The oldest living microorganisms ever found in rocks could be useful to scientists when looking for life on other planets.
Scientists excavated a 2 billion year old rock in South Africa and unexpectedly discovered that it contained groups of living, even well-developed, microorganisms. IFL Science reported on October 4. This is the oldest example of living microorganisms ever found in ancient rocks.
“We don’t know whether 2 billion year old rocks are still suitable for life. Previously, the oldest geological layer in which living microorganisms were found was a 100 million year old sediment layer at the bottom of the ocean. Therefore, the new discovery is very interesting. By studying the DNA and genome of such microorganisms, we can understand the evolution of early living organisms on Earth. “, Yohey Suzuki, expert from the University of Tokyo, main author of the new study published in the journal Microbial Ecologysaid.
Microorganisms live in a sealed crack in an ancient rock, excavated from the Bushveld Eruptive Complex – a body of intrusive rock formed when magma cools below the Earth’s surface. This massive complex is almost the size of Ireland and contains some very large ore deposits, including about 70% of the world’s mined platinum. It has remained relatively intact since its formation, providing perfect conditions for ancient microorganisms to survive. Such creatures live deep below the Earth’s surface, evolve extremely slowly and have extremely slow metabolic rates, meaning they can survive for a long time in volcanic rocks – up to 2 billion years as shown in research. new.
With support from the International Continental Scientific Drilling Program (ICDP), the team drilled 15 m deep to retrieve a 30 cm long rock core sample. Upon closer inspection, they discovered microbial cells living close together in cracks in the rock, separated from the outside environment by chambers filled with clay.
To confirm that the microorganisms originated from the rock sample and were not just introduced from drilling or testing, the team of experts stained their DNA. They also used infrared spectroscopy to observe proteins inside the microorganisms and proteins in the surrounding clay. This allowed them to determine that they were alive and not a new intrusion.
With the oldest living microorganisms ever found in rock, the new discovery has a huge impact. “I am very interested in the existence of microorganisms under the surface, not only on Earth but also the potential to find them on other planets,” Suzuki shared.
Martian rocks are typically much older, about 20 – 30 billion years old. “However, NASA’s Perseverance robot is preparing to bring back rocks similar in age to the rocks we used in the new study. Finding living microorganisms in samples on Earth from 2 billion years ago And being able to authenticate them makes me very excited about what can be found in the Martian sample,” Suzuki added.