Not asteroids, not dark matter, not any other explanation. The greatest mass extinction of our planet of about 252 million years ago and that wiped out 90% of all species , could be caused by a tiny but controversial culprit: a microbe. This is the conclusion of a team of researchers from the Massachusetts Institute of Technology (MIT) whose study has been published in the journal Proceedings of the National Academy of Sciences .
The bacteria in question, called Methanosarcin , is a methane-producing microbe that would have flourished explosively in the oceans, spewing massive amounts of methane into the atmosphere and dramatically changing both the climate and the chemistry of the planet’s oceans. The reason for this sudden growth could have been its ability to use nickel , emitted non-stop by volcanoes at that time in history, after the Siberian eruptions.
The evidences presented by the MIT researchers are three: first, the analyzed sediments show a sudden increase in the amount of nickel; second, the exponential increase in carbon dioxide in the oceans; and, third, the genetic change in this species of microbe, which allowed it to produce methane from CO2 in water.
Although, a priori, volcanoes could have been responsible for the methane emission, MIT scientists showed that these eruptions were not enough to explain the amount of carbon found in the sediments and did not fit the volcanic model either.
“A rapid initial injection of carbon dioxide from a volcano would be followed by a gradual decrease. Instead, we saw the opposite: a rapid and continuous increase; that suggests a microbial expansion, ”says Gregorio Furnier of MIT.
Thanks to the rapid growth and expansion of this microbe and the consequent massive boiling of methane, a sudden and extreme increase in temperatures and acidification of the oceans occurred on the planet that, although, do not conclusively demonstrate that these microbes caused extinction , they do rule out other alternative theories.
