The earliest known existence of microbial life on land has been extended by 580 million years following the discovery of fossils in 3.48 billion year-old hot spring deposits in Western Australia’s Pilbara region. The discovery was made by scientists from the University of New South Wales.
UNSW PhD candidate and study first author, Tara Djokic, said the findings may have implications for an origin of life in freshwater hot springs on land – in a version of Charles Darwin’s ‘warm little pond’ theory – rather than the idea that life developed in the ocean before adapting to land.
Ms Djokic also said the research had significant implications for the search for life on Mars, as the red planet’s crust has ancient hot spring deposits of a similar age to the Dresser Formation in the Pilbara.
The study was conducted by Ms Djokic and Professors Martin Van Kranendonk, Malcolm Walter and Colin Ward of UNSW Sydney, and Professor Kathleen Campbell of the University of Auckland. By identifying the presence of geyserite, a mineral deposit only found in a terrestrial hot spring environment, the team interpreted that deposits were formed on land rather than in the ocean.