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. Last Updated: 07/27/2016

Bringing Back The Beast




It has been 10,000 years since the woolly mammoth took its last steps along the Siberian plains. But that is no stumbling block to a team of Japanese and Russian scientists, who dream of resurrecting the extinct creature. Their plan? To find some frozen mammoth DNA and use it to procreate a resurrected beast. Science writer Richard Stone joined them on their quest to find live mammoth meat.


I touch the brown fuzz sticking out of a cliff facing the Kolyma River. It looks like coconut husk, although that's a crazy thing to think here above the Arctic circle. I tug gently. Could this be the hair of a woolly mammoth, its body locked inside the black Ice Age sediment?


Big-boned Sergei Zimov lumbers toward me, splashing through the shallows and plunging into the muck above his ankles. Behind him, larch trees lean drunkenly on the horizon, unable to get a good grip in the thin soil. A few snowflakes flutter from the drab sky. In my hunt for mammoth flesh, time is running out.


Littering this stretch of beach called Duvanny Yar, archaic Russian for "windy cliff," is a jumble of bones of mammoths, steppe bison, woolly rhinos and other creatures that roamed Siberia 10,000 years ago before disappearing from the land. Those exotic animals are gone, but the sucking noise from Zimov's boots as he struggles against the silt have me imagining the lost sound of a mammoth grasping a willow bush with the hand-like tip of its trunk f so different from an elephant's f and slurping the plant into its mouth.


Zimov approaches, mosquitoes caught in his mussy blonde beard, and sidesteps a rust-colored mammoth femur. He rips a chunk of the ancient hair from the pungent sediment and rubs it between his fingers and thumb. Now is the moment of truth. "Steppe bison," he says at last, yanking out the rest.


That evening I return to camp empty-handed, my cameo in one of the most fantastic science adventures of our time ending in failure. But the main actors will be back this August to chase their dream: to resurrect the woolly mammoth.


A team of Russian and Japanese scientists is scouring northern Siberia for frozen mammoth tissue, looking for sperm or exquisitely preserved cells from other body parts. They have two possible strategies for bringing the mammoth back to life. One idea is to thaw sperm and inject it into the egg of a close relative of the mammoth f such as the Asian elephant f to breed a hybrid. Each generation of hybrids would look more and more like mammoths. Alternatively, if the researchers find frozen cells in superb condition, they could try to clone a pure mammoth.


"I know it sounds unbelievable," says Kazufumi Goto, the reproductive biologist who launched this improbable quest seven years ago. "But no science can deny our idea."


Indeed, experts say that the scientists have a shot at pulling off their miracle. If the researchers find sperm with intact DNA, producing an embryo "is not so farfetched when you consider the technology we have today and will have in the future," says John Critser, scientific director of the Cryobiology Research Institute in Indianapolis, Indiana. The project is "a brave idea," adds Ryutoro Yanagimachi, whose team at the University of Hawaii last year was the first to clone a mouse.


But Yanagimachi and other experts wonder whether permafrost is a chilly enough refrigerator to preserve mammoth DNA. That question could be answered soon. Over the past several months the Japanese scientists have received tips on two frozen carcasses in the Kolyma-Indigirka flood plain that are still in the ice. The researchers plan to mount an expedition there this August.


If the Japanese beat the odds and find their frozen mammoth, the first attempts to fertilize an elephant egg or clone the beast could begin this fall in Japan. If they succeed in creating an embryo, the unprecedented experiment would then shift back to Siberia, where Zimov is leading a pioneering effort to recreate an ice age ecosystem. This replica of a lost world would become the home of the first mammoth in thousands of years to walk the Earth.


Western Europe didn't know what to make of reports in the late 1700s that traders in northern Russia were coming across tusks and giant frozen mummies with stubby legs and trunks. Scientists concluded at the time that biblical floods had washed the carcasses of elephants and other African animals up Asia's northward-flowing rivers, depositing them in the far north. Others disputed this idea in the 1800s, arguing that the hairy, fatty beasts seemed to be adapted to the cold and therefore were native to the region.


