Researchers have reconstructed the genetic codes of woolly mammoths, horses, steppe bison, and ground squirrels that inhabited the Canadian Arctic grasslands during the last ice age by analyzing DNA extracted from frozen squirrel excrement found in the Yukon.
The fossilized feces, rich in DNA from various animals such as wolves, big cats, mammoths, horses, birds, bats, insects, and plants like sages and sedges, were detailed in a recent study published in Nature Communications.
“We were able to comprehensively capture the entire ecosystem, from large animals to plants, fungi, insects, and a wide array of microorganisms,” stated Tyler Murchie, the lead author of the study and a scientist at the Hakai Institute in Campbell River, B.C.
Recent research on eroding permafrost in the Yukon reveals that fossilized squirrel feces have preserved remnants of ancient plants, seeds, and bones dating back tens of thousands to hundreds of thousands of years.
Preserved in Nature
For hundreds of millennia, Arctic ground squirrels have dug burrows with dedicated toilet chambers.
These dung-filled compartments have been emerging from valley walls along rivers. In the Yukon, Murchie’s colleagues and co-authors have been gathering and safeguarding these burrows, which contain various fragments collected by squirrels between 30,000 and 700,000 years ago, ranging from plant matter to bones to insects.
“They act as natural archivists, amassing a wide range of items in their dens, exhibiting a diverse diet and depositing feces in concentrated spots,” Murchie explained.
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