Scientists have extracted ancient human nuclear DNA from a small scoop of cave dirt in Spain, dating to around 22,000 years ago, despite the absence of any human remains in the sediment layer. The achievement, led by researchers at the University of Vienna and published in Science Advances, adds crucial genetic data from a period when skeletons are extremely rare and demonstrates the growing power of sedimentary DNA analysis.
The sediment sample, weighing no more than a few grains of rice, was sequenced 100 times to yield enough usable data. Researchers sifted through more than a billion DNA fragments to find human traces, accounting for modern contamination. The genetic material likely came from skin, hair or blood shed by ancient humans sheltering in El Mirón Cave during the coldest part of Europe’s last ice age.
The technique, known as sedimentary DNA or sedaDNA, is on track to transform archaeology by recovering genetic information without requiring bones or teeth. A 2025 review argued that with further work it could lead to a much deeper understanding of human dispersal, hunter-gatherer interactions, early agriculture, domestication and disease, predicting that its application will increase rapidly in coming years.
The recovered DNA suggests the inhabitants belonged to a western ancestry group with dark skin, hair and eyes. The sample appears to contain genetic material from several individuals, with more males than females. Unlike mitochondrial DNA, which is passed only through maternal lines, nuclear DNA comes from both parents and provides richer information about lineage.
Lead author Pere Gelabert and colleagues compared the El Mirón DNA with remains from an ancient woman in France dated to roughly 31,000 years ago and a tooth from northern Spain dated to around 25,000 years ago. Both earlier individuals appear to have had some eastern ancestry, suggesting that human populations at both ends of Europe were interbreeding before the last glacial maximum. However, the 22,000-year-old El Mirón DNA shows only western ancestry.
"Crucially," the authors conclude, "our genomic data argue against a major population replacement or discontinuity at this juncture." Instead, the population in southwest Europe between 30,000 and 20,000 years ago appears to have remained relatively continuous. SedaDNA techniques have practically doubled the evidence at hand.
The paper notes that "this result highlights the capacity of sedaDNA for uncovering previously inaccessible genetic dynamics in absence of human remains, and decisively connects archeological records with human genetic identities." The authors call for future work integrating additional skeletal genomes and sedaDNA datasets to further resolve how Upper Paleolithic populations in Europe were shaped.
Analysis
Why This Matters
- Sedimentary DNA allows archaeologists to recover genetic information from sites where no bones or teeth survive, dramatically expanding the potential evidence base for ancient human populations.
- The technique can help answer fundamental questions about human migration, interbreeding and continuity during critical periods such as the last ice age.
- Nuclear DNA from sediment provides lineage information from both parents, offering richer detail than earlier mitochondrial-only studies.
Background
The last glacial maximum, roughly 26,000 to 19,000 years ago, was the coldest phase of the last ice age in Europe. Human remains from this period are exceptionally rare, limiting genetic studies. Sedimentary DNA analysis has emerged in recent years as a way to bypass the need for physical fossils, with previous studies recovering mitochondrial DNA from cave floors and walls at sites in Georgia and Argentina.
What to Watch
- Whether future sedaDNA studies confirm the apparent population continuity in southwest Europe or reveal more mixing than currently detected.
- Integration of sedaDNA datasets with skeletal genomes to build a more complete picture of Upper Paleolithic population dynamics.
- Application of the technique to other caves and open-air sites across Europe and beyond.
Checked
12 claims in this story checked against 1 source: 10 supported.
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- SupportedThe headline says human DNA about 22,000 years old was recovered from cave dirt without bones.ScienceAlert: “A small scoop of sediment from a cave in Spain has now offered up ancient DNA from several individuals who lived roughly 22,000 years ago. No human remains exist in this layer of the El Mirón Cave”
- SupportedThe summary says nuclear DNA from El Mirón Cave sediment sheds light on Ice Age populations.ScienceAlert: “This new research goes even further and extracts nuclear DNA from the cave's sediment. [...] This data can help scientists better understand whether or not Western and Eastern populations in Europe during the last ice age mixed”
- SupportedThe research was led by University of Vienna researchers and published in Science Advances.ScienceAlert: “The findings from the study, led by researchers at the University of Vienna in Austria, are published in Science Advances .”
- SupportedThe authors conclude that their genomic data argue against a major population replacement or discontinuity at that point.ScienceAlert: “"Crucially," the authors conclude , "… our genomic data argue against a major population replacement or discontinuity at this juncture."”
- SupportedThe authors say the result highlights sedaDNA's capacity to uncover genetic dynamics without human remains and connect archaeological records with human genetic identities.ScienceAlert: “"This result highlights the capacity of sedaDNA (sedimentary DNA) for uncovering previously inaccessible genetic dynamics in absence of human remains," the authors conclude , "and decisively connects archeological records with human genetic identities."”
- Partly supportedThe genetic material likely came from skin, hair or blood shed by people sheltering in the cave.ScienceAlert: “What little genetic information the team found was probably shed long, long ago, possibly from the skin, hair, or blood of ancient humans sheltering in the cave”
- Partly supportedThe DNA suggests the cave's inhabitants belonged to a western ancestry group with dark skin, hair and eyes.ScienceAlert: “This ancient human DNA suggests that the people who once inhabited this cave probably belonged to a western ancestry group with dark skin, hair, and eyes.”
- SupportedA 2025 review said sedaDNA could deepen understanding of human dispersal, hunter-gatherer interactions, early agriculture, domestication and disease, and predicted its application would increase rapidly in coming years.ScienceAlert: “with work, a 2025 review argues that sedaDNA could lead to a much deeper understanding of human dispersal dynamics, hunter-gatherer interactions, early agriculture, domestication, and disease. [...] "The application of sedaDNA to a wide variety of archaeological sites and questions will increase rapidly in the next few years," the authors predicted.”
- SupportedThe sediment weighed no more than a few grains of rice and was sequenced 100 times to yield enough usable data.ScienceAlert: “The sediment taken from the El Mirón Cave weighed no more than a few grains of rice and had to be sequenced 100 times to yield enough usable data.”
- SupportedResearchers sifted through more than a billion DNA fragments to find human traces and account for modern contamination.ScienceAlert: “The team had to sift through more than a billion DNA fragments in the sample to find any human traces. Plus, modern contamination had to be accounted for as well.”
- SupportedThe DNA appeared to come from several individuals, including more males than females.ScienceAlert: “The DNA seems to have come from a mix of individuals, including more males than females.”
- SupportedTwo earlier individuals with some eastern ancestry suggest populations at both ends of Europe were interbreeding before the last glacial maximum, while the El Mirón DNA shows only western ancestry.ScienceAlert: “Both individuals appear to have had some Eastern ancestry, suggesting that human populations at both ends of Europe were interbreeding before the last glacial maximum. But perhaps that mixing didn't last. Human DNA from the El Mirón cave, which is roughly 22,000 years old, only shows signs of western ancestry.”
