Tiny Microbes Almost Killed All Life On Earth
Small microbes found on the bottom of the ocean floor may have been the reason for the largest extinction event ever happened on the earth, according to a new study.
Scientists suggested that these microbes of death were so small that more than 1 billion of them could easily fit in a thimble-full of ocean sediment.
"It was not as dramatic as the impact that probably killed the dinosaurs, but it was worse," said Gregory Fournier, an evolutionary biologist at MIT in a press release. "Things were very close to being over for good."
According to geologic record, there was a sharp uptick in CO2 levels at that time that caused the oceans to acidify and the Earth to heat up. However, what caused that CO2 to rise has remained a mystery.
One school of thoughts hint an asteroid impact while other proposed that volcanic activity or coal fires might be the real reason.
In the latest study, researchers are blaming a new unlikely suspect which is a tiny methane-spewing microbe known as Methanosarcina.
"The growth was like what you might see in a real estate bubble, or a financial bubble," explained MIT geophysicist Dan Rothman, according to LA Times. "If the CO2 came from the sudden combustion of a coal field in Siberia it wouldn't behave this way. It has this special character that is consistent with microbial processes."
This is the first time a study has suggested that microbes might be involved with the end-Permian extinction.
"It is absolutely normal that microbes are mediating the great elemental cycles," said Rothman. "What they do is crucial. And if they do better or worse, things change."
"Our proposal is unusual, but it does bring together many observations, and ties a lot of stuff together. That doesn't make it right, but it is consistent, and that's what is necessary to move forward and provide further tests."
The study has been published in PNAS.