"Talk about a long nap. Scientists said they have revived worms buried in Siberian permafrost for 46,000 years.
The half-dozen creatures, a type of nematode or roundworm, were last awake when Neanderthals and woolly mammoths roamed the Earth. They survived for millennia in permafrost by entering a state of suspended animation, according to a paper published Thursday in the journal PLOS Genetics. Genetic testing suggests the worms are a newly discovered species, researchers said.
"This paper could make people consider this third condition between life and death," said Teymuras Kurzchalia, co-author of the study and a biologist at the Max Planck Institute of Molecular Cell Biology and Genetics in Germany.
Nematodes are among so-called microanimals that can survive extreme conditions including being frozen or deprived of water and oxygen by entering a state called cryptobiosis. In that state, an organism's metabolism comes to a halt and it stops reproducing, developing and repairing itself. When conditions improve, it can revive.
Scientists have awoken nematodes after long periods of cryptobiosis as well as rotifers, microscopic aquatic creatures, and tardigrades, tiny eight-legged animals also known as water bears. A rotifer was rejuvenated after being trapped in Siberian permafrost for some 24,000 years, according to a 2021 study in the journal Cell. Tardigrades found locked in frozen moss in Antarctica were revived after about 30 years of cryptobiosis, a 2016 paper in the journal Cryobiology reported.
A protein thought to be unique to tardigrades has been shown to protect their DNA from damage, and introducing the protein to human cells has made them more resistant to radiation damage.
Single-celled organisms including bacteria have been shown to spend millions of years in a state of cryptobiosis but 46,000 years is a record for animals. "Cryptobiosis in this organism could be indefinite," Kurzchalia said.
Could the secrets of cryptobiosis help people survive being frozen or hurtled into outer space? That remains in the realm of science fiction, scientists said, but further study could reveal mechanisms such as the workings of genes or proteins that help cryptobiotic creatures survive in extreme conditions. Such insight could one day be harnessed to make people more resilient, researchers said.
"Perhaps you can develop molecules that achieve the same things," said Craig Marshall, a biochemist at the University of Otago in New Zealand who wasn't involved in the study.
The revived nematodes were found in permafrost some 130 feet underground near the Kolyma river in eastern Russia. Researchers collected samples of the permafrost in the early 2000s and kept them frozen.
Reanimation of the nematodes was first described in a 2018 paper in the journal Doklady Biological Sciences. Researchers said they placed the frozen nematodes in petri dishes with a nutrient solution and kept them at about 70 degrees Fahrenheit for several weeks. Some nematodes awakened and started reproducing. Carbon dating determined permafrost the nematodes were found in was 30,000 to 40,000 years old, the paper said. Biologists said at the time that the samples could have been contaminated.
The new paper's authors said they tested the samples more rigorously to confirm the earlier finding and to learn more about the ancient nematodes. The permafrost samples were carbon-dated again and shown to be around 46,000 years old, the researchers said.
They conducted genome sequencing and phylogenetic analysis, a study of evolutionary relationships among organisms. The analyses suggested the nematodes are a newly discovered species in the Panagrolaimidae family of roundworms. They named the nematodes Panagrolaimus kolymaensis after the river near where they were found. None of the reanimated worms are still alive but they have progeny from asexual reproduction, researchers said.
The progeny appear to use a sugar called trehalose to guard against stressors such as dehydration, the study showed. Research in other nematodes has shown that trehalose freezes into a glasslike substance that can protect cells.
Byron Adams, a biologist at Brigham Young University and who wasn't involved in the study, said contamination was still possible because areas near the collection site and sampling equipment weren't tested to ensure younger nematodes weren't collected by mistake. Still, he said the findings were plausible.
"If I were a betting man, I would bet that it could actually happen and these things really are this old," he said." [1]
Still I think, electing normal politicians in Lithuania is a better bet.
1. After 46,000 Years, Worms Live Again. Mosbergen, Dominique.
Wall Street Journal, Eastern edition; New York, N.Y. [New York, N.Y]. 28 July 2023: A.1.
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