Animals resurrected in permafrost after 24,000 years

For 24,000 years, they offered their time in the permafrost of Siberia, but now crawling Rotifer thawed again. An international team of scientists led by the Russians managed to thaw frozen rotifers in the soil alive. They have achieved their achievement Announced this week at current biology.

Rotifers or rotifers are microscopic animals. They get their name from the rotating discs with which they suck the water from which they filter bacteria. There are free-swimming and stick-to-foot types.

Remarkably, a multicellular animal can survive such prolonged freezing. When freezing, the cells of most animals are irreparably damaged by the growth of ice crystals. Some animals can withstand frostbite in a state of crypts or suspended animation, in which their metabolism stops completely. Once the temperature rises again, they can resume life.

thaw alive

Previous research has already shown that rotifers can survive six years from frostbite. British researchers thaw in 2005 is a rotor from the freezer that was actually collected in Antarctica in 1999. Some of the same researchers were also involved in Research From 2018, the 30,000-year-old nematode worms were thawed alive.

Rotifers were frozen at the bottom of the Siberian tundra at about seventy degrees north, near the bank of the Alazia River. From a depth of half a meter, the ground there freezes all year round, with an average temperature of less than ten degrees Celsius.

The rotifers were dug out of the ground to a depth of 3.5 meters. Because the soil at the edge of the cores had thawed, the researchers scraped layer by layer until only the frozen core remained. Carbon dating indicates that the soil is 25,000 years old.

average crystal crystals

Then the researchers implanted a piece of the drill core. A week later, life was visible, and a month later, researchers saw dozens of rotifers. Four more rotis can be bred. The descendants of these rotifers could also have been refrozen and thawed alive again.

Little is known about how rotifers survive frostbite. The researchers noted that as long as the freeze was gradual, the animals could apparently resist the growth of perforated ice crystals.

Rotifers from the time of the mammoth are harmless. But can dangerous bacteria or viruses emerge from permafrost? In a review article published last month figuredResearchers find that the risk is small. Arctic residents have more to fear than people who bring in pathogens from elsewhere.