Scientists from Stockholm University recovered the oldest-known RNA — from a 39,000‑year‑old woolly mammoth named Yuka — more than doubling the previous age record. The team identified over 300 mRNAs and ~60 microRNAs in muscle tissue, revealing gene activity tied to muscle metabolism and indicating Yuka was male with predominantly slow‑twitch fibers. While not an immediate route to de‑extinction, the finding shows ancient RNA can be recovered and used to study gene expression and traits DNA alone cannot reveal.
39,000-Year-Old RNA Discovered in Woolly Mammoth — A Milestone for De‑Extinction Research
Scientists from Stockholm University recovered the oldest-known RNA — from a 39,000‑year‑old woolly mammoth named Yuka — more than doubling the previous age record. The team identified over 300 mRNAs and ~60 microRNAs in muscle tissue, revealing gene activity tied to muscle metabolism and indicating Yuka was male with predominantly slow‑twitch fibers. While not an immediate route to de‑extinction, the finding shows ancient RNA can be recovered and used to study gene expression and traits DNA alone cannot reveal.
10:35 PM, 11/14/2025Science
Ancient RNA from a 39,000‑year‑old mammoth offers new insight into extinct biology
Researchers from Stockholm University have recovered the oldest-known RNA to date from a woolly mammoth preserved in Siberian permafrost — a discovery that advances understanding of gene activity in extinct animals and could inform future de‑extinction efforts.
The team sampled tissue from 10 mammoth specimens and found exceptionally well-preserved RNA in a male individual nicknamed Yuka. The RNA is roughly 39,000 years old, more than double the previous record of about 14,300 years from a wolf skin. Because RNA degrades far faster than DNA, this finding challenges assumptions about the survival of fragile biomolecules in deep time.
Why RNA matters
Whereas DNA functions as a genetic “catalogue,” RNA reflects which genes were actively expressed in particular tissues at particular times. High-quality ancient RNA therefore provides information about gene regulation and dynamic biological processes that DNA alone cannot reveal — for example, which genes were switched on in skin or muscle and how those genes functioned.
Dr Emilio Mármol Sánchez, the study’s lead author, said the team’s aim was to deepen understanding of mammoth biology rather than immediately resurrect the species. He noted that RNA data can reveal how genes were expressed and regulated — information important to any effort that seeks a faithful reconstruction of extinct traits.
Findings from Yuka’s muscle
From Yuka’s muscle tissue the researchers identified reliable evidence of more than 300 protein-coding mRNAs and roughly 60 microRNAs. These molecules are linked to skeletal muscle organization and contraction, and the profiles suggest mammoth muscles functioned similarly to those of modern elephants. The RNA also indicated that Yuka was male and that its musculature was dominated by slow‑twitch fibers suited to endurance rather than explosive power — a detail that offers a snapshot of the animal’s physiology shortly before death.
Prof Love Dalén, co-author and evolutionary genomics professor, emphasized that the particular RNA fragments recovered are "not directly relevant for de‑extinction" today. Still, the demonstration that ancient RNA can be recovered and analysed opens the door to future tissue-specific studies that might pinpoint which genes produced distinctive mammoth traits such as dense fur or specialized skin.
Broader implications
The methods described in the paper, published in Cell, could be applied beyond paleogenomics — for example to degraded modern RNA or samples from other historical periods. While this work is not an immediate roadmap to bringing mammoths back, it provides an important molecular layer of information that complements ancient DNA and improves our ability to reconstruct extinct organisms more accurately.
Takeaway: Recovering ancient RNA offers a new window into how extinct animals lived at the molecular level — revealing gene activity, tissue function and clues about traits that DNA alone cannot fully explain.