A roundworm that had been in deep freeze for 46 millennia was revived in a lab and reproduced.
Scientists recently reexamined the worm, which had been in suspended animation in Siberian permafrost and was first discovered in 2002. Initially, the worm was estimated to be 42,000 years old, but scientists later realized they were off by a “few” years, according to Scientific American.
Several roundworms were found in more than 300 samples of the permafrost “spanning different ranges and genesis” in a fossil burrow left by arctic gophers, the study’s authors said.
The creature’s hibernation is a “state of suspended metabolism called cryptobiosis,” according to a study published in the journal PLOS Genetics.
Looking at the plant matter found in the area, the scientists said the worms, called Panagrolaimus kolymaensis, had been frozen for 46,000 years. They added that the worm was a new species of nematode. Nematodes are among the most common life forms on the planet, living in the dirt, water and on the ocean floor, The Washington Post reported.
There are so many nematodes that haven’t been “described,” nematologist William Crow told the newspaper via email. Crow was not part of the study that worked with the organism.
He said that the one being studied may have gone extinct, “However, it very well could be a commonly occurring nematode that no one got around to describing yet.”
The worms were reanimated by slowly warming the soil, being careful not to cook the nematodes when they started moving, eating and reproducing, The Washington Post reported. They multiply without a mate through parthenogenesis.
The original one dug up from the permafrost has since died, but scientists have raised more than 100 generations from it, the newspaper reported.
Not everyone agrees with the study’s findings, saying that while the organic material used to date the samples could be 46,000 years old, the worms may be modern contamination.
Byron Adams, a biologist at Brigham Young University, discounts the findings, but added that there’s a chance they could be right.
“I would love to believe that the animals they are describing have survived being frozen for 40,000 years in permafrost,” Adams said, according to Scientific American. “And if I were a betting man, I would bet that it could actually happen, and these things really are this old.”
Adams said the dating confirms that the organic material was as old as testing found, but the worms may not be.
“The authors haven’t done the work to show that the animals they have recovered are not simply surface contaminants,” he said.
The study said there have been organisms that have survived much longer than this roundworm, with a spore preserved in the abdomen of bees in amber for 25 to 40 million years.
