In 2013, Russian scientists discovered the stunningly well-preserved carcass of a woolly mammoth buried in the permafrost of a remote region of Siberia. In addition to analyzing the remains to discover more about how the animal lived and died some 40,000 years ago, geneticists believe the mammoth skeleton--nicknamed Buttercup--might hold the key to bringing the long-extinct species back to life.
A group of scientists from Siberian Northeastern Federal University traveled to Maly Lyakhovsky Island, in far northern Siberia, in May 2013 to track down rumors of a woolly mammoth skeleton trapped in the region’s permafrost. After finding two giant tusks protruding from the ground, they kept digging and unearthed a stunning find: an almost-complete mammoth carcass, including three legs, most of the body, part of the head and the trunk. What they found most extraordinary was the fact that the meat of the carcass was exceedingly well preserved, and even oozed a dark red blood-like liquid.
Mammoths, which belong to the genus Mammuthus, first appeared around 5 million years ago in Africa, then migrated through Eurasia and North America. The best-known mammoth species, M. primigenius–better known as the Siberian, northern or woolly mammoth–arose around 250,000 years ago. Scientists believe mammoths went extinct some 10,000 years ago, though small populations might have survived for even longer.
The scientists transported the woolly mammoth remains from Maly Lyakhovsky Island to Yakutsk, Russia, where experts were able to examine it over several days before it had to be refrozen in order to prevent further decomposition. Carbon dating of the flesh revealed that the mammoth, a female that scientists nicknamed Buttercup, lived some 40,000 years ago. By measuring growth rates on the tusks and teeth, scientists determined that Buttercup probably died in her mid-50s. They also concluded that she gave birth to eight live calves, and possibly lost an additional one. Finally, tooth marks on the mammoth’s bones indicated that Buttercup appears to have met a gruesome end: They speculate that she may have been eaten alive by wolves and other predators after getting stuck in an ancient peat bog.
The burning question now is whether DNA extracted from Buttercup can be used to clone the long-extinct woolly mammoth. According to an upcoming television documentary airing in Britain and the United States later this month, a team from the South Korean biotechnology company Sooam believes cloning may be a viable possibility given the high quality of the specimen. If the geneticists can find an intact cell nucleus with the full genome, they could insert that nucleus into an elephant egg and then implant it into a mother elephant. Sooam has been cloning dogs for years using this process, charging some $100,000 per clone.
But DNA is extremely fragile, and must be stored at low temperatures with uniform humidity in order to survive intact. Past mammoth carcasses recovered by scientists have also oozed a blood-like substance, but ultimately did not contain enough DNA to reconstruct and clone the mammoth gene. In the case of Buttercup, scientists didn’t find any intact blood cells either; the red color of the liquid came from surviving hemoglobin, the cells that carry oxygen in the blood. Woolly mammoths evolved a type of hemoglobin that was resistant to the cold, and allowed them to survive in the frigid temperatures of the Ice Age.
So far, the scientists working on Buttercup’s remains haven’t yet found a complete copy of the mammoth genome, but they continue to search. Meanwhile, Harvard University researcher George Church is leading an alternative effort at cloning. He plans to fuse pieces of DNA associated with distinctive mammoth traits (such as its thick woolly coat, extra fat and cold-resistant hemoglobin) with that of modern-day elephants, the mammoth’s living relatives. Last month, Church told NBC News that his team was making progress and could start testing organ-like structures in a laboratory setting within a couple of years.
As these efforts continue, some in the scientific community strongly oppose cloning on ethical grounds, pointing out the problems involved in using female elephants as surrogate mothers for the prospective mammoth clones. According to paleobiologist Dr. Tori Herridge of London’s Natural History Museum, who consulted on the upcoming documentary: “Cloning a mammoth will require you to experiment on probably many, many Asian elephants.” In addition, a successfully cloned woolly mammoth would instantly become an endangered species, and would have to contend with modern environments and life in captivity, among other difficulties.