Судлаачид агуйн хананд хадгалагдан үлдсэн эртний хүний удамшлын материалыг шинжлэх ухаанд анх удаа амжилттай олборлосон нь археологийн судалгаанд шинэ боломж нээж байна.
Испани болон Португалийн судлаачдын тэргүүлсэн “First Art” төслийн хүрээнд эрдэмтэд агуйн хадны зураг болон тэдгээрийн химийн найрлагыг судлах явцдаа энэхүү нээлтийг хийжээ. Max Planck Institute for Evolutionary Anthropology-той хамтран ажилласны үр дүнд судлаачид ясны үлдэгдэл эсвэл тунамал хурдас бус, агуйн хананы гадаргуу дээрх ДНХ-г илрүүлэх нарийн аргачлалыг боловсруулсан байна. Энэхүү судалгаанд 11 агуйн 24 хадны зураг бүхий хэсэг болон зураггүй хананы хэсгүүдээс нийт 54 дээж авч шинжилжээ.
Шинжилгээний үр дүнд таван дээжээс хүний митохондрийн ДНХ илэрсний гурав нь ямар нэгэн зураггүй, хүний үйл ажиллагааны ул мөр илт харагдахгүй агуйн хананаас олдсон байна. Эрдэмтэн Маттиас Мейер болон Альба Боссомс Меса нарын тайлбарласнаар, зарим дээжинд амьтны ДНХ илрээгүй нь эртний хүмүүс шүлс болон бусад биеийн шингэнээр дамжуулан ДНХ-г хананд шууд үлдээсэн байх магадлалтайг харуулж байна. Нөгөө гурван дээжийн хувьд усны урсгал эсвэл хурдас зөөгдөх замаар дамжин хүний болон амьтны ДНХ холилдсон байх талтай ажээ.
Судлаачид ДНХ-гийн шинжилгээгээр Covarón агуйгаас олдсон дээжүүд нь Homo sapiens буюу орчин цагийн хүн төрөлхтөнтэй холбоотой болохыг тогтоосон бөгөөд тэдгээр нь Иберийн хойгийн эртний анчин-түүвэрлэгчдийн генетикийн бүлэгт хамаарч байна. Хэдийгээр олдсон ДНХ-г зураг зурсан уран бүтээлчидтэй шууд холбох боломжгүй ч, энэхүү арга нь эртний хүмүүс агуйг хэрхэн ашиглаж байсан, тэдний хүйсийн харьцаа болон хүн амын бүтэц зэрэг асуултад хариулах боломж олгож байгаа юм.
Гэсэн хэдий ч энэхүү судалгааны арга нь одоогоор хязгаарлагдмал байна. Судлаачдын тэмдэглэснээр, агуйн хананд ДНХ хадгалагдах нөхцөл маш хувьсамтгай бөгөөд орчин үеийн хүний бохирдолд өртөх эрсдэлтэй тул дээж олборлох үйл явц ихээхэн хүндрэлтэй байдаг. Цаашид энэхүү аргыг боловсронгуй болгож, эртний хүмүүсийн нууцлаг амьдралын ул мөрийг илүү өргөн хүрээнд судлах шаардлагатай байгааг эрдэмтэд онцоллоо.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
Researchers have recovered ancient human DNA from cave walls for the first time, showing that genetic material can survive on rock surfaces for thousands of years. The finding grew out of the First Art project, an interdisciplinary effort led by researchers from Spain and Portugal that aims to date the earliest cave art and characterize its chemical composition. Institutions in the UK, China, and Germany take part too. Collaboration with the Max Planck Institute for Evolutionary Anthropology carried the work into DNA analysis, extending the search for ancient genetic material beyond bones, sediments, and, more recently, bone artifacts.
The premise was straightforward. Some cave art was applied by blowing or rubbing pigment onto the wall, and today’s ancient DNA techniques are remarkably sensitive. According to Hipólito Collado Giraldo, an archaeologist and rock art specialist from the Extremadura Government who brought the team together, the hope was that such contact might leave DNA behind, potentially yielding genetic profiles of the makers.
Unpainted Walls Turn Out to Hold DNA
The team examined 24 rock art panels from 11 caves, including simple marks and hand stencils, plus pigment that had naturally fallen from figurative paintings in the Cave of Altamira. They analyzed pigmented and unpigmented wall fragments, sediments, bones, and a rare prehistoric bird bone airbrush used to blow red ochre onto the walls.
Of 54 samples, only five produced authentic ancient human mitochondrial DNA. One came from a calcite crust with pigment beneath it on Panel 11 in Escoural Cave, Portugal. Two more came from unpigmented walls in a deeper gallery of the same cave, and two from unpigmented surfaces beside rock art in Covarón Cave in northern Spain.
Two samples contained no detectable mitochondrial DNA from other animals, a rare pattern that strongly suggests humans deposited the DNA directly, through saliva or other bodily fluids. The other three, all from unpigmented walls, held both human and animal DNA, which points to an indirect route such as sediment transfer or water movement.
“This study fundamentally changes how we think about where ancient DNA can be found,” says senior author Matthias Meyer, a paleogeneticist at the Max Planck Institute who co-led the work with Collado Giraldo.
What the DNA Says about the Visitors?
Even without naming any artist, the DNA revealed something. Three samples came mostly from females, one mostly from males, and the fifth remained undetermined. Further analysis of the two unpigmented Covarón samples showed they came from Homo sapiens, and nuclear DNA placed them in the Western hunter-gatherer genetic cluster, consistent with findings for other ancient Iberian populations.
“We were surprised to see that ancient DNA can be recovered not only from pigmented samples, but also from cave walls that show no visible evidence of past human activity. We can now ask new questions: Who touched this wall? Was it a man or a woman? Which population did they belong to? How far did ancient humans venture into deep cave systems?” Meyer asks.
Sampling cave walls could also offer a way to investigate prehistoric behavior without disturbing archaeological deposits, and could help establish the sex and ancestry of the underground chambers users even where no recognizable images or objects were left.
“This is not just about rock art,” says Collado Giraldo. “It’s about understanding how people used caves and where they left their marks.”
Why Finding Ancient DNA Is So Difficult
None of this means the cave artists have been identified. Alba Bossoms Mesa, first author and doctoral researcher at the Max Planck Institute in Leipzig, says the traces cannot be directly connected to the creation of rock art, though the study offers the first evidence of human DNA preservation on cave walls for thousands of years.
Recovery remains hard. The Altamira bird bone airbrush, an object expected to have touched saliva, yielded no ancient human DNA, most likely because of extremely high contamination by present-day human DNA and the minimal material sampled.
Across the study, featured in Nature Communications, ancient DNA turned up in just one of the 24 panels and in two spots adjacent to other panels, which suggests pigment surfaces rarely retain enough DNA to survive for thousands of years, particularly without mineral crusts or sealed environments to protect them.
“The preservation of human DNA on cave walls is highly variable,” says Bossoms Mesa, who argues that:“when it does survive, it tells a powerful story. And while these first results are promising, I think our priority now should be to refine the methods and to understand under what conditions we can expect a higher success rate.”
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