New research from the Massachusetts Institute of Technology (MIT) suggests ancient microbes were behind the largest mass extinction in the Earth's history.

Some 252 million years ago, 90 percent of all the Earth's species were completely wiped away and it has not been easy to determine why. It is easily the largest of the five known mass extinctions in the planet's history and the catalysts are not even visible to the naked eye.

According to a press release, the mass extinction was due to methane-producing microbes called Methanosarcina. This spread quickly in the oceans and made its way into the atmosphere, influencing a wild and rapid climate change.

A previous theory was massive volcano eruptions caused the die-off, but that may not be incorrect either. The new theory states that volcanoes acted more as an exaggeration to the problem.

The research team published their work this week in the journal Proceedings of the National Academy of Sciences.

"A rapid initial injection of carbon dioxide from a volcano would be followed by a gradual decrease," MIT postdoctoral student Gregory Fournier said in the release. "Instead, we see the opposite: a rapid, continuing increase.

"That suggests a microbial expansion."

The theory is based on three evidential pieces. Firstly, geochemical analysis reveled a spike in carbon dioxide levels in the oceans right around the end of the Permian period, or the time of the extinction. Secondly, Methanosarcina underwent a genetic change beforehand to become the prolific producer of methane than it apparently was. Lastly, sediment samples show an increase in Nickel throughout this exact timeline.

The increase in methane would have influenced the acidification of the world's oceans from higher levels of carbon dioxide.

"A lot of this rests on the carbon isotope analysis," Daniel Rothman, a professor of geophysics at MIT, said in the release. "If it wasn't such an unusual signal, it would be harder to eliminate other possibilities."

The research does not actually prove the microbes were the leading force in the mass extinction, but does eliminate other popular theories. Rather than using any one piece of evidence to try and prove his theory correct, Rotham said "the cumulative impact of all these things is much more powerful than any one individually."