Full Breakdown
Ancient DNA Treasure Trove Unearthed in Yukon Squirrel Coprolites
6/12/2026, 4:30:27 AM
Background: Squirrels as Natural Archivists
Arctic ground squirrels (Urocitellus parryii) in the Yukon awaken only four months a year, gathering nuts, seeds, bones and other material for burrow storage. Permafrost later sealed many burrows, preserving feces as capsules that retain DNA from the squirrels’ diet and from material they inadvertently collected, providing a snapshot of the Beringian ecosystem that once linked Asia and North America.
Researchers and Institutions
The study was led by paleogenomics researcher Tyler Murchie (McMaster University, Hakai Institute) with co-author Hendrik Poinar, director of the Ancient DNA Centre at McMaster. Published in *Nature Communications*.
DNA Findings from the Coprolites
Coprolites dated 3,000–700,000 years yielded 18 mitochondrial genomes, including six distinct woolly mammoth lineages and genomes for steppe bison, horses, snowshoe hare and the squirrel. Weaker signals included lemmings, caribou, gray wolves, a big cat (likely a cougar or extinct American cheetah), and 200 plant groups, fungi and bacteria. The 700,000-year-old sample is the oldest mitochondrial genome ever retrieved from ancient feces.
Implications for Paleogenomics and De-Extinction
The coprolite archive shows frozen rodent droppings can serve as “exceptional repositories” for reconstructing paleoenvironments, megafaunal evolution and extinction patterns. Mammoth DNA abundance has drawn interest from Colossal, a U.S. company that announced plans to resurrect the species using the newly released genomic data.
Official Statements
Murchie highlighted the unexpected biodiversity uncovered and the scientific potential of overlooked material. Poinar stressed the value of coprolites for understanding evolutionary and ecological change over time. Colossal declared its intention to bring back the woolly mammoth, citing newly available genomic resources.
Verbatim Quotes
- “I can't believe that we were able to get these insights from squirrel feces,” — Tyler Murchie, paleogenomics researcher, McMaster University
- “It helps reconstruct paleoenvironments in much deeper time, providing insights into environmental change, megafaunal evolution, dispersal and ultimately extinction,” — Hendrik Poinar, director, Ancient DNA Centre, McMaster University
- “The thing I hope people take away from this kind of work is the unexpected mystery that you could find in remains that you might otherwise overlook,” — Tyler Murchie, paleogenomics researcher, McMaster University
Criticism of De-Extinction Claims
Independent experts argue that a resurrected mammoth would likely resemble an Asian elephant with genetic tweaks rather than a true replica, and that the available DNA may not resolve the complex traits needed for a functional animal.
Conflicting Interpretations of DNA Sources
Researchers note that some non-squirrel DNA could stem from carrion or prey captured by the squirrels, or from predators entering the burrows, complicating attribution of genetic signals.
Future Directions
Murchie’s team is preparing a follow-up study on what the mammoth genomes reveal about the species’ evolutionary history. The released dataset will be available to other investigators, including Colossal, for de-extinction and climate-change research.
