Scientists revived 24,000-year-old bdelloids, blowing away prior research which suggested such rotifers could survive for a decade in a deep freeze. Then, began reproducing through parthenogenesis, a clonal process. As an all-female cloning species, they can take incredible torture and keep going.
“They’re the world’s most resistant animal to just about any form of torture,” said Matthew Meselson, a molecular biologist at Harvard University.
Russian scientists at the Soil Cryology Laboratory, Institute of Physicochemical and Biological Problems in Soil Science, in Pushchino, Russia, made the find in a new study.
“Our report is the hardest proof as of today that multicellular animals could withstand tens of thousands of years in cryptobiosis – the state of almost completely arrested metabolism,” said study author Stas Malavin.
Once again, truth appears stranger than fiction.
“The takeaway is that a multicellular organism can be frozen and stored as such for thousands of years and then return back to life – a dream of many fiction writers.'”
Bdelloids Versus Tardigrades
It seems the bdelloids, an all-female asexual species, have knocked the tardigrades (water bears) off the top of the list for the “world’s toughest creature.” So far, it’s known that tardigrades can survive frozen in suspended animation (cryptobiosis) for at least 30 years.
Will the tardigrades prove as adaptable one day? Possibly, but for now, the bdelloids take the lead by a vast margin.
However, a plant has proven even more adaptable. As the study states, scientists regenerated campion plants from seed tissue preserved in 32,000-year-old permafrost. Therefore, the campion is the champion.
In 2012, the Times reported the campion was “the oldest plant by far that has ever been grown from ancient tissue.” By comparing the ancient and living campions, scientists could “study evolution in real-time.”
Previously a 2000-year-old date palm grown from an ancient seed held the record.
Animals That Lived With Woolly Mammoths
Thousands of years ago, the bdelloids were moving around at the time when Woolly Mammoths were alive in Siberia.
“We revived animals that saw woolly mammoths,” said Stas Malavin, a co-author and scientist at Russia’s Institute of Physicochemical and Biological Problems in Soil Science, “which is quite impressive.”
First, scientists drilled 11 feet down into the Siberian permafrost, where temperatures hover around 14 degrees Fahrenheit. Then, they used radiocarbon dating that showed the rotifers were 24,000-years-old. Nevertheless, the creatures were alive and able to reproduce.
Notably, these microscopic creatures are all around us on the ground, in puddles, gutters, and anywhere there’s moisture. At only 0.008 of an inch, you need a microscope to view them.
As adaptable as bdelloids are, scientists don’t know how they survive. Somehow, they can restore damaged DNA and may even survive in space.
Along with the ancient bdelloids, the researchers found living nematode worms. Now, the researchers will continue to search for other tiny animals that can withstand long-term cryptobiosis.
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Bdelloids are tiny aquatic creatures that can survive radiation and years of desiccation, similar to tardigrades. Notably, there are about 400 species of these creatures living in fresh and brackish waters worldwide. As tiny as they are, they have guts, brains, muscles, and reproductive systems.
“In Mother Nature’s edition of the TV reality show Survivor, the bdelloid rotifers would probably be the last animals standing,” writes Science.
Amazingly, they can survive drying up completely in the soil or sewage-treatment tanks.
“For perhaps 80 million years, all bdelloids have been shes, contentedly reproducing without males — and defying biologists’ ideas about the centrality of sex,” Science reported.
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Bdelloids: ‘An Evolutionary Scandal’
Furthermore, they have survived for millennia without sex, appropriating genes from fungi, bacteria, and plants like a “genetic mosaic.” In one 2008 study, scientists found a bdelloid adopted DNA from 500 other species. However, it wasn’t clear how the creatures were obtaining the foreign DNA.
“We have a joke in the lab that every time you investigate these animals … they come out with something weird,” molecular biologist Alan Tunnacliffe said. “It’s like they’re here to keep us entertained and surprised.”
Today, it seems Tunnacliffe was correct, and the bdelloids continue to impress with their incredible durability and adaptability.
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