I can't believe we got these insights from squirrel feces
Beneath the permafrost of Canada's Yukon, the humble burrows of arctic ground squirrels have yielded something profound: a biological record stretching back 700,000 years, written not in stone or ice but in feces. Researchers at McMaster University, led by paleogenomicist Tyler Murchie, have recovered DNA from woolly mammoths, wolves, bison, horses, and hundreds of plant species — a testament to how nature, indifferent to human ambition, quietly archives its own history. The discovery reminds us that the past does not always announce itself grandly; sometimes it waits, sealed in the most unassuming of chambers, for someone patient enough to look.
- Scientists set out to study squirrel gut microbiomes and stumbled instead onto a genetic library spanning nearly three-quarters of a million years — a reminder that the most transformative discoveries often arrive sideways.
- The arctic ground squirrel's frantic four-month waking season, spent hoarding bones, seeds, and organic debris, inadvertently created sealed time capsules when rising permafrost locked their burrows shut forever.
- Researchers reconstructed 18 mitochondrial genomes — including six woolly mammoths from distinct eras — by computationally stitching together fragile DNA fragments that had no business surviving this long.
- The findings land directly in the orbit of de-extinction: Colossal's mammoth resurrection project could draw on this publicly released data, though Murchie himself calls it 'a drop in the bucket' against what the company already holds.
- Broader scientific skepticism lingers over whether any resurrected mammoth would be a true mammoth or merely a genetically modified Asian elephant — a question this discovery enriches but does not resolve.
In the frozen ground of Yukon territory, scientists have found a biological archive preserved in the most unlikely medium: the feces of arctic ground squirrels. The DNA recovered from sealed burrows — some of it between 3,000 and 700,000 years old — contains genetic fragments from woolly mammoths, wolves, bison, horses, a cheetah, and hundreds of plant species, all locked away in nature's own time capsule.
Tyler Murchie, a paleogenomics researcher at McMaster University, led the study. He acknowledges the irony: digging through ancient squirrel droppings lacks the romance of unearthing a mammoth tusk. Yet the volume and diversity of genetic material preserved here suggests feces represents a long-overlooked pathway into Earth's distant past. The team had initially set out to study the squirrels' microbiome — what they found instead was a surprising biodiversity of organisms spanning geological time.
The arctic ground squirrel proved an ideal archivist by accident of biology. Conscious for only four months each year, these animals spend their brief waking season frantically hoarding food, bones, seeds, and organic debris into their burrows. When permafrost rose and permanently sealed some of those chambers, it created conditions stable enough for fragile DNA to survive intact. One burrow even contained a squirrel frozen mid-hibernation — a small creature, Murchie noted warmly, who simply never woke up.
Using computational methods, the team reconstructed 18 mitochondrial genomes, including sequences from six woolly mammoths that lived in different eras. The work, published in Nature Communications, represents a meaningful contribution to paleogenomics. The data will be made publicly available, including to Colossal, the U.S. company pursuing mammoth de-extinction — though Murchie tempered expectations, noting it would be a small addition to what researchers already possess.
Skepticism about de-extinction remains substantial, with experts questioning whether Colossal's approach would yield a true mammoth or something closer to a modified Asian elephant. Murchie steered clear of that debate, focusing instead on what the discovery itself represents: the unexpected richness of information waiting in sources most scientists would have dismissed. 'I can't believe that we were able to get these insights from squirrel feces,' he said — a line that captures both the genuine surprise and the quiet power of patient, careful science.
In the frozen ground of Yukon territory, scientists have uncovered something unexpected: a biological archive spanning hundreds of thousands of years, preserved not in amber or ice, but in the feces of arctic ground squirrels. The DNA recovered from these sealed burrows—some of it between 3,000 and 700,000 years old—offers a window into how life on Earth has transformed across millennia. Among the genetic material are fragments from woolly mammoths, wolves, bison, horses, a cheetah, and hundreds of plant species, all locked away in what amounts to nature's own time capsule.
Tyler Murchie, a paleogenomics researcher at McMaster University in Hamilton, Ontario, led the study that uncovered this trove. He acknowledges the irony of the discovery's source material—digging through ancient squirrel droppings lacks the romantic appeal of unearthing a mammoth tusk. Yet the sheer volume and diversity of genetic information preserved in these burrows suggests that feces represents an overlooked pathway into Earth's distant past. The researchers had initially set out to study the squirrels' microbiome. What they found instead was something far more expansive: a "really surprising biodiversity of organisms," as Murchie described it.
