Life on Earth may have started 3.2 billion years ago, which is about one billion years earlier than previously believed, if new research is to be believed.

According to ABC News, scientists from the University of Washington (UW) and the University of Johannesburg collaborated to examine 52 rock samples found in South Africa and northwestern Australia. The rocks date back between 2.75 billion and 3.2 billion years.

A professor of Earth and space sciences at UW, Roger Buick co-authored the study published in the journal Nature.

"People always had the idea that the really ancient biosphere was just tenuously clinging on to this inhospitable planet, and it wasn't until the emergence of nitrogen fixation that suddenly the biosphere become large and robust and diverse," he said in a press release. "Our work shows that there was no nitrogen crisis on the early Earth, and therefore it could have supported a fairly large and diverse biosphere.

"We'll never find any direct evidence of land scum one cell thick, but this might be giving us indirect evidence that the land was inhabited.

"Microbes could have crawled out of the ocean and lived in a slime layer on the rocks on land, even before 3.2 billion years ago."

The rocks at the center of the study are said to be among the oldest samples the Earth has to offer. They came from the Earth's continental shelf, the landmass of a continent that extends down into the depths of the ocean.

"Imagining that this really complicated process is so old, and has operated in the same way for 3.2 billion years, I think is fascinating," study lead author Eva Stüeken, who performed part of her doctoral research at UW, said in the release. "It suggests that these really complicated enzymes apparently formed really early, so maybe it's not so difficult for these enzymes to evolve."