Researchers have discovered living microbes within a sealed fracture in a 2-billion-year-old rock sample from the Bushveld Igneous Complex in South Africa. This is the oldest example of living microbes found within ancient rock and could provide insights into early evolution and the search for extraterrestrial life in similarly aged rock samples. By perfecting a technique involving infrared spectroscopy, electron microscopy, and fluorescent microscopy, the team was able to confirm that the microbes were indigenous to the ancient core sample and not caused by contamination during the retrieval and study process.
The microbial colonies found deep within the 2-billion-year-old rock offer a glimpse into ancient life and evolution. These resilient organisms living far beneath the surface appear to live life at a slower pace, allowing researchers to trace back the history of life on Earth. The discovery of living microbes in such ancient rocks opens up new possibilities for studying early evolution on Earth, as well as the potential for finding microbial life on other planets. By studying the DNA and genomes of these microbes, scientists hope to gain a better understanding of very early life on Earth.
The rock sample was taken from the Bushveld Igneous Complex, an area known for its rich ore deposits and geological stability that has provided a habitat for ancient microbial life to survive over millions of years. The core sample was obtained from about 15 meters belowground with the help of the International Continental Scientific Drilling Program. By analyzing thin slices of the rock, the research team discovered living microbial cells densely packed into cracks in the rock, with any gaps near these cracks clogged with clay, preventing the organisms from leaving or other contaminants from entering.
The team’s technique involved staining the DNA of the microbial cells and using infrared spectroscopy to analyze the proteins in the microbes and surrounding clay to confirm the authenticity of the microorganisms. This careful analysis ensured that the living microbes found within the ancient rock sample were truly native to the environment and not a result of contamination. The discovery not only sheds light on the potential for life to exist in extreme environments on Earth but also has implications for the search for microbial life on other planets, such as Mars.
Lead author Yohey Suzuki, an associate professor from the University of Tokyo, expressed excitement at the discovery of living microbes in the 2-billion-year-old rock sample and its implications for future research. The findings open up new possibilities for studying early evolution and understanding the survival mechanisms of ancient microbial life. With NASA’s Mars rover Perseverance set to bring back rocks that are a similar age to the samples used in this study, researchers are hopeful for new discoveries that could provide insights into the potential existence of microbial life on other planets.
Overall, the discovery of living microbes in a 2-billion-year-old rock sample from the Bushveld Igneous Complex in South Africa represents a significant breakthrough in the study of ancient life and the search for extraterrestrial life. By perfecting a technique to confirm the authenticity of the microorganisms found within the rock sample, researchers have provided valuable insights into the potential for life to exist in extreme environments over geological time spans. This discovery paves the way for future research on early evolution and the search for microbial life on other planets, offering new opportunities to explore the origins of life in the universe.