Scientists visiting Ellesmere Island in the Canadian Arctic discovered something remarkable and fascinating .

Led by Catherine LaFarge, a geologist from the University of Alberta in Edmonton (Canada), they were exploring an area called the Sverdrup Pass, which until just recently had been covered by ice. The Teardrop Glacier had spread all across Ellesmere Island during the Little Ice Age, a global cold spell that affected weather and climate conditions in the Northern Hemisphere between 1550 and 1850.

While trudging across newly exposed ground, the scientists found clumps of moss that were mostly browned or blackened. But in among this dead plant life were some spots of green, indicating that a process of regeneration and regrowth had started to occur.

This was remarkable, because LaFarge and the other scientists knew they were not looking at moss that had grown recently. What they’d discovered had originally lived and died several hundred years ago, and it had been trapped beneath the ice for several centuries. Incredibly, moss that had been buried and frozen solid beneath the Teardrop Glacier had begun to regenerate, as if it hadn’t been affected by its centuries-long entombment at all.

LaFarge was able to identify these moss samples as bryophytes, which are extremely resilient plants that have been on Earth for millenia. They are vital contributors to the health and vitality of polar ecosystems, playing a role in their creation and maintenance. They’d been hardy enough to survive in the harsh Arctic climate in the first place, and now that warming trends had exposed them to the open air they had sprung to life once again. They had likely been exposed to the open air for about two years by the time they’d been discovered by the Canadian scientists.

The scientists took samples of the bryophytes back to their laboratory for further study and experimentation. Radiocarbon dating methods confirmed that the moss was approximately 400 years old, yet its ability to produce new life had not been extinguished by the trauma it had experienced.

To test its potency, LaFarge and her team sliced the moss into sections and placing them in controlled environments where light, temperatures and nutrition were ideal for growing. Eventually, seven out of 24 samples sprouted new plants, which to all appearances were perfectly healthy and vibrant.

As LaFarge explained, new moss doesn’t grow from seeds or spores, but from individual plant cells that can create copies of themselves directly. This unique quality may contribute to moss’s ability to regenerate quickly and robustly, even after being placed in suspended frozen animation underneath a glacier for more than four centuries.

More Moss Miracles

This important discovery forced biologists to revise their ideas about the ability of life to survive frozen conditions. But as remarkable as this finding was, scientists affiliated with the British Antarctic Survey and Reading University did their Canadian counterparts one better .

In 2014, just one year after the Ellesmere Island discovery, the British scientists retrieved moss samples from deep inside a frozen moss bank found on the Antarctic tundra. Using radiocarbon dating, they discovered the moss was approximately 1,500 years old. But despite its tremendous antiquity, when the plants were sliced into sections and placed inside an incubator, after a few weeks they, too, began to regenerate.

Even after suffering through the deepest of deep freezes in the coldest continent on our planet, these moss samples had not lost their capacity to regenerate when given enough light, water and nutrition.

“This experiment shows that multi-cellular organisms, plants in this case, can survive over far longer timescales than previously thought,” said Professor Peter Convey, one of the lead scientists involved in this study. “These mosses, a key part of the ecosystem, could survive century to millennial periods of ice advance.”

“If they can survive in this way,” he continued,” then recolonisation following an Ice Age, once ice retreats, would be a lot easier than migrating trans-oceanic distances from warmer regions. It also maintains diversity in an area that would otherwise be wiped clean of life by the ice advance.”

And while the idea may seem farfetched, Convey mentions another possibility that has probably occurred to everyone who has heard this story.

“Although it would be a big jump from the current finding, this does raise the possibility of complex lifeforms surviving even longer periods once encased in permafrost or ice.”

Convey doesn’t specify what he means by “complex lifeforms.” But it boggles the mind to think about what might be buried under the glaciers that cover the polar realms. One thing we know for sure is that thanks to global warming, much of the land that is currently ice covered above the Arctic Circle and near the South Pole may eventually be exposed.

Could Rampaging Viruses —or Vegetable Men —Be Next?

There are many science fiction movies that feature the reanimation of living creatures frozen solid in ice. In 1951’s “The Thing from Another World,” a man-eating, six-foot tall vegetable from another planet, originally encased in a block of ice, terrorizes the occupants of an Arctic research station after accidentally being thawed out by an electric blanket. In 1967’s “The Frozen Dead,” a mad scientist thaws and resuscitates Nazi soldiers he’s kept stored on his English country estate, unaware that they’ve been converted into bloodthirsty zombies.

Far-out storylines like this might appear to have no connection to defrosted and revived moss. But just because moss is benign, that doesn’t mean there aren’t dangers inherent in thawing out lifeforms that lived in others epoch. Some of these lifeforms could very well represent a threat to the health and safety of humanity, and scientists should think carefully about the possible ramifications before opening Pandora’s box and reviving everything they can find.

In the real world, the concern is not so much about frozen animals, Neanderthals, or aliens from crashed spaceships. The real fear is that scientists might mistakenly activate long-dormant viruses or bacteria that we would have no capacity to resist. As human activity continues to heat the planet, the thawing of the tundra in Siberia and the retreat of the glaciers inside the Arctic Circle and in Antarctica could release and reactivate hidden and potentially lethal microorganisms. If such a scenario were to be realized, we could be exposed to hazards that might be even more deadly than Nazi zombies or alien vegetable-men.

The possibility of such an event is not strictly theoretical. In 2014, a group of French scientists revived an ancient virus found frozen in a soil sample taken from 30 metres below the icy tundra of eastern Siberia. Dubbed Pithovirus Sibericum , this gigantic virus was far larger and more complex than the viruses we see today, and is believed to evolved entirely separately from modern infectious agents.

Fortunately, this virus was found to be harmless to humans. But the next one or the next one after that could be lethal, and if humans are unwittingly exposed to it because of thawing tundra there is no telling how much damage it might do.

Top image: Regenerating moss. Credit: mllevphoto / Adobe Stock

By Nathan Falde