Blanket in the Permafrost

Back in 1996, an ecologist named Sergey Zimov drove an old Soviet armored vehicle across northeastern Siberia to bulldoze larch trees. He created a reserve called Pleistocene Park, which he now runs with his son Nikita, testing whether heavy grazing animals originally maintained the Pleistocene steppe—the vast prehistoric grassland that disappeared alongside Ice Age megafauna. An armored machine flattened timber easily enough, but as Zimov famously observed, military tanks make no dung.

A listener got in touch after hearing about a startup trying to resurrect mammoths. They asked what an extinct giant offers that living elephants cannot, whether researchers really engineered a woolly mouse, and why anyone would try. In a warming world, the debate touches everyone. Proponents like Colossal Biosciences argue that reviving lost ecological roles aids climate mitigation and biodiversity, as Harvard geneticist George Church put it, while conservationists warn it pulls critical money from surviving species. We will follow that quest from Siberian permafrost into advanced genetics labs, see what elephants are missing, examine other candidates in development, and test whether engineered megafauna can actually cool the Arctic.

That ambition began on a shoestring. Zimov funded his Siberian station by raising just over 100,000 dollars through online donations to import cold-hardy grazing animals. But when George Church teamed up with entrepreneur Ben Lamm to spin off Colossal Biosciences in 2021, the venture launched with 15 million dollars in seed funding.

By 2025, that private capital had grown to 435 million dollars, turning a remote northern trial into a biotechnology heavyweight. Yet before anyone could release an engineered giant onto the tundra, scientists had to resolve a far more fundamental hurdle: can you actually resurrect an animal whose genetic code has spent thousands of years decaying in the cold?

It is easy to imagine scientists plucking an intact cell from Siberian permafrost, placing its nucleus into an elephant egg, and growing a replica. But ancient DNA is degraded into tiny fragments, leaving far too little usable material to guide an embryo. True cloning is impossible. Instead, Colossal Biosciences uses CRISPR to edit living Asian elephant cells, which share 99.6 percent of the mammoth's DNA. The goal is a functional proxy: an engineered hybrid taking over that lost ecological role.

To modify an animal that size, researchers need cellular clay: induced pluripotent stem cells, adult cells reprogrammed to form any tissue. Elephants carry extra copies of TP53, a cancer-suppressing gene pathway that resists reprogramming. Colossal announced stem cells in March 2024 after suppressing those pathways, publishing in Nature Methods in June 2026, which proponents argued could open fresh ways to study elephant biology and tackle lethal conditions like elephant endotheliotropic herpesvirus.

That brings us to what the listener heard about a woolly mouse. Startups have not cloned a mammoth or created a separate species. In late 2024, Colossal tested its editing in lab mice, altering nine mammoth genes for coat traits and lipid metabolism to yield golden-furred pups. Chief executive Ben Lamm summed it up: “Besides the adorability factor – we did not factor in how cute they would be – now we have produced healthy living animals that have the exact phenotypes that we predicted, based on using ancient DNA and computational analysis in genome engineering,”

A mouse pregnancy takes 20 days; an elephant gestates for 22 months. That biological gap leaves onlookers asking when will a calf actually walk across the northern tundra. And if the mission is flattening trees and packing snow, why not simply ship modern Asian elephants straight to Siberia?

Putting Asian elephants straight onto the Siberian tundra might sound like an easy shortcut, but geneticist George Church points out that living herds could never survive the climate. The entire genetic effort is about giving them cold-weather traits so they can endure and restore northern habitats.

An Asian elephant is shaped from head to tail for tropical warmth. It carries almost no hair, and its oversized ears act like biological car radiators. Packed with blood vessels, those wide flaps vent heat so the animal avoids overheating under a blazing sun. But in sub-zero northern gales, that cooling setup turns into a fatal liability, bleeding away critical warmth straight into the freeze.

Woolly mammoths were adapted for the deep freeze. Think of them as walking blubber fortresses, covered in long, shaggy hair and shielded by an insulating fat layer up to 10 centimeters deep. Their ears shrank to roughly 10 percent of an elephant's, and their tails stayed short, minimizing exposed flesh where frostbite could bite or warmth could leak out.

The protection went right down to their chemistry. Standard elephant blood chills and has trouble unloading oxygen to icy limbs. Mammoths carried cold-adapted hemoglobin—the protein inside red blood cells responsible for transporting oxygen—with 3 distinct genetic mutations that allowed it to keep supplying oxygen at freezing temperatures. That prevented outer tissues from failing in bitter weather. But surviving northern cold is just the prelude. The real puzzle is what a herd of cold-tolerant proxies is supposed to accomplish for Earth's climate once they actually reach the Arctic.

All that cold-weather armor exists to protect an immense underground vault. Scientists estimate that 1.4 trillion tons of carbon sit locked in Arctic permafrost. Church says this equals two and a half times the carbon stored across the Amazon rainforest. Should that frozen terrain melt, the released gases could drive catastrophic global heating. Church saw that threat firsthand in 2018 while visiting Siberia. Standing beside a softening bog, a teammate struck a match over seeping gas, and Church saw ignited permafrost methane burst into flame over the mud. “That was an ominous sign,” he remembered.

