A group of
scientists in Russia claim to have revived a pair of frozen nematodes, or
roundworms, that were between 30,000 and 42,000 years old. One of the specimens
was found in a soil sample collected from a ground squirrel burrow located
around 100 feet underground, and other burrows nearby have been radiocarbon
dated to be around 32,000 years old.
A second
viable nematode was found in a permafrost sample approximately 41,700 years old
collected around 11 feet below the surface. The samples were stored in a
laboratory at around -4 degrees Fahrenheit. Isolated nematodes were then later
brought up to 68 degrees and surrounded by food. After several weeks of
cultivation, the nematodesbegan showing signs of life and reportedly began
moving and eating.
"Thus,
our data demonstrate the ability of multicellular organisms to survive
long-term (tens of thousands of years) cryobiosis under the conditions of
natural cryoconservation," the researchers said in a study published in
Doklady Biological Sciences.
While other
studies have shown that some species of nematodes can survive extreme
environments -- such as 25.5 years in below-freezing temperatures and 39 years
of dessication -- this study appears to be the first to demonstrate nematode
survival after such an extreme length of time.
"Theoretically,
it is possible that if the organisms are protected from physical damage that
would compromise their structural integrity during their frozen internment,
they should be able to revive upon thawing/rehydration for very long periods of
time," Robin Giblin-Davis, director of the University of Florida's Fort
Lauderdale Research and Education Center, told Gizmodo. But there's still a
chance these nematodes aren't what they seem. "The biggest issue is the
potential for contamination of 'ancient samples' with 'contemporary'
organisms," he added.
The
researchers say they maintained proper sterility procedures during the
collection and transportation of their samples and noted that seasonal thawing
wouldn't have reached the depths at which these nematodes were found, severely
limiting sample movement or the introduction of present-day nematodes. If these
findings are legitimate, they could help researchers understand how some
species survive such extreme temperatures and how these particular nematodes
have evolved over time.
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