New Species of Nematode Still Alive After 46,000 Years in Permafrost

Scientists find that roundworms in Siberian permafrost that are still alive after 46,000 years belong to a new species

Gunnar De Winter
Predict
Published in
3 min readFeb 6, 2022

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C. elegans (National Human Genome Research Institute)

What lurks in the ice?

Since the 1980s, we’ve been able to extract DNA from long-gone organisms, so-called ancient DNA. The first big leap in ancient DNA sequencing came in 1984 when a bit of genetic material from a Quagga — a subspecies of zebra that went extinct in the late 19th century — was extracted from a museum specimen and sequenced 150 years after the Quagga had died.

150 years? Puh, that’s nothing compared to what we can do today.

The next big leap came in 2013. Pleistocene horse DNA over 500,000 years old was extracted from bones found in the permafrost of Canada’s Yukon territory.

And just last year, we may have broken the 1 million year mark with mammoth DNA extracted from molars found in the Siberian permafrost.

There’s a common theme here. Cold.

As soon as an organism dies, its DNA begins to unravel (‘denature’). This process is temperature-dependent. The hotter it gets, the quicker the unraveling. The reverse is also true. The colder it gets, the slower the process.

But ancient DNA is just that, chunks of DNA. What about actual organisms? You may have heard about bacteria and viruses of around 15,000 years old uncovered in glacier ice, for example.

A new study does one better: 46,000-year-old nematodes found in Siberian permafrost. That belong to a new species. And wiggle when they wake up.

(Note: the study is a preprint, so not yet peer-reviewed.)

Suspended animation

Before we go back to the mid-Eocene, let’s start the way the study’s authors did: by showing that larvae of Caenorhabditis elegans — a common and very popular roundworm species in scientific research — can enter cryptobiosis for a very long time.

Think of cryptobiosis as supercharged hibernation. During inhospitable times, animals capable of cryptobiosis can (almost) completely stop all metabolic…

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