Supporters argue that massive cold-tolerant beasts could keep that underground vault sealed. The strategy hinges on winter snow. Unpacked snow forms a fluffy blanket that keeps summer heat locked in the earth. But when heavy animals stomp that snow flat, freezing winter air can penetrate deep into the ground. According to Sergey Zimov, active herds can chill the permafrost by 4 degrees Celsius. Field measurements at Pleistocene Park support the idea, finding dirt stayed 1.9 degrees colder where animals grazed. Clearing dark forest canopies to revive open pastures also triggers an albedo feedback, since pale grass reflects solar radiation back into space rather than soaking it up.

Many ecologists doubt the premise. In 2026, BioScience Journal evaluated potential ecosystem disruption. The study rated releasing mammoth proxies into northern tundra at 7.8 out of 10, the highest risk assigned to any candidate species. Paleobiologist Adrian Lister argues that northern forests spread in the first place because the regional climate warmed, not because ancient giants disappeared. In Lister's words, “the idea that the forests and tundra only expanded across the entire northern hemisphere because megafauna went extinct is patently false.”

The ground itself presents another barrier. In 2016, an ecological review headed by Douglas McCauley warned that millennia of rising moisture may have made Arctic soils too acidic to sustain prehistoric grasses, a chemical obstacle that resurrection proposals never addressed. Even Sergey Zimov has acknowledged that shifting worldwide climate patterns would take tens of millions of grazing beasts spread through Siberia. Still, while mammoths capture the public imagination, de-extinction ventures are looking well beyond elephants.

Well before startups looked to the Arctic, modern de-extinction began in the canopy. In 2012, Revive & Restore launched The Great Passenger Pigeon Comeback as its flagship effort. Flocks billions strong once filled North American skies, until intense hunting and habitat loss left only Martha. On September 1, 1914, she died alone at the Cincinnati zoo. Ben Novak, who directs the comeback, explained that their goal is “about the pigeon’s place in the forests of tomorrow,” studying how those lost flocks shaped the forest.

Biotech ventures soon pushed that ambition across marsupials, birds, and predators. Colossal Biosciences started work to revive Australia's apex marsupial hunter, the thylacine, or Tasmanian tiger. Reviving the dodo takes a different strategy since birds cannot be cloned like mammals. Researchers rely on primordial germ cells—embryonic precursors that mature into eggs or sperm—to introduce dodo traits into the Nicobar pigeon and rear chicks carrying dodo traits. Beside research on the extinct moa, late in 2024 domestic hound surrogates gave birth to 3 gene-edited wolf pups carrying dire-wolf features such as lighter coats and wider skulls.

What catches many people by surprise is that conservation cloning is already aiding living endangered species. Supporters point to genetic rescue, the process of using cloning or gene edits to restore lost diversity to inbred, endangered populations. Back in 2020, Revive & Restore helped clone Kurt, a Przewalski’s horse developed from a frozen historic cell line. That December, the group welcomed Elizabeth Ann, the first black-footed ferret created by cloning. For advocates, those births show reproductive technology can prevent genetic collapse. Yet that very breakthrough sharpens the central debate: whether investing private millions to revive extinct creatures actually aids living wildlife, or pulls urgency away from species fighting to survive right now.

Many conservation biologists see a steep cost. In that 2026 BioScience study, a survey showed that 78.4 percent of consulted specialists felt de-extinction siphons resources away from living species without equal benefits. That mammoth funding alone could instead protect 1,247 critically endangered species through conventional conservation.

Then comes the toll on surrogate mothers. Asian elephants are endangered, social animals, and that 22-month pregnancy makes embryo trials ethically fraught. Geneticist Alison van Eenennaam cautioned, “There could be some genes they’re targeting for specific traits that have effects that are not compatible with survival.” Bioethicist Robert Klitzman warned, “There’s a risk of death. There’s a risk of side effects that are severe. There’s a lot of suffering involved in that.”

Colossal counters that venture capital expands capacity rather than raiding public budgets. Beyond 435 million dollars in private backing, the firm committed 50 million to non-profits. Chief science officer Beth Shapiro views gene editing as a “both and” tool to help surviving species weather disease, never a replacement for saving habitats.

Still, critics point to a moral hazard in conservation—the risk that the promise of de-extinction weakens public urgency to protect existing species from dying out. Curator Hein van Grouw warned that if people think we can just bring them back, conservation initiatives may suffer. And if you wonder when will a calf actually walk, birth targets slipped from 2028 into the early 2030s. Meanwhile, the required genetic edits climbed to about 150.

That grounds the answer for the listener. Mammoths had cold adaptations modern elephants lack, but no startup cloned one or made a real woolly mouse species. And while fears of ignited permafrost methane spurred this drive, proxy herds will not arrive in time to cool the Arctic. Zimov’s reminder that military tanks make no dung holds true: ecosystems cannot run on venture schedules. Beth Shapiro conceded, “Some people argue that our whole company is a stunt.” As biologist Paul Ehrlich warned, reviving extinct species is “an awful idea” that diverts us from protecting the planet. De-extinction offers no undo button.

If this sparked questions about what genetic revival could mean, look into de-extinction. And follow science; we have more stories there so you stay ahead as research moves forward. That's our story for today. Thanks for listening to Angle, and until next time.