Not until this century did the homegrown theory prevail, partly thanks to discoveries of Paleolithic cave paintings in France and Germany that depict hunters pursuing scraggly behemoths with high foreheads, long, curling tusks, stubby tails and tiny ears. The ancient art evoked mammoths trudging across the Siberian steppe, pelted by spears and driving snow. What killed off these fantastic creatures is an ongoing debate. A global warming at the end of the last ice age no doubt played a big role by shifting Siberia's dominant vegetation from grasses to low-nutrient mosses and sedge. Bands of prehistoric hunters also helped do them in. With the blood of the woolly mammoth staining our ancestors' hands, "it is our duty to revive ancient animals that went extinct around that time," says Akira Iritani, the team's scientific leader. "By reviving the mammoth," adds Goto, "I would like to teach people the importance of coexisting with animals."


Just a decade ago nobody except science-fiction writers would have entertained the notion of trying to revive an extinct species. Although sperm can survive many hours after a man dies, they were considered useless if frozen without chemical preservatives.


Such was the state of the art when Goto, a skinny man with bristly hair and a constant smile, became an assistant professor at Kagoshima University in Japan. In the early 1980s Goto toiled as a foot soldier in his country's pursuit of the ultimate steak. "We have to compete with American beef," he says.


Goto's task was to use artificial insemination to develop beef with better marbling. Collecting sperm from well-marbled bulls was easy: all he had to do was hook them up with an artificial vagina f a tube warmed with hot water and dabbed with pheromones. For eggs Goto went to a slaughterhouse, where he took fresh ovaries from well-marbled cows.


The work, however, failed to quench Goto's desire to do cutting-edge science. Then in 1986, while peering through a microscope at sperm swarming an egg, Goto had an epiphany. "Once a sperm attaches to the egg's membrane, it stops moving," he says. After the membranes fuse, the sperm's tail breaks off and its head is engulfed by the egg. "I had been taught that the sperm gets into the egg by its own movement," he says. "But I was so surprised f that wasn't true." It dawned on Goto that the tail-less sperm, deprived of energy, is dead before its DNA ever mixes with the egg's.


Following this insight Goto started an experiment that would challenge the meaning of life. He instructed a graduate student to freeze and thaw bull semen until the sperm were dead. The rough handling poses little threat to the sperm's genes, however. "We could freeze and thaw 20 times, and the sperm DNA would never break," Goto says. After injecting the dead sperm into hundreds of eggs, one day they got an embryo. They promptly implanted it in a cow, which "got pregnant on the first try," Goto says.


In 1992, Goto flaunted his findings f the first account of the use of dead sperm resulting in a live birth f at an international conference in Denver. After his talk, Goto talked to a reporter about the possibility of using the technique to revive extinct species f like the mammoth.


"That was the beginning," says Goto. He wrote to several Russian scientists over the next few years, seeking information about frozen mammoths. He got no reply. He asked at the Russian Embassy in Tokyo, but staff were suspicious, asking Goto if he were after the valuable ivory in mammoth tusks. "I had no success at all," he says.


Then in 1995, a university colleague told Goto about a feces-eating fly that was the pinnacle of an intense breeding program at a secret Russian institute, which had hoped to use the fly to dispose of cosmonaut waste on long space voyages. Goto revealed his mammoth dream and the researcher put him in touch with a fly dealer: Kazutoshi Kobayashi, president of Field Co., Ltd., in nearby Miyazaki.


Kobayashi remembers vividly his first meeting with Goto, in February 1996. "He talked like a child about his dream to make a mammoth, but he was serious," says Kobayashi. "My friends always thought I was the most foolish person in the world, but there before me was someone even more foolish." Still, he recognized a kindred spirit. "I told Goto we would realize the dream together."


Far from your typical businessman, Kobayashi prefers a turtleneck and jeans to a suit, and blue suede boots instead of wingtips. When he started his company in 1981, Field Co. worked mostly in advertising, winning contracts to design everything from office space to logos for the Japanese air force. But in December 1993, the businessman embarked on a new adventure. He flew to Khabarovsk to look for Russian scientists who might be willing to license inventions.


