Despite efforts to resurrect the wooly mammoth through cloning, bringing back the creatures, which went extinct 4,000 years ago, are littered with obstacles.
The successful cloning of Dolly the sheep about 20 years ago freed imaginations to ponder that other animals could be essentially manufactured from a single working nucleus of any cell. Writing in the Washington Post, though, Jackson Landers points out that in the case of the mammoth, the chances of success are slim.
For one thing, while frozen mammoth samples seem to provide all the raw materials that's required to bring back the animal, biological samples that have been frozen for so long may be too damaged to provide any functional cells and genetic material that can be used for cloning.
"Unless an organism contains some type of antifreeze, the freezing process tends to destroy cells," Landers writes.
Among those seeking to clone mammoths are researchers at Kyoto University, as well as scientists at Sooam Biotech Research Center in South Korea, in partnership with Russia's North-Eastern Federal University.
George Church at Harvard Medical School also is doing cloning work on the mammoth. Unlike the Japanese and South Korean researchers, though, who are trying to find viable cells or nuclei from mammoth samples for cloning, Church wants to find mammoth genes associated with cold weather adaptation and then insert them into the nuclei of elephant cells, something he tells the Post he has already achieved.
Landers expresses skepticism about the claim, however, since Church has not published any research on his work.
Landers also notes that if bringing back the mammoth requires using elephants as surrogates, there will be problems, starting with a paucity of captive Asian elephants of breeding age that could serve as surrogates. Asian elephants are more closely related to mammoths than the African variety, and so would theoretically be better suited as a surrogate mother for a cloned baby mammoth.
But in North America, for example, there are only about 40 Asian elephants in the breeding population. While that figure could be increased through captive breeding programs, such programs have been unsuccessful, Landers says. Globally, only 45 Asian elephants were born in captivity in 2013.
"In the long run, the trouble with making a mammoth will not be the mammoth," Landers writes. "It will be the elephant. Perhaps the future of more than one species is at stake."