28 July 2023 By CARLY CASSELLA
“An international effort to revive an ancient roundworm, frozen in Siberian permafrost for millennia, has unleashed a lifeform even older than scientists once thought.
“In 2018, several resurrected nematodes, of the genus Panagrolaimus, were dated to around 32,000 years old. But now, more precise radiocarbon dating suggests these soil worms have remained ‘dead awake’ in parts of Siberia since at least the late Pleistocene, around 46,000 years ago.
“If correct, the record absolutely smashes the longest known state of extreme inactivity observed among animal life, a phenomenon known as cryptobiosis.
“After reviving the frozen worm in the lab and cultivating it for over 100 generations, researchers, led by experts at the Max Planck Institute in Germany, ran a genome analysis.
“They claim this creature is a newly recorded species, which they call Panagrolaimus kolymaensis.
“To date, scientists know of very few animals capable of suspending themselves in a limbo-like state in response to tough environmental conditions.
“Tardigrades, nematodes, and microscopic aquatic organisms, called rotifers, are just a few of the animals known to enter cryptobiosis. For all we know about the unique state of life, these animal could very well remain in this desiccated, or dried out, state ‘indefinitely’ – or at least until conditions are better for survival.
“The longest recorded time spent in cryptobiosis among living worms is only 39 years.
“Even tardigrades have only re-entered their normal metabolic state after 30 years of a frozen one.
“The new crytobiosis queen is tens of thousands of years older than that.
“The ancient worm was found in Siberian permafrost, roughly 40 meters deep. When researchers dated some plant material found near the creature, they settled on an initial freezing period somewhere between 45,839 and 47,769 years ago…”
Read the full article here.