Ancient giants could enjoy a rapid resurrection
UNITED STATES: For most scientists, the story of the woolly mammoth ended 4000 years ago on the bleak Arctic tundra of Wrangel Island. Hunted by humans, pushed to the brink by climate change, here the last mammoth made its last stand, its tomb unmarked amid the permafrost.
George Church is not most scientists. The Harvard professor believes that far from ending, the mammoth’s story has merely had a hiatus. To prove it, in as little as two years he plans to make the creature rise again, with the creation of the first mammoth embryo.
Thanks to advances in genetics, he believes the mammoth will be the first animal to be ‘‘deextincted’’.
‘‘We’re not there yet,’’ he said of his task as leader of the Harvard Woolly Mammoth Revival team, ‘‘but it could happen in a couple of years.’’
It will be some time after that, though, before the first fully grown mammoth lets out a bellow over the steppes of Asia once more, and some scientists believe that even then, it won’t really be a mammoth.
Church’s controversial recipe for creating a mammoth begins with an elephant. Just as most human DNA is shared by chimpanzees, most mammoth DNA is shared by elephants.
By examining the genome of mammoths, extracted from corpses frozen for millennia, he and his colleagues believe they have identified the bits of mam- moth DNA that aren’t elephant - generally, they are the hairy, fatty and ginger bits.
‘‘Elephants and mammoths have almost identical genomes,’’ he said.
The parts that are not identical ‘‘affect things that contribute to success ... in cold environments. We already know about ones to do with small ears, subcutaneous fat, hair and blood, but there are others that seem to be positively selected.’’
His plan is to use advanced gene editing techniques to change the genome of an elephant, sticking in the bits that will make it more mammoth-like, and initially just growing it to the embryo stage. One of the key obstacles to creating a ‘‘mammophant’’ has been that it would require an elephant womb. Not only are elephants inconvenient additions to Harvard laboratories, but they are also endangered. To get around this, the Harvard team wants to create the embryos in a petri dish. It is already experimenting with mouse embryos. Achieving that alone would be a significant advance.
Ultimately though, Church wants to grow the embryos to term and reintroduce herds of them back to the Arctic.
Part of the reason, he admits, is that doing so would be an audacious and inspiring feat. Previously he has referred to it as biology’s version of the Apollo Moon landings.
Another reason is environmental. Before their extinction, mammoths maintained a very different ecosystem, which helped keep the ground colder, locking in greenhouse gases.
‘‘They keep the tundra from thawing by punching through snow and allowing cold air to come in,’’ he said. ‘‘In the summer they knock down trees and help the grass grow.’’ — The Times