An illustration of a family of Woolly Mammoths grazing on what is left of the grasses as winter approaches in this ice age scene. (Credit: iStock)
JERSEY CITY, N.J. — Woolly mammoths have been extinct for more than 4,000 years, but with new gene-editing techniques, they could help mitigate the effects of a modern problem: climate change.
Most of the hype so far has focused on bringing these shaggy beasts back to life using their permafrost-preserved DNA. But this time, scientists aren't aiming for a "Jurassic Park" scenario — they're not trying to bring back entire mammoths exactly as they were in the last ice age. Rather, they're hoping to mingle some of the mammoths' ancient genes with those of today's Asian elephants (Elephas maximus), to increase the elephants' tolerance to the cold, said George Church, a Harvard and MIT geneticist who is heading the Harvard Woolly Mammoth Revival team.
"I don't even think it's desirable" to bring back the entire mammoth, Church told Live Science Friday (May 11) here at the 2018 Liberty Science Center Genius Gala. He thinks a few ancient genes will do more good, by boosting the survival chances of threatened elephants, which could then be reintroduced to northern parts of the globe. Once there, the genetically tweaked elephants would topple trees that keep the area warm in the winter, thereby restoring a more climate-friendly ecosystem. [6 Extinct Animals That Could Be Brought Back to Life].
Restoring the steppe
When mammoths roamed in a northern area known as the "mammoth steppe," that ecosystem was rich in grasses. But after the woolly mammoth (Mammuthus primigenius) went extinct and other grazers left the area, grasses gave way to shrubs and a tundra ecosystem, an environment that the Harvard Woolly Mammoth Revival team says is "contributing to human-driven climate change."
"The elephants that lived in the past — and elephants possibly in the future — knocked down trees and allowed the cold air to hit the ground and keep the cold in the winter, and they helped the grass grow and reflect the sunlight in the summer," Church said. "Those two [factors] combined could result in a huge cooling of the soil and a rich ecosystem."
In the absence of large creatures to knock down trees and trample the snow, the opposite happens, Church said, as tall trees and a fluffy blanket of snow keep the permafrost warm in the winter months.
"Fluffy snow is like a down blanket keeping the warm summer soil away from the -40 degree winter winds," Church said. And trees absorb light and heat in the summer and keep cold winds out in the winter, he added.
With already warmer temperatures, this leads to the melting of permafrost and the release of greenhouse gases like methane, Church said. In fact, 1,400 gigatons of carbon — the amount equivalent to 43 times as much carbon as fossil fuels and industry produced last year, according to the International Energy Agency — is at risk of escaping into the atmosphere if permafrost melts, he added.
The elephants on our planet right now can't tolerate the cold climate of the steppe. So the idea is to use gene-editing techniques such as CRISPR to insert the ancient robust genes from mammoths into Asian elephant cells and create embryos that may grow up to be elephant-mammoth hybrids that can.
"It could just be 44 genes [that] might be sufficient to make them adapted again to the cold," Church said. He hopes to insert a few others that could help elephants in other ways as well — such as genes that could allow them to eat certain toxins and thus increase the range of vegetation they can nibble, or genes that decrease their tusk size so they are less likely to be poached.
Because of the ethical concerns of implanting the embryos into elephants, the scientists hope to be able to grow the mammoth-elephant hybrid in the lab. But whether that's possible is still to be determined, Church said. First, the researchers will try growing mice from mouse embryos in the lab. So far, they have managed to insert some mammoth genes into elephant cells in the lab, such as those for more hair growth or fat production, according to a previous Live Science report.
Of course, many questions remain. For example, how would these genes interact with other genes? Would the embryos survive in the lab environment? How would these massive hybrids fare in today's ecosystems, and would they alter them? Of course, there are ethical considerations as well: Even if humans can manipulate the ecosystem, should they?
Originally published on Live Science.