A team of scientists from the University of Alberta and the University of Johannesburg has found evidence that Earth was primed for the explosion of life at least 2.7 billion years ago.

The team analyzed tiny diamond crystals found in Western Australia that were formed deep beneath the Earth's surface 2.7 billion years ago. The diamonds contain high concentrations of carbon-13, a rare isotope of carbon that is associated with biological processes.

The researchers say the presence of carbon-13 in the diamonds indicates that there was a significant amount of biological activity on Earth at the time, and that the planet's atmosphere and oceans were already oxygenated.

"This is the first evidence that the Earth had an oxygen-rich atmosphere and oceans as early as 2.7 billion years ago," said Dr. Chris Smith, a professor in the University of Alberta's Department of Earth and Atmospheric Sciences. "This suggests that the conditions for the evolution of complex life were already in place by that time."

The findings, published in the journal Nature Geoscience, have important implications for our understanding of the evolution of life on Earth. They suggest that life may have originated much earlier than previously thought, and that the planet's early atmosphere and oceans were much more conducive to life than previously believed.

"This discovery changes our understanding of the early history of life on Earth," said Dr. Smith. "It suggests that life may have arisen much earlier than we thought, and that the conditions for life on Earth were much more favorable than we thought."

The team's findings also have implications for the search for life on other planets. If conditions on Earth were conducive to life as early as 2.7 billion years ago, it is possible that life may have arisen on other planets with similar conditions.

"Our findings suggest that it is possible for life to arise on other planets with similar conditions to Earth's," said Dr. Smith. "This is an exciting possibility, and it opens up the possibility of finding life beyond our solar system."