
No one is seriously suggesting the Neanderthal should be brought back - at least not yet. But the prospect is so intriguing that speculation on how it might be done already has begun. One approach might be to insert key genes from the Neanderthal into the chimpanzee genome, which is very similar to humans' and Neanderthals' genetic blueprint. The resulting embryo could be implanted in a chimpanzee.
"The big issue would be whether enough people felt that a chimp-Neanderthal hybrid would be acceptable, and that would be broadly discussed before anyone started to work on it," geneticist George Church of Harvard Medical School recently told the New York Times.
PAdd Site Content : CGS Administrationoinar would like the scrutiny about the ethics of reviving extinct species to start now.
"I would like to see it debated from all fronts," he says. "How soon people think it will happen. What it will really take to make it happen. And should it happen."
Poinar says he was approached by entrepreneurs who wanted to explore what it would take to resurrect the mammoth after some of his gene sequencing work was published in 2006. "They were very interested," Poinar says, while declining to name the entrepreneurs.
But he says the group convinced him it is time to set boundaries on the use of ancient DNA. He'd like to see a ban on patenting of DNA from extinct species, in a bid to head off the day when the mammoth and the creatures that roamed the Earth along with it might be trotted out for profit in a prehistoric amusement park.
As the British journal Nature put it in a report on resurrecting the mammoth: "Perhaps the whole idea will remain too strange, too expensive and too impractical, even too unappealing for anyone to take seriously. But the fact that just 15 years ago, cloning mammals was confidently ruled out by many as being impractical should give people pause before saying such a thing is impossible."
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