Earliest Signs Of Life
Scientists have found clues for how life on Earth originated. They have discovered exceptionally preserved microbial remains in some of Earth’s oldest rocks in Western Australia.
Researchers from The University of New South Wales found the organic matter in stromatolites. They are fossilized microbial structures. Researchers discovered them from the ancient Dresser Formation in the Pilbara region of Western Australia.
The stromatolites have been thought to be of biogenic origin ever since they were first discovered in the 1980s. The theory was unproven for nearly four decades despite strong textural evidence. Scientists had failed to prove this hypothesis. This discovery by the UNSW researchers has finally come up with some evidence.
Dr. Raphael Baumgartner, the lead researcher, said that for the first time, his team could show the world that these stromatolites are definitive evidence for the earliest life on
Earth. Dr. Baumgartner is a research associate of the Australian Centre for Astrobiology.Professor Van Kranendonk says the discovery is the closest the team has come to prove the existence of such ancient life.
The study represents a significant advance in the knowledge of these rocks. Scientists can also use this study to find life on Mars.
Earliest Signs Of Life- The Approach Used by the Scientists
Ever since the Dresser Formation was discovered in 1980, scientists have wondered whether the structures were genuinely microbial and therefore the earliest signs of life.
Dr. Baumgartner says that in this study, his team spent a lot of time in the lab, using micro-analytical techniques to look very closely at the rock samples. This proved their theory once and for all.
Stromatolites in the Dresser Formation are usually sourced from the rock surface and are therefore highly weathered. For this study, the scientists worked with samples that were taken from further down into the rock, below the weathering profile, where the stromatolites are exceptionally well preserved.
This approach helped scientists to look at a perfect snapshot of ancient microbial life.
Dr. Baumgartner and team used a variety of cutting-edge micro-analytical tools and techniques, including spectroscopy, high-powered electron microscopy, and isotope analysis.
He found that the stromatolites are mainly composed of pyrite. It is a mineral also known as ‘fool’s gold’ – that contains organic matter.
Dr. Baumgartner says that the organic matter that the team found preserved within pyrite was exceptional. They found coherent filaments and strands that typically remained of microbial biofilms.
The researchers say that such remains have never been observed before in the Dresser Formation. He adds that he never expected to find this level of evidence before he started this project. Dr. Baumgartner had that ‘eureka’ moment when he finally figured out that he was looking at biofilm remains at the electron microscope.
Earliest Signs Of Life- Can This Help Find Life on Mars?
Last month, NASA and European Space Agency (ESA) scientists spent a week in the Pilbara with Martin Van Kranendonk for specialist training. It was the first time that Van Kranendonk shared the region’s insights with a dedicated team of Mars specialists. It included a group consisting of the Heads of NASA and ESA Mars 2020 missions.
Professor Van Kranendonk says that Australia’s ancient rocks, coupled with expert scientific knowledge, are making a significant contribution to search for extra-terrestrial life and unlocking the secrets of Mars.
