Microbial fossils discovered in Australia and dated 3.48 billion years indicate that terrestrial life would have appeared hundreds of millions of years earlier than estimated.
A team of scientists from the University of New South Wales claims to have discovered in the Pilbara area (a large, dry, thinly populated region in the north of Western Australia) 3.48 million years old rocks containing structures a priori sculpted by life forms of microbial. These rocks were formed near a hot, terrestrial source, so on land.
If this discovery is confirmed, it would be the oldest trace of terrestrial life ever detected: previously the oldest proof of life outside the water was about 2.8 billion years ago and originated in South Africa.
Search for life on Mars
This field of study is nevertheless very controversial, since scientists rarely agree with each other. Several recent studies point to evidence suggesting that life appeared underwater near hydrothermal vents about 3.7 billion years ago, but researchers who rely on discoveries that are still subject to caution, evoke a period of up to 4.1 billion years. They rely on the examination of rocks called stromatolites that are the result of microbial activity. The rocks have the appearance of bubbles once mineralized, as seen in the picture above. Their description is the subject of an article published in the journal Nature Communications .
„Our research has major implications for the search for life on Mars, because the red planet has ancient deposits of hot springs of an age similar to those of the Pilbara formation“, explains Tara Djokic, lead of the study.