In a breakthrough that rewrites the boundaries of molecular archaeology, researchers have successfully extracted and sequenced RNA from a woolly mammoth that died nearly 40,000 years ago in Siberia. The discovery, published in the journal Cell, represents the oldest RNA ever recovered and offers an unprecedented molecular snapshot of life during the Ice Age. Scientists long believed that RNA molecules were far too fragile to survive more than hours or days after death, making this find all the more extraordinary.
The mammoth, nicknamed Yuka after the Siberian village near where she was discovered, has become one of paleontology's most valuable specimens. Found in 2010 by tusk hunters along a riverbank near the Arctic coast, Yuka's mummified remains included patches of reddish fur, an intact brain, and muscle tissue preserved in exquisite detail by the permafrost. This exceptional preservation created ideal conditions for the survival of delicate genetic material that normally degrades rapidly.
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A Molecular Time Capsule From the Pleistocene
RNA molecules serve as crucial messengers in all living organisms, carrying instructions from DNA to create proteins and regulate which genes become active at any given moment. While scientists have successfully extracted ancient DNA from numerous extinct animals, RNA has remained frustratingly elusive due to its single-strand structure and susceptibility to breakdown. The Stockholm University-led team's success with Yuka changes that paradigm entirely.
According to a Stockholm University release, lead author Emilio Mármol explained the significance:
"With RNA, we can obtain direct evidence of which genes are 'turned on', offering a glimpse into the final moments of life of a mammoth that walked the Earth during the last Ice Age. This is information that cannot be obtained from DNA alone."
Structural differences between DNA and RNA molecules. (Sponk/CC BY-SA 3.0)
The researchers identified distinct patterns of gene expression in Yuka's frozen muscle tissue, revealing which proteins were being produced when the young mammoth died.
Among the more than 20,000 protein-coding genes in the mammoth genome, only specific ones showed activity in the preserved tissues. The RNA molecules detected coded for proteins involved in muscle contraction and metabolic responses to stress. Perhaps most tellingly, the team found molecular signatures of cellular stress, which correlates with previous research suggesting Yuka may have been attacked by cave lions shortly before death.
MicroRNAs Reveal Gene Regulation in Real Time
Among the most exciting discoveries were non-coding RNA molecules called microRNAs, which regulate gene activity rather than producing proteins directly. Marc Friedländer, associate professor at Stockholm University, noted that:
"The muscle-specific microRNAs we found in mammoth tissues are direct evidence of gene regulation happening in real time in ancient times. It is the first time something like this has been achieved."
These microRNAs helped confirm the authenticity of the findings and revealed rare mutations that served as a "smoking gun" demonstration of their mammoth origin. The findings demonstrate that RNA preservation extends far beyond what scientists previously thought possible.
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'Yuka' - mammoth specimen showing remarkable preservation. (Cyclonaut/CC BY-SA 4.0)
Implications for Viral Detection and De-Extinction
The discovery holds profound implications for multiple fields of research. Love Dalén, professor of Evolutionary Genomics at Stockholm University and senior author of the study, explained that RNA preservation means scientists can now search for ancient viral infections in Ice Age specimens.
"This means that we will not only be able to study which genes are 'turned on' in different extinct animals, but it will also be possible to sequence RNA viruses, such as influenza and coronaviruses, preserved in Ice Age remains," Dalén stated.
While Yuka's tissues showed no evidence of viral infection, future specimens might reveal the genetic signatures of ancient pathogens that plagued Ice Age megafauna. This could provide crucial insights into disease patterns, extinction events, and even help modern virologists understand viral evolution over tens of thousands of years.
For de-extinction efforts, the RNA findings offer new possibilities, according to National Geographic. While the specific muscle-development RNA found in Yuka may not differ significantly from modern elephants, discovering RNA in other tissues like hair follicles could reveal the genetic switches responsible for the mammoth's iconic woolly coat. This information could prove invaluable for companies like Colossal Biosciences, which aims to create mammoth-elephant hybrids.
Rewriting Yuka's Story
In an unexpected twist, the genetic analysis revealed that Yuka was actually male, contradicting years of previous research that classified the specimen as female based on anatomical features. The discovery of both X and Y chromosomes forced researchers to reexamine their interpretations of Yuka's life history, including growth patterns and developmental milestones. Daniel Fisher, a paleontologist at the University of Michigan, noted that extensive post-mortem damage to Yuka's body likely contributed to the initial misidentification.
The team examined samples from ten different Siberian mammoths, with three yielding RNA and Yuka providing the longest, most complete strands. The permafrost of northern Siberia continues to yield remarkable discoveries as climate change causes the frozen soil to thaw, from mummified saber-toothed cats to ancient wolf pups. Each find adds new chapters to our understanding of life during Earth's last great glaciation.
As researchers continue to push the boundaries of ancient biomolecule recovery, Mármol envisions a future where scientists can integrate prehistoric RNA with DNA, proteins, and other preserved biological materials.
"Such studies could fundamentally reshape our understanding of extinct megafauna as well as other species, revealing the many hidden layers of biology that have remained frozen in time until now," he concluded.
The breakthrough suggests that RNA, once thought impossibly fragile, may survive far longer than anyone imagined when conditions are right.
Top image: One of Yuka’s legs, illustrating the exceptional preservation of the lower part of the leg after the skin had been removed, which enabled recovery of ancient RNA molecules. Photo credit: Valeri Plotnikov. Source: Valeri Plotnikov/Cell
By Gary Manners
References
Mármol, E. et al. 2025. Ancient RNA expression profiles from the extinct woolly mammoth. Available at: https://www.cell.com/cell/fulltext/S0092-8674(25)01231-0
Stockholm University. 2025. Scientists recover 40,000-year-old mammoth RNA still packed with clues. Available at: https://www.sciencedaily.com/releases/2025/11/251115095920.htm
Stockholm University. 2025. The world's oldest RNA extracted from woolly mammoth. Available at: https://www.eurekalert.org/news-releases/1105073
Wei-Haas, M. 2025. World's oldest RNA found in 40,000-year-old woolly mammoth. Available at: https://www.nationalgeographic.com/animals/article/woolly-mammoth-rna-discovery
