46,000-year-old worms discovered on Arctic expedition. Now they’re being revived

While the great pyramids were being erected, they slumbered. The Roman Empire came and went, and they carried on napping. In fact, they slept through all recorded human history.

They’re a group of roundworms, and they’ve been lying dormant in the Siberian permafrost for 46,000 years — until now.

The worms, known as nematodes, just woke up. Scientists coaxed them out of cryptobiosis, a state of metabolism cessation that can occur in extreme environments, according to a study published on July 27 in the journal PLOS Genetics.

Their awakening has “implications for our understanding of evolutionary processes, as generation times may be stretched from days to millennia,” scientists, who are affiliated with research institutes in Europe, said.

The worms’ epic snooze also begs the question: Just how long can organisms survive, given the right conditions?

Discovering the ancient worms

Researchers first came upon the worms while exploring a stretch of permafrost — a layer of perennially frozen soil — north of the Arctic Circle in eastern Russia.

The creatures were nestled inside a chunk of soil found about 130 feet below the surface alongside ice wedges and gopher burrows. Using radiocarbon dating, researchers determined the soil dates to the late Pleistocene era and is around 46,000 years old.

Upon sequencing the worms’ genome, researchers realized the creatures were members of a previously unknown species of nematode. The new nematodes were named Panagrolaimus kolymaensis after a river which they were found near.

While invisible to the naked eye, nematodes are everywhere. They’re found on every continent and throughout the ocean. “Almost any shovel full of soil, freshwater or marine sediment is likely to have thousands of worms including new species,” according to the University of California, Riverside’s Department of Nematology.

Waking up the worms

While the process of cryptobiosis is complicated and not well understood, easing individuals out of it is more straightforward, researchers said.

“Slow gradual thawing at room temperature is done, as it would happen in spring in nature,” Philipp Schiffer, one of the study’s authors, told McClatchy News.

With a little warm air, and some added water, the ancient nematodes bounced back to life.

The reanimated creatures were then given E. coli bacteria to snack on. Afterward, they even broke their multi-millennium-long dry spell and resumed reproductive activity, which resulted in the production of offspring.

This isn’t the first time such a feat has been accomplished. Other organisms have been known to enter cryptobiosis, researchers said, including a lotus seed dating back at least 1,000 years that was able to germinate.

But when it comes to nematodes, the newfound species are by far the oldest ever to be resuscitated. Before this discovery, the longest known period of cryptobiosis for a nematode was only several decades.

The worms’ lengthy sleep, spanning geological time frames — once thought to be the stuff of science fiction — will likely be used to advance research into longevity.

“These organisms have evolved a way to protect their cells, proteins, (and) DNA in very stressful conditions,” Schiffer said. “They stop cells, proteins, DNA from degrading. Such degradation happens when humans age.

“If we dig deeper into the genetics of what these species do doing cryptobiosis, we might find new avenues to understand human aging and maybe develop new drugs in the future that help people during old age.”

This story was originally published July 28, 2023 at 3:04 PM with the headline "46,000-year-old worms discovered on Arctic expedition. Now they’re being revived."