40,000-year old worms revived from Siberian permafrost

Scientists have managed to revive worms (similar to the one pictured) that were frozen in the...
Scientists have managed to revive worms (similar to the one pictured) that were frozen in the Siberian permafrost for up to 42,000 years (Credit: K-State Research and Extension/CC BY 2.0)

The Siberian permafrost is famous for preserving the remains of life from the Pleistocene period, but it’s really outdone itself this time. Two worms frozen for around 40,000 years have now been thawed and revived, making them the oldest living creatures on the planet and the first multicellular organisms to have survived such long-term cryobiosis.

After gathering and analyzing over 300 samples of permafrost deposits, the team found that two of them contained viable specimens of soil nematodes (worms). One of these samples was taken from a ground squirrel burrow in the Duvanny Yar outcrop, which has previously been radiocarbon dated to about 32,000 years. The second sample was a drilled ice core from a glacial deposit near the Alazeya River, which corresponds to around 41,700 years of age.

After years of sitting in cold storage in a lab at -20° C (-4° F), the samples were defrosted in a Petri dish with an enrichment culture to promote their growth. They were warmed at 20° C (68° F) for a few weeks and sure enough, the nematodes began to move again, as well as chowing down on E. coli that had been added as a food source.

“Our data demonstrate the ability of multicellular organisms to survive long-term (tens of thousands of years) cryobiosis under the conditions of natural cryoconservation,” say the scientists in a statement. ‘It is obvious that this ability suggests that the Pleistocene nematodes have some adaptive mechanisms that may be of scientific and practical importance for the related fields of science, such as cryomedicine, cryobiology, and astrobiology.”

Scanning electron microscope images of the revived nematodes

The two worms, both female, are now the oldest living things on the planet by quite a wide margin. This kind of cryobiosis has been known to work for single-celled organisms such as bacteria and amoeba, and the seeds of certain plants have been viable after years of being frozen, but the nematodes represent the first time multicellular organisms have been able to be revived.

Still, these worms are very simple creatures, and as amazing as the find is we’re not likely to be able to mimic the effects to help preserve or revive ourselves or other large animals. The best we might be able to achieve is a revival of Pleistocene creatures like the woolly mammoth, through a Jurassic Park-style mix of cloning and cross-breeding.

The research was published in the journal Doklady Biological Sciences.

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