Cosmos newsroom journalists look back at the most popular stories of 2023.
Our world is undoubtedly warming.
But while we try and turn the ship around, the permafrost slowly melts, uncovering more and more organisms and compounds from under the ice.
In August, European researchers published a paper showing they revived a 46,000 year-old Siberian roundworm preserved in permafrost.
The animal was collected from the frozen burrow of Arctic gophers located about 40 metres below the surface, in never-thawed late Pleistocene permafrost in the northeastern Arctic. Researchers used radiocarbon analysis of nearby plant material to determine the worm’s age as around 46,000 years old.
Roundworms, or nematodes, are known for their ability to survive long periods of time in cryptobiosis – a state of suspended metabolism – enabling animals to survive desiccation and freezing.
But previously known records for cryptobiosis in nematodes were much lower – about 25 years for an Antarctic species Plectus murrayi and 39 for freshwater species Tylenchus polyhyphus.
Also in August, researchers revealed a 70-million-year-old dinosaur track site about the size of a soccer field discovered in Alaska.
Dubbed “The Coliseum” by the researchers who discovered it, the site in the Denali National Park and Preserve is the largest single dinosaur track site in the US state.
The Coliseum contains the footprints of multiple species of dinosaur spanning many generations who roamed interior Alaska toward the end of the Cretaceous period (145–66 million years ago), just before the demise of dinosaurs.
In July, researchers used a computer simulation to suggest there is a “substantial risk” from ancient ‘zombie’ microbes emerging from melting permafrost.
The scientists used a program called Avida which is an ‘artificial life system’ of digital microorganisms. Although this sounds a little far away from microbes like the giant permafrost viruses already uncovered, scientists regularly do these types of ‘in sillico’ experiments when they don’t have easy access to the tests in the real world.
They showed in these simulations that the electronic pathogens could often survive and continue evolving. A small number of them – around 3% – were able to effectively invade and even become dominant. In about 1% of cases these ‘invaders’ either substantially increased or decreased the ‘richness’ of the electronic microbe population.
This is a low percentage, but the team suggest that because so many potential viruses and bacteria could be revived with the continued melt of the ice sheets, this is still a ‘substantial risk’.
Finally, an paper published earlier this year tried to dispel the myth that occurrences of ‘live’ viruses are rare.
They noted that 13 new viruses had been isolated from seven different Siberian permafrost samples. These viruses don’t infect humans, but they have been ‘extinct’ for a very long time, and so understanding more about them is a priority.