A discovery has been made that could challenge our existing understanding of the evolution of life on Earth. Scientists have uncovered living microbes within a 2-billion-year-old rock, marking the oldest known example of life found inside ancient stone.
The discovery, led by Yohey Suzuki, an associate professor at the University of Tokyo, involved the identification of ancient living microbes in a rock formation in South Africa’s Bushveld Igneous Complex.
“We didn’t know if 2-billion-year-old rocks were habitable,” Suzuki said, adding that this is “the oldest example of living microbes being found within ancient rock so far discovered.” Before this, the oldest known microorganisms were from a 100-million-year-old deposit beneath the ocean floor, making this an extraordinary breakthrough in microbial science.
The microbes in question, confirmed to be indigenous to the stone, appear to have evolved incredibly slowly over time. This slow evolutionary process, combined with their preservation inside the rock, positions them as a living “time capsule,” potentially offering scientists a window into early life on Earth. The earliest life on Earth is thought to have emerged around 3.5 billion years ago, and these ancient microbes, by comparison, offer a rare opportunity to study life that existed just over a billion years after its inception.
According to Suzuki, further study of these microbes’ DNA and genomes could provide unprecedented insights into early evolutionary processes. “By studying the DNA and genomes of microbes like these, we may be able to understand the evolution of very early life on Earth,” he noted.
NASA’s Perseverance mission to Mars, which seeks to retrieve physical samples from the Martian surface, is similarly focused on investigating ancient microbial life.
Given that some of the samples from Mars may be of a similar age to the ancient stone, Suzuki believes this discovery serves as a valuable test run for interplanetary science.
“Finding microbial life in samples from Earth from 2 billion years ago and being able to accurately confirm their authenticity makes me excited for what we might be able to now find in samples from Mars,” Suzuki said.
This discovery is reported in a study published in Microbial Ecology.
