Microbes rock
A very old rock – or rather, what’s inside it – could force scientists to rewrite what we know about the evolution of life on Earth.
As described in a new study published in the journal Microbial ecologyscientists discovered living microbes trapped in a 2 billion year old rock.
It is “the oldest example of living microbes yet found in ancient rocks,” according to a press release.
“We didn’t know whether 2-billion-year-old rocks were habitable,” lead study author Yohey Suzuki, an associate professor at the University of Tokyo’s Graduate School of Science, said in a statement. “Until now, the oldest geological layer in which living microorganisms were found was a 100-million-year-old deposit beneath the ocean floor, so this is a very exciting discovery.”
In a sense, the rock is a kind of time machine. Our current scientific understanding is that the earliest life on Earth emerged about 3.5 billion years ago. By comparison, humans have only existed for a few hundred thousand years.
As the researchers write in their study, the microbes confirmed to be native to the stone appear to have evolved incredible slowly over time. This means further research into the newly unearthed organismS’ genetic makeup could reveal unprecedented insights.
“By studying the DNA and genomes of microbes like these,” Suzuki said, “we may be able to understand the evolution of very early life on Earth.”
In, then out
The ancient stone was discovered in the Bushvelt Igneous Complex in South Africa through ultra-deep drilling.
The international coalition of scientists believes that further research into the rock’s microbial community could have implications for ongoing research into life on Earth. other planets too.
A major goal of NASA’s Perseverance mission is to retrieve physical samples from Mars. As the study authors note, these specimens are likely to be of the same age as the Earth rock that was just broken open, making this discovery seem like a test for interplanetary microbial science.
“Finding microbial life in samples from Earth from 2 billion years ago and being able to accurately confirm its authenticity makes me excited about what we might now find in samples from Mars,” Suzuki said in a statement.
More about surprising things in rocks: Microplastics found in sediment layers untouched by modern humans