The arctic ground squirrel proved to be an ideal subject for this work, not by accident but by virtue of its peculiar biology. These animals remain conscious for only about four months each year, spending the remainder in hibernation. During their brief waking season, they must consume as much food as possible, frantically gathering nuts, seeds, leaves, bones, fur, and whatever else they can find. They pack these materials into their burrows, creating dense caches of organic matter. Over time, as permafrost rose and sealed off some of these burrows permanently, they became perfectly preserved repositories—sealed chambers holding the accumulated debris of thousands of years.
One such chamber even contained a squirrel itself, frozen in place. "He just went to sleep one season, then he never woke up," Murchie said, describing the discovery of what he called a "super cute little guy" preserved in time until a paleontologist happened upon him. These sealed burrows, locked away by rising permafrost, created conditions so stable that DNA—fragile and prone to degradation—survived intact.
Using computational methods, the research team reconstructed 18 mitochondrial genomes from the recovered DNA, including sequences from six woolly mammoths that lived in different eras. The process resembles assembling a puzzle: scientists use computers to stitch together fragments of genetic code, building complete sequences from incomplete pieces. This work was published in Nature Communications and represents a significant methodological contribution to paleogenomics—the study of ancient genetic material.
The discovery arrives at a moment when de-extinction has moved from science fiction into corporate ambition. Colossal, a U.S. company, has announced plans to resurrect the woolly mammoth, which disappeared roughly 4,000 years ago. The genetic data recovered from the Yukon squirrel burrows could theoretically support such efforts. Murchie confirmed that the team's findings will be made publicly available for other researchers to use, including those at Colossal. However, he tempered expectations: the company already possesses extensive genetic material from multiple organisms, he noted, so this new data would be "a drop in the bucket."
Scientific skepticism about de-extinction remains substantial. Experts have questioned whether Colossal's approach would actually produce a woolly mammoth or instead create something closer to an Asian elephant with genetic modifications designed to mimic mammoth traits. Murchie, who does not work for Colossal, steered clear of that debate. What he emphasized instead was the value of the discovery itself—the unexpected richness of information preserved in a medium most scientists would have overlooked. The team is already working on a follow-up study examining what the DNA reveals about woolly mammoth evolution, though Murchie could say only that it was "super cool." "I can't believe that we were able to get these insights from squirrel feces," he added, capturing the genuine surprise at what patient, careful science can extract from the most unlikely sources.
Citações Notáveis
The DNA found in sealed burrows offers a rare window into how life has changed over millennia, and feces represents an overlooked pathway into Earth's distant past.— Tyler Murchie, paleogenomics researcher, McMaster University
Arctic ground squirrels' natural hoarding behavior during their brief waking season created perfectly preserved time capsules when permafrost sealed their burrows.— Tyler Murchie, paleogenomics researcher, McMaster University
A Conversa do Hearth Outra perspectiva sobre a história
So you're telling me scientists found mammoth DNA in squirrel poop. How does that even happen?
Arctic ground squirrels are hoarders by necessity. They're only awake four months a year, so they cram their burrows with everything—nuts, seeds, bones, fur, plant matter. Over thousands of years, permafrost sealed some of those burrows shut, turning them into perfect time capsules.
And the DNA just... survived in there?
Yes. The sealed, frozen environment is stable enough that genetic material doesn't degrade the way it normally would. It's like nature created a freezer specifically designed for preservation.
What can you actually do with mammoth DNA at this point?
Researchers reconstructed complete mitochondrial genomes from six different mammoths across different time periods. That shows you the genetic variation and how the species changed over millennia. It's valuable data for understanding evolution.
Is Colossal going to use this to bring mammoths back?
They could. The data will be public. But honestly, the company already has enormous amounts of genetic material. This is more about understanding what we lost than necessarily resurrecting it.
What surprised the researchers most?
That they found anything at all, really. They went in expecting to study squirrel microbiomes. Instead they found hundreds of plant species, wolves, bison, horses, a cheetah—an entire ecosystem preserved in feces. It changed how they think about where ancient DNA can hide.