Climate change is actually nothing new to our old planet. It has long driven the evolution of Earth’s flora and fauna and good thing, too: Without those major shifts, we wouldn’t be here today. But as human-driven climate change accelerates, looking back at how ecosystems once responded to drastic climate swings could help prepare us for what lies ahead.
Now, a major gap in our understanding of one key Ice Age period has been filled thanks to a rare discovery: the remains of 46 animal species from around 75,000 years ago, uncovered in a little-explored cave in northern Norway.
Researchers from Norway and the UK say that studying how wildlife once adapted, or failed to adapt, to sudden climate shifts is vital for conservation efforts today. Their findings were published in PNAS.
Bone Treasure Trove in a Cave
According to the study, sedimentary records older than 10,000 years are extremely rare in glaciated regions like the Arctic. So, when researchers began excavating Arne Qvamgrotta, a remote cave in Northern Norway, they hit a goldmine: They found remains of polar bears, walrus, bowhead whales, Atlantic puffins, rock ptarmigans, Atlantic cod, and many more, dating back 75,000 years.
“We have very little evidence of what Arctic life was like in this period because of the lack of preserved remains over 10,000 years old,” said senior author Sanne Boessenkool, a professor at the University of Oslo, in a press release. “The cave has now revealed a diverse mix of animals in a coastal ecosystem representing both marine and terrestrial environments.”
The team also discovered a species never before found in Scandinavia: the collared lemming, a cold-adapted rodent that disappeared from Europe around 11,000 years ago, at the end of the last Ice Age.
Read More: These Ice Age Puppies Were Actually Wolves
An Arctic Oasis in a Changing Climate
The animal variety suggests that after glaciers melted, the Norwegian coast became a largely ice-free haven. It supported migratory reindeer, inland lakes and rivers teeming with freshwater fish, and coastal waters with seasonal sea ice, suitable for both bowhead whales and ice-avoiding harbor porpoises.
DNA testing showed that many of these animals did not survive when the cold returned. Unable to migrate as ice once again covered the land, entire populations disappeared. The study paints a picture of an Ice Age Arctic that looked quite different from the iconic woolly mammoths and saber-toothed cats of glacial megafauna fame.
During the last glacial period (roughly 118,000 years to 11,700 years ago), the Arctic underwent dramatic ecological reshuffling, driven by cycles of glacial advance, retreat, shifting sea levels, and sea ice expansion. Radiocarbon dating of bones and sediments in the cave helps researchers trace how wildlife responded to these upheavals.
Cold-Adapted Species in Today’s Warming World
“These discoveries provide a rare snapshot of a vanished Arctic world,” said lead author Sam Walker of Bournemouth University and the University of Oslo in the press statement. “They also underscore how vulnerable cold-adapted species can be under changing climate conditions, which can help us to understand their resilience and extinction risk in the present.”
Importantly, Boessenkool noted that the ancient climate shift documented in the cave was from warmer to colder. Even then, cold-adapted species struggled. Today, with rapid warming, those same species face even greater threats.
“This highlights how cold adapted species struggle to adapt to major climatic events. This has a direct link to the challenges they are facing in the Arctic today as the climate warms at a rapid pace,” said Walker. “The habitats these animals in the region live in today are much more fractured than 75,000 years ago, so it is even harder for animal populations to move and adapt.”
Read More: How Ice Age Humans Mastered Fire During the Coldest Era in History
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Having worked as a biomedical research assistant in labs across three countries, Jenny excels at translating complex scientific concepts – ranging from medical breakthroughs and pharmacological discoveries to the latest in nutrition – into engaging, accessible content. Her interests extend to topics such as human evolution, psychology, and quirky animal stories. When she’s not immersed in a popular science book, you’ll find her catching waves or cruising around Vancouver Island on her longboard.
