Wait, what are they trying to do?

The plan is to genetically engineer a hybrid of the Asian elephant using the DNA of the woolly mammoth. The result will have key traits of its extinct cousin, and thrive in the Arctic—which was the original habitat of the mammoth. According to the lead scientist George Church:

“Our goal is to make a cold-resistant elephant, but it is going to look and behave like a mammoth. Not because we are trying to trick anybody, but because we want something that is functionally equivalent to the mammoth, that will enjoy its time at -40C, and do all the things that elephants and mammoths do, in particular knocking down trees.”

Point to note: Woolly mammoths roamed the planet nearly 13,000 years ago—and have been extinct for 4,000 years.

And who are these people? 

This “de-extinction” company is called Colossal—whose stated aim is to “jumpstart nature’s ancestral heartbeat.” The venture is co-founded by tech and software entrepreneur Ben Lamm and George Church—a famous and controversial professor of genetics at Harvard Medical School. Church, to put it simply, is considered a genius in gene editing—and his use of powerful tools such as CRISPR, the revolutionary gene editing tool that essentially rewrites the genetic code to alter the characteristics of living species. He’s made headlines before for plans to reverse aging in mice—and eventually in humans—and editing pig DNA so their organs can be transplanted safely into people.

The funding: The project is making headlines because Colossal just received $15 million from the likes of Climate Capital, a private equity firm that backs efforts to lower carbon emissions, and the Winklevoss twins—best known for their battle royale with Mark Zuckerberg over the ownership of Facebook.

How will they do it?

Here’s how it will work:

Step one: Identify and extract the genetic code for specific traits from frozen woolly mammoth DNA:

“These traits... include a 10-centimeter layer of insulating fat, five different kinds of shaggy hair including some that is up to a meter long, and smaller ears that will help the hybrid tolerate the cold. The team also plans to try to engineer the animal to not have any tusks so they won’t be a target for ivory poachers.”

Step two: Take skin cells of Asian elephants and edit them to carry the mammoth’s genetic code. The scientists believe they will need to simultaneously program “upward of 50 changes” to the code.

Step three: Create an elephant embryo using stem cells—and swap out its nucleus with that of the reprogrammed skin cell.

Step four: Carry the embryo to term in an artificial womb—which could be tricky—or in a surrogate elephant. The plan is to build a mammoth uterus lined with uterine tissue grown from stem cells.

Point to note: The Asian elephant already shares approximately 99.6% of the mammoth’s genome.

Surely this can’t be easy…

Nope, there are a number of significant obstacles in the way.

One: How will we identify the correct genes in the woolly mammoth DNA? As one sceptical scientist points out: “We, of course, have very little clue about what genes make a mammoth a mammoth. We know a little bit but we certainly don’t know anywhere near enough.”

Two: We still don’t have the technology to create artificial wombs. As Church himself admits:

“The editing, I think, is going to go smoothly. We’ve got a lot of experience with that, I think, making the artificial wombs is not guaranteed. It's one of the few things that is not pure engineering, there's maybe a tiny bit of science in there as well, which always increases uncertainty and delivery time.”

So far, Church has managed to grow a mouse embryo in an artificial womb for 10 days—which is half the gestation period. The gestation period for elephants: 22 months.  He hasn’t ruled out using elephants as surrogates—but that raises serious ethical questions about the would-be mother’s health, as Church admits: “It would be unreasonable to put female reproduction at risk in an endangered species.”

Three: Who will raise these motherless babies? One leading philosopher says:

“You don’t have a mother for a species that—if they are anything like elephants—has extraordinarily strong mother-infant bonds that last for a very long time. Once there is a little mammoth or two on the ground, who is making sure that they’re being looked after?”

Mammoths and elephants are as different as chimps and humans. As a zoologist points out, there is no guarantee that one will parent the other. He says, “The mammoth was not simply a set of genes”—and its potential suffering surely must be weighed.

Four: How will they ensure that these calves have the right microbes so that they can develop immunity from disease? Colossal plans to equip them “with an appropriate microbiome by means of an artificial birth canal or tailored probiotics.” But the team also concedes that they only have remains of an extinct animal to guide them:

“[I]t’s hard to differentiate between bacteria that colonize the gut while the organism is alive, and the bacteria that have colonized and contaminated the mammoths postmortem in the thousands of years since their death.”

So why do this at all?

Colossal frames “de-extinction” as an attempt to tackle climate change—and preserve existing species from extinction. For starters, it will endow the endangered Asian elephant with traits that will allow it to thrive in a whole new habitat—i.e. the Arctic tundra. But the bigger pitch is about fighting climate change.

The argument: Releasing hordes of mammoth hybrids will “rewild” the Arctic region which is under great threat due to global warming—which is melting the permafrost (the permanently frozen mix of soil and ice that forms its surface). This in turn is releasing huge amounts of CO2 into the atmosphere. The mammoths would change all of that:

“Today the tundra is dominated by moss. But when woolly mammoths were around, it was largely grassland. Some researchers have argued that woolly mammoths were ecosystem engineers, maintaining the grasslands by breaking up moss, knocking down trees and providing fertilizer with their droppings… The restored grassland would keep the soil from melting and eroding… and might even lock away heat-trapping carbon dioxide.”

Is any of this true?

Lots of scientists think Colossal’s plan is a pipe dream: “The scale at which you’d have to do this experiment is enormous. You are talking about hundreds of thousands of mammoths which each take 22 months to gestate and 30 years to grow to maturity.”

Also this: There is a huge risk in reintroducing mammoths to an already fragile and complex ecosystem—and knocking down trees isn’t always a great idea: “[W]e know in the forested Arctic regions that trees and moss cover can be critical in protecting permafrost, so removing the trees and trampling the moss would be the last thing you’d want to do.”

And this: The mammoths have been extinct for thousands of years. And the hybrids are not the same animals. Also not the same: The Arctic environment which has dramatically changed since. As one academic paper warned: “Any proxy will be placed in an ecosystem that has either never encountered the extinct species or has not done so for a long time.”

Last but not least: Many say that Church has absolutely no proof for his claim that mammoths can impact climate change—“and it was hard to imagine herds of cold-adapted elephants making any impact on an environment that's grappling with wildfires, riddled with mires and warming faster than anywhere else in the world.”

The bottomline: Here’s the upside. We may never end up with a woolly mammoth, but the project may well birth revolutionary technological breakthroughs that will help us preserve existing species. Imagine gene-editing an endangered bird or lizard so it can better survive rising temperatures? There is great good in that.

Reading list

CNN offers a good overview. The Guardian is best at describing how Colossal plans to engineer the mammoth hybrid. The New York Times offers a big picture view of the company, founders and their plans. Futurism does an excellent job of outlining the scientific challenges facing Church and his colleagues. Watch this older PBS interview with Church to get a sense of his vision. Also: Stat News has a tongue-in-cheek take on his scientific career.