Scientists have successfully revived one of the smallest frozen animals, from the 24,000 year-old permafrost in Siberia. Known as Bdelloid rotifer, this animal is microscopic and multicellular and can endure some of the toughest conditions and resist the harshest radiations. The group of scientists published their experiment and its results in the Current Biology journal earlier this month.
For their study the team of international scientists recovered the animal from northeastern Siberian permafrost. This constituted the longest reported case of rotifer survival in a frozen state. The study mentions that the researchers confirmed their finding by identifying rotifer actin gene sequences in a metagenome obtained from the same sample. On comparison of the DNA samples, the morphological and molecular markers showed that the discovered rotifer belonged to the genus Adineta, and aligns with the modern day animal Adineta vaga isolate collected from Belgium.
The study described the Ice Complex of the permafrost from which the rotifer was extracted as well developed with wide distribution of ice wedges, and occasional finding of well-preserved mammal mummies that supported its syncryogenetic formation. Syncryogenetic formation happens when layers of sediments are frozen relatively quickly after its creation and are never melted. Scientists also found that no significant vertical movement by the rotifer could have occurred in the studied sediments and the isolated microbes were likely trapped in permafrost at the same time as the radiocarbon-dated organics. After its extraction, the rotifer was thawed and brought back to life and was even able to reproduce through parthenogenesis.
The study has brought new information in the world of zoology and evolution. Rotifers ability to withstand such inhospitable conditions for so long. The evolution of rotifers through asexual reproduction has also presented scientists with new questions.
This is not the first time that a living organism was brought back to life after it remained frozen for years. In an earlier research, stems of Antarctic moss were successfully regrown from a 1000-year-old sample covered by ice for about 400 years. While, whole campion plants were regenerated from seed tissue preserved in relict 32,000-year-old permafrost.