Specifically, the scientists examined about 3.5 billion-year-old barites from the Dresser Formation in Western Australia. The barite thus dates from a time when early life developed on Earth. “In the field, the barites are directly associated with fossilized microbial mats, and they smell like rotten eggs when freshly scratched. Thus, we suspected that they contained organic material that might have served as nutrients for early microbial life,” said Dr. Helge Missbach of the Institute of Geology and Mineralogy and lead author of the study. In the fluid inclusions, the team identified organic compounds such as acetic acid and methanethiol, in addition to gases such as carbon dioxide and hydrogen sulfide. These compounds may have been important substrates for metabolic processes of early microbial life. Furthermore, they are discussed as putative key agents in the origin of life on Earth. “The immediate connection between primordial molecules emerging from the subsurface and the microbial organisms — 3.5 billion years ago — somehow surprised us. This finding contributes decisively to our understanding of the still unclear earliest evolutionary history of life on Earth,” Missbach concluded. Reference: “Ingredients for microbial life preserved in 3.5 billion-year-old fluid inclusions” by Helge Mißbach, Jan-Peter Duda, Alfons M. van den Kerkhof, Volker Lüders, Andreas Pack, Joachim Reitner and Volker Thiel, 17 February 2021, Nature Communications.DOI: 10.1038/s41467-021-21323-z
