Scientists resurrect ancient microbes in ice— but is it worth it?

Some resilient creatures, like tardigrades, rotifers, and nematodes, have the remarkable ability to survive harsh conditions by entering a state of dormancy called "cryptobiosis."

Recently, a team of researchers led by Anastasia Shatilovich at the Institute of Physicochemical and Biological Problems in Soil Science RAS in Russia made a peculiar discovery.

They managed to reanimate nematode individuals from fossilized burrows in Arctic silt deposits.

By analyzing plant material from the burrows using radiocarbon analysis, they determined that these frozen deposits remained undisturbed between 45,839 and 47,769 years ago, or since the late Pleistocene.

Through genome sequencing and phylogenetic analysis, they identified a new nematode species, Panagrolaimus kolymaensis, with shared genes involved in cryptobiosis with a model organism, Caenorhabditis elegans.

Both species increased trehalose production, a sugar that aids in surviving harsh conditions when mildly desiccated and frozen.

Their experiments extended the longest recorded cryptobiosis in nematodes by tens of thousands of years, highlighting their extraordinary resilience.

However, the ecological risks posed by these revived microbes have raised questions.

Community invasion

A separate study led by Giovanni Strona of the European Commission Joint Research Centre sought to address these concerns.

Through artificial evolution experiments, they observed digital virus-like pathogens from the past invading communities of bacteria-like hosts.

The invaders' effects on the diversity of host bacteria were compared to control communities with no invasion.

Their simulations revealed that ancient invading pathogens could survive and evolve in modern communities, with about 3 percent becoming dominant.

While most dominant invaders had minimal impact on the larger community, approximately 1 percent yielded unpredictable results. Some caused significant losses in host species, while others increased diversity compared to control simulations.

The risks posed by this 1 percent of released pathogens may seem small, but the sheer number of ancient microbes regularly entering modern communities makes outbreak events a substantial hazard.

These findings indicate that 'time-traveling pathogens,' once confined to science fiction, may indeed drive ecological changes and pose real threats to human health.

Ultimately, both studies provide crucial insights into the resilience and implications of ancient life forms.

As the world faces ongoing environmental changes, understanding the potential consequences of reawakening ancient microbes becomes increasingly important for safeguarding ecosystems and human wellbeing.