A new study reveals that microbes that remain dormant for millions of years can be revived, raising interesting new questions about the nature of life itself.
According to an article published in Nature, a research team led by the Japan Earth and Sea Science and Technology Agency experimented with sediment samples from the South Pacific deposited more than 100 million years ago. Because there are few nutrients in the sediments, the area would not theoretically be hospitable to life forms. However, scientists were able to revive almost all of the microorganisms in the samples through an incubation process, indicating that they may have survived in a dormant state for millions of years due to traces of oxygen within the sediment.
A key factor in understanding the importance of study? Microbes on the seafloor were able to survive while expending much less energy than microbes on the surface. This could help explain how they were able to live within the unique hostile conditions of the deep-sea sediment, though it adds to the mystery of how the microbes themselves were also able to adapt to life on the surface.
“The main relevance of this study is that it challenges an understanding of the ‘rules of life,'” Steven D’Hondt, a geomicrobologist who contributed to the study, told Salon by email. “It is still not understood how any community of any type of organism can survive that long with so little energy and then return to normal activities when it returns to the conditions of the surface world.”
He added: “The most important contribution to our understanding of ancient life is the demonstration that ancient life is still present in the world. I say this because these underground populations probably have not reproduced at very fast rates or have accumulated many mutations new since they were buried. “
A particularly notable detail of the study, as the authors wrote in their article, is that “the sampled communities have probably been trapped in the sediment since shortly after deposition. The physiological status and growth potential of these buried communities, and in Overall, the fractions of these energy-deprived, live, inactive, or dead microbes in the subsoil have been essentially unknown. “
Virginia Edgcomb, a microbial ecologist at the Woods Hole Oceanographic Institution who was not involved in the study, told Science magazine that the study indicates that “microbial life is very persistent and often finds a way to survive.”
Another scientist who was not involved in the study, the microbiologist Andreas Teske of the University of North Carolina, told the magazine that “if the surface of a particular planet does not appear promising for life, it may be resisting underground.” .
Salon asked D’Hondt if the microbes discovered in the sediment meet all the requirements to be “alive”. This is not always a simple question, as there is an intense debate among scientists about whether microscopic entities such as viruses can technically be considered “life” forms. However, D’Hondt was confident that these microbes made the cut.
“Something is generally considered alive if it can grow, reproduce and harvest energy on its own,” D’Hondt told Salon. “As shown in our article, Yuki Morono’s experiments directly showed that 99% of microbes in our buried communities do these things (grow, reproduce, and harvest energy).”
When asked if the experiments could provoke real-world manifestations of science fiction scenarios, such as the “Jurassic Park” premise, in which dinosaurs were brought from extinction, he was deeply skeptical.
“I suppose it is conceivable that someone could revive something like yeast this way,” he replied. “But something like a ‘Jurassic Park’ scenario (for example, live dinosaurs) would require the recreation of dinosaurs rather than the reactivation of living organisms (such as our bacteria).”
