It may sound like something out of a Jurassic Park spin-off, but plans to revive ancient history’s most iconic herbivore, the woolly mammoth, are already underway. The organization Revive & Restore are aiming towards the cloning and reintroduction of the mammoth, and if successful, could set in motion ecological changes that may reverse the melting of the permafrost, a layer of ice and soil which acts as a vast storage of underground carbon, sitting below a quarter of the land in the Northern Hemisphere.
The endearingly named ‘Woolly Mammoth Revivalists’ spearheading the effort to cloning and reintroducing mammoths are Dr George Church and his Harvard-based team, who are collaborating with Revive & Restore toward cloning a so-called “neo-mammoth”, and introducing them to the Arctic tundra.
A compromise to a true mammoth clone, their planned neo-mammoth will be more like a turbo-charged Asian elephant. The revivalists are using the both woolly mammoth and Asian elephant genomes to identify key characteristic mammoth genes, such as those for long fur, and cold-resistant haemoglobin.
Although nuclei don’t cope well after 10,000 years of cryonic preservation, enough tissue samples have been collected from the best-preserved mammoths to piece together the complete mammoth genome. The first mammoth genome was published in 2008, with a much less erroneous genome released seven years later by the journal Current Biology.
Since these publications, 45 synthetic mammoth genes have been created in-vitro, and spliced into the genome of an Asian elephant cell using CRISPR gene-editing technology. The plan is to test each gene individually, then create an embryo containing all the successful genes, using the Asian elephant genome as a template. Dr Church believes the Mammoth Revivalists Team will have an embryo ready for cloning in 2019, with the first neo-mammoth arriving after several more years of testing and a two-year pregnancy period.
However, the reintroduction of the mammoth into Northern Russia will probably not occur until decades after the first successful clone is born. It will take a long time to create enough mammoths to form a self-sustaining population as every new neo-mammoth will require a surrogate Asian elephant mother and a 22-month gestation. As Asian elephants are themselves endangered, the scientists face a paucity of ethically sourced egg cells, and candidates for surrogate mothers are hard to come by.
Rather than simply being a play-thing for geneticists, the cloning and subsequent reintroduction of mammoths could have profoundly beneficial effects towards restoring the Arctic environment. Ecologist Sergey Zimov and his son Nikita are experimentally showing the effects mammoths once had on the Siberian permafrost by creating a mock-up mammoth ecosystem in a Russian nature reserve called Pleistocene Park. Talking to Ottawa Life magazine, Nikita revealed that their experiment found that at an ambient air temperature of -40°C, herbivore trampled snow is markedly less insulating than fresh snow, allowing the ground below to cool to -30°C, instead of the -5°C measured below fresh snow.
Zimov notes that by compacting air-filled snow and devouring small saplings, mammoths once acted as ecological engineers, the “keystone species” of a now extinct grassland habitat known as mammoth steppe. The nature of the steppe prevented the insulation of the underlying permafrost, but disappeared 10,000 years with the disappearance of the continental mammoths.
It is not known for sure why mammoths went extinct. Warming climates probably contributed, though it seems likely that our ancient ancestors pushed this once-great species over the edge through excessive hunting—a story that has since been repeated with dozens of other megafauna species.
If all goes to plan—and that’s a big if—returning the woolly mammoth to the arctic tundra will allow the mammoth steppe grasslands to once again flourish, stabilising the permafrost below. The significance of stabilising the permafrost is vast. As the permafrost melts, it releases stored carbon as carbon dioxide, a greenhouse gas which contributes to global warming. Our climate is now dangerously close to slipping into a feedback loop whereby CO2 from the melting permafrost accelerates global warming, which in turn further accelerates the melting of the permafrost, and thus the release of yet more CO2. This feedback loop would have catastrophic results on our climate.
The determination of scientists like George Church and Sergey Zimov is carrying the revival project forwards, and whilst this drastic approach to tackling climate change is still in the laboratory phase, one thing seems increasingly clear: the mammoths are coming.