Researchers analyze ancient DNA to reveal how Adélie penguins adapted to climate change
A groundbreaking study of ancient sedimentary DNA (sedaDNA) has provided a 6,000-year glimpse into the lives of Adélie penguin colonies along Antarctica’s Ross Sea coast. The research, published in Nature Communications, offers new insights into how these birds—and the ecosystems they belong to—have responded to environmental changes over millennia.
The international team of scientists sequenced 156 sediment samples, uncovering genetic traces of penguins, seals, fish, and other species that interacted with them throughout history.
A changing diet and ecosystem
One of the key discoveries was that Adélie penguins haven’t always relied on the Antarctic silverfish as their primary food source.
“Four thousand years ago, the bald notothen, a cryopelagic fish, was a major part of their diet,” said Dr. Jamie Wood, lead author and ecologist from the University of Adelaide. “Its decline in the southern Ross Sea—likely due to shifting sea ice conditions—forced the penguins to adapt to new food sources.”
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Another surprising find was evidence of southern elephant seals breeding on Cape Hallett over 1,000 years ago.
“It was a complete surprise,” said Dr. Chengran Zhou of BGI Research, Wuhan. “Until now, we had no evidence that these seals ever lived on the Antarctic mainland. Our DNA analysis has rewritten that history.”
A window into the past—and the future
By studying biological records spanning thousands of years, researchers hope to better predict how species will respond to modern climate change.
“Looking at long-term environmental and climate trends gives us crucial insights into species resilience,” said Dr. Theresa Cole of the University of Adelaide. “This helps us refine conservation strategies for Antarctic wildlife facing rapid change today.”
Unlocking deeper secrets of Antarctica’s past
The study’s findings suggest that even older DNA—potentially hundreds of thousands of years old—could still be preserved in Antarctic sediments.
“The preservation quality of the 6,000-year-old DNA is remarkable,” said Professor Guojie Zhang of Zhejiang University. “This opens the door for future discoveries that could stretch even further back in time.”
With continued advances in sedaDNA technology, researchers anticipate even more unprecedented insights into Antarctica’s ecological past—helping to shape its future.
