Rabu, 15 September 2021

The controversial science behind woolly mammoth de-extinction - The Verge

A flashy new biotech startup launched yesterday called Colossal is on a mission to make an elephant-woolly mammoth mashup — with the ultimate goal of promoting biodiversity and combating climate change, it says. The effort has gotten a lot of hype and big-name backers, but scientists who work in conservation are still pretty skeptical.

The science behind Colossal is in very early stages and is mired in ethical quandaries. The company won’t actually bring back a woolly mammoth, which hasn’t roamed the Earth in about 10,000 years. Instead, Colossal’s de-extinction effort aims to create a hybrid between a woolly mammoth and its distant relative (the two share a common ancestor): the Asian elephant, which itself is an endangered species.

Mammoths are a poor choice for de-extinction — a field of research that has picked up steam in recent years — and this project might steal the spotlight from more important conservation efforts, ecologists and biologists tell The Verge. The woolly mammoth’s pseudo-resurrection is also a risky proposal as a fix for climate change, experts say, given the short timeline humanity has to slash greenhouse gas emissions that have given Earth a fever.

“I guess I confess, the five-year-old in me would just love to see a mammoth,” says Joseph Bennett, an assistant professor at the Institute of Environmental Science and Department of Biology at Carleton University. “It’s just fascinating from a scientific standpoint. But if it’s called conservation, and if it’s called fighting climate change, that’s when the problems arise.”

How de-extinction might work

Imagine a furrier, fatter elephant with smaller ears and a high-domed head. That’s what Colossal might one day create using CRISPR technology to edit the DNA of an Asian elephant to introduce traits from woolly mammoths. Over the next four years or so, the aim is to produce embryos with those traits by building off the work of Harvard geneticist George Church, a co-founder of the company. To create the embryo, they might harvest eggs from an elephant or try to create stem cells using elephant tissue. Colossal also wants to create an artificial uterus to carry the embryo, which would take about two years to develop into a 200-pound fetus.

Church and his team of researchers have been working toward that goal for about a decade, and said in 2017 that it was just a couple of years away from creating the embryo. But Church’s team, until now, has lacked the funding to make that happen, according to Colossal co-founder and CEO and tech entrepreneur Ben Lamm. Colossal’s investors, which include private equity firms and self-help guru Tony Robbins, will infuse the project with $15 million. That builds on a previous $100,000 contribution from PayPal co-founder Peter Thiel that Church’s team received before Colossal was founded.

If all that funding ultimately results in a real-life Asian elephant-mammoth hybrid, there will still be a lot of ecological and ethical questions with which to grapple. Colossal bills itself as an effort to tackle biodiversity loss. Earth is probably losing a species or more a day, according to Bennett. There is evidence of a mass extinction taking place, the likes of which hasn’t been seen on Earth for millions of years. When it comes to protecting biodiversity on our planet, resurrecting a prehistoric creature is low on the priority list.

“Even within endangered species that we want to keep from going extinct, we have to prioritize what are the winners and the losers,” says Ginger Allington, a landscape ecologist and assistant professor at George Washington University.

Funding de-extinction could hurt other conservation efforts by siphoning off limited resources, Bennett’s previous research has found. Spending the same amount of money on traditional conservation efforts could save up to eight times more species than if the money was to be spent on de-extinction. The Asian elephant itself could use help; its numbers have dropped in half over the past three generations.

Lamm believes Colossal’s work might benefit the elephants and draw more attention to other conservation efforts. “We’re trying to make sure that we do this in the most transparent and ethical way as possible,” Lamm tells The Verge. “We feel very confident about what we can do to help the elephant lineage … For us it’s about giving the species additional tools to survive.” An elephant with mammoth traits would be better able to survive in the Arctic’s cold temperatures, away from urbanization that threatens its species, he says.

