After being frozen in Siberian permafrost for 46,000 years, an ancient worm has reanimated, marking an impressive revival for these hardy creatures known as nematodes. These microscopic organisms, commonly referred to as roundworms, were in a dormant state since the late Pleistocene era, approximately 45,839 to 47,769 years ago, as indicated by radiocarbon analysis. This remarkable endurance is matched by their newfound species identity: Panagrolaimus kolymaensis.
Nematodes are exceptional survivors, enduring extreme conditions by entering a state known as “cryptobiosis,” wherein all measurable metabolic processes cease until the environment becomes more favorable. A similar instance occurred in 2018 when nematodes were revitalized after an estimated 42,000 years of cryptobiosis. This recent discovery extends that timeline by several millennia.
Tardigrades and rotifers are among the other organisms capable of such remarkable feats. An astonishing case involved a bacterial spore found preserved in amber for a span of 25 to 40 million years.
By utilizing radiocarbon analysis on the plant material found within the permafrost samples, researchers determined their origin to be in the late Pleistocene period. Furthermore, through genomic analyses of the nematodes, it was established that these creatures belong to a previously unidentified species.
“These findings have implications for our understanding of evolutionary processes, as generation times may be stretched from days to millennia, and long-term survival of individuals of species can lead to the refoundation of otherwise extinct lineages,” the authors conclude.
The study is published in PLOS Genetics.