Sometimes the best historical archives aren’t hidden in caves or locked in ice—they’re sitting in the frozen burrows of arctic ground squirrels in Canada’s Yukon territory.
Scientists at McMaster University have unearthed an extraordinary treasure trove of ancient DNA from animal droppings buried deep in sealed permafrost chambers. Tyler Murchie, a paleogenomics researcher and lead author of the study published in Nature Communications, led a team that discovered genetic material spanning 700,000 years of natural history. Among the finds: woolly mammoths, wolves, bison, horses, a cheetah, and DNA from hundreds of plant species. The data comes from the burrows themselves—sealed off by rising permafrost over millennia, creating perfectly preserved time capsules.
What makes this discovery so remarkable isn’t just the age or the diversity of what they found. It’s that arctic ground squirrels are nature’s ultimate hoarders. These creatures are only conscious for about four months each year, so when they’re awake, they scramble to pack their burrows with everything: nuts, seeds, leaves, bones, fur, and whatever else they can find to survive the long hibernation. Over thousands of years, those burrows transformed into a biological museum, complete with squirrel feces that preserved DNA like amber.
Murchie acknowledged the unsexy reality of the find—digging through poop isn’t as thrilling as discovering a mammoth tusk. But the team had actually set out to study the squirrels’microbiome and stumbled into something far bigger. They reconstructed 18 mitochondrial genomes, including six from woolly mammoths from different eras, offering a window into how the species evolved before it went extinct around 4,000 years ago. It’s detective work at its finest, using DNA fragments like puzzle pieces to rebuild ancient life.
The implications ripple across paleontology and even into the world of de-extinction. Colossal, the US company working to resurrect the woolly mammoth, will have access to this genetic data—though skeptics argue the result would be more like an Asian elephant with genetic tweaks than a true mammoth. Murchie noted the team’s data is“a drop in the bucket”compared to what Colossal already has, but more complete genomic information never hurts. The real win here is proof that squirrel feces—long overlooked as a research source—holds keys to understanding how our planet’s ecosystems have shifted over hundreds of thousands of years.
Murchie put it best:“I can’t believe that we were able to get these insights from squirrel faeces.”Neither can we. And that’s exactly why science keeps surprising us.
About the Author
Andrew Johnson
Andrew Johnson is a contributor to LocalBeat, covering local news and community stories.
