The earth's climate was far cooler - perhaps more than 50 degrees - billions of years ago, suggesting the advent of life could have been earlier than believed.
Mike Tice, researcher in the department of geology and geophysics at Texas A&M University, says the findings could change current ideas about the earliest forms of life on earth.
The team includes scientists from Yale and Stanford Universities.
Tice says the team examined rocks from the Buck Reef in South Africa that are known to be about 3.4 billion years old, among the oldest ever discovered.
They found features in them that are consistent with formation at water temperatures significantly lower than previous studies have suggested, a Texas A&M release said.
"Our research shows that the water temperature 3.4 billion years ago was at most 105 degrees, and while that's potentially very warm, it's far below the temperatures of 155 degrees or more than previous research has implied," Tice explains.
The research found that conditions were considerably cooler, probably by 50 degrees or even more. That means that conditions for life were much easier, and that life that did exist at the time and was not under as much stress as previously believed.
The research was published in the current issue of Nature magazine