Tardigrades are up against some tough competition in the world of microscopic creatures. Bdelloid rotifers, like tardigrades, can withstand drying, freezing, starvation, and even low-oxygen circumstances. Scientists claim to have resurrected some of these rotifers after they had been frozen for at least 24,000 years in Siberian permafrost.
The amazing findings were published in the journal Current Biology. The researchers retrieved permafrost samples that were about 3.5 meters (11.5 feet) deep and gently warmed them, resulting in the resurrection of a variety of microscopic species, including these tiny mammals.
In a statement, co-author Stas Malavin of the Institute of Physicochemical and Biological Problems in Soil Science in Pushchino, Russia, said, “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.”
The team specializes in studying frozen organisms in permafrost and extracted this sample with great care. Given the creatures’ tenacity, it was critical to ensure that the sample was free of contamination from more recent strata. Other independent methods, like as radiocarbon dating, were used to determine the age of the permafrost and the organisms trapped beneath it.
When frozen, rotifers have been known to live for up to ten years, according to scientific literature. Clearly, the mechanism that allows them to resist such conditions is superior to what was previously believed to be conceivable.
Scientists are baffled as to how the critter and other similar species defend their cells and organs from ice crystals formed during the freezing process. The monsters should be dismantled, but they aren’t. As these small animals progressively freeze, something strange must be occurring to them.
“The conclusion is that a multicellular organism can be frozen and stored for thousands of years before being brought back to life – a dream of many fiction writers,” Malavin continued. “Of course, the more complex the organism, the more difficult it is to keep it alive frozen, and this is currently not conceivable for mammals. Even if the transition from a single-celled organism to one with a gut and a brain is minuscule, it is a significant stride forward.”
The found rotifers were not only able to return to the living world, but they could also reproduce asexually via parthenogenesis. The researchers will continue to investigate the permafrost to see if other animals possess comparable abilities and to learn more about the mechanisms that allow an organism to survive frozen for thousands of years.