Kobayashi's office walls are a tribute to his success, adorned as they are with photos of scientists with whom he has struck deals on everything from metal-cutting blowtorches to oxygen generators used aboard the Mir space station. Mammoth meat was one commodity, however, in which Kobayashi had never traded. But he did have ties to the semiautonomous Sakha Republic, which oversees the vast Siberian province known as Yakutia f a region haunted by the memory of Stalin-era prison camps. Field Co. had helped designed the inside of a new sports center, whose head put him in touch with Pyotr Lazarev, the director of the Mammoth Museum in Yakutsk, the capital.


Lazarev invited Goto to visit, and in August 1996 the scientists and a few colleagues went on a kind of get-to-know-you excavation on the Lena River. They found mammoth tusks and bones, but no meat.


Kobayashi brought Lazarev to Japan in early 1997 to plot a major expedition that summer. A few months later he founded the Creation of Mammoth Association, which will share custody of any mammoth with the Sakha government. Field Co., of course, designed the association's logo, a cartoon mammoth with an oversized bright red heart.


Goto, meanwhile, invited Iritani to join the team. Iritani came with impeccable credentials: A stellar reproductive biologist and chairman of the Department of Genetic Engineering at Japan's prestigious Kinki University, Iritani and his team in 1986 achieved the first birth of a mammal (a rabbit) using intracytoplasmic sperm injection f a technique that was later adopted by human fertilization clinics. Like Goto, Iritani is pushing the frontiers of Japanese cuisine. Only while Goto is Mr. Fat, Iritani is Mr. Lean: He is using genetic engineering to breed leaner pork. "The younger generations don't like fatty meat so much," says Iritani. He also has an abiding interest in saving endangered species, keeping on ice the sperm of a few dozen rare animals, including the mountain gorilla and the lion-tailed monkey.


Iritani eagerly joined the mammoth sperm hunters. But he worries about how long it will take to succeed. If a mammoth sperm and an elephant egg unite to create an embryo that, in turn, takes to a surrogate mother, a hybrid would be born some 20 months later f elephants have the longest gestation time of any creature. If the hybrid is not sterile, like mules, it would take another 10 to 15 years for it to reach reproductive age. If all works flawlessly, it would take at least 35 years, from start to finish, to get a hybrid that is almost 90 percent mammoth.


"I can't wait 30 years to see a mammoth," says Iritani, who is 69. He prefers cloning. Just a few months before Iritani joined the mammoth team, Scottish researchers stunned the world with the announcement that they had cloned a sheep, Dolly. "If even a small bit of mammoth tissue is found with normal DNA, it would take only a one-time procedure to clone a pure woolly mammoth," Iritani says.


With two possible game plans and a stellar scientific crew in place, Kobayashi flew to Yakutsk in June 1997 to grease the bureaucratic wheels for the expedition. He also brought a load of cash to sponsor a preliminary dig by Lazarev's group. But on the way to Yakutsk, disaster struck. According to Kobayashi, a bag with his entire wad f $60,000 f was stolen in the customs hall in Seoul, Korea. "It was terrible," he says. "I had to go to Russia without any money."


Arriving empty-handed, Kobayashi scraped up a few thousand dollars from associates and sent Lazarev's team on a 1,000-kilometer helicopter trek to Chokurdakh, a tiny settlement on the Indigirka River. They found a chunk of mammoth leg. Although the meat was too degraded to have good DNA, the find suggested that Chokurdakh was the spot to return to in August. Kobayashi got written permission for his group to enter Chokurdakh, normally closed to foreigners because the village is little more than a military outpost. A week before the Japanese were to depart for Russia, however, Chokurdakh's mayor demanded $70,000 from the expedition to enter his territory. Kobayashi balked, negotiations failed, and Lazarev began mulling alternatives.


The logical choice was Duvanny Yar, a renowned mammoth site reached via Chersky, a town that once served as a base camp for gold and diamond prospectors. Lazarev phoned up Zimov, director of the local Northeast Scientific Station, an ecology field station supported by the Russian Academy of Sciences. Zimov agreed to quickly arrange for a barge that would ferry the 30-member expedition up the Kolyma to the site.


But the expedition soon ran into trouble. Upon arriving at the Khabarovsk airport, customs officials seized a satellite phone and a detailed map of the region published by a U.S. government agency. No matter that Kobayashi had secured the necessary permission from Sakha officials. "The customs officers just wanted us to pay arbitrary fines," Iritani says. Money changed hands, but the complications cost the group three days.