But Asian elephants’ home is tropical South and Southeast Asia. They’re also highly intelligent and social animals that form tight-knit groups. “They have a culture,” Bennett says. All that raises “major” ethical questions for Bennett over whether a mammoth-elephant hybrid would be able to behaviorally manage being transplanted in a new home that’s vastly different from where elephant species currently live.

A feat of mammoth proportions

Even a full-fledged woolly mammoth might struggle to adapt to the Arctic as it is today. “If you were to take a piece from a whole system like a Model T, say a piston, and you were to wait even 100 years and then try to integrate that into a Tesla — that won’t fit because the rest of the system has completely moved on and changed dramatically,” says Douglas McCauley, an ecologist and associate professor at the University of California, Santa Barbara.

Colossal thinks the animals could essentially re-engineer ecosystems, turning mossy tundra back to grasslands that once thrived with mammoths’ help 10,000 years ago. Without mammoths, grasslands where they roamed were slowly replaced by moss and trees. That poses problems for the planet because snow-covered grasslands in the Arctic are better at reflecting radiation from the sun than darker shrublands or woodlands. Bringing herds back could theoretically reverse that trend.

The hybrid animals might also help prevent permafrost (soil that’s frozen year-round) from melting, which releases old stores of planet-heating carbon dioxide. A father-son pair of ecologists in Russia have tried using bison, reindeer, and other animals to achieve something similar in Siberia in a place called “Pleistocene Park.” The hope is that the animals — perhaps one day with the help of elephant-mammoth hybrids — will trample down snow and make it easier for the soil so to freeze.

But for Colossal to be able to fulfill its goals, it would need to ensure that there are enough of the animals to do the job that mammoths once did. Otherwise, the animal could become a sort of “eco-zombie” that doesn’t meaningfully participate in its ecosystem as it once did, as McCauley and other authors describe in their 2017 paper about how to prioritize species for de-extinction efforts. Choosing animals that have recently gone extinct, or are on the verge of extinction, are better candidates, that paper said. They should also be species that perform a unique function or job in its ecosystem, and that can bounce back to big enough numbers to be able to effectively do that job.

One promising route for de-extinction research is research into breeding coral that are more resilient to a warming world — potentially saving them from extinction. It’s an effort that could support fisheries and shield coastal communities around the world from storm surge. Unless greenhouse gas emissions reach net zero by the middle of the century, the planet is on track to reach a level of global warming that would essentially wipe out the world’s coral reefs.

There are other problems that could keep grasslands from coming back. The pH of the soil has become more acidic. There’s also a risk that new animals might disturb soil too much, so that it actually exposes permafrost to melting faster. Whether the animals protect or perturb existing permafrost depends partly on their behavior — which at this point is still a big unknown, as they do not exist.

“Scaling the effect from the small herd scale to the entire permafrost zone which impacts climate also seems futuristic rather than something that can help anytime soon, even if it did help at all,” Ted Schuur, regents’ professor of ecosystem ecology at Northern State University wrote to The Verge in an email.

Even if everything goes as planned for Colossal, Lamm thinks it would take about six years to birth a hybrid calf. Then it would take another fourteen years or so for their first animal to be old enough to reproduce. From there, the efforts would need to scale up massively to have any meaningful effect on the amount of heat-trapping gases in the atmosphere. But even that best-case scenario comes too late for urgent climate goals. It’s nowhere near soon enough to help save coral reefs, which will need global emissions to drop by half by the end of the decade if they are to survive.

To tackle the climate crisis, the world needs deep and immediate cuts to greenhouse gas emissions from burning fossil fuels. Climate action ought to focus on addressing that pollution that’s at the root of the climate crisis, Bennett says, and not on projects that have a massive profile and an uncertain impact.

“My big concern with these things is that investors will be looking to offset their climate footprint, and they’ll look for things to do and somebody will look at something like that and be like, ‘Oh this is cool,’” says Bennett. “It’s a highly, highly risky prospect.”

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2021-09-15 12:30:00Z
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