Эрдэмтэд 75,000 жилийн өмнөх үеийн 46 зүйл амьтны үлдэгдлийг илрүүлснээр тухайн бүс нутгийн уур амьсгалын өөрчлөлтийн үеийн экосистемийн онцлогийг тодорхойлжээ.
Норвегийн Нарвик хотын ойролцоох Кёпсвик тосгоны Арне Квамгротта агуйгаас олдсон энэхүү олдвор нь Европын Арктикийн бүс нутагт бүртгэгдсэн хамгийн эртний бөгөөд хамгийн бүрэн бүтэн экосистемийн баримт болж байна. 1990-ээд онд уурхайн хонгил ухах явцад санамсаргүй нээгдсэн энэхүү агуйг 2021-2022 онд Ослогийн их сургууль болон бусад эрдэм шинжилгээний байгууллагуудын судлаачид бүрэн хэмжээгээр малтан судалжээ. Мөсөн голын нөлөөгөөр ихэнх эртний олдвор устдаг ч, энэ агуйн тунадас давхарга нь амьтдын ясыг 75 мянган жилийн турш гадны нөлөөнөөс хамгаалж чадсан байна.
Судлаачид ясны бүтцийн шинжилгээ болон эртний ДНХ-ийн сорилтыг хослуулан ашигласнаар туйлын баавгай, халим, цаа буга, янз бүрийн шувууд болон загасны төрлийг нарийвчлан тогтоожээ. Ялангуяа Европ тивд устаж үгүй болсон, Скандинавын хойгт өмнө нь бүртгэгдэж байгаагүй “collared lemming” буюу хүзүүвчит леммингийн яс олдсон нь шинжлэх ухааны хувьд чухал ач холбогдолтой юм. Судалгааны багийн ахлагч Сэм Уокер энэхүү олдворыг мөстлөгийн үеийн Арктикийн ертөнцийн ховор тохиолдох цонх хэмээн тодорхойлсон байна.
Агуйгаас олдсон амьтдын төрөл зүйл нь тухайн үед тус бүс нутгийн эргийн шугам мөсгүй, нээлттэй ландшафттай байсныг гэрчилж байна. Цаа буга шиг нүүдлийн амьтад амьдрах боломжтой нээлттэй тал хээр, гол мөрөн байсан бол далайн халим, далайн морь зэрэг амьтдын үлдэгдэл нь далайн мөс улирлын чанартай оршиж байсныг илтгэдэг.
Энэхүү экосистем нь уур амьсгал эрс хүйтэрч, мөсөн гол түрэн орж ирэх үед бүрэн устсан болохыг судалгаагаар тогтоожээ. Тухайн үед амьтдын популяцид нүүдэллэх өөр таатай бүс нутаг байгаагүй нь тэднийг олноор мөхөхөд хүргэсэн байна. Судлаачид өнөөгийн Арктикийн амьтдын амьдрах орчин илүү хуваагдмал болсон нь уур амьсгалын өөрчлөлтийн үед тэднийг илүү эрсдэлд оруулж байгааг онцоллоо.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
Inside a cave on the coast of Northern Norway, researchers have identified the bones of 46 species of mammals, birds and fish that lived in the European Arctic 75,000 years ago, the oldest known record of its kind for the region.
The remains come from Arne Qvamgrotta, a cave near Kjøpsvik in Narvik municipality, and include animals that once shared a coastal habitat long before the last major advance of the ice sheets. The findings appear in a study in the Proceedings of the National Academy of Sciences, and the research team says the bones can help explain how Arctic wildlife responded the last time the region’s climate shifted dramatically.
A Mining Tunnel Opened the Cave In the 1990s
Arne Qvamgrotta was found by chance in the 1990s, when a mining company drilled a tunnel through the mountain above Kjøpsvik. The tunnel exposed an entrance into the cave system, though at the time nobody realized what was sealed inside its sediment layers.
For nearly 30 years afterward, the cave stayed largely unexplored. Its deposits remained undisturbed since the animals within them had died, protected from the weathering and scavenging that normally break down bones over thousands of years.
That changed in 2021 and 2022, when a research team returned to carry out full excavations. They worked through layer after layer of sediment, recovering bone material that had survived largely intact since it was first buried.
The project brought together researchers from the University of Oslo, Bournemouth University, the University Museum of Bergen, the Norwegian University of Life Sciences and other institutions. Organic remains older than 10,000 years are extremely rare in previously glaciated regions, since advancing ice sheets typically scrape away older deposits, which is part of what makes this cave unusual.
Bone Analysis and Ancient Dna Identified the Species
To work out what had been buried in the cave, the team combined traditional bone identification with ancient DNA testing. This dual approach let researchers confirm species even from small or damaged bone fragments that would be difficult to identify by shape alone.
The combined analysis turned up a wide range of animals: polar bear, walrus, bowhead whale, Atlantic puffin, common eider, rock ptarmigan, Atlantic cod and migratory reindeer among them. Together, these represent both marine and land-based branches of the Arctic food web from the same period.
One find stood out from the rest. Bones belonging to collared lemming turned up in the deposits, a species now extinct in Europe that had never before been recorded anywhere in Scandinavia, adding a genuinely new data point to the region’s fossil record.
Lead author Sam Walker of Bournemouth University, in a university statement, called the find “a rare snapshot of a vanished Arctic world.” Taken together, the 46 identified species form the oldest known example of an animal community from the European Arctic during this warmer stretch of the ice age.
Senior author Sanne Boessenkool, a geneticist at the University of Oslo, said the cave revealed an unusually complete coastal ecosystem, with marine and land-based species preserved side by side in the same layers, something researchers rarely get to see from a period this old.
The Bones Point to a Mostly Ice-Free Coastline
The mix of species recovered suggests the coastline was largely ice-free at the time, with glaciers retreated well inland from where they would later advance. That kind of open landscape stands in contrast to the frozen steppe most commonly pictured for the ice age.
Migratory reindeer, among the animals identified, need open land routes to move between feeding grounds through the year. Their presence in the cave supports the idea of a passable, largely unglaciated coastal strip rather than a landscape locked under ice.
Freshwater fish recovered from the same deposits point to a further detail: lakes and rivers running through the surrounding tundra. That combination of open land, running water and migratory animals describes a far more varied habitat than a simple ice-covered coastline.
Marine remains fill in the rest of the picture. Bowhead whales and walruses, both of which depend on sea ice for part of their life cycle, indicate that ice was still forming somewhere offshore during at least part of the year.
Harbour porpoises, found in the same layers, are known to avoid ice-covered water. Their presence alongside ice-dependent species like bowhead whales suggests the sea ice came and went with the seasons rather than lasting year-round.
Populations Died Out When the Ice Returned
Genetic testing on the recovered bones showed something notable: the specific animal lineages living in this coastal ecosystem did not survive once colder conditions returned and glaciers advanced again across the region.
Researchers link this outcome to a lack of alternative habitat. With ice spreading back across the coastline, the animals living there had nowhere nearby to relocate to as their surroundings changed.
Whole populations appear to have died out locally rather than shifting to milder ground elsewhere, since no such ground remained within reach once the ice advanced. The ecosystem captured in the cave effectively disappeared with the climate shift that ended it.
Walker noted that today’s Arctic habitats are far more fragmented than they were 75,000 years ago, leaving far less room for animal populations to move as conditions change, a point the research team says is relevant for conservation work today.
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