Finally, the team reached Yakutsk, where they would meet Lazarev and fly to Chersky. But when Kobayashi went to inspect the chartered plane, he found an unwelcome surprise. "The plane was full of goods for the black market," Kobayashi says. Furious, he demanded that the pilot unload the plane and make room for the expedition's equipment and supplies. The pilot refused. After two days of fruitless negotiations, Kobayashi knuckled under and paid the charter fee, unwilling to waste any more precious time in Yakutsk. As they were boarding, the scientists noticed a few unauthorized passengers crouched behind the illicit goods. "It was all very suspicious," says Kobayashi.


The scientists were relieved to arrive in Chersky and find the Russian ecologists ready for them. The resourceful Zimov had managed to buy a barge and lumber and build a shelter for sleeping, a rudimentary kitchen and a pair of outhouses. "After all the troubles we had," says Kobayashi, "when I saw the houseboat it looked like a luxury hotel."


Energized by warm, sunny weather, the ragtag company set out for the day-long cruise to Duvanny Yar. The adventurers breathed in the fragrance of alpine sage and enjoyed white nights and moose stew. The crimson leaves of birch trees covered Mt. Panteleikha up to the snow line. This beautiful, sparse land, they knew, could someday be the home of a mammoth.


The expedition anchored off Duvannyi Yar, foraying to and from shore by rubber boat. The research station's little black poodle led the way. "He was like a scout, showing us the dangerous places where we shouldn't step," Iritani says. The scientists set to work, scouring the cliff for any sign of mammoth tissue.


From a sperm hunter's perspective, an ideal death would be for a mammoth to have plunged into an ice crevasse in winter and frozen rapidly, or for a mammoth to drown in a small lake and settle into the permafrost. Other accidents are less auspicious. In 1977, for instance, a Siberian gold miner's bulldozer nicked a baby mammoth mummy, now affectionately called Dima and on display at a museum in St. Petersburg. But Dima probably drowned in frigid mud, which is not likely to preserve DNA. "So few mammoths are found," Zimov says. "One would have to be extremely lucky."


Using picks to probe the cliff face, the researchers homed in on spots with a high density of mammoth bones or swatches of hair. They scampered up and down the 30-meter cliffs, avoiding the slick curtains of ice that form when permafrost freezes and contracts. "It was a dangerous place, sometimes sections of the cliff would collapse," says Iritani. The risk and isolation, he says, "made people edgy."


By the third day, all the expedition had to show for its effort was an ancient horse skeleton. The weather started to turn bad, and the Russians pressed to return to Chersky; after heated discussions, the Japanese relented. "It was frustrating not to come back with meat," Kobayashi says.


But the Japanese did not leave Siberia without putting the word out that they are on the lookout for mammoths. Iritani says his university is willing to pay 1 million yen ($9,000) for meat preserved well enough for experiments, a sum that might entice Russians who collect mammoth tusks for ivory. The announcement resulted in some good leads. Last October, Sakha's environment minister told Kobayashi about a couple discoveries. "I know it's more likely that a mammoth will be found when I'm not in the field," says Goto, who can only visit Siberia a few days each year. "But I have to go out there and show my passion. This will encourage the Russians to get serious and find a mammoth."


As the Japanese dream of resurrection, Zimov is preparing a new home for a mammoth. Accompanying the ecologist on an excursion to a fenced-off part of the taiga near Duvannyi Yar on a humid summer day, I watch as he points to a tangle of birch and willows several dozen meters away. Two young male Yakutian horses f off-white and pepper-flecked, the color of snow near a Moscow highway f are picking their way across a ridge. Zimov expects that dozens of these horses, along with moose, reindeer and a herd of rare northern bison imported from Canada, will rip up the moss with their hooves and teeth, allowing grasses to move in. Together with U.S. and Canadian collaborators, Zimov hopes that in a few years the animals will have changed the current ecosystem from a 160-square-kilometer preserve to the grasslands that once made this land so fertile for mammals. A once f and possibly future f stomping ground for the woolly mammoth.


Richard Stone is a deputy news editor at Science magazine.