Around 19,000 years ago, a woman from a group of hunter-gatherers met her end and was laid to rest in a cave located in northern Spain. This cave, now known as El Mirón Cave, would later become the site of one of the most exciting archaeological discoveries of the 21st century. The woman’s remains were found more than a decade ago, and her burial, along with the surrounding artifacts, has been at the heart of numerous archaeological investigations. But it is not only her remains that are revealing incredible details about prehistoric life; new revolutionary methods of extracting ancient DNA from dirt—referred to as sedaDNA—are reshaping what we know about the people and animals that lived long before her.
The Discovery of the Red Lady
In 1996, archaeologists began exploring El Mirón Cave, situated in the Cantabria region of northern Spain. The cave was rich with evidence of prehistoric human activity, providing researchers with a glimpse into the distant past. As the excavation progressed, traces of ancient civilizations began to surface—tools, art, and evidence of rituals and daily life. Yet, it wasn’t until 2010 that a particularly extraordinary find would take place.
That year, Lawrence Straus, Emeritus Leslie Spier Distinguished Professor at the University of New Mexico, and his Spanish colleague David Cuenca Solana, unearthed the remains of a woman buried within the cave. Straus, having worked on the site for many years with his colleague Professor Manuel Gonzalez Morales from the Universidad de Cantabria, had a hunch to dig behind an engraved block at the back of the cave’s vestibule. This intuition led to the discovery of the woman’s jawbone and parts of her skull, which would later come to be known as the Red Lady of El Mirón.
The woman’s age at the time of death was estimated to be between 35 and 40 years. What made her remains even more remarkable, however, was the discovery of a coating of non-local ochre—a red pigment derived from iron oxide. This ochre, known for its brilliant, shimmering appearance due to the presence of specular hematite, suggested that she had been ritually adorned before her burial. The presence of ochre led researchers to conclude that the Red Lady’s burial may have had significant cultural or symbolic importance, potentially related to the spiritual or ceremonial practices of the time.
Since the discovery of the Red Lady’s remains, archaeologists and bioanthropologists have continued to study her and the surrounding artifacts, uncovering a wealth of new information about the prehistoric peoples of the region. But it was an even more recent development in research that would reveal new insights into her origins and the broader prehistoric ecosystem: the use of sedaDNA.
The Rise of SedaDNA Research
Typically, when it comes to extracting DNA from ancient remains, the focus is on the bones or teeth of individuals. In the case of the Red Lady, genetic material was indeed retrieved from her bones and teeth, offering a direct insight into her ancestry. However, in recent years, a groundbreaking method called sedaDNA (sedimentary ancient DNA) has allowed researchers to extract genetic material from the surrounding sediments in which ancient remains were discovered.
In 2010, Professor Ron Pinhasi of the University of Vienna reached out to Lawrence Straus with an exciting proposal: to apply sedaDNA analysis to the sediment layers of El Mirón Cave. Straus, intrigued by the potential of this new technology, provided detailed archaeological and faunal data to aid the project. This method, which had been successfully applied to the DNA of bacteria in the Red Lady’s dental calculus by Professor Christina Warinner and colleagues, was about to reveal a new dimension of information about the ancient inhabitants of the region.
The researchers extracted mitochondrial DNA (mDNA) from the sediments in the cave, which allowed them to study genetic material from both humans and animals. One of the major advantages of this method is that it doesn’t rely on the preservation of well-formed bones or teeth, which are often rare, especially when studying ancient populations. Instead, sediment is abundant and can contain DNA from a variety of sources—human, animal, and even plant.
New Insights from SedaDNA
The first major discovery from this sedimentary DNA analysis was the identification of several carnivores and ungulates—animals whose presence had not been previously indicated by the bone records. Among the animals identified through sedaDNA were the dhole (a species of wild dog now found only in Asia), as well as leopard, hyena, woolly mammoth, rhinoceros, and reindeer. These animals, while familiar from prehistoric ecosystems, were not represented by bones recovered from the site, providing evidence that they either lived in the cave at some point or were present in the form of carcass remains, which were less likely to preserve well over time.
One of the more fascinating revelations from the sedaDNA research was the discovery of genetic markers linking the Red Lady to two distinct groups of prehistoric humans. First, the Fournol genetic ancestry was identified, a lineage known from bones and teeth found at sites in both France and Spain, including La Riera in Asturias, which had been excavated by Straus in the 1970s. These were the Solutrean people, part of a group that survived the Last Glacial Maximum around 25,000 to 21,000 years ago by retreating southward in response to the harsh climatic conditions.
Second, the research also found evidence of Villabruna ancestry in the Red Lady’s DNA. This group had migrated to the Cantabrian region of Spain during the Lower Magdalenian period, arriving from the Balkans via northern Italy. This suggests that the Red Lady’s ancestry was rooted in a complex mixture of peoples from various regions, reflecting the fluid migration patterns that were characteristic of the prehistoric world.
The study of sedaDNA has allowed researchers to confirm the existence of these two ancestral groups and better understand the genetic makeup of the Red Lady and her contemporaries. More importantly, it has opened up a new era of research into ancient human and animal populations, where the study of sediments can reveal vital insights that would otherwise remain hidden.
The Broader Impact of SedaDNA Research
The ability to retrieve DNA from sediments has opened up new possibilities in archaeological and anthropological research. Unlike traditional methods, which are limited by the availability of well-preserved bones or teeth, sedaDNA allows scientists to examine entire ecosystems—from the animals that lived in the region to the humans who once inhabited it. This means that even in the absence of well-preserved remains, researchers can begin to piece together the biological history of a site.
In the case of El Mirón Cave, this method has provided a more complete picture of the people and animals that lived during the Pleistocene era. The research team led by Pere Gelabert and Victoria Oberreiter, along with Straus and Gonzalez Morales, have provided a timeline of DNA from more than 46,000 years ago, spanning the Mousterian-Neanderthal period to the Initial Magdalenian around 21,000 years ago.
As with other groundbreaking discoveries in archaeology, this research is not just about uncovering the past—it also provides insight into the broader methods that may be applied to other sites. The success of sedaDNA in El Mirón Cave has inspired similar research in other parts of the world, where ancient bones are scarce, but the sediment can hold vast amounts of genetic information.
Future Directions and Ongoing Research
The next step for researchers at El Mirón is the extraction of nuclear DNA from the sediments, a more challenging process that could reveal even more about the prehistoric populations that once lived in the cave. The successful recovery of nuclear DNA would mark another major breakthrough, allowing scientists to gather more detailed genetic information about both humans and animals that once occupied this region of Spain.
The work at El Mirón Cave continues to evolve, and with each new discovery, scientists gain a deeper understanding of the people, animals, and environments that existed during the Late Pleistocene. The Red Lady, whose discovery sparked much of this research, remains a powerful symbol of the rich and complex history of prehistoric humans, and her burial—along with the accompanying ochre—continues to captivate archaeologists and bioanthropologists alike.
As researchers like Straus, Gonzalez Morales, and Cuenca Solana continue their work, El Mirón Cave will undoubtedly reveal more secrets about our distant ancestors. Through advanced DNA analysis and the study of ancient ecosystems, we are gaining a clearer, more detailed understanding of the world that existed tens of thousands of years ago—and the people, like the Red Lady, who once called it home.
Reference: Pere Gelabert et al, A sedimentary ancient DNA perspective on human and carnivore persistence through the Late Pleistocene in El Mirón Cave, Spain, Nature Communications (2025). DOI: 10.1038/s41467-024-55740-7