Researchers extract 22,000-year-old human DNA from El Mirón cave sediment
Sedimentary DNA Yields Nuclear Code From El Mirón Cave
This result highlights the capacity of sedaDNA (sedimentary DNA) for uncovering previously inaccessible genetic dynamics in absence of human remains,
the authors concluded, as ScienceAlert reported on research extracting ancient human nuclear DNA from a microscopic amount of dirt collected in Spain.
The Tech TL;DR:
- Researchers successfully extracted 22,000-year-old nuclear DNA from cave sediment containing no physical human remains.
- The genetic sample required sequencing 100 times after sifting through more than a billion DNA fragments.
- Data comparison showed western European genetic continuity through the Last Glacial Maximum without major population replacements.
Researchers Sequence Sediment to Find Ancient Human DNA
The sample taken from the El Mirón Cave weighed no more than a few grains of rice. To secure usable genetic material, the research team had to sequence the sediment 100 times while accounting for modern contamination and sifting through more than a billion total DNA fragments. The genetic data likely originated from ancient humans sheltering during the coldest phase of Europe’s last ice age.
Cave dirt in Spain still holds DNA from people who lived 22,000 years ago.Sediment from El Miron Cave yielded about 14,000 human genetic markers with no bones at all, showing a local ancestry survived the peak of the last Ice Age in southwest Europe (Science Advances).
Nuclear Versus Mitochondrial Genetic Data
While previous digs yielded mitochondrial DNA passed down strictly through maternal lines, this project recovered nuclear DNA containing information from both parents. Lead author Pere Gelabert and his colleagues at the University of Vienna compared this nuclear profile against an ancient woman in France who lived roughly 31,000 years ago and a tooth from northern Spain dated to approximately 25,000 years ago.
According to findings published in Science Advances, the earlier specimens showed signs of eastern ancestry. However, the 22,000-year-old El Mirón sediment displayed signs of western ancestry, indicating that populations in southwestern Europe between 30,000 and 20,000 years ago remained relatively continuous rather than experiencing a major population replacement.
Sedimentary DNA Links Populations and Appears on Cave Walls
Data from southwestern France further linked eastern and western populations more than 30,000 years ago. Senior author Ron Pinhasi noted that sedimentary DNA bridges the gap between archaeological layers and the genetic identity of past occupants. Parallel research conducted this year by Alba Bossoms Mesa, an evolutionary anthropologist at the Max Planck Institute, identified human DNA preservation on cave walls decorated with rock art in Argentina, marking the first evidence for human DNA preservation on cave walls for thousands of years.
Future genetic integrations will rely heavily on combining skeletal genomes with sedimentary datasets to map upper Paleolithic dispersal patterns across Europe.